Progesterone Level Testing in Pregnancy

Indications for Progesterone Level Testing

The American College of Obstetricians and Gynecologists recommends checking progesterone levels in women with singleton pregnancies and prior spontaneous preterm birth (SPTB) at 16-20 weeks gestation, and in women with singleton pregnancies without prior SPTB but with short cervical length (≤20 mm) at 18-24 weeks gestation 1, 2
For women with singleton pregnancies and history of prior spontaneous preterm birth (SPTB), progesterone levels should be checked at 16-20 weeks gestation before initiating 17-alpha-hydroxyprogesterone caproate (17P) therapy, as recommended by the American College of Obstetricians and Gynecologists 1, 3
For women with singleton pregnancies without prior SPTB but with short cervical length (≤20 mm) identified on transvaginal ultrasound at 18-24 weeks, progesterone levels should be checked before starting vaginal progesterone therapy, according to the American College of Obstetricians and Gynecologists 1, 4

The American College of Obstetricians and Gynecologists recommends checking progesterone levels at 16-20 weeks gestation for women with prior SPTB, and at 18-24 weeks gestation for women undergoing cervical length screening 1, 3
Progesterone levels should be checked at 16-20 weeks gestation for women with prior SPTB, and at 18-24 weeks gestation for women with short cervical length (≤20 mm), as recommended by the American College of Obstetricians and Gynecologists 1, 2

Progesterone testing should be performed with proper technique to yield accurate results, with quality control and monitoring, as emphasized by the American College of Obstetricians and Gynecologists 2, 3
In artificial cycles for frozen embryo transfer, progesterone supplementation begins on the day of endometrial transformation and should be continued for 3-4 weeks after pregnancy confirmation, according to the European Society of Human Reproduction and Embryology 5

For women with singleton pregnancies and prior SPTB, the American College of Obstetricians and Gynecologists recommends 17P 250 mg IM weekly from 16-20 weeks until 36 weeks 1, 4
For women with singleton pregnancies without prior SPTB but with short cervical length (≤20 mm), the American College of Obstetricians and Gynecologists recommends vaginal progesterone 90-mg gel or 200-mg suppository daily from diagnosis until 36 weeks 1, 4