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What is the Evidence for Induction for Low Amniotic Fluid in a Healthy Pregnancy?

By Rebecca L. Dekker, PhD, RN, APRN

Today’s post on the Evidence for Induction for Low Amniotic Fluid in a Healthy Pregnancy is a guest post by blogger Rebecca Dekker, owner of  the fairly new blog in the birth world, Evidence Based Birth that has been  very well received and enjoyed by many.  Look for an interview with Rebecca in an upcoming post where we will learn how this Assistant Professor of Nursing who teaches pathopharmacology and studies depression in patients with heart failure ended up writing the Evidence Based Birth blog appreciated by birth professionals.  I look forward to future posts and collaboration with Rebecca and thank her for her contribution today.- SM

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This question came from one of my readers:

“Low fluid seems to be the new “big baby” for pushing for induction. What does the research say about low fluid at or near term? From what I’ve been able to see in research summaries at least, there appears to be no improved outcome for babies, but I’d love to see the research really hashed out. I’m also curious about causes of low fluid (theorized or known), risks of low fluid, and perhaps as important if not more so, measurements of low fluid.”

This is a great question and I felt like it was a perfect topic for my first article for Science and Sensibility. Standard of practice in the U.S. is to induce labor at term if a mother has low amniotic fluid in an otherwise healthy pregnancy. In fact, 95% of physicians who practice maternal-fetal medicine feel that isolated oligohydramnios—low amniotic fluid in an otherwise healthy pregnancy—is an indication for labor induction at 40 weeks (Schwartz, Sweeting et al. 2009).

But what is the evidence for this standard birth practice? Let’s take a look at the evidence together.

First of all, what is oligohydramnios?

Oligohydramnios means low fluid inside the amniotic sac.

(oligo = little, hydr = water, amnios = membrane around the fetus, or amniotic sac).

Not sure how to pronounce oligohydramnios? Click here.

It is standard of care in the U.S. to induce women with isolated oligohydramnios at term.
Image Source drewesque 

What is amniotic fluid, and what does it do?

During pregnancy, the baby is surrounded by a liquid called amniotic fluid. Amniotic fluid helps protect the baby from trauma to the mother’s abdomen. Amniotic fluid cushions the umbilical cord, protects the baby from infection, and provides fluid, space, nutrients, and hormones to help the baby grow (Brace 1997).

During the second half of pregnancy, amniotic fluid is made up of the baby’s urine and lung secretions. This liquid originally came from the mother, and then flowed through the placenta, to the baby, and out through the baby’s bladder and lungs (Brace 1997).

This same amniotic fluid is then swallowed by the baby and re-absorbed by the lining of the placenta. Because the mother’s fluid levels are the original source of amniotic fluid, changes in the mother’s fluid status can result in changes in the amount of amniotic fluid. Amniotic fluid levels increase until the mother reaches about 34-36 weeks, and then levels gradually decline until birth (Brace 1997).

What can cause low amniotic fluid at term?

Both mother and baby factors can contribute to low amniotic fluid at term.

Mother factors:

  • If the mother is dehydrated, this may lower the amniotic fluid levels. (Patrelli, Gizzo et al. 2012)
  • Women are more likely to be diagnosed with low amniotic fluid levels during the summer, possibly because of dehydration. (Feldman, Friger et al. 2009)
  • If a woman with low amniotic fluid levels at term drinks at least 2.5 Liters of fluid per day, she increases the likelihood that her amniotic fluid levels will be back up to normal by the time of delivery. (Patrelli, Gizzo et al. 2012)
  • If the mother rests on her left side before or during the fluid measurement, this can increase amniotic fluid levels. (Ulker, Temur et al. 2012)
  • If the mother’s water has broken (membranes ruptured), this will lead to a decrease in amniotic fluid. (Brace 1997)
  • If the mother’s placenta is not acting sufficiently anymore, this may lead to a decrease in amniotic fluid. When this happens, it may be because the mother has a serious condition such as pre-eclampsia or intrauterine growth restriction. (Beloosesky and Ross 2012)

Baby factors:

  • If the baby has a problem with the urinary tract or kidneys, this may decrease the flow of urine. (Brace 1997)
  • In the 14 days before the start of spontaneous labor, the baby’s urine output starts to decrease. (Stigter, Mulder et al. 2011)
  • As the baby gets closer to term, the baby swallows more amniotic fluid, thus leading to a decline in fluid levels. (Brace 1997)
  • If the baby is post-term (after 42 weeks), he or she begins to swallow significantly more fluid, contributing to a decline in amniotic fluid. (Brace 1997)
  • If the baby has a birth defect, he or she may swallow significantly more fluid, leading to low amniotic fluid levels. (Beloosesky and Ross 2012)

What is the best way to measure amniotic fluid levels?

The gold-standard method is to inject the amniotic sac with dye and then take samples of the amniotic fluid to check the dilution. However, this method is very invasive. So the most commonly used methods instead are 2 ultrasound techniques:  the amniotic fluid index (AFI) and the single deepest pocket (Gilbert 2012).

To calculate the AFI, the technician divides the uterus into 4 areas. The largest fluid pocket in each area is measured, and then these 4 numbers are added make up the AFI. An AFI value of 5 cm or less is considered oligohydramnios. With the single deepest pocket method, the technician looks for the largest pocket of amniotic fluid in the uterus. If the largest pocket is less than 2 cm by 1 cm, then that is considered a diagnosis of oligohydramnios (Nabhan and Abdelmoula 2009).

It is important to understand that amniotic fluid levels exist on a continuum and that there is no agreement among researchers about the cut-off value that predicts poor outcomes—the AFI level of 5 was arbitrarily chosen to define oligohydramnios (Nabhan and Abdelmoula 2009). Furthermore, a large body of research has shown that both AFI and single deepest pocket are poor predictors of true amniotic fluid volume. For example, the AFI catches only 10% of all cases of true oligohydramnios (10% sensitivity)(Gilbert 2012).

