Gestational diabetes mellitus is associated with adverse outcomes in twin pregnancies.

BACKGROUND: Among singleton pregnancies, gestational diabetes mellitus is associated with adverse outcomes. In twin pregnancies, this association may be attenuated, given the higher rate of prematurity and the a priori increased risk of some of these complications. OBJECTIVE: Our aim was to test the hypothesis that gestational diabetes mellitus is less likely to be associated with adverse pregnancy outcomes in twin compared with singleton gestations. METHODS: This retrospective cohort study comprised all twin and singleton live births in Ontario, Canada, 2012-2016. Pregnancy outcomes were compared between women with vs without gestational diabetes mellitus, analyzed separately for twin and singleton births. Adjusted risk ratios and 95% confidence intervals were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, race, body mass index, preexisting hypertension, and assisted reproductive technology. RESULTS: A total of 270,843 women with singleton (n = 266,942) and twin (n = 3901) pregnancies met the inclusion criteria. In both the twin and singleton groups, gestational diabetes mellitus was associated with (adjusted risk ratio, [95% confidence interval]) cesarean delivery (1.11 [1.02-1.21] and 1.20 [1.17-1.23], respectively) and preterm birth at <370/7 weeks (1.21 [1.08-1.37] and 1.48 [1.39-1.57]) and at <340/7 weeks (1.45 [1.03-2.04] and 1.25 [1.06-1.47]). In singletons, but not twins, gestational diabetes mellitus was associated with gestational hypertension (1.66 [1.55-1.77]) and preeclampsia. With respect to neonatal outcomes, gestational diabetes mellitus was associated with birthweight greater than the 90th percentile in both twins and singletons, with the risk being 2-fold higher in twins (2.53 [1.52-4.23] vs 1.18 [1.13-1.23], respectively, P = .004). Gestational diabetes mellitus was associated with jaundice in both twins (1.56 [1.10-2.21]) and singletons (1.49 [1.37-1.62) but was associated with the following complications only in singletons: neonatal intensive care unit admission (1.44 [1.38-1.50]), respiratory morbidity (1.09 [1.02-1.16]), and neonatal hypoglycemia (3.20 [3.01-3.40]). CONCLUSION: In contrast to singleton pregnancies, gestational diabetes mellitus in twins was not associated with hypertensive complications and certain neonatal morbidities. Still, the current study highlights that gestational diabetes mellitus is associated with some adverse pregnancy outcomes including accelerated fetal growth also in twin pregnancies.

Preeclampsia acts differently in in vitro fertilization versus spontaneous twins.

OBJECTIVE: To investigate risk factors and pregnancy outcome of spontaneous vs in-vitro fertilization (IVF) twins complicated with preeclampsia. STUDY DESIGN: A retrospective population-based cohort study comparing maternal and neonatal outcome in IVF vs spontaneously conceived twins was conducted. Deliveries occurred in a tertiary medical center between the years 1988 and 2010. Women who conceived after ovulation induction and those with chronic hypertension were excluded from the study. Multiple logistic regression models were used to control for confounders. RESULTS: The study population included 4428 twin pregnancies, of these 314 (7.1%) had preeclampsia; 64 (20.3%) were IVF twins and 250 (79.7%) were spontaneous twins. Preeclampsia was more common in IVF compare to spontaneous twins (13.8 vs 7.6%, OR = 1.81, CI = 1.50-2.17, P < 0.001). The mothers of IVF twins were significantly older, and were more likely to be nulliparous. The rate of cesarean delivery was higher among IVF twins. The mean gestational age at delivery and the mean birth weight were significantly lower in IVF twins. While controlling for confounders using a multivariate analysis, IVF was found as an independent risk factor for preterm delivery in twin pregnancies with preeclampsia. However, there was no difference in the perinatal mortality or 5 min Apgar scores < 7 between the two groups. CONCLUSION: Preeclampsia is more common in IVF twins compared to spontaneous twin pregnancies. IVF twins with preeclampsia are at an increased risk for cesarean delivery, preterm delivery and low birth weight.

Incidence and risk factors for gestational diabetes mellitus in twin versus singleton pregnancies.

