Science Sunday: Let's Talk About Sex, Babies

Pregnancy and childbirth:
more than one bump in the road

Modesty prohibits me from discussing my own postpartum experiences with sexual health--let's just say that there were some difficulties, and that they have stopped (except for the difficulty of finding time--I think most new parents will sympathize with that one being ongoing)!  However, what I found most interesting about my experience was the fact that my physician never said anything about sex after my daughter was born.  I asked if I could "go ahead," and she said yes.  That was the extent of our discussion.

Later, I had trouble finding good information online about sexual function after childbirth; most of what I read only managed to terrify, rather than inform, me.  So I thought it might be helpful to other new or soon-to-be new moms to compile some information here.

First of all, it may amaze you to know that in one survey of 484 postpartum women, only 18% of them reported receiving any information from their physicians about potential difficulties with sexual function (1).  Yikes!   Poor show, doctors.

Now, let's learn an important medical term:  dyspareunia means pain with sexual intercourse.  But different researchers  will, like Bill Clinton, play fast and loose with the definition of sex.  Some use dyspareunia to refer to pain during penetration only, while others will specifically ask women in the study about continuing pain with intercourse after penetration, or pain with orgasm.

Moving on to the numbers.  How common is dyspareunia after childbirth?  The same study of 484 postpartum first-time mothers cited above provides these numbers:  55% of women experienced painful penetration, and 45% experienced pain with continued intercourse, in the first 3 months after delivery.  At 6 months, 27% of women were still experiencing pain with penetration, and 20% were experiencing pain with continued intercourse.

[Oh, I can hear my medical student friends sounding dubious already!  They want the baseline numbers, which the study provides.  Before pregnancy, in the same group of women, 9% experienced painful penetration and 8% reported pain on continued intercourse.  These numbers are significantly different from the postpartum numbers].

Another study, this one with a prospective design, found roughly similar rates of dyspareunia.  They were also able to tell us a little more about how bad the pain was for the women in their study (2):  at 3 months postpartum, only 4% of women described their pain as "major--precluding any enjoyment of sexual intercourse."  Another study asked women to describe pain with intercourse, if they experienced it, as mild, moderate, or severe (4); at 3 months postpartum, 51% described pain as mild, 45% as moderate, and 4% as severe; those numbers changed to 65% mild, 33% moderate, and 2% severe at 6 months postpartum.

So now you are probably wondering what's different for the roughly half of women who were experiencing pain with intercourse at 3 months, and those who weren't?  Can we point to any differences between the two groups?

Unsurprisingly, the best predictor of dyspareunia is the presence and degree of perineal trauma during childbirth.  The location of the perineum is an area of skin and muscle between the vagina and the anus, shown to the left.

One retrospective study of 626 first-time mothers (4) found that at 3 months postpartum, 33% of women with no perineal tears experienced pain with intercourse, compared to 48% of women with second-degree perineal trauma (which means a tear in the perineum that extends through the layers of skin and into the muscle), and 61% of women with third- or fourth-degree tears (which means a tear that extends through the perineal muscles to the muscles of the anal sphincter and into the tissue underneath).  However, the rates of dyspareunia decreased to 19%, 24%, and 27% by 6 months postpartum.   By the way, in the studies that I looked at, episiotomies were associated with sexual dysfunction at rates equal to or greater than spontaneous second-degree tears (1, 4).

What about C-sections, you ask? A comprehensive review of the few studies that have looked at the question of sexual function after C-section (3) concluded that at 3 months postpartum, women who had undergone caesarean section were equally likely to experience sexual dysfunction as women with unassisted vaginal deliveries (that means vaginal deliveries where no forceps or vacuums were used), but less likely than women with assisted vaginal deliveries.  At 6 months or after, however, rates of sexual dysfunction were roughly the same, according to this review, in women who delivered vaginally and by Caesarean section.

[Are you a medical student?  You may also be interested to know that fast-absorbing sutures may cause less short-term pain and discomfort than catgut sutures (5), and that continuous suture techniques are associated with less short-term pain (up to 10 days) than interrupted sutures, and when continuous sutures were used through all layers, they were associated with less dyspareunia in a subgroup analysis (6)].

Perhaps the most controversial association with postpartum pain in intercourse is that with breastfeeding.  Honestly, there haven't been that many studies in this area, and they do not all agree, although one systematic review (3) concluded that most of the evidence does suggest that women who breastfeed have higher rates of sexual dysfunction.  For example, a prospective study of 150 postpartum women (2) showed that persistent pain with intercourse was associated with breastfeeding (after controlling for type of delivery and episiotomy) at 3 months postpartum but not later than that.  Another retrospective study of 484 women showed that at 6 months postpartum, 40% of women who were still breastfeeding experienced dyspareunia, compared to 25% of women who were not (1).  Yet another prospective study found that breastfeeding women at 6 months postpartum were about 4 times as likely to report dyspareunia compared to women who were not breastfeeding (4).