There are several factors that make it difficult to get an accurate ultrasound measurement. As fluid levels decrease, ultrasound results become less accurate. Inexperience on the part of the technician can reduce the accuracy of the test results, as well as the amount of pressure that the technician puts on the ultrasound probe. The position of the baby can also affect the accuracy of the results. (Nabhan and Abdelmoula 2009; Gilbert 2012).

So which is the best way to measure amniotic fluid?

In a Cochrane review, researchers combined the results from 5 randomized controlled trials with more than 3,200 women. In these studies, women were randomized to either the AFI method or the single deepest pocket method. Researchers found that when the AFI is used to measure amniotic fluid, women were 2.4 times more likely to be diagnosed with oligohydramnios, 1.9 times more likely to be induced, and 1.5 times more likely to have a Cesarean for fetal distress without any corresponding improvement in infant outcomes. The researchers concluded that the single deepest pocket measurement has fewer risks and should be the preferred way to measure amniotic fluid (Nabhan and Abdelmoula 2009).

What is the clinical significance of low amniotic fluid when a mother reaches 37 or more weeks?

In 2009, 91% of physicians believed that isolated oligohydramnios, or low amniotic fluid in an otherwise healthy pregnancy at term, was a risk factor for poor outcomes (Schwartz, Sweeting et al. 2009).

In the U.S., 91% of maternal-fetal physicians believe that isolated oligohydramnios at term is a risk factor for poor outcomes, and 95% will recommend labor induction.
Image Source robenjoyce

However, this belief is not accurate. In early studies on amniotic fluid and outcomes, researchers included babies with congenital defects , women with pre-eclampsia or intrauterine growth restriction (IUGR), and women who were post-term (past 42 weeks) in their samples. These women and babies are more likely to have low amniotic fluid, and they are also much more likely to have poor outcomes. So although early researchers found that babies born to women with low amniotic fluid had higher perinatal mortality rates (Chamberlain, Manning et al. 1984), higher Cesarean rates for fetal distress, and lower Apgar scores (Chauhan, Sanderson et al. 1999), the poor outcomes were due to the complications—not the low amniotic fluid (Gilbert 2012).

So, if a woman has TRUE ISOLATED oligohydramnios at term, meaning low amniotic fluid in a healthy pregnancy with a healthy baby at term (between 37 and 42 weeks), what are the risks?

There is no evidence that isolated oligohydramnios at term is a risk factor for poor outcomes. However, induction for isolated oligohydramnios leads to higher Cesarean rates. In a systematic literature review, I found 5 studies from the last 10 years. I will discuss the 3 highest quality studies here. For results from all 5, you can see my findings summarized in this Google document table here.

  1. Locatelli et al. (2003) studied 3,049 healthy pregnant women who were between 40 and 41.6 weeks pregnant. The purpose of this study was to find out if low amniotic fluid (defined as AFI ≤ 5) led to poor outcomes. Eleven percent of women had low amniotic fluid, and these women had higher induction rates (83% vs. 25%), higher Cesarean rates (15% vs. 11%), and higher Cesarean rates for non-reassuring fetal heart rates (8% vs. 4%). Babies born to women with low amniotic fluid were more likely to have birth weights beneath the 10th percentile (13% vs. 6%). There were no differences between groups with meconium staining, meconium aspiration, umbilical artery pH <7, or Apgar scores. There was only one stillbirth (in the normal fluid group) for a true knot in the umbilical cord.

After controlling for the fact that some women were induced and some women were having their first baby, the researchers found no association between Cesarean for non-reassuring heart rate and amniotic fluid. This means that the inductions were probably responsible for the higher Cesarean rates in the low amniotic fluid group. However, when the researchers controlled for gestational age, they found that the association between low birth weight and low amniotic fluid remained significant. This means that women with low amniotic fluid were 2 times more likely to have a baby that is born beneath the 10th percentile. These babies may have had undiagnosed fetal growth restriction (IUGR), which is a separate risk factor for poor outcomes.

  1. Manzaneres et al. (2006) compared outcomes from 206 healthy pregnant women who were induced for isolated oligohydramnios at term and 206 healthy pregnant women with normal amniotic fluid levels who went into spontaneous labor.  The women in both groups delivered between 37 and 42 weeks. The researchers found that the low amniotic fluid group was more likely to require forceps or vacuum delivery (26% vs. 17%), Cesarean delivery (16% vs. 6%), and have non-reassuring fetal status during labor (8% vs. 2%). The non-reassuring fetal status may have been due to the induction medications, but this explanation was not proposed by the authors. There were no differences between groups with birth weight, Apgar scores, meconium staining, neonatal admissions, or umbilical cord pH. In summary, the authors found that inducing labor for isolated oligohydramnios at term increased Cesarean and operative vaginal delivery rates without any improvement in newborn outcomes.
  1. There was one small pilot study done in which researchers randomized women with isolated oligohydramnios at term to induction or watchful waiting. The researchers randomly assigned 54 women who were 41 weeks pregnant to either induction or watchful waiting. There were no differences between groups in any outcomes, including birth weight, Cesarean delivery, Apgar scores, or neonatal admission. This study was limited by its small sample size and the fact that it only included women who were 41 weeks pregnant (Ek, Andersson et al. 2005).

So what is the evidence for induction because of low amniotic fluid (without any other complications) at term?

There is no evidence that inducing labor for isolated oligohydramnios at term has any beneficial impact on mother or infant outcomes. Based on the lack of evidence, any recommendation for induction for isolated oligohydramnios at term would be a weak recommendation based on clinical opinion alone.

