Second-trimester abdominal circumference discordance and adverse perinatal outcomes in monochorionic twins

Abstract

Objective

The perinatal outcomes in second-trimester abdominal circumference (AC) discordant twins are yet to be established. The aim of this study was to ascertain perinatal risks associated with second-trimester AC discordance in monochorionic (MC) twins.

Method

We conducted a retrospective study of all MC twin pregnancies over a 7-year period. Intertwin AC discordance at 14–26 gestational weeks was analyzed in relation to Doppler abnormalities, obstetric complications, and perinatal adverse outcomes.

Results

A total of 246 MC twin pregnancies were included in the analysis. The smaller twins of second-trimester AC discordant pairs were at increased prevalence of abnormal umbilical artery flow (50% versus 24%, p < .001) and low positive A wave of ductus venous flow (24% versus 9%, p = .002). The second-trimester AC discordant twins were at increased risk of oligohydramnios in smaller twin (OR = 2.44, 95% CI = 1.37–4.32, p < .01), cardiomegaly in larger twin (OR = 2.95, 95% CI = 1.01–8.60, p < .05), birth weight of either twin below the 10th percentile for gestational age (OR = 5.56, 95% CI = 2.67–11.59, p < .001), birth weight discordance > 25% (OR = 9.41, 95% CI = 4.46–19.87, p < .001), IUFD (OR = 3.26, 95% CI = 1.76–6.05, p < .001), and severe neonatal morbidity (OR = 1.83, 95% CI = 1.03–3.26, p < .05). The intact survival rate in discordant and concordant twin pairs was 70% and 89%, respectively (p < .001).

Conclusions

Early and increase fetal surveillance of the second-trimester AC discordant twins should be utilized to establish perinatal risks, thus allowing prenatal care to improve.

Keywords:

• Monochorionic twin pregnancies
• abdominal circumference
• growth discordance
• second trimester
• adverse perinatal outcomes

Disclosure statement

The authors report that there are no conflicts of interest.

This work was supported by Qingdao Social Science Planning Project (QDSKL2001378) and Qingdao Postdoctoral Project (201922).