Placental blood flow and pregnancy outcomes in women with abnormal placental localization and absence of placental “migration”

Abstract

Aim We investigated the arcuate artery blood flow in the region of the abnormally localized placenta in women who had undergone insertion of an obstetric pessary and were receiving micronized progesterone. Materials and methods The study included 120 pregnant women with high perinatal risks and abnormal placental localization. The patients were randomized to receive the Arabin’s pessary and vaginal micronized progesterone (Group A, n = 60) or vaginal micronized progesterone only (Group B, n = 60). Randomization was carried based on the order of hospital admission: odd patient numbers were allocated to Group A and even numbers to Group B. Patients underwent a series of ultrasound scans to evaluate the placental migration and presence of abnormal placental attachment. Depending on the results of the scan, study participants were divided into the following groups: (1) patients without placental migration: A1 (n = 23) and B1 (n = 42); and (2) patients with placental migration: A2 (n = 37) and B2 (n = 18). Women in subgroups A1 and B1 were further divided into the subgroups based on the presence of abnormal placental attachment: A1 x (n = 5) and B1 x (n = 12) with abnormal placental attachment; and A1O (n = 18) and B1O (n = 30) without the abnormal placental attachment. Conclusion In patients with abnormal placental attachment, the resistance of blood flow in the arcuate arteries was significantly higher than in those with normal placental attachment. A significant increase in the blood flow resistance occurred between 24 and 28 weeks of gestation. The combined use of the obstetric pessary and vaginal micronized progesterone in women with abnormal placental localization helped maintain the resistivity index at low levels and reduce the rate of abnormal placental attachment by 1.3-fold (OR 0.694 (95% CI: 0.21–2.29)).