In summary, this is what I found about low amniotic fluid in an uncomplicated pregnancy at term (37-42 weeks):

  • Ultrasound measurement is a poor predictor of actual amniotic fluid volume
  • The single deepest pocket method of measurement has fewer risks than the AFI
  • Poor outcomes seen with low amniotic fluid are usually due to underlying complications such as pre-eclampsia, birth defects, or fetal growth restriction
  • The main risk of low amniotic fluid at term in a healthy pregnancy is induction (and Cesarean delivery as a result of the induction) and potentially the risk of lower birth weight
  • Current evidence does not support induction for isolated oligohydramnios at term

Are women in your local areas being induced for isolated oligohydramnios at term? Are consumers and clinicians aware of this evidence? What is the standard of practice for evaluating amniotic fluid in your local facilities, AFI or Single Deepest Pocket? How do you discuss this in your classes and with your patients, clients and students?

References

  1. Beloosesky, R. and M. G. Ross. (2012). “Oligohydramnios.”   Retrieved 8/20/12, 2012, from www.UpToDate.com
  2. Brace, R. A. (1997). “Physiology of amniotic fluid volume regulation.” Clin Obstet Gynecol 40(2): 280-289.
  3. Chamberlain, P. F., F. A. Manning, et al. (1984). “Ultrasound evaluation of amniotic fluid volume. I. The relationship of marginal and decreased amniotic fluid volumes to perinatal outcome.” Am J Obstet Gynecol 150(3): 245-249.
  4. Chauhan, S. P., M. Sanderson, et al. (1999). “Perinatal outcome and amniotic fluid index in the antepartum and intrapartum periods: A meta-analysis.” Am J Obstet Gynecol 181(6): 1473-1478.
  5. Ek, S., A. Andersson, et al. (2005). “Oligohydramnios in uncomplicated pregnancies beyond 40 completed weeks. A prospective, randomised, pilot study on maternal and neonatal outcomes.” Fetal Diagn Ther 20(3): 182-185.
  6. Feldman, I., M. Friger, et al. (2009). “Is oligohydramnios more common during the summer season?” Arch Gynecol Obstet 280(1): 3-6.
  7. Gilbert, W. M. (2012). Amniotic Fluid Disorders. Obstetrics: Normal and Problem Pregnancies. S. G. Gabbe. Philadelphia, PA, Elsevier. 6.
  8. Locatelli, A., P. Vergani, et al. (2004). “Perinatal outcome associated with oligohydramnios in uncomplicated term pregnancies.” Arch Gynecol Obstet 269(2): 130-133.
  9. Nabhan, A. F. and Y. A. Abdelmoula (2009). “Amniotic fluid index versus single deepest vertical pocket: a meta-analysis of randomized controlled trials.” International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics 104(3): 184-188.
  10. Patrelli, T. S., S. Gizzo, et al. (2012). “Maternal hydration therapy improves the quantity of amniotic fluid and the pregnancy outcome in third-trimester isolated oligohydramnios: a controlled randomized institutional trial.” J Ultrasound Med 31(2): 239-244.
  11. Schwartz, N., R. Sweeting, et al. (2009). “Practice patterns in the management of isolated oligohydramnios: a survey of perinatologists.” J Matern Fetal Neonatal Med 22(4): 357-361.
  12. Stigter, R. H., E. J. Mulder, et al. (2011). “Fetal urine production in late pregnancy.” ISRN Obstet Gynecol 2011: 345431.
  13. Ulker, K., I. Temur, et al. (2012). “Effects of maternal left lateral position and rest on amniotic fluid index: a prospective clinical study.” J Reprod Med 57(5-6): 270-276.
About Rebecca Dekker
Rebecca Dekker, PhD, RN, APRN, is an Assistant Professor of Nursing at a research-intensive university and author of www.evidencebasedbirth.com. Rebecca’s vision is to promote evidence-based birth practices among consumers and clinicians worldwide. She publishes summaries of birth evidence using a Question and Answer style. You can contact Rebecca via email here.

 

 

 

Evidence Based Medicine, Fetal Monitoring, Guest Posts, Healthy Birth Practices, Healthy Care Practices, informed Consent, Maternity Care, Medical Interventions, Systematic Review, Uncategorized , , , , , , , , ,

  1. August 30th, 2012 at 08:04 | #1

    Great to see you here Rebecca and thanks for the article. Will be sharing widely.

  2. August 30th, 2012 at 09:01 | #2

    At the hospital where I am currently employed, AFI is commonly used. I don’t recall ever seeing Single Deepest Pocket being referenced.

    As labor nurses we are aware of the difficulty in getting a true appraisal of amniotic fluid with AFI. I can recall a few instances when the bag of waters ruptured and we were amazed at the amount of amniotic fluid that spilled after a dx of low AFI. Now the doctors are getting repeat ultrasounds, looking for a trend in AFI.It seems like AFI should be just one of several indicators for inducing labor– other factors to help confirm the need for inducing labor.

    I found your information on factors that influence amniotic fluid levels to be helpful. Prenatal care needs to include an emphasis on oral fluids– especially in the summer.

  3. August 30th, 2012 at 10:27 | #3

    Yes, I have had a few clients who have been induced for low amniotic fluid. One client ended up with a c-section after a two day induction. One client had a vaginal birth. The babies were in perfect health and in fact quite “juicy”. It’s very disappointing. In the case of the c-section I was sad that the OB/GYN took the word of a Resident who had done an in-office sono. The OB never looked herself and didn’t send the mom for a sono with a tech. The mom was barely 21 and now has to try for a vbac. We live in Texas. It’s hot and I had wondered about the moms being dehydrated, etc. Thank you for this amazing information that I can share with my childbirth students and doula clients.

  4. August 30th, 2012 at 10:40 | #4

    In my area I’ve never seen Single Deepest Pocket used, and yes, low AFI is a common reason for induction, has been for I’d say for at least 10 years, though it has gotten more common in the past 5-6 years. The cut off for “low fluid” is variable…I’ve seen anything from 6 to 10 cm used as justification for induction.

