Q&A: I am concerned about my baby's lung maturity.

Yes, the best way to determine lung maturity at 37 weeks is with an amniocentesis, which can measure chemicals in the amniotic fluid secreted by mature lungs. But this is only reserved for patients who have some other dangerous condition going on, which would make an early delivery beneficial to the mother.

In the case of normal, uncomplicated pregnancies, you can just wait to the magic 39 weeks, when it is considered safe to have a baby and assume lung maturity. Spontaneous labor after 37 weeks can assume lung maturity, too, but not if you're being electively induced. This type of meddling requires proof of lung maturity before the 39-week mark.