Pregnancy and Lactation Weekly Digest

For the week ending March 12, 2017.

Mildly low thyroid function won’t harm your baby

Since very low maternal thyroid function can be dangerous for the gestating baby, it had been speculated that mildly low thyroid function may be as well. However, a new study has just concluded that this is not the case. Results were published in The New England Journal of Medicine. Read more here.

This is important for you because, if you have mildly low thyroid function, you may be able to leave it untreated without fear of harming your baby. But always consult your doctor first!

The procurement of calories – not social interaction – may explain the evolution of our big brains

Very early humans independently evolved two somewhat contradictory traits: big brains – which require big skulls to protect them – and the ability to walk on two legs – which requires a narrow pelvis and therefore a narrow birth canal. That’s why babies have fontanelles, the soft spots toward the front of their heads where the bones of the skull haven’t fused yet, so the brain can keep growing after the babies are born. Scientists thought that we evolved such big brains to manage the complexities of the social interactions that come from living in groups, but a new mathematical model indicates that the ability to get food may have been a more important driver of brain growth. The original paper is here.

This is important for you because, although childbirth is hard, this “obstetric dilemma” – big brains passing through the narrow birth canal necessitated by walking upright – is a large part of what makes humans unique.

Anne Hathaway admonishes UN for lack of paid parental leave in the US

Anne Hathaway became a U.N. Women Goodwill Ambassador last year. This past week, on International Women’s Day, she addressed the General Assembly and bemoaned the sorry state of paid maternity leave in the United States. According to the Bureau of Labor Statistics, only 14 percent of Americans currently have access to paid family leave. Read more here.

This is important for you because, if you don’t get paid leave, remember that you have people on your side fighting for it!

Blood pressure can be influenced in the womb

Folic acid, or folate, is required during pregnancy to prevent neural tube defects. Wheat flour is fortified with it, so you don’t have to consciously worry about getting enough. Ingesting higher levels while pregnant has also just been correlated with lower blood pressure for the baby later in life in pregnant women with cardiometabolic risk factors (when the risk of developing atherosclerotic cardiovascular disease and diabetes mellitus are significantly enhanced). “Our study adds further evidence on the early life origins of high blood pressure,” said Xiaobin Wang from Johns Hopkins University. Read more here.

This is important for you because, if you have cardiometabolic risk factors, you might want to consult your doctor about folic acid supplements above what you are getting from your diet.

Get a flu vaccine

Your immune system suppresses itself during pregnancy, so you don’t have a reaction to the foreign body inside you. But in mice, at least, other organisms besides from the fetus take advantage of this compromised immunity: notably the flu virus, which uses its time in the pregnant mouse to mutate into more virulent strains. The original paper is here.

This is important for you because it is yet another reason you should get a flu vaccine when pregnant.

There were two equally popular articles on The Pulse this week: Why You Should Get Tested For Group B Streptococcus If You Are Pregnant and Maternity Leave in America: What’s Wrong With This Picture? Highlights are that testing for Group B strep can easily save your baby from some dangerous symptoms, and that astonishingly, the US is the only developed country in the world whose government does not mandate paid parental leave. Read about Group B Strep here and about maternity leave here.

Diana Gitig
Dr. Diana Gitig has a Ph.D. in cell biology and genetics from Cornell University, and has been writing about issues in biology – from molecular biology to cancer to immunology to neuroscience to nutrition to agriculture - for the past fifteen years. She has three teenaged children.

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