  5. avatar
    Rachel
    August 30th, 2012 at 12:04 | #5

    This brought tears to my eyes, seriously. Low fluid measurements have caused more grief, anxiety, and unnecessary interventions for my doula clients then any other issue. I’m eager to share this with them and hopefully, in turn they’ll be able to make truly informed decisions instead of those based on fear and opinion.

  6. avatar
    Katie
    August 30th, 2012 at 12:47 | #6

    Another way of looking at it is that a finding of low AFI in an apparently normal pregnancy may be an indicator that it is NOT a normal pregnancy, but that there is a previously unidentified problem, like IUGR or congenital abnormality, that is difficult to diagnose prenatally.

  7. August 30th, 2012 at 13:47 | #7

    @Tina Castellanos
    Hi Tina, you made 2 really good points! Dehydration can make a significant difference in amniotic fluid levels– it is not a coincidence that the number of inductions for low amniotic fluid goes up in the summer. There was a great randomized, controlled trial that took women with low amniotic fluids and randomized them to different fluid intakes. They found that drinking 2 1/2 liters of fluid per day was enough to normalize amniotic fluid levels. Seems like an easier solution (with fewer risks) than induction! Second, technician experience really does make a difference in readings. Something as simple as how much pressure the technician puts on the sensor can alter the results.

  8. August 30th, 2012 at 14:00 | #8

    @Katie
    Yes, Katie, that is definitely a possibility! For more information, we can look at this study: http://www.ncbi.nlm.nih.gov/pubmed/12928935. We can see that the researchers found low amniotic fluid levels in 113 women out of 7617. In about half (n = 53 women) of these women with low amniotic fluid, there were other complicating factors (premature rupture of the fetal membranes, congenital anomalies, diabetes, hypertension, postdate and intrauterine growth restriction), so these 53 did not have “isolated” oligohydramnios. In the other half (n = 60 women), there were no other complicating factors diagnosed before or after delivery. So isolated low amniotic fluid can exist in a completely healthy pregnancy with a healthy baby– which makes sense, because there are many other factors that can lead to a decrease in fluid, such as overall hydration status, positioning, and proximity to spontaneous delivery.

  9. August 30th, 2012 at 14:08 | #9

    @Rebecca Rebecca, can you share more about “proximity to spontaneous delivery?” I keep seeing Penny’s Arrow in my mind (a representation of what is happening to the placenta, uterus, fetus and mother as the pregnancy draws to a close) and I know that Penny states that amniotic fluid going down happens as the mother moves toward birth. If a reduction in AF is normal as birth becomes closer, do we have information on how low is “normal” or how much of a change” or other things? As you said “isolated low AF can exist in a healthy pregnancy with a healthy baby” in the absence of other factors, why are HCPs moving toward induction if this is a normal sign of the last stages/days of pregnancy?

  10. avatar
    Katie
    August 30th, 2012 at 16:46 | #10

    @Rebecca: Yes, it CAN exist in a healthy pregnancy with a healthy baby, but there seems to be what most would consider a high incidence of it in complicated pregnancies, including pregnancies in which the problem was only identified postpartum. If those babies were born by c/s following failed induction, it is impossible to say which ones would have resulted in fetal death or injury. We’re not talking about a .1% VBAC rupture risk here (not that that’s insignificant), either.

    That study sounds interesting but your link doesn’t go to it.

  11. August 30th, 2012 at 17:34 | #11

    @Katie
    I’m sorry, that is so odd that the link I copied goes to an HIV article! Here is the link I meant to post: http://www.ncbi.nlm.nih.gov/pubmed/12928935.

    If you are interested in more information, I would recommend reading the chapter on Amniotic Fluid Disorders in Gabbe’s Obstetrics: Normal and Problem Pregnancies. It is an excellent review of the evidence (the best I’ve seen so far), and they concluded that although it is true that low amniotic fluid in the presence of IUGR, or preeclampsia, has markedly worse perinatal outcomes, the term (37-42 weeks) patient with isolated oligohydramnios may not need immediate delivery.

    I looked at all the evidence from the past 10 years, and the Gabbe authors looked at evidence prior to that as well, and there is no mention anywhere of major, life-threatening fetal problems that were “missed” and diagnosed post-partum. If you know of any research studies that point out the statistics of isolated oligohydramnios that turned out to NOT be isolated after delivery, please let me know! The only thing that came close to what you are talking about is in the Locatelli study that I mentioned above, and they did find an increased risk of low birthweight– these infants may have been missed IUGR diagnoses. This was an isolated finding that was not replicated in the other studies. However, I did include that risk in my bulleted summary at the end of the article: “The main risk of low amniotic fluid at term in a healthy pregnancy is induction (and Cesarean delivery as a result of the induction) and potentially the risk of lower birth weight.”

    I agree that it is impossible to say what the outcomes would have been for babies who were born by c/s following a failed induction, if they had instead been allowed to be born via spontaneous labor. Wouldn’t it be great if we could answer that question with the evidence? I am sad to say that is one of the major limitations in the evidence for induction for isolated oligohydramnios. There has been only one randomized, controlled trial in which women were randomized to either induction or no induction. That trial was under-powered to detect differences in most outcomes. In all the other observational studies, the women with isolated oligohydramnios were almost always induced, so there is no perfect comparison group for these women.

  12. August 30th, 2012 at 17:39 | #12

    @Rebecca Rebecca, I corrected the original link in your first response to the updated one you provided! thanks!

  13. August 30th, 2012 at 18:06 | #13

    @Sharon Muza
    Hi Sharon, there is a classic 1989 article by Brace (one of the foremost experts in the field of amniotic fluid) that documented the wide variation in amniotic fluid.

