High order parity improves the perinatal outcome of twin deliveries

Objective: We studied the association between parity and the rate of maternal and neonatal complications in twins' deliveries. Study design: A retrospective cohort study of twin gestations delivered between 2012-2018. Inclusion criteria consisted of twin gestation with two live fetuses at ≥24 weeks gestation and no contraindications to vaginal delivery. Women were divided into three groups based on parity: primiparas, multiparas (parity of 1-4), and grandmultiparas (parity ≥5). The primary outcome was mode of delivery. Secondary outcomes were maternal and fetal complications. Results: The study population included 555 twin gestations. One hundred and three were primiparas, 312 were multiparas and 140 were grandmultiparas. Sixty-seven (65%) primiparas delivered the first twin vaginally, as did 294 (94%) multiparas and 133 (95%) grand multiparas (p value <0.05). The need for transfusion of blood products was higher in the primiparous group compared with the other two groups (11.6% vs. 2.5% and 2.8%, p<0.05). The rate of adverse maternal composite outcomes was higher among primiparous women compared with multiparous and grand-multiparous (12.6%, 3.2% and 2.8% respectively, p<0.05). The rate of preterm deliveries <34 weeks was higher among the primiparas compared with multiparas and grand multiparas (8.7% vs. 3.5% and 2%, respectively, p<0.05). Average neonatal birthweight was lower in the primiparas group vs. the multiparas and the grand multiparas (2,420, 2,557 and 2637 g, respectively, p<0.05). The rate of second twin's 5-minute Apgar score <7 was higher in the primipara group (4.8% vs. 0% and 0%, p<0.05). There was a higher rate of composite adverse neonatal outcome among the primiparous group and the multiparous and grand-multiparous groups (8.7%,3.2% and 2.8% respectively p<0.05). Conclusion: There is an association between high-parity and good obstetric outcome in twin pregnancies; high parity seems to serve as a protective, rather than a risk factor for adverse maternal and neonatal outcomes.