Progesterone Supplementation in Early Pregnancy

Key Clinical Context

The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine do not recommend routine progesterone supplementation based solely on low serum progesterone levels in early pregnancy, as current guidelines do not recommend progesterone level testing or treatment decisions based on serum progesterone values alone 1, 2
Current recommendations for progesterone supplementation are based on specific clinical risk factors, such as prior spontaneous preterm birth and short cervical length, not on hormone levels 1, 2, 3

The Society for Maternal-Fetal Medicine indicates progesterone supplementation for singleton pregnancies with prior spontaneous preterm birth: 17P 250 mg IM weekly from 16-20 weeks until 36 weeks 1, 2
The Society for Maternal-Fetal Medicine also indicates progesterone supplementation for singleton pregnancies without prior preterm birth but with cervical length ≤20 mm at 18-24 weeks: vaginal progesterone 90-mg gel or 200-mg suppository daily from diagnosis until 36 weeks 1, 2

The evidence for progesterone in preterm birth prevention is based on clinical risk factors, such as prior preterm birth and short cervix, not serum progesterone measurements 1, 2, 3
Serum progesterone levels are not routinely checked to guide progesterone supplementation decisions in these protocols 1, 2