OBJECTIVE: To compare the incidence and risk factors for gestational diabetes mellitus (GDM) between women with twin and singleton pregnancies. METHODS: Retrospective study of all women who had a twin or singleton birth in Ontario (2012-2016). Risk ratios (RR) and 95% CIs for GDM (stratified by type of treatment) were adjusted for relevant confounding variables. Multivariable Poisson regression analysis was used to identify risk factors for GDM in twin and singleton gestations. RESULTS: Of 270,843 women who met inclusion criteria, 266,942 (98.6%) and 3901 (1.4%) had a singleton and a twin pregnancy, respectively. Women with twins had a significantly higher risk for overall GDM (aRR = 1.13, 95% CI 1.01-1.28) and diet-treated GDM (aRR = 1.20, 95% CI 1.01-1.42) while the association with insulin-treated GDM was not significant (aRR = 1.07, 95% CI 0.89-1.28). Maternal age ≥ 35 years, non-Caucasian ethnicity and BMI > 30 kg/m2 were independent risk factors for GDM among women with twins and singletons, and the magnitude of the association of these factors with GDM was similar. CONCLUSIONS: Women with twins are at increased risk of GDM, mainly due to a higher rate of diet-treated GDM. Despite higher baseline risk of GDM in women with twins, the effect of known risk factors for GDM is similar to that observed in singletons.

The greater risk of preterm birth in triplets is mirrored by a more rapid cervical shortening along gestation.

BACKGROUND: The risk of preterm birth increases with plurality. However, data are limited about the role of cervical length in triplet pregnancies and how the greater predisposition for preterm birth in triplet pregnancies, compared with twin pregnancies, is reflected by cervical length. Specifically, it is unclear whether the greater predisposition of triplet pregnancies for preterm birth is reflected by a more rapid cervical shortening during gestation compared with twin pregnancies (and therefore a shorter cervical length at any given gestational age), by a greater risk for preterm birth per given cervical length at any given gestational age, or both. OBJECTIVE: The purpose of the study was to compare the rate of cervical shortening during gestation and the correlation between cervical length and gestational age at birth in asymptomatic women with triplet vs twin pregnancies. STUDY DESIGN: This was a retrospective study of women with triplet or twin pregnancies who were who were observed in a tertiary center who underwent serial sonographic measurement of cervical length from 16-32 weeks gestation. Change in cervical length during gestation and relationship of cervical length with gestational age at birth were compared between the triplets and twins groups. RESULTS: A total of 431 measurements of cervical length from 86 women with triplets was analyzed and compared with 2826 measurements of cervical length from 441 women with twins. The rate of cervical shortening among triplet pregnancies was higher than among twin pregnancies starting from 18 weeks of gestation (slope of regression line, -1.297 vs -0.907; P < .001). Similarly, the proportion of women with cervical length of <25 mm or 15 mm was higher among triplet pregnancies than among twin pregnancies (34.0% vs 21.0% [P < .001] and 16.7% vs 8.4% [P = .001]), respectively. For any given cervical length measured after 22 weeks of gestation, the associated gestational length at birth in triplet pregnancies was lower by 2.7 weeks on average compared with twin pregnancies (P < .001). CONCLUSION: The higher rate of preterm birth in triplet pregnancies, compared with twin pregnancies, is reflected by both a more rapid cervical shortening during gestation and a lower gestational age at birth per any given cervical length.

Risk factors for obstetric anal sphincter injuries in twin deliveries: a retrospective review.

INTRODUCTION AND HYPOTHESIS: Risk factors for obstetric anal sphincter injuries (OASIS) have been well-established in singleton pregnancies. Considering the unique characteristics of twin deliveries, our aim was to identify risk factors for OASIS that are specific to twins. METHODS: A retrospective study of all vaginal twin deliveries in a tertiary center between 2000 and 2014. Women who experienced OASIS (the OASIS group) were compared with those whose anal sphincter was intact (controls). RESULTS: Overall 717 women were eligible for the study, of whom 20 (2.8 %) experienced OASIS. Women in the OASIS group were more likely to be nulliparous (95.0 % vs 53.7 %, p < 0.001) and were characterized by a higher gestational age at delivery (36.1 ± 2.5 vs 34.6 ± 3.3, p = 0.04), a higher birth weight for both twin A and twin B (2,507 ± 540 g vs 2,254 ± 525 g, p = 0.03, and 25,49 ± 420 g vs 2,232 ± 606 g, p = 0.004 respectively), and a higher rate of episiotomy (40.0 % vs 14.2 %, p = 0.001), instrumental delivery for twin A (80.0 % vs 13.5 %, p < 0.001) or twin B (80.0 % vs 18.7 %, p < 0.001), and inter-twin delivery interval of over 30 min (20.0 % vs 7.5 %, p = 0.04). The only factor that remained significant on multivariate analysis was instrumental delivery: forceps delivery of twin A (OR = 8.8, 95 % CI 2.6-30.1), vacuum extraction of twin A (OR = 9.2, 95 % CI 2.6-34.6), and forceps delivery of twin B (OR = 15.4, 95 % CI 4.9-48.6). In women with certain combinations of risk factors the risk of OASIS was as high as 30 %. CONCLUSION: The overall rate of OASIS in twins is low and instrumental delivery, especially by forceps, is a risk factor.

