A C TA Obstetricia et Gynecologica
AOGS M A I N R E SE A RC H A R TI C LE
Intrapartum management of twin pregnancies: are uncomplicated monochorionic pregnancies more at risk of complications than dichorionic pregnancies? CHARLES GARABEDIAN1,2, CHLOE POULAIN1, ALAIN DUHAMEL3, DAMIEN SUBTIL1, VERONIQUE HOUFFLIN-DEBARGE1,2 & PHILIPPE DERUELLE1,2 1
Department of Obstetrics, Jeanne de Flandre Hospital, Lille, 2Unit EA 4489 Perinatal Environment and Growth, Faculty of Medicine, Henri-Warembourg, University of Lille, Lille, and 3Unit EA2694, Department of Biostatistics, University of Lille, Lille, France
Key words Chorionicity, morbidity, perinatal mortality, pregnancy, twin, mode of delivery, cesarean section Correspondence Charles Garabedian, Department of Obstetrics, Jeanne de Flandre Hospital, CHRU de Lille, Avenue Eug ene Avin ee, 59037 Lille, France. E-mail: [email protected] Conflicts of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Please cite this article as: Garabedian C, Poulain C, Duhamel A, Subtil D, HoufflinDebarge V, Deruelle P. Intrapartum management of twin pregnancies: are uncomplicated monochorionic pregnancies more at risk of complications than dichorionic pregnancies? Acta Obstet Gynecol Scand 2015; DOI: 10.1111/aogs.12558 Received: 26 July 2014 Accepted: 3 December 2014 DOI: 10.1111/aogs.12558
Abstract Objective. To analyze mode of delivery and neonatal morbidity according to chorionicity in a hospital birth center with a policy of vaginal delivery for twins. Study design. Retrospective analysis over a 13-year period. Setting. Department of Obstetrics, University Hospital, Lille, France. Population. In all, 1009 twin pregnancies were included, divided into 171 uncomplicated monochorionic pregnancies (17%) and 838 dichorionic pregnancies (83%). Methods. We compared the monochorionic and the dichorionic populations. Main outcome measures. Rate of cesarean section and neonatal outcome (umbilical artery pH, Apgar score and neonatal complications). Results. The rate of cesarean sections was 45.7% with no difference found based on chorionicity. The reasons for elective cesarean section were mainly noncephalic presentation, which was more frequent in dichorionic than in monochorionic (48.8% vs. 37.2%, p = 0.025) pregnancies. Birthweight was lower in monochorionic twins (2249 469 g vs. 2329 478 g, p = 0.045). The rate of umbilical artery cord blood values with a pH < 7.10 was similar in monochorionic and dichorionic pregnancies. There was no difference in neonatal complications between the two groups. Conclusion. Monochorionic and dichorionic twin pregnancies had similar delivery outcomes. The neonatal outcome for twin 2 was not different between monochorionic and dichorionic pregnancies. Vaginal birth could be offered to women with twin pregnancies regardless of chorionicity. CS, cesarean section; DC, dichorionic; MC, monochorionic; TOL, trial of labor; TTTS, twin-to-twin transfusion syndrome.
Abbreviations:
Introduction Compared to singleton pregnancies, twin pregnancies run a threefold to sevenfold higher risk of perinatal mortality (1). Monochorionic (MC) twins account for 20% of all twins and it is well known that they are at increased risk for perinatal mortality and neonatal morbidity compared
Key Message Intrapartum management is not associated with an increased risk of complications in uncomplicated monochorionic twins compared with dichorionic twins. Chorionicity should not be considered in the discussion to choose the route of delivery.
