When I was in my pediatric residency I was taught that a baby born between 38 and 41 weeks was “full term.” Babies born in that golden four weeks were thought to be one homogeneous group in terms of future development. A baby born at 38 weeks gestation was home free, at least as far as his neurological future went.
Not so fast. A study of more than 100,000 New York children just published in the journal Pediatrics reports that those born at 38 weeks–the low end of the term age bracket–in general don’t perform as well on standardized tests of math and reading in third grade as do children born later in pregnancy.
And not only that:
Each week of increased gestation from 37 to 41 weeks showed an added benefit in both reading and math scores. Further, children born at 37 or 38 weeks performed significantly worse than children born at 39, 40, or 41 weeks, and have a significantly increased relative risk of impaired reading and math skills on standardized school achievement tests.
The brain grows rapidly between 38 and 41 weeks gestation: gray matter increases nearly 50%, and myelinated white matter triples as the brain increases in complexity. It’s not surprising that being born even two or three weeks early might negatively impact some babies.
The study isn’t perfect, and it’s best to keep in mind that increased risk doesn’t equal inevitablility–the large majority of babies born at 38 weeks will be just fine. Still, researchers in Denmark, Belarus, Switzerland, and Scotland have recently reported findings similar to those in the New York study–all of which supports the growing effort to reduce elective, early labor induction.
Best to leave babies in the womb until nature says it’s time to come out!