Although I find these results disconcerting--after all, breastfeeding is in so many ways good for the mother and the healthiest choice for the baby--I do not find the results that surprising.  It makes some intuitive sense to me that frequent breastfeeding is a signal to your body that you are caring for a baby and perhaps are not yet ready to get pregnant again...so vaginal dryness, or discomfort during intercourse, or low desire, may be your body's ways of keeping you from getting pregnant again.  And since a number of studies do seem to agree on this point, I am inclined to think that rather than glossing over this problem, it may be especially important for doctors who are taking care of women who breastfeed their babies to discuss ways to address sexual problems.

But pain isn't the only problem you can have during sex.  The retrospective study of 484 first-time mothers (1) also asked about problems with vaginal dryness (46% at 3 months, 26% at 6 months), vaginal tightness (33% at 3 months, 20% at 6 months), vaginal looseness (20% at 3 months, 12% at 6 months), and loss of sexual desire (53% at 3 months, 37% at 6 months).  I would especially like to draw your attention to the fact that postpartum vaginal tightness was actually more common than looseness--not something that you might expect based on popular stereotypes.

So far this discussion has been pretty hetero-normative, in that I've focused on penetrative, vaginal sex.  There isn't much data about other sexual practices after childbirth, but I'll briefly mention what I found.  In the retrospective study of 484 women (1), researchers asked women which activities they'd engaged in during the year before pregnancy compared to the year after childbirth.  In this study during that time period, rates of oral sex by the woman declined from 71% to 58%, while rates of oral sex by the partner declined from 72% to 52%, anal sex declined from 6% to 3%, and genital contact without intercourse stayed roughly constant, at 71% and 69%.  (It is unclear how many of the respondents were in heterosexual relationships).   I would actually love to see a study comparing sexual function in new mothers who gave birth, to mothers whose female partners gave birth, and mothers who had children via surrogates--that would be a nice way to tease apart some of the environmental factors that you can imagine might affect sexual function for new parents.

Oh, by the way.  I haven't said much here about the Big Question of when women have vaginal intercourse for the first time after childbirth.  I skipped this question because it seems like no matter what the group that is being looked at (caesarean section, vaginal delivery with or without perineal trauma), the averages are about the same--usually 5 to 6 weeks for first vaginal intercourse postpartum.  Since the averages are similar between groups of women with different kinds of deliveries--unlike the percentages of women who experience pain with first postpartum intercourse--I suspect that the timing may be more related to external factors like figuring out parenthood, relationships, and commonly given medical advice.

So what's the summary here?  Most women experience some discomfort with sexual intercourse after having a baby.  With time, most of the discomfort goes away for most women.  Breastfeeding may be associated with more discomfort during sexual intercourse than bottle feeding.   And, perhaps most importantly, given the frequency of problems with sexual function after childbirth, the low rate of physicians who discuss this issue with their patients is pretty embarrassing.  Sexual dysfunction after childbirth can be addressed:  sutures may need to be removed or trimmed, scar tissue may need to be examined, pelvic floor muscles may need to be strengthened with Kegels or with therapy, lubrication may need to be used, or estrogen cream may need to be prescribed.  There are ways to deal with the variety of challenges posed by sexual life after childbirth.  Perhaps most importantly, though, women should know that they are not abnormal if they are having trouble having sex after having a baby.  Challenges are common, and open communication between a woman, her partner, and her physician are essential.

(1) Barrett, G., Pendry, E., Peacock, J., Victor, C., Thakar, R., & Manyonda, I. (2000). Women’s sexual health after childbirth. British Journal of Obstetrics and Gynaecology, 107(2), 186-195.

(2) Connolly, A., Thorp, J., Pahel, L.  (2005).  Effects of pregnancy and childbirth on postpartum sexual function:  a longitudinal prospective study.  International Urogynecology Journal, 16, 263-267.

(3) Abdool, Z., Thakar, R., Sultan, A.  (2009).  Postpartum female sexual function.  European Journal of Obstetrics & Gynecology and Reproductive Biology, 145, 133-137.

(4) Signorello, L., Harlow, B., Chekos, A., Repke, J.  (2001).  Postpartum sexual functioning and its relationship to perineal trauma: A retrospective cohort study of primiparous women.  American Journal of Obstetrics and Gynecology, 184(5), 881-890.