    You can see the figure from his study for free here: http://imaging.consult.com/image/chapter/Obstetrics%20and%20Gynecology?title=Amniotic Fluid Volume: Role in Fetal Health and Disease&image=fig4&locator=gr4&pii=S1933-0332(08)70107-1

    When you look at that figure, you can see that there is a wide range of values for amniotic fluid levels. There is really no consensus among researchers as to where normal ends and abnormal begins, and which value (in an isolated oligohydramnios finding) might be associated with poor outcomes.

    As far as why are care providers liberally inducing for isolated oligohydramnios, despite the lack of evidence, that is a question that I do not know the answer to. I am going to ask several of my obstetrician friends to stop by and comment, to see if they can help us understand. My educated guess is that there are a host of factors going on (fear of liability, feelings that there are too many risks with low amniotic fluid, lack of knowledge about the current evidence).

  14. avatar
    Denise
    August 30th, 2012 at 19:29 | #14

    Our practice uses the single pocket of >2cm as our criteria; however, if we have a total AFI of <5cm, we add extra monitoring and repeat u/s after either oral or IV fluids. If we have someone with a single pocket 10 years. We see a big difference between her u/s and the results from the hospital technicians. If we can, we have the same technician do the repeat u/s so it helps eliminate variation, and we prefer our office technician over the others. With only oligohydramnios and an otherwise normal pregnancy, we discuss everything w/ the mother and make a decision with her that is case-specific.

  15. avatar
    Denise
    August 30th, 2012 at 19:32 | #15

    Some of my first comment was cut off when posted. “If we have someone with a single pocket <2cm and a BPP of 8/10 otherwise, we admit and repeat u/s after 24-48 hours of IV and oral hydration. We also have a benefit of having an u/s technician who has worked in our office for 10 years." That is the correct wording for the sentence that makes no sense above…

  16. avatar
    Katie
    August 30th, 2012 at 19:40 | #16

    This link may help to answer Sharon’s question: http://www.carllp.com/Representative-Cases/Obstetrical-Malpractice.shtml

    The scientific data is skimpy on low AFI, but the malpractice case history bank is not! Do a simple google search, oligohydramnios malpractice verdict. It’s enlightening.

  17. avatar
    sara r.
    August 30th, 2012 at 20:37 | #17

    I have heard of a lot of inductions for this; thanks for the helpful breakdown of statistics!
    Anecdotally, I am pretty sure that I had low fluid levels for both of my babies. When my water broke spontaneously during labor both times, there was not much fluid at all, but both babies were healthy (even if on the small side). I can’t know that for sure because I never had the levels checked, but I really feel that it is true. What on earth did women do before they had all of those late tests in pregnancy? I think they worried a lot less…

  18. avatar
    Michele Deck
    August 31st, 2012 at 08:20 | #18

    I have had 3 moms recently who have been told this. I appreciate the indepth research you have presented with the 2012 research citations. Will refer my moms to them.

  19. avatar
    Holly
    September 1st, 2012 at 05:57 | #19

    Thanks for this article. It is an interesting read. I have just had a client be induced for oligohydramnios at slightly past term (42+2 I think when the recommendation was made). She was 3cm dilated at her last sweep, first baby and very healthy pregnancy, so felt quite confident they wouldn’t be waiting too much longer so had chosen to hold off on the induction for this reason, unless a specific medical problem presented itself. So I’m doing a bit more research on the back of that and stumbled upon this.

    The cynical part of me thinks that it’s almost convenient that whenever I’ve had a client choose to hold off on induction and goes in for an “informal induction chat” they often suddenly get diagnosed with ‘something’, and leaves me wondering how often it might really just be a case of the consultant making something up to get her in for the induction. I’d never share this suspicion with a client though as I wouldn’t encourage people to second guess their medical advice! I guess it’s something I’ll probably never know.

    Anyway I just wanted to ask your thoughts on this: The reason they were advised to have an induction (aside from the statistically higher chance of stillbirth present anyway with going post-dates) is because as the baby is more likely to open its bowels at this stage, if the meconium was inhaled it would present a greater risk due to its higher concentration in the lower waters. Do you have any information on this?

  20. avatar
    Jessica
    September 5th, 2012 at 21:12 | #20

    Have you heard anything about this when it is diagnosed earlier in pregnancy? I was diagnosed at 30 weeks. They tried both AFI and single deepest pocket when they noticed it on an ultrasound they were doing following a GD diagnosis. It was 3-4cm and they put me on IV’s for a day and rechecked, and then had me stay off IV’s for a day to make sure it didn’t go down from where it was at. Then I got to go home on bedrest since it stayed at 5. I’m doing what I can to get plenty of fluids, but I’m wondering if it stays at this level as I get closer to term, is this a level they normally try to induce for at term? I know they are not trying to induce NOW, just worried they will close to due date. I am going to be talking to the doctors more about it, but just wanting to know what to look out for and what is really necessary.

  21. avatar
    Victoria
    September 9th, 2012 at 06:02 | #21

    I live in Victoria, BC. I have met several moms who have had ultrasounds at 38-40 weeks “because their babies were breech.” They were then told they had low amniotic fluid, so they needed a Cesarean. This seems to be common practice here: breech baby + “low fluid”= C-section

  22. September 9th, 2012 at 08:53 | #22

    That is interesting, Victoria, because in many, many parts of the US, breech= cesarean, no matter the fluid level.

