The Relationships of Umbilical Venous Volume Flow, Birthweight and Placental Share in Monochorionic Twin Pregnancies With and Without Selective Intrauterine Growth Restriction

Abstract

This study was conducted to investigate the relationship among umbilical venous volume flow, birthweight and placental share in monochorionic twins with or without selective growth restriction. Having excluded cases complicated with twin-to-twin transfusion syndrome and one co-twin suffering intrauterine fetal death, a total of 51 monochorionic twin pregnancies were divided into two groups as with (group 1) and without (group 2) selective intrauterine growth restriction. Umbilical venous volume flow was calculated by multiplying the umbilical vein cross-sectional area by half of the maximal velocity around mid-trimester. The placentas were cut along the vascular equator into two individual placental masses. The discordance of birthweight was calculated as [(birthweight of larger twin—birthweight of smaller twin)/birthweight of larger twin 100%]. The discordances of umbilical venous volume flow and placental share were calculated in a similar fashion. The median umbilical venous volume flow discordances (68.4% and 15.3% in groups 1 and 2 monochorionic twins, respectively) were similar and correlated well with the placental share discordances (66.6% and 18.5% in groups 1 and 2 monochorionic twins, respectively) but not with the birthweight discordance (28.6% and 6.4% in groups 1 and 2 monochorionic twins, respectively) in both groups. We concluded that the umbilical venous volume flow discordance reflects the placental share discordance rather than the birthweight discordance in monochorionic twin pregnancies.

Fetal venous circulation in monochorionic twin pregnancies with placental insufficiency: prediction of acidemia at birth or intrauterine fetal death

“…A recent study of monochorionic twin gestations evaluated UV volume flow in cases with and without selective growth restriction. This study demonstrated that, in those cases with selective growth restriction, UV flow is significantly lower in the smaller twin than in the larger twin, and UV flow normalized by estimated fetal weight (mL/kg/min) is still greater in the larger twin.…”

Functional Polymorphism Of The Interleukin-1beta Gene Promoter Is Associated With Increased Risk For Cerebral Palsy In Mexican Children With Perinatal Hypoxia-Ischemia Antecedents

“…This is associated with the slowed growth rate of twins during late gestation when compared to the singleton growth rate [142]. The incidence of multiple births is increasing and this is largely attributed to the increase in availability of infertility treatment, such as ovulation induction [143,144]. Monochorionic twins (identical twins that share one placenta) have a much greater chance of being born IUGR than dichorionic twins (twins that do not share the same placenta) [145,146].…”

Preterm Birth and/or Factors that Lead to Preterm Delivery: Effects on the Neonatal Kidney

“…This is associated with the slowed growth rate of twins during late gestation when compared to the singleton growth rate [142]. The incidence of multiple births is increasing and this is largely attributed to the increase in availability of infertility treatment, such as ovulation induction [143,144]. Monochorionic twins (identical twins that share one placenta) have a much greater chance of being born IUGR than dichorionic twins (twins that do not share the same placenta) [145,146].…”