Birth weight discordance, obstetric and perinatal outcome in twin pregnancies at term (37 weeks gestation)

Abstract

TWIN PREGNANCIES AT TERM (37 WEEKS GESTATION) RHONA MAHONY, MICHAEL FOLEY, FIONNUALA MCAULIFFE, PETER MCPARLAND, STEPHEN CARROLL, National Maternity Hospital, Materno-Fetal Medicine, Dublin, Ireland, University College Dublin, Obstetrics and Gynaecology, Dublin, Ireland, University College Dublin, Obstetrics & Gynecology, Dublin, Ireland, National Maternity Hospital, Maternal-Fetal Medicine, Dublin, Ireland OBJECTIVE: Birth weight discordance in twin pregnancies is associated with adverse perinatal outcome. Our aim was to determine the obstetric outcome among discordant twins (DT) at term (R37 weeks gestation). STUDY DESIGN: Annual institutional data for the years 1997-2004 were analysed retrospectively DT were identified (mild R15%, moderate R20% and severe R25% growth discordance), and obstetric and perinatal outcomes recorded. RESULTS: Among 60,557 deliveries at term, 1052 twins (526 twin pairs) were delivered accounting for 0.9% of all deliveries. 127/526 twin pairs (24.1%) were discordant for growth 50/526 (9.5%) mild, 46/526 (8.7%) moderate and 31/526 (5.9%) severe. Compared with twins concordant for weight, DT had a higher incidence of prelabour and intrapartum caesarean delivery [86/258 (33%) vs. 214/792 (27%), p=0.02 and (55/258 (21.3%) vs. 122/792 (15.4%), P=0.035 respectively] and a lower incidence of vaginal delivery [117/258 (45.3%) vs. 456/792 (57.6%), P!0.001)]. DT also had a higher incidence of stillbirth [5/258 (19/1000) vs. 1/792 (1.3/1000), P= 0.004], Apgar ! 7 at 5 minutes [10/258 (3.9%) vs. 6/792 (0.8%), P=0.0035] and intensive care (ICU) admission [71/258 (27.5%) vs. 107/792 (13.5%), P!0.001] but no difference in neonatal death compared with concordant twins. Neonatal outcome was similar in the mild and moderately discordant groups but severe discordance was associated with lower Apgar scores (P=0.008) and increased ICU admission (P=0.001) as was growth discordance associated with low birth weight (%2.5Kg) ; P=0.018 and P!0.001 respectively. CONCLUSION: Growth discordance in twins at term is associated with greater operative intervention and adverse neonatal outcome which is worst in severe growth discordance and discordance associated with low birth weight.