ª 2014 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica
1
Intrapartum management of twin pregnancies
with dichorionic (DC) twins (2,3). The hemodynamic imbalance caused by placental vascular anastomoses could in part explain these differences (4). Over the past two decades, several authors have attempted to find the optimal mode of delivery for twins but without taking chorionicity into account (5–11). Past studies have shown conflicting results. Smith et al. found that intrapartum complications could be prevented by offering planned cesarean section (CS) to all MC twin pregnancies (9). In contrast, other authors suggested that vaginal delivery is a safe option for uneventful MC diamniotic twin pregnancies (8,12,13). Recently, a randomized trial compared planned cesarean with vaginal delivery in twin pregnancies (14). In all, 2804 patients were included and the authors concluded that in twin pregnancies between 32+0 and 38+6 weeks and with cephalic presentation of the first twin, planned cesarean delivery did not significantly decrease or increase fetal and neonatal mortality risks, nor affect the rate of serious neonatal morbidity as compared with planned vaginal delivery. Hence, it was established that vaginal delivery was a possible mode of delivery for twins. However, most studies dealing with mode of delivery and perinatal outcome in twins did not stratify their results according to chorionicity. Three studies have specifically evaluated intrapartum management of uncomplicated MC pregnancies compared with DC pregnancies (15–17). However, they had small numbers of patients, included planned CS on maternal request or reported high CS rates (15–17). According to guidelines from the French College of Obstetricians and Gynecologists, our hospital birth center’s policy on twins has been to propose vaginal delivery to the parents, both before and at term, whatever the presentation of the first twin and even with a past history of one CS (18). Our objective was therefore to analyze mode of delivery and neonatal morbidity by chorionicity in a birth center with a general policy of vaginal delivery for twins.
Material and methods This was a retrospective cohort study of all twin pregnancies managed from January 1997 to January 2011 in the Department of Obstetrics and Gynecology of Jeanne de Flandre Hospital (Lille, France). Ethics approval was granted by the French Committee of Obstetrics and Gynecologic Research Ethics (CEROG OBS 2014-04-02). Twin pregnancies between 28 and 41 weeks of gestation were included. We did not include twin pregnancies between 24 and 28 weeks because of the specific management of very preterm infants. Monoamnionicity, a major structural abnormality in either twin or fetal aneuploidy
2
C. Garabedian et al.
(either suspected or confirmed), stillbirths before labor and termination of pregnancy were also exclusion criteria. MC diamniotic pregnancies were considered as complicated in case of twin-to-twin transfusion syndrome (TTTS) and twin anemia–polycythemia sequence. Chorionicity was determined on the basis of first-trimester ultrasound assessment of the dividing membrane characteristics (absence of “twin peak” sign and presence of thin dividing membrane) and confirmed by postpartum examination of the placenta and the inter-twin membrane. All twin pregnancies were monitored according to the French guidelines (19). Uncomplicated MC pregnancies were delivered between 36 and 39 weeks of gestation and DC between 38 and 40 weeks (20,21). If labor had not spontaneously started at 39+0 and +0 40 weeks of gestation for MC and DC pregnancies respectively, labor was induced. Pelvimetry was proposed if the estimated fetal weight of the second twin was beyond 2500 g. Elective CS was planned in case of unfavorable comparison of cephalic and pelvic measurements, as previously described (22), a past history of two or more cesarean deliveries, active herpes lesions, or a maternal situation requiring prompt delivery [severe preeclampsia, HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome]. In our protocol, chorionicity and presentation of twin 1 were not taken into account when considering the mode of delivery. In case of trial of labor (TOL) management included continuous electronic fetal heart rate monitoring and epidural analgesia at the discretion of the patient. During the second phase of labor, a junior obstetrician in training, a senior obstetrician, senior anesthesiologist, senior pediatrician and two midwives were present in the delivery room. Maternal characteristics and pregnancy complications were collected. Screening for gestational diabetes was achieved by a two-step method (O’Sullivan criteria and 100-g oral glucose tolerance test). Small-for-gestational age was defined as neonatal weight below the 10th centile for gestational age (23). The following intrapartum variables were analyzed: gestational age at delivery, labor induction, mode of delivery and for each twin presentation (vertex, breech or other such as transverse, brow and face) and rate of vaginal birth (spontaneous or instrumental). Postpartum hemorrhage was defined as blood loss >500 mL. CS indications were distinguished as follows: planned CS or CS during labor. Neonatal outcome was assessed by considering Apgar score, umbilical artery pH with a cutoff of 7.10, neonatal sepsis within 72 h after birth, respiratory distress syndrome, and admission to neonatal intensive care unit and neonatal mortality in the first 28 days of life.
