Cerclage, progesterone and α-hydroxyprogeterone caproate treatment in women at risk for preterm delivery.

The most significant action of progesterone appears to be on the cervix and in prevention rather than on treatment of preterm delivery. In women with singleton gestations, no prior PTB, and CL <20 mm at <24 weeks, vaginal progesterone, either 90 mg gel or 200 mg suppository, is associated with reduction of both preterm birth (PTB) and perinatal morbidity/mortality. Cerclage is as effective as vaginal progesterone in women with CL <25 mm. Treatment of women with previous PTB with 17OHP-C from 16 to 20 weeks' gestation until 36 weeks could reduce significantly both the risk of delivery at <37, <35 and <32 weeks' gestation, as well as the rates of NEC, the need for supplemental oxygen and IVH. In women successfully treated with tocolytics progesterone combined with corticosteroid therapy lengthens pregnancy, reduces occurrence of respiratory distress syndrome and low birth weight. However, there is currently insufficient evidence on the role of progesterone after arrested preterm labor. It is reasonable to support an approach with CL screening of women with prior PTB starting at 16 to 19 weeks and administration of progesterone to women with a short cervix. Cerclage may be offered to those with a CL<25 mm. A combination of traditional tocolytics, corticosteroids and progesterone might be beneficial.