  23. avatar
    Amy G
    September 11th, 2012 at 10:24 | #23

    Thank you for this information! At 38 weeks, I was told that I had very low fluid levels. I went in for observation 3 times a week and at 39 weeks, my levels dropped even more (according to the method of observation used- I think it was AFI), so they recommended induction. At the time, I did not have much information about natural birth (I had learned that the closest midwife was 1.5 hours away…), and I looked for information about this condition online and really could not find anything that said that induction was NOT necessary. So, I’m glad that this resource is now available. I was induced, and my daughter was born vaginally and very healthy, but small (5lbs9oz). What bothers me is that I could never figure out why my levels were dropping quickly. I drink TONS of water, so I wasn’t dehydrated, and I had no other conditions. My daughter had no conditions. I supposed I’m the “healthy baby, healthy mama” case listed above. I had noticed increased discharge for the last 3 weeks or so leading to birth, but no other signs of labor, and my membranes did not appear to be ruptured. I am planning to try to get pregnant again soon, and I guess I still wonder, “what happened?” so that I can know for next time. (I’m in a new area with two birth centers and lots of midwifes, so I feel as though I’ll have the support for a natural birth this time around, no matter what happens!)

  24. avatar
    Lisa
    September 11th, 2012 at 22:46 | #24

    @Holly
    “I’d never share this suspicion with a client though as I wouldn’t encourage people to second guess their medical advice!”

    Why not? You should ALWAYS second guess medical advice and do your own research. Doctors are you people. They screw up or choose expediency over the patient. If more people questioned everything, fewer deaths from medical error and unnecessary treatments/surgeries would result.

  25. avatar
    Lisa
    September 11th, 2012 at 22:50 | #25

    That should have been “Doctors are just people”

  26. September 13th, 2012 at 12:05 | #26

    @Holly Sorry everyone I am back now! I wasn’t following the comments as diligently as I should have been! To answer your question about the higher concentration of meconium when there are lower levels of amniotic fluid, Holly, that is a good question. I honestly have not read anything about that in the literature. However, I do want to clarify that the literature review I did for this article was specifically for healthy moms at term. So we can’t really extrapolate these data to women who go past 42 weeks, as that is a different population.

    As I mentioned earlier, one of the BEST literature reviews I’ve seen done on amniotic fluid is in Gabbe’s 2012 Obstetric textbook. In the chapter on amniotic fluid, one of their main conclusions is “Although the evidence for induction in the prolonged pregnancy is solid, the term or preterm patient with isolated oligohydramnios may not need immediate delivery.” (Chapter 33, page 763).

  27. September 13th, 2012 at 12:39 | #27

    @Jessica
    Hi Jessica, again sorry for the delay in my response. Low amniotic before term is really a different topic, with different things that can cause it and slightly different clinical implications. I didn’t do a thorough literature review on your situation, but I did quickly look on PubMed and there have been a few studies done. Here is an interesting study on isolated oligo diagnosed before 37 weeks published recently in the American Journal of Obstetrics and Gynecology; http://www.ncbi.nlm.nih.gov/pubmed/22071052.

    The authors state that very little research has been done on 3rd trimester-preterm isolated oligo, and that there is a great need for research in this area. They followed 108 women with pre-term isolated oligohydramnios and compared them to other pre-term women with normal fluid levels.

    They researchers had 5 main conclusions:
    1. Only 0.5% of pregnant women are diagnosed with isolated oligohydramnios before 37 weeks
    2. 8% of these cases resolved spontaneously
    3. Women diagnosed with isolated oligohydramnios at preterm were more likely to be induced pre-term and then were at much higher risk for induction failure and cesarean section
    4. Isolated oligohydramnios at preterm is related to worse newborn outcomes, which appeared to be mainly related to the higher rate of medically induced prematurity and c-section delivery, and not because of the low fluid problem.
    5. Those women who were managed with “watchful waiting” had newborn outcomes that were no different than women who had normal fluid levels, but there was a higher risk of delayed fetal growth and meconium at birth (but no meconium aspiration occurred). The authors concluded that low amniotic fluid at pre-term may be an early sign of placental sufficiency and as such it should be closely monitored.
    ~It should be noted that this study was underpowered to detect any differences in mortality between groups.

    The research in this area (pre-term isolated low fluid) is very sparse and I wish we had more to go on! The problem is that your problem (low amniotic fluid pre-term) is so rare that it is really hard for researchers to find enough women to include them in studies.

    I hope this information is helpful to you!

  28. September 13th, 2012 at 13:07 | #28

    @Victoria
    Hi Victoria, I know of one mom recently who was going for a VBAC, but her baby was breech and when she went for her ultrasound, the fluid was too low and she was not given the option to have a version to turn the baby.

    For a great article by the American Academy of Family Physicians about versions for breech babies that the public can read for free go here: http://www.aafp.org/afp/1998/0901/p731.html

    As you can see, one of the contraindications that the AAFP lists to an external cephalic version is amniotic fluid abnormalities, although they do not list a cut-off for fluid levels. Their decision to make amniotic fluid abnormalities a contraindication is interesting, considering that measurements of amniotic fluid at term can be inaccurate. It’s also interesting to note that ACOG does not list low amniotic fluid as a contraindication to version in their practice guidelines.

    However, it makes sense that it would be hard to flip a baby if there isn’t enough fluid to help the baby turn around. And in fact research has shown that lower fluid levels (AFI <10) predict a lower success rate with the procedure. (http://www.ncbi.nlm.nih.gov/pubmed?term=14526307)

    Interestingly, a 2009 systematic review by Sela et al. found that for women with a previous Cesarean delivery, the average version success rate for subsequent breech presentation was incredibly high– 74% So women who want a VBAC but have a breech presentation generally have a great chance of success with a version– but only if they are allowed to have one. http://www.ncbi.nlm.nih.gov/pubmed?term=sela%20version%20cesarean

    Writing an article about external cephalic version for women with a prior Cesarean delivery is on my agenda for some day… whenever I get a chance to write it!

  29. avatar
    Tammy
    October 8th, 2012 at 17:41 | #29

    Thank you for sharing this and putting some clarity to the issue! It’s amazing how this is now the new trend to promote induction. I will be sharing this!

