CLINICAL OBSTETRICS AND GYNECOLOGY Volume 58, Number 2, 294–308 Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.

Management of Twins: Vaginal or Cesarean Delivery? CAROLINA BIBBO, MD, and JULIAN N. ROBINSON, MD Brigham and Women’s Hospital, Boston, Massachusetts

Abstract: Recent level I evidence from a single randomized-controlled trial has shown that there is no difference in fetal or neonatal outcomes (composite of fetal/neonatal death or serious neonatal morbidity) between planned cesarean delivery and planned vaginal delivery for twins between 32 and 38 6/7 weeks. As long as the presenting twin is vertex, vaginal delivery should be considered regardless of the presentation of the second twin. To avoid unnecessary cesarean deliveries and maternal morbidity, it is important to continue to train residents to perform obstetrics maneuvers necessary for vaginal delivery of twins such as vaginal breech extraction. Key words: twins, vaginal delivery, breech extraction, internal podalic version, cesarean delivery

hypertensive disorders, and postpartum hemorrhage are more frequent in twin gestations.4 The management of these maternal complications is similar to that of singletons and it rarely presents a challenge for most obstetricians. The most concerning feature of twin pregnancies is that they are associated with an increased risk of fetal and infant morbidity and mortality. Most of the perinatal morbidity seen in twin gestations is associated with their much higher risk of prematurity.5 Women with twin gestations have a much higher risk of preterm delivery in comparison with singleton gestations, 58.8% versus 10.4% risk of delivery before 37 weeks and 11.4% versus 1.6% risk of delivery before 32 weeks.6 Twin pregnancies have an infant mortality rate of 23.6 per 1,000 live births in comparison with an infant mortality rate of 5.4 per 1000 live births for singleton gestations, secondary to complications of prematurity.7 Specifically, twins are at a higher risk of highgrade intraventricular hemorrhage (IVH) and periventricular leukomalacia if they are born before 32 weeks,8 increasing the prevalence of cerebral palsy.9 Spellacy and colleagues demonstrated in a case-control study that twin pregnancies

Background: Rise in Twins and Cesarean Delivery Twin births accounted for 3.37% of all births in the United States in 2013.1,2 The rate of twin births has continued to rise over the last decades due to the increase in maternal age and increased use of assisted reproductive technology.3 Maternal complications such as gestational diabetes, Correspondence: Carolina Bibbo, MD, Brigham and Women’s Hospital, 75 Francist St, Boston, MA 02115. E-mail: [email protected] The authors declare that they have nothing to disclose. CLINICAL OBSTETRICS AND GYNECOLOGY

294 | www.clinicalobgyn.com

/

VOLUME 58

/

NUMBER 2

/

JUNE 2015

Delivery of Twins had higher fetal and neonatal mortality rates than singletons. In this cohort of over 100,000 women, there were 1253 twin pregnancies.10 The perinatal mortality rate for the first twin was 48.8, 64.1 for the second twin, and 10.4 per 1000 births for the singleton controls.10 Kiely11 also showed a higher neonatal mortality rate for twins. He evaluated computerized vital records of >16,800 multiple pregnancies in New York City from 1978 to 1984. He showed that if the birth weight was 2500 g, twins had a much higher rate of intrapartum death (RR 3.54; 95% CI, 1.82-6.88).11 The former findings probably reflect the earlier maturation of twins; however, we do not have a clear explanation for the latter findings. The overall cesarean delivery rate in the United States was 32.8% in 2011 for singleton and multiple gestations, and this rate was unchanged in the preliminary data for the year 2012.12,13 For all twin births, the national cesarean delivery rate has increased steadily from 53.9% in 1995 to 75% in 2008. Even among vertex presenting twins, the cesarean delivery rate dramatically increased from 45% in 1995 to 68% in 2008.14 In a recent study that published data from a large multicenter national retrospective cohort that participated in the Consortium on Safe labor, multiple gestation was stated as the indication for primary cesarean in 1187 women (3.1% of primary cesarean deliveries, involving 1035 sets of twins and 152 higher-order multiples).15 In the 1035 sets of twins, both fetuses were in the vertex presentation in 263 cases (25.4%), the first twin was vertex and second twin was nonvertex in 255 cases (24.6%), the first twin was nonvertex in 276 cases (26.7%), and the presentation was not recorded in 241 cases (23.3%).15 The high rate of cesarean deliveries for twin gestations that have a presenting

295

vertex twin is concerning as it encompasses at least 50% of twin deliveries, and a substantial percentage of these deliveries may have been avoided if decision making had been based on current level I evidence. Twin gestation in itself is not an indication for cesarean delivery; however, the most likely explanation for the increased rate in cesarean delivery is the rise in elective primary cesarean section, the decrease in provider experience in vaginal breech delivery, and the concern for potential combined delivery.

Presentation of Twin Pairs and the Dynamics of Labor The presentation of twin pairs at term is 40% vertex/vertex, 35% to 40% vertex/ nonvertex, and 20% nonvertex.5,16,17 In approaching the mode of delivery for twin pregnancies, some providers may be concerned that twins will change their presentation during the later stage of pregnancy and the delivery process. Chasen et al18 published a retrospective cohort study that included 207 twin pregnancies in which fetal presentations across different gestational ages were studied (20 to 23, 24 to 27, 28 to 31, 32 to 36 wk, and birth). They found that the presentation of twin pairs was different across the different timepoints established, but there was no statistically significant difference in the distribution of fetal presentations at 32 to 36 weeks and at birth. Their conclusion was that twin pregnancies in which the presenting twin was in the vertex presentation at >28 weeks were very likely to have a vertex presenting twin at birth. A nonvertex presenting twin at >28 weeks was not a good reliable predictor of presentation at birth.18 Divon and colleagues also reported that the change in fetal position depends on gestational age, 60% of twin pregnancies change fetal position at 28 to 30 weeks and 30% change at term. Furthermore, he showed that vertex/vertex presentation are the least www.clinicalobgyn.com

296

Bibbo and Robinson

likely to change (7%) and transverse/transverse presentations are the most likely to change (100%).19 Several studies have supported that spontaneous version is common in the third trimester.4 The majority of twins are in the vertex/vertex presentation at birth, and the vertex presentation of the first twin is unlikely to change after 32 to 36 weeks. However, obstetricians need to be prepared for the second twin to change position after the first twin is delivered as it occurs about 20% of the time.20

The Role of Cesarean Section in Twin Delivery Prior literature has suggested that elective cesarean delivery could prevent the risks of cord prolapse, placental abruption, and compound presentation for the second twin. Yang et al21 published data obtained from birth certificates that showed that when infants were vertex/ vertex and weighed >2500 g, vaginal delivery of the second twin was associated with an increased risk of death [adjusted odds ratio (AOR) 2.69; 95% CI, 1.2-8.39] and ventilation use (AOR 1.24; 95% CI, 1.11-1.4) when compared with cesarean delivery. Furthermore, they found that when twins were vertex/nonvertex and weighted between 1500 and 4000 g, cesarean delivery was protective for infant injury (AOR 50.88; 95% CI, 11.2-899.2), Apgar score

Management of twins: vaginal or cesarean delivery?

Recent level I evidence from a single randomized-controlled trial has shown that there is no difference in fetal or neonatal outcomes (composite of fe...
184KB Sizes 1 Downloads 13 Views