Are Dichorionic Twin Pregnancies Resulting from In Vitro Fertilization Different from Spontaneous Dichorionic Twin Pregnancies? A Retrospective Cohort Study

<b>Background</b>: We aimed to compare the perinatal outcomes of dichorionic/diamniotic twin (DC/DA) pregnancies resulting from in vitro fertilization (IVF) with those resulting from spontaneous DC/DA pregnancies. <b>Methods</b>: The study group included 99 women with DC/DA pregnancies resulting from IVF, and the control group included 92 women with spontaneous DC/DA pregnancies. Maternal demographic characteristics (age, parity, and gravidity), pre-existing conditions (chronic hypertension and pregestational diabetes mellitus), and obstetric history were recorded. Pregnancy outcomes included gestational age at delivery, number of fetuses, and mode of delivery. The antepartum complications that we evaluated include first- and second-trimester bleeding, placenta previa, preterm birth, fetal growth restriction (FGR), oligohydramnios, and tocolytic use. The obstetric complications that we assessed include prematurity, twin-to-twin transfusion syndrome (TTTS), and hydrops fetalis. Additionally, neonatal data such as 1st minute and 5th minute Apgar scores, birth weight, neonatal intensive care unit (NICU) admission, presence of congenital anomalies, and neonatal death were recorded, and comparisons were made between the groups. <b>Results</b>: Women in the IVF group were older (34.7 ± 6.9 vs. 32.3 ± 6.1 years, <i>p</i> = 0.03) and more frequently primiparous (73.7% vs. 37.0%, <i>p</i> < 0.001). The mean gestational age at delivery was slightly lower in the IVF group, though this was not statistically significant (34.3 ± 3.5 vs. 35.1 ± 2.5 weeks, <i>p</i> = 0.101). Cesarean delivery was common in both groups, with comparable overall rates (90.9% vs. 94.6%, <i>p</i> = 0.411), but emergency cesarean section occurred more frequently in IVF pregnancies (81.8% vs. 55.8%, <i>p</i> = 0.001). No significant differences were found regarding chronic hypertension or pregestational diabetes. However, several differences were demonstrated in terms of obstetric complications. For example, preterm births and fetal growth restriction (FGR) were significantly more frequent in IVF pregnancies (59.8% vs. 30.4%, <i>p</i> < 0.001), and tocolytic use was also more frequent (56.6% vs. 29.7%, <i>p</i> < 0.001). No significant differences were observed in terms of placenta previa, oligohydramnios, TTTS, hydrops fetalis, and neonatal outcomes. The logistic regression analysis revealed that IVF pregnancies were associated with an increased risk of preterm birth: OR 3.45, 95% CI 1.85-6.78 (<i>p</i> < 0.001); the risk of FGR was also higher in IVF pregnancies: OR 2.11, 95% CI 1.02-4.37 (<i>p</i> = 0.015). However, tocolytic use was not significantly associated with IVF: OR 1.49, 95% CI 0.50-4.44 (<i>p</i> = 0.471). <b>Conclusions:</b> Although DC/DA pregnancies conceived through IVF have a higher risk of preterm birth, fetal growth restriction, and greater use of tocolytic agents than spontaneous DC/DA pregnancies, their neonatal outcomes are similar.