Participants characteristics
There were 43,914 births between 2012 and 2018 at Virgen del RocĂ­o University Hospital (Seville, Spain). Over these 6-year period, there were 84 MCDA twin births later than 30 weeks of gestation of pregnancies who were fully followed-up in our department, from the first-trimester ultrasound to delivery.
Of those, cases with twin-to-twin transfusion syndrome (TTTS) (n = 5), stillbirth (n = 3), severe preeclampsia (n = 1), severe intrauterine growth restriction (IUGR) (n = 2), and gestational age at birth < 32 weeks (n=5) were excluded from the study (some of the pregnancies shared more than one of the above criteria). In total, 12 pregnancies were excluded.
The final analysis included 72 uncomplicated MCDA twin pregnancies: 42 women (58.3%) in the TOL group and 30 women (41.7%) in the PCS group. The flow chart of participant enrolment is shown in Figure 1.
The demographic, clinical, and neonatal characteristics are described in table 2. No differences were found in most baseline characteristics, including maternal age, smoking habit, previous delivery, weight, use of artificial reproductive techniques (ART), gestational diabetes, or pre-gestational diabetes mellitus. No statistically significant differences were found regarding mean gestational age at birth (TOL: 36.2 weeks vs. PCS: 35.3 weeks, p=0.15). The mean weight at birth was lower in the PCS group, both for the first twin (2,228 g vs. 2,413 g, p=0.07) and the second one (2,134 g vs. 2,385 g, p=0.02). There were no maternal deaths or severe morbidity in this study.