Fertility treatment as a risk factor for maternal request of cesarean delivery in twin pregnancies.

OBJECTIVE: A marked increase in the overall cesarean delivery (CD) rate of twin pregnancies has recently been observed. We sought to examine the obstetrical characteristics of patients who chose a non-indicated CD and to investigate the trends in the rate of CD for maternal request over a 5 years period. STUDY DESIGN: A cross sectional retrospective study of twin pregnancies, compared obstetrical characteristics between patients who chose a non-indicated CD and those who delivered vaginally. Deliveries occurred during 2006 and 2011 in a regional tertiary medical center. Patients with any indication for a CD were excluded. A multivariate logistic regression was used to control for confounders. RESULTS: 525 twins were included at the study, 61.7 % (n = 324) were delivered by CD. Of these, 28.7 % (n = 93) were non-indicated. Between the years 2006 and 2011, there was a significant decrease in the rate of non-indicated CD (34.9 vs 23.8 %, OR = 0.58, 95 % CI 0.35-0.94, P = 0.02). Deliveries after fertility treatments or a previous CD had a higher rate of non-indicated CD (51.6 vs. 27.4 %, P < 0.001 and 26.9 vs. 3.5 %, P < 0.001; respectively). In the multivariate analysis, maternal age (OR = 1.08, 95 % CI 1.01-1.15), previous CD (OR = 15.75, 95 % CI 5.82-42.67) and fertility treatments (OR = 2.16, 95 % CI 1.14-4.10) were found to be independent risk factors for a non-indicated CD. Furthermore, parity was found to be an independent protective factor (OR = 0.75, 95 % CI 0.61-0.92). CONCLUSION: In our study population, there was a significant decrease in the rate of non-indicated CD over a five-year period. Maternal age, fertility treatments and previous CD were found to be independent risk factors for non-indicated CD in twin pregnancies.

[TRIAL OF LABOR AFTER CESAREAN IN TWIN GESTATIONS: DOES IT INCREASE MATERNAL OR NEONATAL COMPLICATIONS?]

OBJECTIVES: To investigate the rate, success and pregnancy outcome following a trial of labor after cesarean (TOLAC) in twin gestations. Study design: A retrospective study including all twin pregnancies with a single prior cesarean delivery between the years 2006 to 2011 was performed. Women with medical indications for cesarean delivery (CD) were excluded. Maternal and neonatal outcomes were compared between women who delivered by CD to those who underwent TOLAC. Stratified analysis using a multiple logistic regression model was performed to control for confounders. RESULTS: During the years 2006-2011, 110 women met the inclusion criteria. Of these, 20% (n=22) underwent a TOLAC. The success rate of vaginal birth after cesarean was 77.2% (n=17). No cases of uterine rupture or dehiscence were noted. No significant difference was documented in neonatal outcome (including pH and Apgar scores) between the TOLAC and the CD group. Fertility treatment was noted as a risk factor for repeated CD (35.2 vs. 4.5%, OR=8.6, 95% CI 1.21-61.3, P=0.005). Using a multivariable analysis, with repeated CD as the outcome variable, controlling for confounders such as maternal age, and gestational age, fertility treatment was an independent risk factor for repeated CD (adjusted OR=5.2, 95% CI 0.01-0.70; P=0.02). CONCLUSIONS: A TOLAC in twin gestation seems to be a safe option for the mother and newborn. Fertility treatment is an independent risk factor for repeated CD in twins.

Gestational diabetes mellitus in twin pregnancies is not associated with adverse perinatal outcomes.

