Perinatal outcomes of single intrauterine fetal demise in monochorionic diamniotic twins

Objective: To compare the pregnancy outcomes of surviving fetuses in monochorionic diamniotic (MCDA) twin pregnancies after selective feticide or spontaneous single intrauterine fetal demise (sIUFD), and to explore the influencing factors of prognosis.

Methods: A total of 219 cases of intra-uterine death of one fetus in MCDA twin pregnancies admitted to Peking University Third Hospital from September 2010 to August 2021 were collected. According to the mode of fetal death, they were divided into the spontaneous sIUFD group (120 cases) and the selective feticide group (99 cases). Data on the maternal conditions during pregnancy, the situation of the intrauterine-dead fetus, and pregnancy outcomes were collected for retrospective case-analysis.

Results: The live-birth rates of surviving fetuses in the spontaneous sIUFD group and the selective feticide group were 85.0% and 81.8% respectively, and the total perinatal survival rates of surviving fetuses were 73.3% and 81.8% respectively, and there were no statistically significant differences. Compared with the spontaneous sIUFD group, the selective feticide group had a greater gestational week at delivery, and lower rate of preterm birth before 37 weeks, neonatal asphyxia, and early neonatal mortality. Using the gestational week at delivery as the outcome variable, Cox regression analysis showed that the mode of fetal death was not a risk factor affecting the gestational week at delivery of the surviving fetus, while gestational hypertension and the gestational week of fetal death were independent risk factors affecting the gestational week at delivery of the surviving fetus. Using preterm birth before 37 weeks, intrauterine death of the surviving fetus, and abnormal neonatal cranial ultrasound as outcome variables respectively, unconditional logistic regression analysis showed that the mode of fetal death, the gestational week of fetal death, the position of the dead fetus, and fetal complications were independent risk factors affecting the outcomes of the above-mentioned surviving fetuses. According to the results of the univariate analysis, the above risk factors were included in the multivariate regression analysis, and the results were the same as those of the univariate analysis.

Conclusions: For MCDA twin pregnancy patients with severe twin-related complications, the prognosis of surviving fetuses after selective feticide is better. The proactive intrauterine intervention and treatment are of great significance for improving the prognosis of surviving fetuses.