About the SA Blog Network

Context and Variation

Context and Variation

Human behavior, evolutionary medicine… and ladybusiness.
Context and Variation Home

Get This Baby Out of Me! On Induction and Ending #occupyuterus

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

An ultrasound of my daughter during her #occupyuterus movement

An ultrasound of my daughter during her #occupyuterus movement

Summer 2001. I had just graduated from college with a joint degree in biological anthropology and women’s studies which, as my father pointed out, was not a degree with an obvious vocational angle. I was headed to graduate school in anthropology that fall, an experience for which I was woefully underprepared. I spent the summer loafing. It was the last summer I would ever have to just loaf around, so I was going to loaf, dammit.

But I did have one job. A dear friend was pregnant and asked me to attend her birth. I prepared like a champ: I watched A Baby Story twice a day while lounging on my boyfriend’s couch (I squeezed these in between yoga, George R. R. Martin novels, and trips to Whole Foods). I also read through some of my old textbooks, including books recommended to me by a few professors, The Woman in the Body, Birth as an American Rite of Passage and Immaculate Deception II.

One early morning in July, my friend called. “We’re on our way to the hospital. I’m in labor. It will be a while, so don’t hurry,” she said. I hurried. When I got there, conditions couldn’t have been worse: as it turns out, the nurses at the hospital were on strike, the doctor my friend hated the most was the one on call, and the epidural she got once active labor commenced slowed down her contractions. The doctor broke my friend’s water without her consent then began pressuring her and her husband to have Pitocin. Pitocin was the one intervention my friend had been adamant she wanted to avoid, but the doctor kept pulling the husband to the side telling him they were risking the baby.

The nurses were not familiar with the hospital or the doctor and so could offer little support. The husband was beside himself with worry. The doctor had the bedside manner of cardboard. I thought, This is my moment. My college degree will be useful for something!

“How about nipple stimulation?” I asked.

My friend and her husband looked at me blankly. The doctor had already left the room to attend to another patient.

“Pitocin is synthetic oxytocin. Oxytocin is produced by nipple stimulation, like when you breastfeed a baby. Maybe making your own oxytocin will bring back your contractions.”

My friend and her husband continued to stare at me.

“Well, some people do use nipple stim…” one nurse said, sounding unconvinced.

That was all the endorsement the husband needed. Eyes wild, he reached across his wife’s body… and, er, stimulated her nipples. Aggressively.

My friend’s contractions started back up again, and didn’t let up for the remainder of labor. A few hours later she gave birth to a gorgeous, big baby boy.

* * *

Ten years later, I’m in the same position. My sister has asked that I attend her birth along with her husband. Her official due date was Sunday, so we’re within the window when he will be born and are playing a waiting game. Culturally, we consider the due date as a sort of deadline; if you are still pregnant after that deadline your baby is “overdue,” and you may feel you have failed as a mother (you haven’t). You may also just be sick of being pregnant, or eager to meet your new kid. Maybe your favorite midwife or obstetrician is about to go on vacation and you won’t be able to deliver with her.

Two issues contradict the notion that inducing labor when “overdue” is a good idea. First, due dates are notoriously inaccurate, as they are calculated by date of last period instead of by ovulation or implantation. This makes sense, of course, because women rarely know their ovulation or implantation days. The first half of the cycle, or follicular phase, is even more variable than the second half (Lenton et al., 1984), meaning the assumption built into calculating a due date – that the follicular phase is fourteen days long – introduces a lot of error.

Second, if you are past your due date but your baby is happy inside of you, that means you have produced a healthy, hospitable environment for her or him. More hospitals are creating 39-week cutoffs before which doctors cannot schedule inductions; this is because birth before that point carries increased risks for the baby. Further, many researchers support the maternal crossover hypothesis, which suggests a fetal trigger for the onset of labor: once the fetus begins to starve, it sends a stress signal to the mother, which commences labor (Ellison, 2001; Wildman et al., 2011). The idea is that the mother has “crossed over” some point after which she cannot provide adequate nutrition for the growing fetus through the umbilical cord. If she or he wants to keep growing, then it makes more sense to be born and receive more energy dense food, and fat, through the nipple in the form of breastmilk.

