As every expecting parent learns to their dismay, modern medicine cannot accurately predict when your baby will arrive. The optimistically named “due date” is, from a predictive standpoint, fiction. Only 5% of births occur on the actual due date, and about two-thirds fall within a week before or after the due date. Not knowing when […]
Read moreArticles by Amy Kiefer, PhD

About Amy
Amy Kiefer is a researcher by training, and earned her Ph.D. from the University of Michigan. She currently lives in the Bay Area with her husband and three children where she writes about fertility, pregnancy, and breastfeeding. Check out her blog, expectingscience.com, for more great evidence-based pregnancy and parenting info.
Modern Medicine Has Transformed Preterm Birth But We Still Have a Long Way to Go
By Amy Kiefer, PhDSkin so translucent and fragile it tears like tissue paper. Faces obscured by oxygen masks. Alarms going off very few minutes. Bassinets covered in plastic wrap. This is the world of babies born extremely preterm—at less than 28 weeks of pregnancy. Yet for all the almost sinister machines surrounding these tiny humans–tubes and incubators, oxygen […]
Read moreWhenever I think about pregnancy weight gain, I think of Renée Zellweger playing Bridget Jones, the role that catapulted her to true stardom—and for which she had to gain some 30 lbs. After losing the weight and then regaining it for the second Bridget Jones film, Zellweger was fed up with the yo-yo-ing. She griped […]
Read moreThe glucose tolerance test for gestational diabetes is something of a second trimester rite of passage. If your pregnancy has proceeded uneventfully so far, nearly all the standard tests are behind you. Only one standard test left. And for this final one (typically between 24-28 weeks), you get to choke down a disgustingly sweet drink* […]
Read moreStressful. That was the word that best captured Jessica’s diagnosis with Gestational Diabetes Mellitus (GDM). The 35-year-old’s first pregnancy had proceeded uneventfully until her glucose tolerance test. When, at 28 weeks, her test results came back positive. The positive result came on a Friday. She could not see her doctor until after the weekend. The […]
Read more(*Trigger warning*: this story is about pregnancy loss.) When I recently reached out on social media to find women who had experienced preeclampsia, Kerry was one of the first to reply. A sharp, vivacious, and vibrant 36-year-old nurse practitioner, Kerry seems like the last person you’d imagine developing preeclampsia, a poorly understood pregnancy condition characterized […]
Read moreWomen carrying twins. Women who begin pregnancy with diabetes, or hypertension, or lupus. African-American women who become pregnant after age 35. What do these different groups of pregnant women have in common? The American College of Obstetricians and Gynecologists (ACOG) now considers them candidates for early aspirin therapy—a daily baby aspirin starting at the end […]
Read moreWhat is preeclampsia? Preeclampsia is one of the most common, serious disorders of pregnancy. It affects 2-8% of all pregnancies in the U.S, and typically begins with newly elevated blood pressure (readings above 140/90 on two or more occasions) sometime after 20 weeks of pregnancy. (Women who enter pregnancy with chronic high blood pressure can […]
Read moreAt a routine 36-week prenatal exam, Jessie Ha’s blood pressure measured 120/80. These numbers were on the high side for her. She has an autoimmune disease that normally causes her blood pressure to run low. But the 35-year-old disability advocate was not overly worried. Nor was her doctor. They chalked it up to normal pre-birth […]
Read moreIn addition to weird aches and discomforts (sciatica, anyone?), weight gain, and puking, pregnancy can make routine decisions—what should I eat right now?—annoyingly complex. For every meal, it’s a series of questions. Does this contains any “no-nos” like soft cheese or deli meats? Is it healthy enough? Did I get at least two servings of […]
Read morePostpartum Weight Retention is a Thing. And It’s Totally Normal.
By Amy Kiefer, PhDCall me naive, but I went into my first pregnancy expecting that after having my baby, the extra pounds would more or less fall off on their own. It was a huge wake up call, when a year out, I was still a steady 5 lbs above my pre-baby weight. My son was finally sleeping […]
Read moreWhen you’re pregnant, it’s hard to escape the eat fish, don’t eat fish dilemma. On the one hand, pregnant women are told that fish–rich in iodine, selenium, and omega-3 fatty acids, and other vital nutrients–is good for our babies’ rapidly growing brains. Recent studies have linked fish consumption during pregnancy with faster processing times and […]
Read morePositive pregnancy test in hand? Wiped out just by getting up from the couch? Mapping out the best places to discretely puke while at the office? Congratulations, and welcome to the first trimester! Assuming you’ve had your first prenatal visit and seen that galloping heartbeat, you’re ready for the next step—testing. So much testing. You’ll […]
Read moreLast month, the measles outbreak in Washington State prompted its governor to declare a state of emergency. Some parents have wised up and finally vaccinated their kids. But others have dug in, even gathering to protest universal vaccine policies. As a researcher who knows how thoroughly the autism-vaccine hypothesis has been debunked*, it’s hard to watch […]
Read moreAs you near the end of your pregnancy (hello, cankles!), you will be screened for Group B Strep, a common and normally harmless bacteria found in between 10-25% of women’s digestive and reproductive tracts. Although mostly benign in adults, Group B Strep (GBS) can cause serious infections in newborns, whose immune systems are still developing. […]
Read moreA Balancing Act With No Easy Solution: The Controversies of Treating All Pregnant Women for Group B Strep
By Amy Kiefer, PhDSince 2002, The Centers for Disease Control (CDC) has recommended that doctors screen all pregnant women for Group B Strep between 35-37 weeks, and that all women who test positive receive IV antibiotics during labor. This policy has more than halved the rate of early onset newborn GBS disease (GBS infection occurring within the first […]
Read moreFrom colostrum to coming to volume… Most expecting moms I know expended a ton of energy preparing for their baby’s arrival. They prepped for labor, studied up on their birth options, and set up their baby’s nursery. But despite all their effort, one major challenge still tended to trip them up after baby arrived: Breastfeeding. […]
Read moreWhen a close friend was trying for a second child in her late 30s, her husband mentioned that all the mothers he saw at the playground seemed old enough to be grandmas. Naturally, she was stung… but not surprised. Her experience is all too familiar. Our society tends to view older-age parenting–well, really older motherhood–as […]
Read moreDid you know that you can protect your newborn by receiving a Tdap vaccine during your third trimester? This approach is 90% effective at preventing Whooping Cough in newborns!
