The comparison of the perinatal outcomes in monochorionic twin pregnancies with and without selective intrauterine growth restriction

Objective Both fetuses may be affected negatively as a result of the non-equal share of the placenta and vascular anastomoses in monochorionic pregnancies with selective intrauterine growth restriction (sIUGR). In our study, we aimed to investigate the perinatal outcomes of both larger and smaller fetuses in monochorionic pregnancies with and without sIUGR (non-sIUGR) separately. Methods A total of 196 monochorionic twin pregnancies were evaluated retrospectively between January 2013 and January 2019. The cases were grouped as sIUGR and non-sIUGR pregnancies. The pregnancies with sIUGR were also separated into sub-groups as the cases with normal umbilical flow pattern and the cases with abnormal umbilical flow pattern. The perinatal outcomes were investigated separately between the groups for larger and smaller fetuses. Results Of 153 monochorionic pregnancies included in the study, 17.6% (n=27) were sIUGR cases and 82.4% (n=126) were non-sIUGR cases. While the umbilical artery flow pattern was normal in 59.3% (n=16) of the pregnancies which developed sIUGR, 40.7% (n=11) of them had abnormal umbilical artery flow pattern. The preeclampsia rate was found significantly higher in sIUGR pregnancies than non-sIUGR pregnancies (25.9% vs. 11.1%, p=0.042). The need for intensive care for both larger and smaller newborns was significantly higher in sIUGR pregnancies compared to non-sIUGR pregnancies (p<0.001). Three (11.1%) of newborns in sIUGR pregnancies passed away during neonatal period. All of the newborns that passed away were the smaller newborns from sIUGR pregnancies with abnormal umbilical artery flow pattern. Conclusion The pregnancies with selective intrauterine growth restriction (sIUGR) are more associated with high risks in terms of perinatal outcomes compared to the pregnancies with non-sIUGR. In pregnancies developing sIUGR, the risk increases for larger fetus as well as smaller fetus. More prospective studies are needed to investigate whether this increased risk in the pregnancies with sIUGR is associated with prematurity which is more common or is a result of sIUGR.