(5) Kettle, C., Dowswell, T., Ismail, K.  (2010).  Absorbable suture materials for primary repair of episiotomy and second-degree tears.   Cochrane Database of Systematic Reviews, 6, Art. No. CD000006.

(6) Kettle, C., Hills, R., Ismail, K.  (2009).  Continuous versus interrupted sutures for repair of episiotomy or second-degree tears.  Cochrane Database of Systematic Reviews, 4, Art. No. CD000947.

Science Sunday: Purées vs. Lumpy Foods

Today I'd like to revisit something that I mentioned earlier this week, namely that we've decided to largely skip purées in favor of introducing our daughter to whole foods that she can grasp on her own, a practice known as "baby-led weaning."

A friend asked, "what does the actual research say about first foods to give babies?  Is there any benefit--or reason--to giving rice cereal and the like, rather than fruits or vegetables?"

I had been given the same advice by our pediatrician:  that the best thing to start with was rice cereal, and then to advance slowly through single-ingredient fruit and vegetable purees, introducing a new one every 4 to 5 days.  But, he cautioned, "parenting is more of an art than a science."

Indeed, the advice given by our pediatrician is the recommendation by the American Academy of Pediatrics Committee on Nutrition (1).  The reason given for introducing rice cereal and puréed meats first is two-fold: 1) they are unlikely potential allergens, and 2) store-bought rice cereal is artificially fortified with, and meats are naturally high in, iron.  The thought is that infants who are exclusively breast-fed can no longer get adequate iron from breast milk, and their own reserves may have run out, by about 6 months of age.

It may be helpful to know that UpToDate, a well-regarded online reference for national recommendations in medical practice, labels the standard "rice cereal and single ingredient purée" recommendation a Grade 2C recommendation.  In their rating system, Grade 2C refers to a "very weak recommendation;" it is based on "low-quality evidence," including evidence from "observational studies,  unsystematic clinical observations, or from randomized, controlled trials with serious flaws."  Indeed, the only type of research I was able to find to support this recommendation consisted of observational studies demonstrating that some, but by no means all, mothers in the United States choose to introduce solids in this way.  I'm not even going to bother with citing those studies; they really only show that that's what some people do, not that that way is associated with any better outcomes.

The evidence that exclusively breastfed babies require supplemental iron is slightly stronger in comparison, at least based on calculations (2) of how much iron babies need per day, the size of their iron stores, the amount of iron available in human milk, and the bioavailability of iron in human milk (how much of that iron can actually be absorbed).  Going by all of these estimates, it seems like breast-fed babies should require supplemental iron after about 6 months of age from foods other than breast milk in order to avoid iron deficiency anemia (low levels of red blood cells, which could lead to growth restriction).

HOWEVER. Actual observational studies of mothers who are breastfeeding past 6 months are by no means conclusive.  One small study (n=4) studied infants who were exclusively breastfed from 8 to 18 months; all of them had normal iron status (3).  A somewhat larger study (n=30) similarly found that exclusive breastfeeding (EDIT: meaning no formula, cow's milk, or iron-fortified cereal supplementation), as long as it continued, protected infants from anemia, although once breastfeeding had stopped--even if it had continued for a long time--those infants who were not given iron-fortified or high-iron content foods were likely to become anemic (4).  In short, there's not much actual evidence that infants who are being exclusively breastfed are in great danger of becoming anemic; giving iron fortification is largely a matter of playing it safe.  [Note that the amount of iron in human milk does decrease with increasing duration of lactation, and the amount of iron available in breast milk varies a lot from one woman to the next--furthermore, giving iron supplements to mom doesn't change how much iron is available in her milk!**]  Given the universality of the recommendation for iron supplementation, I am slightly shocked by the paucity of actual evidence.  Someone needs to get out there and do a good randomized controlled trial in this area!

OK.  So here's where we are:  there's virtually no evidence that starting with rice cereal and purées offers any advantages, and I couldn't find much good evidence that breastfed babies require iron supplementation via fortified rice cereal, either.  So what about the alternative?  Is there any benefit to be had by introducing lumpier, more whole foods, earlier?

There isn't much work in this area either, to be honest.  I really only found one relevant study (5), and was comforted that an expert in the area of children and food textures who was forwarded my post about "baby-led weaning" sent back the same study for reference.  The authors of this UK study looked at children who had first been given "lumpy" or chewy foods at ages before 6 months, between 6 and 9 months, and after 9 months, and examined correlations between the age of introduction and the frequency of eating different types of fruits and vegetables much later, at 7 years old.