Read moreSome Women Have a Harder Time Maintaining A Milk Supply — That’s Just Biology
By Amy Kiefer, PhDMy obstetrician used to tell me that if I had been born two hundred years ago, with my ability to maintain a milk supply, I would have been a wet nurse. But I am not the rule. If anything, I am probably the exception. Many women have trouble maintaining milk supply at some point. And […]
Read moreA few years ago, while in that happy but anxious limbo of expecting my first baby, I dutifully read up on labor–its stages, birth plans, and the best ways to “achieve” a natural childbirth. On this last point—achieving a natural childbirth—a theme quickly emerged: My mental state was key. Without the proper level of mindfulness, […]
Read moreWhen it comes to postpartum weight loss, ceding to our body’s message that it desperately needs more rest is not lazy. It is wise. Consider this a pass to take that nap, mama!
Read moreWhen a baby is born, anywhere from 25-60% of the fetal blood supply remains in the placenta. Delaying cord clamping allows this extra blood to pump to baby and has been shown to have long-term mental and physical benefits.
Read moreBecoming pregnant after 35 comes with some derogatory labels: geriatric pregnancy, advanced maternal age, older mom (wait, what?!) It’s hard to escape the warnings about your pregnancy being at “high risk” for complications, such as birth defects, high blood pressure, and diabetes just because you passed a certain age bracket. But does your age actually […]
Read moreOur modern bodies continue to maintain a nocturnal birth rhythm. But are we messing with the natural rhythm by basking in unnatural light in the middle of labor? Why night-time labor could stall when you reach the hospital and what you can do about it.
Read moreVitamin D—The magical vitamin that our body makes when we bask in the sunshine. In an ideal world, every pregnant woman would soak up vitamin D by relaxing her nine months away somewhere tropical and warm. But if you can’t pass your pregnancy at the beach and, like most of us, only manage to squeeze […]
Read moreStill thinking about Zika in 2018? Thanks to that research, we now have good answers for many of the earlier questions on the things to know about Zika and pregnancy.
Read moreWhen it comes to prenatal genetic testing, chorionic villus sampling (CVS) and amniocentesis (amnio) are rarely the first types of tests discussed. Most doctors tend to recommend prenatal screenings for women under 35. But screenings have their shortcoming— they miss at least half of certain types of genetic problems and only provide a likelihood of […]
Read moreThe Risk of Amniocentesis Causing a Miscarriage Is So Small It Might Be Zero.
By Amy Kiefer, PhDMany women shy away from amniocentesis and chorionic villi sampling for fear of miscarriage—but this risk of amniocentesis causing miscarriage has been widely overblown and the evidence is outdated.
Read moreIgnore the Tough It Out Messages–New Parents Need to Prioritize Their Own Sleep
By Amy Kiefer, PhDPrioritizing Sleep as a New Parent Your newborn wakes up for the day at 5 a.m. And it’s brutal. You’ve only managed a couple of hours of uninterrupted sleep (maybe!), and your first thought is how many hours until nap time? You’re not alone. For loads of us, sleep is the central challenge of early […]
Read moreEvery day we hear more and more about the benefits of exercise in pregnancy for mom and baby. Most doctors recommends an average of 30 minutes of moderate exercise a day. But for some reason, there is still old and out-of-date advice floating around. Let's get to the bottom of this and clear up those myths once and for all.
Read moreRoughly 2 out of 3 laboring women in the U.S. will get an epidural. As a highly effective form of pain relief during labor, it’s no wonder that the epidural is enormously popular. But along with the epidural, comes the controversy. And at the heart of the controversy, the idea that epidurals raise the chances […]
Read moreNon-invasive prenatal testing can revolutionize how we screen for genetic disorders. So why do we restrict the recommendation for it? A look at NIPT vs. first trimester screening.
Read moreWhile we have less control over our new baby’s sleep than we would like, we have more control over our own. Plus, the lessons of baby sleep can help us manage our own sleep.
Read moreYour baby’s gut microbiome may shape her later health… Here’s what you can do to give her the best start possible. Ah, the gut microbiome, that teeming collection of fungi, viruses and bacteria that lives inside our intestines. We hear so much about it nowadays, that you could almost believe a healthy gut was […]
Read moreHow soon after a miscarriage can you try to conceive? Sooner than you think.
By Amy Kiefer, PhDDoctors often recommend waiting at least 3 months after a miscarriage. But there’s no compelling evidence that waiting improves your chances of conceiving.
Read moreDoes weight gain actually follow a neat and tidy curve right up until the end? Probably not!
Read moreWhy doesn’t anyone believe the research on epidurals and C-sections? As we discussed in our earlier post, Does an epidural lead to a C-section? studies on how epidurals affect the C-section rate present something of a conundrum. Observational studies in the early 1990s originally found a much higher chance of a C-section with an epidural. Since then, […]
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