By WHY ARE PREGNANT WOMEN SO SWEATY?
Jessica Grose
A lot of parenting questions boil down to: Is this a thing, or is something wrong? We’re doing an occasional series explaining why certain things seem to happen to your kid (or to your body or to your relationships) as your child grows. This week, we’re talking about prenatal and postpartum night sweats.
For this week’s edition, I put out a call on Twitter for questions about your weird prenatal and postpartum symptoms — and, wow, did you all deliver. In a beautiful and bizarre outpouring, you told us about painful carpal tunnel, constipation, thyroid malfunctions, excess drool, itchy nipples, strange divots in your thighs and shins that won’t go away, cured aversions to cilantro … the list goes on, because the human body is a magical, horrible wonderland. I tallied the responses, and by my extremely unscientific calculations, night sweats seemed to be the most common unexplained symptom from our respondents (e.g., “I had to sleep on a beach towel because of all the sweat and the milk leaking”). So that’s what I’m delving into today.
Q: Are pregnant and postpartum night sweats really a thing?
A: Waking up with a soaking nightgown during or after pregnancy is common. In a study of about 430 women published in 2013, for instance, researchers found that 35 percent reported nocturnal hot flashes while they were pregnant, and 29 percent reported them postpartum. In pregnant women, night sweats peaked during week 30, while in postpartum women, they peaked during the second week after birth.
Why it’s happening is a little more complicated, so we asked four ob-gyns and a researcher who has studied night sweats about what might be going on in your body, and what you can do about it.
Why are pregnant women so damn sweaty?
The short answer is, we don’t know for sure, because there’s a lack of systematic research on the topic (more on that in a bit). But it probably has to do with their ever-shifting hormones.
During pregnancy, there’s a huge rise in the levels of progesterone and estrogen. Once you give birth, the levels of those hormones fall off a cliff.
Rebecca Thurston, Ph.D., a professor of psychiatry and director of the women’s biobehavioral health program at the University of Pittsburgh who studies night sweats and hot flashes, said that nocturnal hot flashes in pregnancy seem to mirror hot flashes in menopause, and that those hormonal fluctuations might play a role. (Several of the experts I spoke with said that prenatal and postpartum night sweats were a rehearsal for menopause … yay?)
Do all pregnant women get hot flashes?
No. While every person who has given birth experiences these hormonal fluctuations, not all of them get night sweats, and we still don’t fully understand the underlying physiology as to why this might be, said Dr. Thurston. More than just hormones are probably causing the hot flashes, and they don’t just happen at night.
The hormonal shifts are part of a complex set of changes that happen during pregnancy, said Dr. Jen Gunter, M.D., an ob-gyn, frequent New York Times contributor and author of “The Vagina Bible.” (Dr. Gunter said she remembered sweating so much at night when she was pregnant with triplets that she’d think, “my bed is a swimming pool.”) “There’s an increase in body temperature, and there’s changes in the blood vessels — they dilate more and increase blood flow to the skin,” said Dr. Gunter. So some women may find that they’re more sweaty in general, not just at night.
According to what little research has been done, African-American women and women with depressive symptoms are more likely to report night sweats during pregnancy and the postpartum period. Women with high pre-pregnancy B.M.I.s were also more likely to have night sweats during pregnancy but not necessarily postpartum.
I find the connection between night sweats and depression particularly intriguing, as there is evidence that women who were depressed during and after their pregnancies may also be more sensitive to hormonal shifts.
What can we do about our sweaty, sweaty bodies?
First, report your night sweats to your doctor or midwife, said Dr. Dara Matseoane-Peterssen, M.D., chief of general obstetrics and gynecology at New York-Presbyterian Allen Hospital. If you’re experiencing other symptoms along with night sweats, such as a fever or a racing pulse, that may be a sign of a more serious problem, such as an infection or a thyroid issue.
If your sweats aren’t a sign of something more serious, exercising can be an effective first line of attack — whether you’re pregnant or not. Dr. Julie Chor, M.D., an assistant professor of obstetrics and gynecology at the University of Chicago, said there’s some evidence that women who exercise are less likely to experience nighttime hot flashes than women who don’t. While experts aren’t sure why this may be, exercising during and after your pregnancy is beneficial to your health in general, so you might as well try it (as long as you’re following safe exercising guidelines).
Focusing on creating an optimal sleep environment can help you avoid creating a veritable saltwater marsh in your bed, too. If your household and energy bill can tolerate it, set your bedroom’s temperature to around 65 degrees at night, said Dr. Thurston. Dr. Colleen Denny, M.D., assistant clinical professor in the department of obstetrics and gynecology at N.Y.U. School of Medicine, also suggested keeping cool water and a cold compress by your bed, and dressing in layers so you can take them off as the night, and your sweating, progresses.
As a fellow night sweater during pregnancy, my personal suggestion is to keep a second set of night clothes by your bedside so that you can make a quick change out of your wet pajamas in the middle of the night without groping around in the dark.
Why don’t we know more about night sweats?
“There are major gaps in knowledge about women’s health and women’s bodies,” said Dr. Thurston. Women overall have been less likely to be represented in clinical trials, because researchers have historically been men. And pregnant women in particular are “severely underrepresented,” in part because of fear of harm to their fetuses. Many of the experts I spoke with mentioned that we’re just starting to care about the health of the mother, and not just the health of the fetus, as vital to the overall health of the pregnancy.
But there is also a lack of study on the day-to-day experiences of women, said Dr. Gunter. Something like night sweats could just be a “nuisance” symptom — which is to say, uncomfortable but ultimately not harmful. But these sorts of symptoms could also be associated with better or worse pregnancy outcomes, and “we don’t know because they haven’t been studied,” Dr. Gunter said. In preparation for our interview, Dr. Gunter scanned her copy of the latest edition of a 1,400-page medical text book, and there were just two lines about sweating, referred to as “increased cutaneous blood flow” — she couldn’t even find the word “sweating” in the index.
Dr. Thurston emphasized the importance of reporting these kinds of symptoms to your midwives or doctors, not just to rule out serious problems, but also to add to the body of knowledge that exists on women’s health. “The more we know about these symptoms in the medical community, the more we can generate research around them,” she said.