OBJECTIVE: To investigate the influence of gestational diabetes mellitus (GDM) on maternal and neonatal outcomes in twin pregnancies. METHODS: A retrospective population-based study was conducted, comparing maternal and neonatal outcome in women carrying twins with and without GDM. Deliveries occurred in a tertiary medical center between the years 1988 and 2010. Multivariable analysis was used to control for confounders. RESULTS: The study population included 4,428 twin pregnancies, of these 341 (7.7 %) were complicated with GDM. Twin pregnancies complicated with GDM had higher rates of fertility treatment, chronic hypertension, preeclampsia and cesarean deliveries (CD). Nevertheless, using a multivariable analysis, with CD as the outcome variable, controlling for confounders such as maternal age, fertility treatments and hypertensive disorders, GDM in twins was not found to be an independent risk factor for CD (adjusted OR = 1.8, 95 % CI 0.9-1.4; P = 0.18). Rates of low 5 min Apgar scores (<7) and perinatal mortality were lower among twins with GDM (2.9 % vs. 5.3 %, OR = 0.5, 95 % CI 0.3-0.8 0; P = 0.005 and 2.3 % vs. 4.4 %, OR = 0.5, 95 % CI 0.3-0.8; P = 0.005, respectively). CONCLUSION: In our population, GDM in twin pregnancies was not associated with increased rates of adverse perinatal outcomes. In addition, GDM was not found to be an independent risk factor for CD in twin pregnancies.

Risk factors for neonatal brachial plexus paralysis.

PURPOSE: The study was aimed to identify risk factors for neonatal brachial plexus paralysis. METHODS: A retrospective case-control study was designed. A comparison was performed between cases of brachial plexus paralysis, with all consecutive deliveries during the same 5 months period, without brachial plexus paralysis. Statistical analysis was performed using the SPSS package. RESULTS: The prevalence of brachial plexus paralysis was 1.62/1,000 (9/5,525) vaginal births. Independent risk factors for brachial plexus paralysis were shoulder dystocia (OR = 525; 95% CI 51-4,977, P < 0.001), vacuum delivery (OR = 16.4; 95% CI 3.7-70.5, P < 0.001), macrosomia (birth weight >4,000 g; OR = 16.3; 95% CI 3.7-70.2, P < 0.001), prolonged second stage (OR = 40.8; 95% CI 7.9-188.2, P < 0.001) and vaginal breech delivery (OR = 36.1; 95% CI 4.5-262.5, P = 0.032). CONCLUSIONS: In our population, shoulder dystocia, macrosomia, labor dystocia, vacuum delivery and vaginal breech deliveries were significant risk factors for neonatal brachial plexus paralysis, while maternal characteristics such as obesity and diabetes were not. Despite our growing knowledge concerning the risk factors associated with brachial plexus paralysis, unfortunately, this condition cannot be predicted or prevented.

Differences in fetal growth patterns between twins and singletons.

Objective: Twin fetus growth is delayed during the third trimester compared to singletons. Whether this phenomenon should be considered a normal physiologic characteristic of twins or a pathologic process inherent to twin pregnancies is currently unclear. Information on the growth rate of the individual fetal biometric indices may provide more insight into the mechanisms underlying these differences between twins and singletons. Our aim was to compare fetal growth pattern between twin and singleton fetuses.Methods: This was a retrospective study of women with an uncomplicated twin pregnancy who underwent sonographic fetal weight estimation between 16 and 38 weeks' gestation in a single referral center. Twins-specific regression models were generated for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) and fetal weight as a function of gestational age and were compared to published singletons-based curves.Results: Overall 543 women were eligible for the study and underwent a total of 3401 sonographic weight estimations. Estimated weight of twin fetus emerged as lower than that of singletons starting at 26 weeks of gestation, and these differences increased with gestational age, reaching a mean difference of 300-350 g or of ∼10% at term. The growth of all four biometric indices was slower in twins compared to singletons, but the differences were most pronounced for AC which had the largest relative contribution to the lower fetal weight in twins (51.7 ± 7.3%), while the relative contribution of FL, HC, and BPD was smaller (26.4 ± 10.7, 15.5 ± 3.0, and 6.4%±5.7%, respectively). This was also reflected by a higher HC/AC ratio in twins compared with singletons starting at 22 weeks of gestation. The likelihood of a twin fetus being diagnosed as small for gestational age (fetal weight <10th percentile) was significantly lower when the newly developed twins-based curves (rather than singletons-based curves) were used (OR: 0.39, 95%-CI: 0.34-0.44).Conclusion: Twin fetus experience slowing of growth beginning at ∼26 weeks of gestation and a greater degree of asymmetric growth pattern compared with singletons. These findings suggest that the slower growth of twins may reflect a state of "relative growth restriction" compared with singleton gestations.