More of the children who had an earlier age of introduction of lumpy solids (before 9 months) later consumed all 10 types of fruits and vegetables.  More of the children with the earliest age of introduction (before 6 months) later consumed green leafy vegetables.  Not only did children who were introduced to lumpy foods at a younger age eat more varied diets later; also, children who were NOT introduced to lumpy foods till after 9 months were more likely to have problems with eating at age 7 years.  Problems included "not eating sufficient amounts, refusal to eat the right amounts, and being choosy with food."  Note that the study did control for standard demographic variables like mother's level of education, as well as things like duration of breastfeeding.

In short, I think my pediatrician's parting comment to me about introduction of solids, that "parenting is more of an art than a science," is about right.  Given the (surprising!) lack of good science in this area, it makes sense to do what seems right and good for you and your child.  There is some evidence that there could be advantages to introducing lumpy, real foods earlier, in the form of a less picky eater later on.  And if you still are worried about your breastfed baby's iron levels?  You could always try giving her what my baby had for dinner last night.  A steamed carrot, a steamed piece of cauliflower, toast...and pâté!  


(1).  Committee on Nutrition American Academy of Pediatrics. Complementary feeding. In: Pediatric Nutrition Handbook, 6th ed, Kleinman, RE (Ed), American Academy of Pediatrics, Elk Grove Village, IL 2009. p.113.


(2).  Griffin IJ, Abrams SA.  Iron and Breastfeeding.  Ped Clinics North Amer.  2001; 48: 


(3).   McMillan JA, Landaw SA, Oski FA. Iron sufficiency in breast-fed infants and the availability of iron from human milk. Pediatrics. 1976; 58:686-691.


(4).  Pisacane A, De Vizia B, Valiante A. Iron status in breast-fed infants. J Pediatr.  1995; 127:429-431.


(5).  Coulthard H, Harris G, Emmett P.  Delayed introduction of lumpy foods to children during the complementary feeding period affects child's food acceptance and feeding at 7 years of age.  Matern Child Nutr.  2009; 5: 75-85.

Introducing Science Sundays!

Starting next Sunday, and hopefully every Sunday after that, I'll be discussing some scientific research on a topic related to childbirth, breastfeeding, or baby parenting.  This will be sort of similar to my previous post on whether you can tell baby boys apart from baby girls (from the neck up).

On a given week, I may either highlight one particularly interesting study, or, if the topic is narrow enough, provide an overview of all of the work that has been done in the area.  I'll also comment on the scientific strengths and weaknesses of the work that I discuss--in other words, do I believe the results?  I have a fair amount of training in the sciences, but that doesn't mean that I automatically believe everything I read in a scientific journal--if anything, the more I've learned about scientific research, the more I've learned how to be skeptical of some results!

Rather than picking each Sunday's topic myself, I would love to respond to someone's question.  Have you always wondered what the evidence is for or against a particular medical intervention?  Or are you just curious why baby's eyes are blue?  Or whether babies who have regular nap-times are healthier?  Email me at ahaircutandashave at gmail dot com with a question you'd like to see featured!  I'll let you know if I use your question (and I will ask permission to quote you).  Or you can just leave your question in the comments.

Happy Sunday!

Teaching some science

Can you tell a baby boy from a baby girl?

I had just rolled up to a checkout line at the grocery store when the cashier began to coo over my baby.  We get that a lot.  She's awfully cute.  That day, she was sporting an especially adorable blue sweatshirt with a small ruffle around the neck, and the corduroy pull-ups from Baby Gap mentioned in a previous post.

The cashier was a big guy, I'm guessing upwards of 300 pounds, which made his effusiveness all the more fun.  "Who's mama's big boy?" he gushed.  "You certainly are a big strong baby boy, aren't you?"

"Oh...," I said, "um, thank you!"

Sometimes it just isn't worth it to me to correct people when they think my baby is a boy, not a girl.  I don't really care at all if they get it wrong, but when I do correct people, it seems to somehow upset them; they often wind up apologizing over and over, becoming especially vehement in their declarations of how pretty my baby is, etc. etc.  So this time, I didn't say anything.

But he went on and on.  And then 2 more people peered into the stroller and began making similar exclamations about what a big, healthy baby boy I had... .  At this point, I sort of wanted to correct them, but it had gone on so long that it was just not possible.  So I meekly paid and we made our exit.

And it got me thinking.  Is it even possible to tell a baby boy from a baby girl?  I mean, from the neck up, if they're not wearing any bows or baseball caps?