When Push Comes to Shove
According to Listening to Mothers II, a survey of U.S. women giving birth in 2005, 17% of women having vaginal birth reported a “health professional pressing down on her belly to help push the baby out” (Declercq 2006, p. 35). This is called fundal pressure, and 17% is fairly common, so I decided to look at its safety and effectiveness in the chapter I’m working on now for the new edition of Obstetric Myths Versus Research Realities. Here’s what I found out:
Fundal pressure can harm mothers. Three studies concluded that fundal pressure increased likelihood of anal sphincter injury. A small study comparing 34 women who had fundal pressure with 34 similar women who didn’t found that fundal pressure was a disaster for the anal sphincter when combined with midline episiotomy. Ten of 16 women—a whopping 63%—who had fundal pressure and episiotomy had an anal sphincter tear compared with only 1 woman of the 16—6%—who had episiotomy and no fundal pressure. A larger study of 845 women reported that fundal pressure increased the risk of anal sphincter injury 4.6-fold after adjusting for correlating factors. Rates in the overall population were 6% while rates with no fundal pressure were 3%, and rates with fundal pressure were 21%. A very large study of 238,500 women having spontaneous vaginal birth and 46,300 women having instrumental vaginal delivery found much smaller differences, but the addition of fundal pressure increased risk of anal sphincter injury with spontaneous birth (2.1% vs. 1.7%) and forceps delivery (5.2% vs. 4.7%), although, not, oddly enough, with vacuum extraction. Finally, a study looked at factors associated with painful intercourse 12 to 18 months after delivery. Investigators excluded women who had had anal sphincter tears. Even so, fundal pressure popped up as a problem. Among women experiencing painful intercourse, 35% had had fundal pressure compared with 13% of women not experiencing painful intercourse.
But we’re not done. Fundal pressure can harm babies too. A study of 13,700 vacuum extractions reported more brachial plexus injuries (a cluster of nerves serving the shoulder and arm) in babies when fundal pressure was used—2% versus 1%. Study authors theorized that fundal pressure may jam (the word they used was “impact”) the baby’s shoulder behind the pubic bone. So much for safety.
Still, every intervention has potential harms. The question is: “Does fundal pressure do sufficient good to counterbalance those harms?” Despite its fairly common use, until this year, we had no evidence that it did. Now we do, and it doesn’t. In a randomized controlled trial (women assigned by chance to one form of treatment or the other), investigators allocated healthy women with full-term, head-down babies and no epidural analgesia or oxytocin (Pitocin or “Pit”) infusion to have fundal pressure or not when they reached full dilation and felt an urge to push. (RCTs produce the strongest evidence because random assignment eliminates many sources of bias.) Second-stage duration rates were similar in the group overall as well as among first-time mothers and among women with prior births. Ominously, umbilical cord oxygen levels at birth were lower in the fundal pressure group and carbon dioxide levels were higher. All newborns were in good condition at birth, but these were healthy pregnancies, and the same might not be true for babies already having some difficulty. So much for efficacy.
I could speculate on why the practice has persisted and continues to persist in the absence of any evidence to support it—in fact, I will in the book—but the take-home pay here is if progress is slow in second stage, women would be much better off trying an upright position, or better yet, preventing the slow progress by staying off her back in the first place and choosing a provider who practices patience rather than imposing time limits on second stage. Most women can get upright even with an epidural and confined to bed. Modern epidurals can relieve pain while still leaving sufficient feeling and muscle strength in the legs, for example, to rest on hands and knees between contractions and push back onto heels during contractions, or to kneel upright using a stack of pillows or a stability ball (A.K.A. “birth ball”) for support, or to sit between contractions and use the help of labor companions or a squatting bar to pull into a squat during contractions. Women with weak contractions would also be better off using breast stimulation or having I.V. oxytocin to bring strength up to par before resorting to more aggressive means of getting the baby born. And if push does come to pull, instrumental vaginal delivery isn’t entirely harmless, but at least it’s effective. Fundal pressure is neither. The wise woman whose care provider wants to press on the top of her belly either alone or in conjunction with instrumental delivery, will, in the words of a famous campaign, “just say, ‘No.’”’
Click on the extended post to see the references.
Api, O., Balcin, M. E., Ugurel, V., Api, M., Turan, C., & Unal, O. (2009). The effect of uterine fundal pressure on the duration of the second stage of labor: A randomized controlled trial. Acta Obstet Gynecol Scand, 88(3), 320-324.
Cosner, K. R. (1996). Use of fundal pressure during second-stage labor. A pilot study. J Nurse Midwifery, 41(4), 334-337.
Declercq, E., Sakala, C., Corry, M. P., & Applebaum, S. (2006). Listening to mothers ii: Report of the second national u.S. Survey of women’s childbearing experiences. New York: Childbirth Connection.
de Leeuw, J. W., Struijk, P. C., Vierhout, M. E., & Wallenburg, H. C. (2001). Risk factors for third degree perineal ruptures during delivery. BJOG, 108(4), 383-387.
Ejegard, H., Ryding, E. L., & Sjogren, B. (2008). Sexuality after delivery with episiotomy: A long-term follow-up. Gynecol Obstet Invest, 66(1), 1-7.
Mollberg, M., Hagberg, H., Bager, B., Lilja, H., & Ladfors, L. (2005). Risk factors for obstetric brachial plexus palsy among neonates delivered by vacuum extraction. Obstet Gynecol, 106(5 Pt 1), 913-918.
Zetterstrom, J., Lopez, A., Anzen, B., Norman, M., Holmstrom, B., & Mellgren, A. (1999). Anal sphincter tears at vaginal delivery: Risk factors and clinical outcome of primary repair. Obstet Gynecol, 94(1), 21-28.