Observational study: To determine factors affecting inter-twin delivery interval

1. Observational study: To determine factors affecting inter-twin delivery interval Quek Y.S. (1), Woon S.Y. (1), Ravichandran N. (2), Kaliammah MK (1), Shantala V. (3), Ravichandran J. (1) 1. Hospital Sultanah Aminah Johor Bahru, Malaysia 2. Singapore General Hospital 3. Kokilaben Dhuribhai Ambani Hospital, India (Visiting MFM Consultant) OPTIONALLOGO HERE OPTIONALLOGO HERE Objectives Results Results Conclusions Twin pregnancies occur in approximately 1% of all pregnancies, but approximately 10% of perinatal complications occur in twin pregnancies1. Following vaginal delivery of the first twin, the further management to delivery the second twin is in dispute. Population based twin studies are scarce and have not dealt with factors influencing twin-to-twin delivery time interval2. This study examines the relationship of maternal, intra-partum intervention and fetal characteristics with inter-twin delivery interval time. The vaginal delivery of twin gestation is a challenge for obstetricians. The delivery of the second twin is complicated by uterine inertia following the delivery of the first tiwn, and the abnormal lie or high presentation of second twin. For these reasons, many studies have been conducted on safe modes of deliveries for second twins, but the conclusion were inconsistent 1,2. In our study, maternal and fetal characteristics were not related to inter-twin delivery time interval. The occurrence of intrapartum fetal distress requiring intra-partum intervention (i.e. instrumental assisted vaginal delivery) was found to be more likely with increasing inter-twin delivery time interval. It is relatively safe to plan for a vaginal delivery but further studies should be conducted in exploring the relationship between inter-twin delivery intervals with perinatal outcome. Total 63 sets of twins were included in the study. There mean inter-twin delivery time interval for the study groups was 9.33 ±7.52 minutes. Maternal parameters, such as age, height, weight, body mass index or parity were not related to increased time interval of inter-twin delivery (Table 1). Our study have observed that instrumental assisted vaginal delivery of 2nd twin has significant relationship with prolonged inter-delivery time interval. Mean time interval taken for instrumental group was 18.5 mins ± 13.67 mins compared to non-instrumental group 8.4 ± 5.99 mins. All instrumental assisted deliveries in these cases were due to fetal distress. There was no relationship between oxytocin augmentation and manipulation of 2nd twin with inter-twin delivery time interval (Table 3). Table 1. Relationship of maternal factor with inter-twin delivery interval time Table 3. Relationship of fetal factor with inter-twin delivery interval time Methods This is a prospective observational study on twin births delivered at ≥34 weeks in the largest maternity unit in Malaysia (Hospital Sultanah Aminah Johor Bahru) from January to December 2009. Total 63 twin pregnancies with vaginal delivery of 1st twin were included in the study. Multiple possible factors including maternal factors (age, height, weight, BMI, parity), intrapartum intervention (oxytocin augmentation, manipulation of 2nd twin, mode of vaginal delivery), and fetal factors (chorionicity, gestational age of delivery, presentation of 2nd twin, weight discordance) were identified. Spearman correlation tests and student t-test were used to reveal any correlation of these factors with intertwin delivery interval time. The level of significance was chosen to be P < 0.05 in all the analyses. Table 2 shows fetal factors in relation to the inter-twin delivery time interval. There was no significant relationship in all the factors identified including chorionicity, presentation of 2nd twin, gestational age of delivery or weight discordance. References • Werner Stein, Bjorn M., Stefan S. Twin-to-twin delivery interval: influencing factors and effect on short-term outcome of the second twin. Acta Obstetricia et Gynecologica 2008; 87: 346-353. • Kwon JY, Yoon WS, Lee GSR, Kim SJ, Shin JC, Park IY. Umbilical Arterial Blood Gas and Perinatal Outcome in the Second Twin according to the planned mode of delivery. Int J Med Science 2011; 8(8):643-648. • Erdemoglu E, Mungan T, Tapisiz OL, Ustunyurt E, Carglar E. Effect of inter-twin delivery time on Apgar scores of the second twin. Aust NZ Obstet Gynecol 2003; 43:203-206. Table 2. Relationship of intrapartum intervention with inter-twin delivery interval time