Guest post by Allie Sakowicz

Soon after a woman finds out she is pregnant and her due date is calculated, she promptly proceeds to mark that special date on the calendar with circles, hearts, lines, ribbons, bows, you name it.  Even though there is only about a 5% chance that the baby will be born on his or her due date, it still provides an adequate estimation as to when the stork may be arriving with a special package.  Once a woman reaches 37 weeks of gestation, she is considered to be term, meaning that the birth could safely take place at any point from then on.  However, a recent study conducted by a group of physicians associated with the March of Dimes organization points out that considering babies term at 37 weeks may not be such a good idea after all.

The article says that “term birth (37– 41 weeks of gestation) has previously been considered a homogeneous group to which risks associated with preterm (less than 37 weeks of gestation) and post-term births (42 weeks of gestation and beyond) are compared.”  But there seems to be new evidence that suggests that the outcome for a baby born after less than 37 completed weeks of pregnancy is significantly different for one born after 38 completed weeks.  The study proposes that the phrase “late preterm” be used when describing neonates born between 37 0/7 weeks and 38 6/7 weeks because of the new research which states that babies born during this period suffer from increased mortality and neonatal morbidity when compared to children born later in the pregnancy. 

This finding is particularly interesting considering that most scheduled cesarean sections are performed at 39 weeks, which is only one day after the late preterm risk would pass.  The most common reason for scheduling c-sections at this time is so that the mother does not go into labor on her own, since there are some rare cases where a vaginal delivery could be dangerous to mom and baby.  Also, there are some conditions that might cause a physician to schedule an induction at this time.  While an ultrasound-calculated due date can be a good estimation of a baby’s birthday, it is certainly not a perfect science and there is a very real possibility that it could be misleading.  Therefore, it’s not unlikely that some of the babies that are being delivered at 39 weeks actually fall into the category of late preterm and are at risk for some complications.

While the article makes very few conclusions, it does offer an interesting perspective into something that we had been making assumptions on for decades.  There’s only so much that medical professionals and parents can do to dictate when a baby’s birthday will be, but perhaps this new analysis will cause doctors to rethink performing cesareans and inductions at 39 weeks.  Because, at the end of the day, it’s that 7 pound bundle of joy that’s calling all of the shots.

What are your thoughts on this new article?  Was your baby born in the late preterm category?  Do you think that scheduled c-sections and inductions should be done at 40 weeks instead of 39 weeks?  I welcome all of your questions or comments.

Allie reviewed the article Rethinking the Definition of “Term Pregnancy” by Alan R. Fleischman, MD, Motoko Oinuma, BA, and Steven L. Clark, MD which appeared in July 2010’s Green Journal.