C-section and induced births dipped or spiked on
Halloween and Valentine’s Day…but so, intriguingly, did natural births.
With the rise of cesarean sections and scheduled births, it’s no surprise that expectant mothers might favor some dates over others for their children’s births. But a recent study drawing on US birth certificates from a ten-year period suggests that even with natural, spontaneous births, the mother may be able exert some kind of control over when she goes into labor. The team found that there were about 5% fewer births on Halloween and about 4% more on Valentine’s Day than there were on any day in the surrounding two weeks.
The researchers think that the frightening connotations of Halloween—skeletons, zombies, and so on—as experienced by the mother might be enough to affect the hormones that control labor, putting the birth off (and vice versa when it comes to the positive connotations of Valentine’s Day). But the specific biological connection between a mother’s holiday-influenced emotional state and labor is still an open question.
In cultures that don’t celebrate Halloween and Valentine’s Day but consider other days particularly auspicious or inauspicious, does this effect also happen? Inquiring minds want to know.
[via New Scientist]
What’s the News: A new analysis finds that many of the genes behind the development of modern mammalian pregnancy are controlled by mysterious genetic elements called transposons, long referred to as “junk DNA.” The results suggest that the placental uterus did not evolve gradually but instead arose from a massive, transposon-driven genetic rewiring.
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What’s the News: A blood test can reliably tell a mother-to-be whether to expect a boy or girl as early as seven weeks into pregnancy, according to a new analysis published today in the Journal of the American Medical Association. The test can distinguish the sex of a fetus up to three months earlier than an ultrasound can, and doesn’t carry the slight risk of miscarriage that accompanies invasive tests such as amniocentesis.
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Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.
The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.
“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]
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In a remarkable medical feat, researchers used a blood sample from a pregnant woman to work out the entire genome of her unborn fetus. The technique, published in the journal Science Translational Medicine, could provide a safer and less invasive way to check a fetus for fatal genetic mutations.
Currently, determining a fetus’s genome requires either amniocentesis, in which a needle is inserted through the mother’s abdomen into the amniotic sac, or chorionic villus sampling, in which a piece of placenta is removed. But both techniques carry a small risk to the baby, and are reserved for cases when there is an increased risk of genetic defects.
“The major advantage of the technique in this paper is that there’s no risk of miscarriage,” said Dr. Diana W. Bianchi, a reproductive geneticist at Tufts University who called the work a “technological tour de force.” Amniocentesis and CVS testing carry about a 1% risk of miscarriage, she said. [LA Times]
The new technique sequences the fetal genome from fragments present in the mother’s blood. In the late 1990s researchers discovered that fragments of fetal DNA are present in maternal plasma, presumably because the DNA gets broken down and crosses over the placental barrier.
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You are what you eat, and perhaps in some ways, what your mother ate. Back in 2003, Cheryl Rosenfeld’s team found that the diet they fed to pregnant mice caused a “striking variation” in the sex ratios of the offspring: High fat favored males, low fat favored females. Now Rosenfeld has a new study in the Proceedings of the National Academy of Sciences that says the mother’s diet can also affect the very way genes are expressed in the placenta.
To figure this out, Rosenfeld’s team studied the placentas attached to fetal mice 12 and a half days after conception, when the mice were midway through gestation but had yet to produce sex hormones like estrogen or testosterone (those can also alter gene expression, which would have confounded the study). They found that gene activity in the placentas differed significantly depending on whether the mom was fed a high- or low-fat diet. The biggest differences were found when comparing the high- and low-fat placentas linked to female fetal mice, suggesting that placentas nourishing females do a better job of responding to diet—and potentially protecting the fetus from harmful ingredients—than do those connected to males [ScienceNOW]. Specifically, of the 700 genes that they saw behave differently between the sexes, 651 were expressed more in females than males. In all, their study saw changes in the expression of nearly 2,000 genes.
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There’s been lots of gloating, arguing, and tossing around of cliches like “game-changing” in the wake of a new study on abstinence education and its potential to reduce sexual activity in teens. But the study isn’t exactly what the political forces trumpeting its arrival would like you to believe.
The study appears in the journal Archives of Pediatrics & Adolescent Medicine. In its introduction, study leader John B. Jemmott III concludes that “Theory-based abstinence-only interventions may have an important role in preventing adolescent sexual involvement.”
So what’s actually in the study? Between 2001 and 2004, Jemmott’s team studied 662 African-American middle schoolers in the northeastern United States, who were each paid $20 a session to attend sex-education classes. The kids were randomly assigned to one of several different programs: One program emphasized only abstinence, one both safe sex and abstinence, one just safe sex, and the last was a control group that simply taught healthy living—eating well, exercise, and the like.
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Breast-feeding may significantly cut a woman’s risk of breast cancer if she has an immediate relative that has ever had the disease, according to a study published in the journal Archives of Internal Medicine.
Among women with close family members who have had breast cancer, the risk of developing the disease before menopause sank by 59 percent if she ever breast-fed, according to the research, which used data from more than 60,000 subjects of the Harvard Nurses’ Health Study. The risk of breast cancer in women without the disease in the family was unaffected by breast-feeding. The findings suggest that breast-feeding may prove just as effective a strategy for high-risk women as the use of Tamoxifen, a drug that interferes with estrogen activity and is often used in high-risk women to reduce breast cancer risk [The New York Times]. For women with a high risk of breast cancer, due to factors like a family history of the disease or a genetic predisposition to develop it, the only preventive measures currently used are Tamoxifen and the prophylactic removal of the breasts.
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