  30. October 17th, 2012 at 17:12 | #30

    Rebecca-as a nurse that both trains and works as a doula, how would you suggest we bring this up with our clients and their medical providers if they are suggesting induction in the case of low AFI with no other indications?

  31. October 17th, 2012 at 17:13 | #31

    @New Beginnings Doula Training
    Sorry, I should say I’m a nurse that both trains and works as a doula.

  32. avatar
    Kayla
    April 12th, 2013 at 11:37 | #32

    They induced me for this reason, and it took FIVE DAYS. My body and baby weren’t ready, and their diagnoses weren’t correct (placental insufficiency, oligohydraminos, and IUGR), buy do you think that is listed in my medical charts? No, of course not. Everything in my chart before labor says “bad, bad, bad! Must induce, distressed baby, dying placenta, blah blah blah” and everything after is healthy baby (albeit small because I was only 37 weeks), healthy placenta, etc. but nothing that items the fact that their previous diagnoses were WRONG. I’m currently in discussions (read: arguments) with the hospital because even after insurance, we owe almost 20k because of my useless extended expensive hospital stay, for an induction that was unnecessary, risky, and prolonged.

  33. avatar
    Ian de Vries
    August 22nd, 2013 at 01:16 | #33

    Hello Rebecca

    Thanks very much for the article. My wife was 37 weeks pregnant, and ultrasound showed low amniotic fluid, but doplers, heart, etc were healthy. he wanted to book an induction. His measurement on ultrasound seemed accurate and honest. my wife was hydrating well, and feeling quite fine so we said no to induction. However, 38 weeks she still had low amniotic fluid, and gynae wanted to induce straight away which we politely declined. at 39 weeks, he refused to scan again and said his recommendation had not changed. At which point I found this article, read it to my wife and we both felt happier. thanks. The very next day, she went into labour naturally, and a beautiful healthy baby girl was born at HOME, 3kg, no drugs. Midwife had to break waters, and said actually was a normal amount of fluid.
    thanks again.
    Ian

  34. avatar
    moi
    August 30th, 2013 at 14:44 | #34

    This is an excellent and informative forum.So glad to find it.

    I am currently 33 weeks and have been told on my last routine scan (yesterday) all was fine (movement, size, blood flow, placental position)EXCEPT the AFI was only 5 cm. My doc is concerned and I will be getting bi-weekly scans to keep a close eye on AFI, from now on. He says I MAY be induced or sectioned soon if level drops (by how much im unsure yet, doc will decide).
    Im grateful, that this was spotted now and that my doc is going to closely monitor it, but I actually feel really well, no leaks , no pains, plenty of energy PLUS baby seems to be doing well (bar the low AFI).

    It would be difficult to refuse well meaning intervention from the doctor, if he deems it necessary, but I also wonder is isolated low AFI sufficient to warrant an early induction/section?

    I will keep well hydrated and rested in the mean time, and let u know the outcome.

  35. avatar
    moi
    September 7th, 2013 at 14:27 | #35

    Just to update you all, at approx 34 weeks, my AFI measured at 2 cm, there was almost no fluid to be seen around the baby. Sonographer even got a second opinion as she wanted to be sure. Drs were concerned, because within the space of a week, over 3 scans, my AFI had dropped from 8 to 5 to 2. With my consent, a c-section was planned for the next day, even though I was only at 34 weeks.
    Thankfully, my consultant decided for me to have one more scan on the day of the planned section,and low and behold, it had jumped back up to 8 cm. Obviously, c-section was called off! Relief all round. After 3 more days of rest and hydration and excellent care in hospital, my next scan measured AFI of 12 cm!! Result!! Sonographers said they had never seen the AFI recover so well in a short space of time. Am out now from hospital, and was told to take it easy, and am scheduled for weekly (possibly bi-weekly) scans, from here on in, so will keep u posted. Please God, things will stay good.

  36. avatar
    Erik
    September 9th, 2013 at 11:36 | #36

    My wife was diagnosed with oligohydramnios at 32 weeks. She had an AFI of 6 and had one pocket over 2×2. It is summer in Texas, and my wife had not been eating or drinking as much as she should due to serious heartburn that started when she was 5 months pregnant. All the baby’s organs and limbs appear normal, however the baby is slightly underweight. Both my wife’s and my families are small people, men under 5’8″ and women under 5’5″. I asked the doctor if this could explain the slightly lower birth weight, and he said yes, but never mentioned it again.
    We were rescheduled for 5 days later to do a repeat u/s. That is happening today. After doing hours of research online, we decided not to do an induction on a healthy, albeit slightly smaller baby, unless something else crops up during the next 6-10 weeks.

    Did the author post that there is no data suggesting that life-threatening problems are ever discovered post-natal? Also, my wife is in the .5% of the population with early, isolated oligohydramnios. Shouldn’t she be in a study, especially since we plan to carry to term? How do we find out if these studies exist.

  37. avatar
    Reshma
    September 13th, 2013 at 23:29 | #37

    Hello.
    I am in 37 week of pregnancy,my due date is september 27 my doctor is suggesting me for Cesarian on 19 september,due to my AFI is 400 ml, but i want normal delivery.
    please suggest me what i have to do,,,,

  38. avatar
    sakina
    November 2nd, 2013 at 10:27 | #38

    hi, im 30wks pregnant and my AFI is 13cm. My sonography doc asked me whether i was leaking..but i said no..she says water level has really gone down. She has advised me to take lots of fluids and nutrients..my baby not moving inside. The cord is around the baby neck..plz help..is the 13cm AFI normal???

  39. avatar
    Christian
    November 4th, 2013 at 03:44 | #39

    Hello,
    My wife came to the hospital just yesterday because of minor discharges and was told she had to stay immediately because of her low AFI at 3.6. at that point she was close to her 39 weeks. We asked that the test would be repeated and reluctantly that was done with a result just under 5. we trusted the doctors who suggested immediate induction. my wife responded quite intense to the induction and had very strong contractions. they gave her epidurial which reduced the contractions and eventually distressed the Baby so much they had to perform a C-section.
    She is now suffering under the results of the C section and has not even asked for the baby. I am quite devestated after what I am reading here which makes me think a natural child birth would have been possible.