Twin pregnancy: is it a risk factor for long-term cardiovascular disease?

OBJECTIVE: To investigate whether twin pregnancy increases the risk for long-term maternal cardiovascular disease (CVD). STUDY DESIGN: A retrospective population-based cohort study compared the incidence of long-term CVD in a cohort of women with and without a previous twin delivery. SETTING: Deliveries occurred between the years 1988 and 2012. PATIENTS: Patients who had a twin birth between years 1988 and 2012 were included in the study, patient that had a singleton delivery included in the control group. MAIN OUTCOME MEASURES: CVD was divided into four categories according to severity and type. Kaplan-Meier survival curve was used to estimate cumulative incidence of cardiovascular hospitalizations. Cox proportional hazards model was used to estimate the adjusted hazard ratios (HR) for CVD. RESULTS: During the study period, there were 100 387 women that met the inclusion criteria, 4.6% (n = 4647) delivered twins at least once during the period. The incidence of CVD was 1% in women who had a twin delivery and 1.12% in women who had a singleton delivery. There was no difference in the cumulative incidence of cardiovascular hospitalizations among women who had twin deliveries as compared with singletons. When performing a Cox proportional hazard model, a history of twin delivery did not increase the risk for long-term maternal cardiovascular hospitalizations (adjusted HR = 1.0, 95% CI = 0.8-1.1, p = 0.698). CONCLUSIONS: Twin pregnancy is not associated with an increased risk for long-term maternal CVD.

Is the risk of obstetric anal sphincter injuries increased in vaginal twin deliveries?

OBJECTIVE: Vaginal twin deliveries have a higher rate of intrapartum interventions. We aimed to determine whether these characteristics are associated with an increased rate of obstetric anal sphincter injuries compared with singleton. STUDY DESIGN: Retrospective study of all twin pregnancies undergoing vaginal delivery trial was conducted from January 2000-September 2014. Sphincter injury rate compared with all concurrent singleton vaginal deliveries. Multivariable analysis was used to determine twin delivery association with sphincter injuries while adjusting for confounders. RESULTS: About 717 eligible twin deliveries. Outcome was compared with 33 886 singleton deliveries. Twin pregnancies characterized by a higher rate of nulliparity (54.8% versus 49.5%, p = 0.005), labor induction (42.7% versus 29.1%, p < 0.001), and instrumental deliveries (27.5% versus 16.7%, p < 0.001), lower gestational (34.6 ± 3.3 versus 38.8 ± 2.3, p < 0.001), and lower birth weight. Total breech extraction was performed in 29.0% (208/717) of twin deliveries. Overall obstetric sphincter injury rate was significantly lower in the twins group (2.8% versus 4.4%, p = 0.03, OR = 0.6, 95% CI 0.4-0.9), due to lower rate of 3rd degree tears in twins versus singletons (2.2% versus 4.0%, p = 0.02), rate of 4th degree tears similar among the groups (0.6% versus 0.4%, p = 0.5). In multivariable analysis, sphincter injuries were associated with nulliparity (OR = 3.9, 95% CI 3.4-4.5), forceps (OR = 6.8, 95% CI 5.8-7.8), vacuum (OR = 2.9, 95% CI 2.5-3.3), earlier gestational age (OR = 0.2, 95% CI 0.1-0.3), episiotomy (OR = 0.8, 95% CI 0.7-0.9), and birth weight over 3500 g (OR = 1.8, 95% CI 1.6-2.0). However, the association between twins (versus singletons) deliveries and sphincter injuries was lost after adjustment for delivery gestational age (OR = 0.7, 95% CI 0.4-1.2). CONCLUSION: Despite a higher rate of intrapartum interventions, the rate of sphincter injuries is lower in twins versus singleton deliveries, mainly due to a lower gestational age at delivery.

The effect of maternal anemia on maternal and neonatal outcomes in twin pregnancies.

