If you want your unborn kid to grow up super-smart, then keep it in your
uterus as long as possible. At least that's what the latest research
claims. According to two new studies, the way you're born can have
long-lasting effects on things like your academic performance and mental
The first study looked at babies that fell within the 37 to 41 week period that most consider full term. Researchers looked at 128,000 kids in the New York City public school system and found that being born at 37 weeks or 41 weeks had a significant impact on learning skills: by third grade, the kids born at 37 weeks were a third more likely to have severe difficulties in reading, and they also had a 19% greater chance of having moderate problems in math than those born at 41 weeks. (So does this mean Jessica Simpson's baby is a genius?)
As for babies born earlier than 37 weeks, it's not looking so good. Another study conducted by researchers at Kings College London found that babies born prematurely were far more likely to suffer from mental health problems like schizophrenia, major depression, and bipolar illness. The researchers used birth and hospital records for more than 1.3 million people born in Sweden between 1973 and 1985, and they compared data from those born at full term and those born very premature (less than 32 weeks). They found the premature babies were more than twice as likely to land in the hospital for schizophrenia, three times as likely to have major depression, and a whopping seven times more likely to be bipolar. And even if babies were not extremely premature but were instead born between 32 and 36 weeks, they were still at increased risk: a 60% higher chance of schizophrenia, 34% chance to develop major depression, and twice as likely to be bipolar.
As for why there is a connection between being premature and having mental illness, researchers explained that the "preterm brain" is especially prone to injury, and MRIs of kids who were born very early have found that there are "disruptions in brain networks" that are like what you'd see in a psychiatric patient. It's also possible that there is some genetic factor that is triggered by being born early. The researchers believe these findings could lead to earlier or more careful mental health screenings for people who are born prematurely.