Comparative study of neonatal outcome between first and second twin babies delivered by vaginal route

Introduction: The incidence of twinning has been increasing due to availability and increased use of ovulation inducing drugs and assisted reproductive technology. Despite substantial concerns over the well-being of the second twin with regard to intra partum events, outcome studies on this issue are conflicting. Some have reported no increase in perinatal complications, while others showed significant associations between labor and delivery of the second twin and increased perinatal morbidity and mortality. Material and methods: 106 cases of twin pregnancy fulfilling of age 18 - 35 years, at more than 32 weeks gestation, first twin with cephalic presentation and selected for vaginal delivery were included in the study. Intrauterine death of either one of the twins before the onset of labour, pregnancies complicated or fetal malformations and those with contraindication to vaginal birth were excluded. After thorough screening of included cases delivery was performed according to fixed protocol. After delivery, mode of delivery, cry, APGAR score, birth weight, complications, birth injury, time interval between deliveries, NICU admission and condition on discharge of each baby was noted. Results: 106 twins were included as delivered vaginally, including 3 patients who were delivered by vaginal delivery for 1st twin followed by caesarean delivery for 2nd twin. Stillbirth and early neonatal deaths resulted in 24 deaths. There is no significant difference between mortality of 1st and 2nd born twins. The neonatal mortality was equal in first and second twin. Neonatal morbidity was more in 2nd twin than 1st twin (27.65% v/s 15.95%). There were 41 NICU admissions (19.34%), out of those 36.6% were for first twin (n=15) and 63.4% for second twin (n=26), (p value 0.056). Incidence of RDS, invasive ventilator support, NICU Stay >7 days is significantly higher in second twin as compared to first twin. Breech presentations were associated with 10% neonatal mortality for second twin compared to none for first twin. Most common group for neonatal mortality and morbidity was birth weight 1000-1499 gm. Neonatal morbidity was 100% for discordancy 30 to 40% group while 85.71% for discordancy 20 to 30% group. These results are significant when compared for heavier twin v/s lighter twin (p value 0.001).Neonatal mortality and morbidity between first and second twin is statistically significant when compared according to Apgar score (p value 0.037). Incidences of stillbirth + early neonatal death for 2nd twin less in early preterm group but increased in in late preterm group. Neonatal outcome of 2nd twin was better in dichorionic pregnancies 11% v/s 16.67% in monochorionic pregnancies (p>0.05). Conclusion: Twin vaginal delivery is safe in first cephalic presentation in twin pregnancy. Caution should taken while delivering babies < 1500 gm, birth discordancy > 20% , gestational age < 34 weeks, as vaginal delivery in these conditions is associated with increased early neonatal morbidity and neonatal mortality.