Effect of micronized progesterone on fetal-placental volume in first-trimester threatened abortion

To compare the effect of oral micronized progesterone (OMP) on the first-trimester fetal and placental volumes using three-dimensional ultrasonography and extended imaging virtual organ computer-aided analysis (XI VOCAL) method in threatened abortion.

This randomized controlled trial enrolled women with threatened abortion and a singleton pregnancy from 6-8 6/7 weeks of gestation. A total of 60 women with threatened abortion were randomly assigned to one of two groups: OMP (400 mg/day) (n = 30) and control groups (n = 30). The XI VOCAL method was used for all volume measurements using three-dimensional ultrasonography. All patients were evaluated for fetal, amniotic, and placental volumes during the initial diagnosis and after 4 weeks.

After treatment, placental volume difference was significantly higher in the OMP group (336%, 67-1,077) than in the control group (141%, 29-900) (p = 0.007). The mean differences in gestational sac, amniotic sac, and embryonic volumes between the OMP and control groups were not statistically significant.

Hormonal support with OMP is associated with increased placental volume in first-trimester threatened abortion when compared with the control group. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:14-19, 2017.