OBJECTIVE: The objective of this study is to investigate the effect of second trimester anemia on maternal and perinatal outcomes in twin pregnancies. METHODS: A retrospective population-based study was conducted, comparing maternal and neonatal outcomes in women carrying twins, with second trimester anemia (defined as hemoglobin < 10 g/dl) to those without anemia (defined as hemoglobin > or equal to 10 g/dl). Deliveries occurred in a tertiary medical center in 2013. RESULTS: During the study period, there were 307 twin deliveries. Hemoglobin levels were available for 247 (80.4%) twins; 66 (26.7%) of these had anemia (<10 g/dl) during the second trimester. Women with second trimester anemia had a higher parity (p=0.03), and needed more blood transfusions than those with hemoglobin level > or equal to 10 g/dl (OR = 1.6; 95% CI 1.11-2.43, p < 0.001). No significant differences were noted between the groups regarding other obstetrical outcomes or regarding perinatal outcomes. CONCLUSION: Second trimester anemia in women carrying twins is associated with a high parity and increases the risk for blood transfusions. However, in our population, maternal anemia in twin gestations does not increase the risk for adverse perinatal outcome.

The Likelihood of Change in Fetal Presentation During the Third Trimester in Twin Pregnancies.

OBJECTIVE: To estimate the likelihood and identify predictors of spontaneous fetal version during the third trimester in twins using data from a multicenter randomized controlled trial on mode of delivery in twin pregnancies. METHODS: Women with twin pregnancies after 32 weeks of gestation in which twin A was vertex were randomized to planned cesarean or planned vaginal delivery. In the current study we analyzed the likelihood of a spontaneous version of any of the twins between ultrasound assessment at the time of randomization and delivery. RESULTS: A total of 2,603 women were analyzed. Twin A tended to persist in the vertex presentation after 32 weeks of gestation with a spontaneous version rate to nonvertex presentation of 3.0% (95% confidence interval [CI] 2.3-3.7%). Twin B was less stable and underwent spontaneous version in 24.8% (95% CI 23.1-26.5%) of cases; the rate remained higher than 20% even after 34 weeks of gestation. On multivariable analysis, twin A was more likely to undergo version when twin B was smaller (adjusted odds ratio [OR] 2.0, 95% CI 1.04-3.3), when twin B was breech (adjusted OR 3.7, 95% CI 2.2-6.4) or transverse (adjusted OR 2.9, 95% CI 1.6-5.5), and when the interval to delivery exceeded 4 weeks (adjusted OR 2.5, 95% CI 1.3-5.0). Twin B was more likely to undergo version when it was in the breech presentation (adjusted OR 1.7, 95% CI 1.4-2.1) or transverse lie (adjusted OR 3.1, 95% CI 2.5-3.9) compared with vertex presentation, when it was smaller (adjusted OR 1.7, 95% CI 1.1-2.0), when the interval to delivery exceeded 4 weeks (adjusted OR 1.7, 95% CI 1.3-2.4), and in multiparous women (adjusted OR 1.3, 95% CI 1.04-1.5). CONCLUSION: The likelihood of spontaneous version of twin A after 32 weeks of gestation is low when twin A is in the vertex presentation but is much higher for twin B, even late during the third trimester. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00187369. LEVEL OF EVIDENCE: II.

Is induction of labor risky for twins compare to singleton pregnancies?

OBJECTIVE: The aim of this study was to investigate whether induction of labor in twin pregnancies is associated with higher rates of maternal complications as compared to singletons. METHOD: A retrospective population-based study was conducted to compare maternal complications following induction of labor in twin pregnancies and singletons at Soroka University Medical Center, Be'er-Sheva, Israel, between 1988 and 2010. Stratified analysis using a multiple logistic regression model was performed to control for confounders. RESULTS: The study population included 25 913 patients following induction of labor, of these 191 (0.73%) were in twin pregnancies. Induction of labor in twin pregnancies was not associated with adverse maternal outcomes such as cervical tears, third degree perineal tears, uterine rupture, peripartum hysterectomy, post-partum hemorrhage or retained placenta. However, labor induction in twins was significantly associated with cesarean deliveries (31.2% versus 17.1%; p < 0.001). Using a multivariable analysis controlling for confounders, induction at twins was an independent risk factor for cesarean delivery (CD; adjusted OR = 2.2, 95% CI 1.7-2.7, p < 0.001). CONCLUSION: Induction of labor in twin pregnancies does not increase the risk for maternal complications. However, it is an independent risk factor for CD.