  40. November 4th, 2013 at 14:11 | #40

    Hi there! Unfortunately, we are not able to provide clinical advice to our readers. We do encourage you to do your own research and have a conversation with your health care provider. Additionally, should you find it helpful, you may want to get a second opinion. Best wishes.

  41. November 4th, 2013 at 14:16 | #41

    Thank you for sharing your experience. You and your wife may want to consider seeking out some local organizations who may be able to offer support during the immediate postpartum period. A postpartum doula can help, and make additional referrals. International Cesarean Awareness Network can connect you with your local chapter. Also, Postpartum Support International.

  42. avatar
    moi
    November 11th, 2013 at 14:16 | #42

    Just updating my story, my amniotic fluid index (AFI) at 34 weeks, went down to 2cm. This was seriously low for 34 weeks. A c- section was arranged for the next day, but miracalously, the AFI increased again and section was called off.

    I was scanned twice a week thereafter.It increased transiently in the following few days (with bed rest and hydration), but as time went on we realised that the amniotic fluid surrounding baby was consistently low (average of about 5 or 6 cm). I agreed to an elective c-section at 37 weeks. ( I requested the c-section rather than induction) because had a bad experience with induction on my first pregnancy (ended up in emergency c section).

    Anyway, the result was a healthy 7 pound 4oz baby boy (at exactly week 37)! He was apparently very blue and the cord was wrapped twice around his neck. He was put in an incubator for a few hours. We all agreed that the c section at 37 weeks was without doubt the best solution. If we had left it any longer, who knows??

    I am in no doubt, that in my situation, if I had insisted on postponing delivery until full-term OR even had an induction, the outcome would NOT have been nearly as good.

    My conclusion is, IF YOU HAVE LOW AFI EARLY IN THIRD TRIMESTER, LIKE ME, monitor levels closely, try and keep baby inside as long as you can, but DONT always insist on postponing delivery until full term. Often the baby is much better off outside than inside.

    And as for having a c section, I recovered really well with relatively little pain. For me, a natural birth is not the bee all and end all- whats most important is a safe ( controlled) delivery and whats safest for the baby.

  43. avatar
    Ann
    December 12th, 2013 at 00:07 | #43

    I just wanted to mention a thought of mine. The article refers to “healthy” women as the ones who may not benefit from an induction when a pregnancy has low fluid. However, how do you REALLY know that a woman is “healthy”? I think another poster above asked the same thing? Maybe the low fluid is a result from something wrong happening either with mom , baby and/or placenta? I know for myself I have thromobophilia (inherited blood clotting disorders) so I know I’m not considered healthy but if my doctor hadn’t ordered a complete blood clotting panel (which costs several thousands $) there is no way I would have know about my disorder. In fact, with my first pregnancy I was considered a healthy low risk patient when I really was not based on later blood work. I read somewhere that researchers estimate that up to 43% of the population could be heterozygous for MTHFR which is a blood clotting issue. MTHFR is just one of the many blood clotting factors on the spectrum, there are so many more such as FVL, PAI, lupus anticogulant, protein deficiency, etc. If you have never been tested how would you know you are definitely “healthy”? The symptom I had was 2 previous miscarriages which where not in a row. As far as i know, many doctors do not test until a women has three recurrent early mc’s or one late term loss? To me having low fluid which I only had this complication with one pregnancy (3 children) was a big deal. No matter how much heparin they prescribed it did not change the fluid levels. I drank over a gallon of water a day, went swimming, took it easy, laid on my left side and had bi weekly appoinments for scans /nst’s. I still lost fluid every week and it hovered around 4-5cm from 36-38 wks. At which time, both my reg ob and my MFM specialist made the decision that the placenta was losing efficiency with age and there was an increased risk of having a stillborn.

  44. avatar
    Javier Segura
    December 13th, 2013 at 00:51 | #44

    I really need your feedback Dr. Rebecca urgently my wife is going to be induced tomorrow at 4pm because she was a 9 in low fluid. Is our first baby I really feel that this doctor want to induced her so it wont mess with his holidays the reason why I say this is because my wife is do the 21 and he wants to do it the 14. We currently live in Midland tx and usually everything thing shutsdown the 15 for the holidays. Ive been reading your research and I concluded many things such as why we sign papers for induction and the lead of cesarean. There so much going on that I wish I could explain Dr. I personally do not feel comfortable being our first baby and my wife going to cesarean because after one cesarean there no more natural labor. I would appreciate your answer.

  45. avatar
    John
    December 24th, 2013 at 22:44 | #45

    It would seem to me that if isolated low af is hard to identify pre-delivery, then you either do the invasive ink test or you reduce the risk of iugr by ending the pregnancy. But what you may not want to do is wait for an in útero situation that may be getting worse

  46. avatar
    John
    December 24th, 2013 at 22:49 | #46

    *reduce the damage caused by a potential iugr

  47. January 19th, 2014 at 13:45 | #47

    Thank you so much Rebecca. I only wish my wife and I had known this before she was induced. We fought so hard for a natural birth, but due to low AFI she was induced early and suffered through 3 days of labor before our son was born. Her body was clearly not ready, and I wish we had seen this and had the knowledge to hold the doctor at bay until she was ready.

  48. avatar
    Dr Vikas Bansal
    January 21st, 2014 at 08:03 | #48

    Hi Rebecca. i am a Radiologist in india.i also use AFI method to calculate AMNIOTIC FLUID. I Just want to know whether is it possible that level of amniotic fluid fall from 10 cm to 4 cm in just 5 hours without leaking PV.

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