This means a baby usually should be born when it wants to be born, rather than when you, your mother in law, your boss or *cough* your sister want him to be born.

However, the cervix of a woman who hasn’t had any children yet does take longer to ripen, and so first pregnancies can be longer than the second or third (Mittendorf et al., 1993). And so the question is whether there is anything the mother can do safely to encourage the fetus to consider starting things up, or to help the cervical ripening so that any signal the fetus is sending will be more effective. Some of the most common interventions mothers try on their own include exercise, sex, and eating spicy foods (Chaudhry et al., 2011).

I am about to share some of the literature on these and other interventions. I do not explicitly recommend any particular course of action, as I’m not a licensed midwife or obstetrician. As I learned when I had my own daughter, having book knowledge is not the same as practical knowledge.

Exercise certainly makes sense as a mechanism to induce labor: bouts of physical activity temporarily increase systemic inflammation biomarkers (Kasapis and Thompson, 2005), which are associated with labor onset. Exercise also increases energy expenditure, which might increase fetal stress and cause it to decide it can get more calories out than in.

However, the evidence doesn’t seem to support exercise inducing labor or shortening pregnancy. Many studies support a role for exercise in supporting normal-weight babies (Bell et al., 1995; Campbell and Mottola, 2001; Klebanoff et al., 1990; Leiferman and Evenson, 2003), which is a great thing: have a too-big baby and birth complications can arise, and a small baby can have health issues. Exercise may also reduce the risk of cesarean deliveries in nulliparous women (that’s women who haven’t had any prior kids) (Bungum et al., 2000). And, exercise reduces the incidence of pre-term birth (Hatch et al., 1998; Hegaard et al., 2008; Jukic et al., 2011), though work-related and potentially stressful forms of physical activity may slightly increase the risk (Misra et al., 1998). So it seems as though habitual physical activity has a very beneficial effect on mother and baby. But it doesn’t make the baby come out any faster.

Unprotected sex with a man can be fun if you’re straight or bi and it’s consensual, and its role in triggering labor has mixed support. Semen contains prostaglandins, and prostaglandins can bring on uterine contractions. Further, oxytocin is produced at orgasm, which ripens the cervix (and of course, you don’t need a consenting male partner for this one). I found one study that showed that women who were scheduled for an induction but had sex at term to avoid it had a shortened gestation length (Tan et al., 2006). The same author also found, however, that both sex and orgasm were inversely correlated with spontaneous labor (Tan et al., 2009).

Spicy foods? So far, no one has systematically looked at it, though intestinal distress may trigger contractions (Chaudhry et al., 2011). And while a few herbal preparations may increase your chances, the side effects and lack of FDA regulation dictate caution without a licensed midwife or physician overseeing the process.

But there is one more intervention worth further study. Remember when my friend’s husband semi-publicly twiddled my friend’s breasts? Nipple stimulation is effective not only at helping contractions along once labor has started, but possibly also inducing labor. One paper I read reviewed the varying recommendations by midwives for inducing labor, and their nipple stimulation protocol included massaging with oil by hand until one feels contractions, or using an electronic breast pump for fifteen minutes on, fifteen off (Knoche et al., 2008). One study demonstrated that nipple stimulation leads to greater cervical ripening than a control group (Adewole et al., 1993). So the mechanism is there, the link between nipple stimulation and cervical ripening pretty well established, and cervical ripening is one of the major first steps to labor.

That said, think of late pregnancy as an #occupyuterus movement. If current events are any indicator, no good comes of forcing peaceful protestors to leave by violent means.


Adewole I, Franklin O, Matiluko A. 1993. Cervical ripening and induction of labour by breast stimulation. African journal of medicine and medical sciences 22(4):81.

