Placental characteristics of monochorionic twin pregnancy complicated with selective fetal growth restriction / 中华围产医学杂志

ABSTRACT

Objective To evaluate the placental characteristics in monochorionic (MC) twin pregnancy with selective fetal growth restriction (sFGR). Methods Fifty-five placentas from women with MC twin pregnancy were included, who had terminated pregnancy in the Peking University Third Hospital between June 1, 2013 and June 1, 2014, including 23 cases with sFGR and 32 uncomplicated cases as control group. We perfused the placentas within 24 h after delivery, and pigment of four different colors was used to perfuse the umbilical arteries and veins of both twins and determine the types of vascular anastomosis. Umbilical cord insertion, placental territory discordance (PTD, the territory difference between two placentas/the bigger one), and the type, number and diameter of placental superficial vascular anastomosis were analyzed using two independent samples t-test, nonparametric test,χ2 test or Fisher's exact test. Results The PTD was 0.60(0.10-0.80) vs 0.22(0.00-0.90) in sFGR group and control group (Z=-3.913) respectively, and the proportion of placenta with uneven share was 91.3%(21/23) vs 50.0%(16/32) (Fisher's exact test), which were significantly higher in sFGR group (both P 0.05). The number of AA, AV and VV anastomosis in sFGR group and control group was 1.0 (0.0-2.0) vs 1.0 (0.0-4.0), 3.0 (0.0-10.0) vs 2.0 (0.0-5.0), and 0.0 (0.0-1.0) vs 0.0 (0.0-3.0) (Z=-0.256, -0.142 and -0.123);the total diameter of AA, AV and VV anastomosis was 2.7 (0.0-7.0) vs 2.2 (0.0-9.7), 4.0 (0.0-13.7) vs 3.4 (0.0-11.5), and 0.0 (0.0-7.9) vs 0.0 (0.0-7.1) mm (Z=-0.070, -0.087 and -0.087);there were no significant differences between two groups (all P>0.05). The total number of all anastomosis was 3.5 (0.0-10.0) vs 3.5 (0.0-6.0) (Z= - 0.567); the total diameter of all anastomosis was 6.9 (0.0-22.4) vs 5.9 (0.0-17.1) mm (Z= - 0.556); there were no significant differences between two groups (all P>0.05). Conclusions Placental sharing discordance and non-central cord insertion may be the risk factors for MC pregnancies complicated with sFGR.