To evaluate whether 400 mg daily oral micronized progesterone from 16 to 34 weeks' is effective in preventing recurrent spontaneous preterm birth (RSPB) and whether micronized progesterone use increases maternal serum progesterone levels.
To evaluate whether daily oral micronized progesterone is effective in preventing recurrent spontaneous preterm birth (RSPB) and whether micronized progesterone use increases maternal serum progesterone levels.