Bell RJ, Palma SM, Lumley JM. 1995. The Effect of Vigorous Exercise During Pregnancy on Birth‐Weight. Australian and New Zealand journal of obstetrics and gynaecology 35(1):46-51.

Bungum TJ, Peaslee DL, Jackson AW, Perez MA. 2000. Exercise during pregnancy and type of delivery in nulliparae. Journal of Obstetric, Gynecologic, & Neonatal Nursing 29(3):258-264.

Campbell MK, Mottola MF. 2001. Recreational exercise and occupational activity during pregnancy and birth weight: a case-control study. American Journal of Obstetrics and Gynecology 184(3):403-408.

Chaudhry Z, Fischer J, Schaffir J. 2011. Women’s Use of Nonprescribed Methods to Induce Labor: A Brief Report. Birth.

Ellison PT. 2001. On Fertile Ground. Cambridge, MA: Harvard University Press.

Hatch M, Levin B, Shu XO, Susser M. 1998. Maternal leisure-time exercise and timely delivery. American Journal of Public Health 88(10):1528.

Hegaard HK, Hedegaard M, Damm P, Ottesen B, Petersson K, Henriksen TB. 2008. Leisure time physical activity is associated with a reduced risk of preterm delivery. American Journal of Obstetrics and Gynecology 198(2):180. e181-180. e185.

Jukic AMZ, Evenson KR, Daniels JL, Herring AH, Wilcox AJ, Hartmann KE. 2011. A Prospective Study of the Association Between Vigorous Physical Activity During Pregnancy and Length of Gestation and Birthweight. Maternal and Child Health Journal:1-14.

Kasapis C, Thompson PD. 2005. The Effects of Physical Activity on Serum C-Reactive Protein and Inflammatory Markers: A Systematic Review. Journal of the American College of Cardiology 45(10):1563-1569.

Klebanoff M, Shiono P, Carey J. 1990. The effect of physical activity during pregnancy on preterm delivery and birth weight. American Journal of Obstetrics and Gynecology 163(5 Pt 1):1450.

Knoche A, Selzer C, Smolley K. 2008. Methods of Stimulating the Onset of Labor: An Exploration of Maternal Satisfaction. The Journal of Midwifery & Women’s Health 53(4):381-387.

Leiferman JA, Evenson KR. 2003. The effect of regular leisure physical activity on birth outcomes. Maternal and Child Health Journal 7(1):59-64.

Lenton EA, Landgren B-M, Sexton L, Harper R. 1984. Normal variation in the length of the follicular phase of the menstrual cycle: effect of chronological age. BJOG: An International Journal of Obstetrics & Gynaecology 91(7):681-684.

Misra DP, Strobino DM, Stashinko EE, Nagey DA, Nanda J. 1998. Effects of physical activity on preterm birth. American Journal of Epidemiology 147(7):628-635.

Mittendorf R, Williams MA, Berkey CS, Lieberman E, Monson RR. 1993. Predictors of human gestational length. American Journal of Obstetrics and Gynecology 168(2):480-484.

Tan P, Yow C, Omar S. 2009. Coitus and orgasm at term: effect on spontaneous labour and pregnancy outcome. Singapore medical journal 50(11):1062-1067.

Tan PC, Andi A, Azmi N, Noraihan MN. 2006. Effect of coitus at term on length of gestation, induction of labor, and mode of delivery. Obstetrics & Gynecology 108(1):134.

Wildman DE, Uddin M, Romero R, Gonzalez JM, Than NG, Murphy J, Hou ZC, Fritz J. 2011. Spontaneous Abortion and Preterm Labor and Delivery in Nonhuman Primates: Evidence from a Captive Colony of Chimpanzees (Pan troglodytes). PLoS One 6(9):e24509.

