A week or two may make a big difference when it comes to smarts in children — with a new study in the journal Pediatrics saying that the longer a baby stays in the womb, the higher the IQ years later.

Normally, we consider a full term kid to be one born between 37 and 41 weeks. Hit that mark, and everything should be peachy.

But this study compared kids who were born within that full-term time frame and it found the longer the kid hangs out in the uterus, the better chance of brain cells developing and working better.

Now we know kids born premature — before 37 weeks, have a higher risk of learning problems. This study looked at kids who, technically, shouldn’t have had issues since they made it to the finish line of full term.

But after comparing more than 128,000 kids in elementary school, the ones most likely to struggle a bit more with reading, math, and so forth, were the kids who came out at, say, 37 compared to 40.

The study, btw, did take into account maternal illness, low birth weight, and smoking, and didn’t include those kids in the study.

So what’s the take from this one? Obviously, preemies are preemies and we still don’t totally know how to stop a baby from being born at 36 weeks. If it happens, it happens.

Frankly, the same goes for labor at 37+ weeks – once the process gets going, you can’t stop it.

But here’s the bottom line: if you’re inducing labor or having an elective C-section at 37 or 38 weeks, maybe you should revisit your thinking on the timing. Holding off for a couple of weeks may add up to a couple of extra points on the IQ scale down the line.