ª 2014 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica
Intrapartum management of twin pregnancies
C. Garabedian et al.
Statistical analysis Qualitative variables are expressed as number and percentage, quantitative variables by mean and standard deviation. The chi-squared test was used to compare qualitative parameters whereas Student’s t-test or the Mann–Whitney U-test were used for quantitative variables. The neonatal comparisons were further adjusted for maternal co-factors associated with chorionicity type in bivariate analysis (p < 0.10). We used linear regression for quantitative variables and logistic regression for binary variables. A p-value
AOGS M A I N R E SE A RC H A R TI C LE
Intrapartum management of twin pregnancies: are uncomplicated monochorionic pregnancies more at risk of complications than dichorionic pregnancies? CHARLES GARABEDIAN1,2, CHLOE POULAIN1, ALAIN DUHAMEL3, DAMIEN SUBTIL1, VERONIQUE HOUFFLIN-DEBARGE1,2 & PHILIPPE DERUELLE1,2 1
Department of Obstetrics, Jeanne de Flandre Hospital, Lille, 2Unit EA 4489 Perinatal Environment and Growth, Faculty of Medicine, Henri-Warembourg, University of Lille, Lille, and 3Unit EA2694, Department of Biostatistics, University of Lille, Lille, France
Key words Chorionicity, morbidity, perinatal mortality, pregnancy, twin, mode of delivery, cesarean section Correspondence Charles Garabedian, Department of Obstetrics, Jeanne de Flandre Hospital, CHRU de Lille, Avenue Eug ene Avin ee, 59037 Lille, France. E-mail: [email protected] Conflicts of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Please cite this article as: Garabedian C, Poulain C, Duhamel A, Subtil D, HoufflinDebarge V, Deruelle P. Intrapartum management of twin pregnancies: are uncomplicated monochorionic pregnancies more at risk of complications than dichorionic pregnancies? Acta Obstet Gynecol Scand 2015; DOI: 10.1111/aogs.12558 Received: 26 July 2014 Accepted: 3 December 2014 DOI: 10.1111/aogs.12558
Abstract Objective. To analyze mode of delivery and neonatal morbidity according to chorionicity in a hospital birth center with a policy of vaginal delivery for twins. Study design. Retrospective analysis over a 13-year period. Setting. Department of Obstetrics, University Hospital, Lille, France. Population. In all, 1009 twin pregnancies were included, divided into 171 uncomplicated monochorionic pregnancies (17%) and 838 dichorionic pregnancies (83%). Methods. We compared the monochorionic and the dichorionic populations. Main outcome measures. Rate of cesarean section and neonatal outcome (umbilical artery pH, Apgar score and neonatal complications). Results. The rate of cesarean sections was 45.7% with no difference found based on chorionicity. The reasons for elective cesarean section were mainly noncephalic presentation, which was more frequent in dichorionic than in monochorionic (48.8% vs. 37.2%, p = 0.025) pregnancies. Birthweight was lower in monochorionic twins (2249 469 g vs. 2329 478 g, p = 0.045). The rate of umbilical artery cord blood values with a pH < 7.10 was similar in monochorionic and dichorionic pregnancies. There was no difference in neonatal complications between the two groups. Conclusion. Monochorionic and dichorionic twin pregnancies had similar delivery outcomes. The neonatal outcome for twin 2 was not different between monochorionic and dichorionic pregnancies. Vaginal birth could be offered to women with twin pregnancies regardless of chorionicity. CS, cesarean section; DC, dichorionic; MC, monochorionic; TOL, trial of labor; TTTS, twin-to-twin transfusion syndrome.
Abbreviations:
Introduction Compared to singleton pregnancies, twin pregnancies run a threefold to sevenfold higher risk of perinatal mortality (1). Monochorionic (MC) twins account for 20% of all twins and it is well known that they are at increased risk for perinatal mortality and neonatal morbidity compared
Key Message Intrapartum management is not associated with an increased risk of complications in uncomplicated monochorionic twins compared with dichorionic twins. Chorionicity should not be considered in the discussion to choose the route of delivery.