Kate Clancy About the Author: Dr. Kate Clancy is an Assistant Professor of Anthropology at the University of Illinois. She studies the evolutionary medicine of women’s reproductive physiology, and blogs about her field, the evolution of human behavior and issues for women in science. Find her comment policy here. Follow on Twitter @KateClancy.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 6 Comments

Add Comment
  1. 1. 11:48 am 11/30/2011

    #occupyuterus! Ha! Love it! Being a science-minded person who is intrigued by the low-intervention, midwife-approach to childbirth (and totally turned off by the all-too-common experience you describe with your friend’s birth), these references and your analysis of labor-inducing methods are a breath of fresh air! I’m forwarding this to all my friends…

    BTW, my biggest beef is that women aren’t educated about their care options before getting pregnant – I have so many friends who are unfamiliar with the midwife model of care and only find out about it after they could use the info… there are a gjillion ways to give birth, but somehow none of it gets talked about. How can we get this info out there, I wonder?

    Also, how do we reform the totally silly and inaccurate dogma we’re taught about ovulating on day fourteen? There are perfectly good signs of ovulation that are pretty reliable, right (not if you’re using it as a birth control method, of course, but for purposes of tracking conception)? Why not counsel women to track that as well as the length of their cycles? It would only help make the due-date guesswork a little more accurate… of course, what you say about the trigger for labor being caused by “starvation” is fascinating and would vary in time for each woman, I’d presume…

    Anywhoo, great stuff, Kate. Thanks!!

    Link to this
  2. 2. kclancy 5:33 pm 11/30/2011

    I hear you, and thanks for your comment. For the first point on lack of education, I do hope blogs like mine and others help raise some awareness — it’s always nice when my stuff ends up on Jezebel or Boing Boing because I know it’s reaching a whole new audience. But people have to come to blogs, or somehow be curious about or seek out this information. We need to figure out how to push this TO them. I still don’t have a good solution for this aside from getting into more mainstream media outlets (so being on SciAm does help at least some!).

    For your second question, I agree! Last year I wrote a post on this for the guest blog:

    Some women are very interested in learning more about their bodies and track ovulation when trying to get pregnant, some aren’t. I think it would be nice, even for those who don’t want to track that kind of stuff, to help teach them, via MSM or their own doctors what a due date really means, how to understand variation, etc. So that way even if the due date isn’t totally error-free the patient can understand it in the broader context and have a more relaxed approach to being “overdue.”

    Link to this
  3. 3. rusalka 12:19 pm 12/1/2011

    Excellent post as usual! Although it does make me worried for what will become of my pregnant friends when they end up at the hospital. One tiny quibble: isn’t oxytocin produced throughout sexual arousal, and not just at orgasm? I think that’s right, and it would certainly be a more useful state of affairs for women who have difficulty achieving orgasm. :)

    Link to this
  4. 4. kclancy 12:41 pm 12/1/2011

    Thanks rusalka! You know, I think you are right. Oxytocin is secreted just by physical touch, so I’m sure sex causes oxytocin secretion even without orgasm :) .

    Link to this
  5. 5. Jen@PlusSizeBirth 11:10 pm 12/1/2011

    Fabulous and informative post! This topic comes up often with the work I do so I’ll be sharing it a lot :)

    Link to this
  6. 6. jc2929 4:12 pm 12/3/2011

    What a horror story, reminds me of my own birth experience when I had my son. Everything that could go wrong did go wrong. In my case I went in for a doctor’s appointment and was told that I had preclampsia and had to be induced at once. I checked into the hospital to be induced on June 13 and didn’t have my son until June 16. It was the worse 3 days of my life. My doctor disappeared, I didn’t want any drugs, but the nurses insisted that I must have something so after days of pain I finally agreed to the epidural, which the anesthesiologist screwed up and had to do the procedure twice!! Only to feel everything anyway, because it wasn’t administered correctly. Then finally when I was ready to push the doctor on duty was nowhere to be found. Hopefully it won’t be like this if I have a second child. I too am a believer that no intervention will make a baby come sooner, it will come when it’s well and ready to do do.

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article