Term labor model

PMG (0.2 mg/dam), P4 (1 mg/dam), or a vehicle was administered subcutaneously in 100 μL corn oil/ethanol at gestation days 14.5, 15.5, 16.5 (n=8; term GD, 19.5). P4-treated and PMG-treated animals that carried pregnancy to full term (GD, 19.1–19.9) were sacrificed during labor. Our criteria of labor was the delivery of at least 1 pup. Mice that did not deliver at term were sacrificed 24 hours postterm (GD, 20.5). The effects of PMG on delivery time, maternal weight gain, litter size, and weight of neonates (for vehicle and P4 groups) and fetal weight (PMG group) were assessed (Table 1). In a replicate group of animals, pregnant PMG-treated and vehicle-treated mice (n=6 per group) were sacrificed before term delivery on GD 18.75 from 6 to 8 PM. We recorded the maternal weight gain, litter size, and the fetal and placental weight (Table 2). Maternal (myometrium, plasma) and fetal tissues were collected for analysis.

Delivery, maternal and neonatal outcome measurements of pregnant mice

Data are presented as mean±standard deviation, unless otherwise indicated.

GD, gestational day; Promegestone, synthetic progestin.

Shynlova et al. Promegestone delays preterm labor in mice. Am J Obstet Gynecol 2021.

Fetal and placental outcome measurements at term pregnant mice (GD 18.75)

Data are presented as mean±standard deviation, unless otherwise indicated.

GD, gestational day; PMG, synthetic progestin.

Shynlova et al. Promegestone delays preterm labor in mice. Am J Obstet Gynecol 2021.