ª 2014 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica
1
Intrapartum management of twin pregnancies
with dichorionic (DC) twins (2,3). The hemodynamic imbalance caused by placental vascular anastomoses could in part explain these differences (4). Over the past two decades, several authors have attempted to find the optimal mode of delivery for twins but without taking chorionicity into account (5–11). Past studies have shown conflicting results. Smith et al. found that intrapartum complications could be prevented by offering planned cesarean section (CS) to all MC twin pregnancies (9). In contrast, other authors suggested that vaginal delivery is a safe option for uneventful MC diamniotic twin pregnancies (8,12,13). Recently, a randomized trial compared planned cesarean with vaginal delivery in twin pregnancies (14). In all, 2804 patients were included and the authors concluded that in twin pregnancies between 32+0 and 38+6 weeks and with cephalic presentation of the first twin, planned cesarean delivery did not significantly decrease or increase fetal and neonatal mortality risks, nor affect the rate of serious neonatal morbidity as compared with planned vaginal delivery. Hence, it was established that vaginal delivery was a possible mode of delivery for twins. However, most studies dealing with mode of delivery and perinatal outcome in twins did not stratify their results according to chorionicity. Three studies have specifically evaluated intrapartum management of uncomplicated MC pregnancies compared with DC pregnancies (15–17). However, they had small numbers of patients, included planned CS on maternal request or reported high CS rates (15–17). According to guidelines from the French College of Obstetricians and Gynecologists, our hospital birth center’s policy on twins has been to propose vaginal delivery to the parents, both before and at term, whatever the presentation of the first twin and even with a past history of one CS (18). Our objective was therefore to analyze mode of delivery and neonatal morbidity by chorionicity in a birth center with a general policy of vaginal delivery for twins.
Material and methods This was a retrospective cohort study of all twin pregnancies managed from January 1997 to January 2011 in the Department of Obstetrics and Gynecology of Jeanne de Flandre Hospital (Lille, France). Ethics approval was granted by the French Committee of Obstetrics and Gynecologic Research Ethics (CEROG OBS 2014-04-02). Twin pregnancies between 28 and 41 weeks of gestation were included. We did not include twin pregnancies between 24 and 28 weeks because of the specific management of very preterm infants. Monoamnionicity, a major structural abnormality in either twin or fetal aneuploidy
2
C. Garabedian et al.
(either suspected or confirmed), stillbirths before labor and termination of pregnancy were also exclusion criteria. MC diamniotic pregnancies were considered as complicated in case of twin-to-twin transfusion syndrome (TTTS) and twin anemia–polycythemia sequence. Chorionicity was determined on the basis of first-trimester ultrasound assessment of the dividing membrane characteristics (absence of “twin peak” sign and presence of thin dividing membrane) and confirmed by postpartum examination of the placenta and the inter-twin membrane. All twin pregnancies were monitored according to the French guidelines (19). Uncomplicated MC pregnancies were delivered between 36 and 39 weeks of gestation and DC between 38 and 40 weeks (20,21). If labor had not spontaneously started at 39+0 and +0 40 weeks of gestation for MC and DC pregnancies respectively, labor was induced. Pelvimetry was proposed if the estimated fetal weight of the second twin was beyond 2500 g. Elective CS was planned in case of unfavorable comparison of cephalic and pelvic measurements, as previously described (22), a past history of two or more cesarean deliveries, active herpes lesions, or a maternal situation requiring prompt delivery [severe preeclampsia, HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome]. In our protocol, chorionicity and presentation of twin 1 were not taken into account when considering the mode of delivery. In case of trial of labor (TOL) management included continuous electronic fetal heart rate monitoring and epidural analgesia at the discretion of the patient. During the second phase of labor, a junior obstetrician in training, a senior obstetrician, senior anesthesiologist, senior pediatrician and two midwives were present in the delivery room. Maternal characteristics and pregnancy complications were collected. Screening for gestational diabetes was achieved by a two-step method (O’Sullivan criteria and 100-g oral glucose tolerance test). Small-for-gestational age was defined as neonatal weight below the 10th centile for gestational age (23). The following intrapartum variables were analyzed: gestational age at delivery, labor induction, mode of delivery and for each twin presentation (vertex, breech or other such as transverse, brow and face) and rate of vaginal birth (spontaneous or instrumental). Postpartum hemorrhage was defined as blood loss >500 mL. CS indications were distinguished as follows: planned CS or CS during labor. Neonatal outcome was assessed by considering Apgar score, umbilical artery pH with a cutoff of 7.10, neonatal sepsis within 72 h after birth, respiratory distress syndrome, and admission to neonatal intensive care unit and neonatal mortality in the first 28 days of life.
ª 2014 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica
Intrapartum management of twin pregnancies
C. Garabedian et al.
Statistical analysis Qualitative variables are expressed as number and percentage, quantitative variables by mean and standard deviation. The chi-squared test was used to compare qualitative parameters whereas Student’s t-test or the Mann–Whitney U-test were used for quantitative variables. The neonatal comparisons were further adjusted for maternal co-factors associated with chorionicity type in bivariate analysis (p < 0.10). We used linear regression for quantitative variables and logistic regression for binary variables. A p-value
