Outcomes In Dichorionic Twin Pregnancies Research Articles

Outcomes of dichorionic twin pregnancies with fused versus separate placentas.

In a certain proportion of dichorionic twin pregnancies, the two placentas are fused. The clinical significance of this finding remains unclear. Our objective was to compare outcomes of dichorionic twin pregnancies with fused versus separate placentas as determined on first-trimester ultrasound. Retrospective study of patients with dichorionic twins followed at a tertiary center between 2014 and 2022. The co-primary outcomes were fetal growth restriction and preeclampsia. Associations between fused placentas and the study outcomes were estimated using multivariable Poisson regression and were reported as adjusted relative risk (aRR) with a 95%-confidence interval (CI). Of the 328 eligible patients, 175 (53.4%) and 153 (46.6%) had fused and separate placentas, respectively. Compared with pregnancies with separate placentas, patients with fused placentas had a lower risk of preeclampsia [aRR 0.48 (95%-CI 0.24-0.97)] but a higher risk of fetal growth restriction [aRR 1.23 (95%-CI 1.02-1.48)] and admission to the neonatal intensive care unit [aRR 1.31 (95%-CI 1.01-1.71)]. In addition, pregnancies with fused placentas were more likely to have a total placental weight below the 10th percentile than those with separate placentas [aRR 1.93 (95%-CI 1.16-3.21)]. Dichorionic twin pregnancies with fused placentas have a lower risk of preeclampsia but are more likely to be complicated by fetal growth restriction, observations that may be attributed to the lower total placentas mass in pregnancies with fused compared with separate placentas. Fused placentas can be used as a potential biomarker for the prediction of pregnancy complications in dichorionic twin pregnancies.

Maternal and neonatal outcomes of dichorionic twin pregnancies achieved with assisted reproductive technology: meta-analysis of contemporary data.

Assisted reproductive technology (ART) is commonly used to achieve pregnancy and often results in dichorionic diamniotic (DCDA) twin pregnancies. However, the potential risks of ART on maternal and neonatal outcomes in these pregnancies are not well understood. The objective is to compare the maternal and neonatal outcomes in DCDA twin pregnancies between those achieved through ART and those spontaneously conceived (SC). We carried out a systematic comprehensive search of electronic databases; namely, PubMed, Embase, Scopus, and the Cochrane Library, from inception to March 2023 with a study period of recruitment between 2003 and 2023. We included all studies comparing the maternal and neonatal outcomes of DCDA twin pregnancies between those achieved by ART and those SC. We analyzed data from 18 cohort studies involving 10,485 women with DCDA twin pregnancies. The meta-analysis showed that ART-conceived pregnancies had a significantly higher risk of preeclampsia or gestational hypertension (GH), gestational diabetes mellitus (GDM), placenta previa (PP), placental abruption (PA), postpartum hemorrhage (PPH), and elective and emergency cesarean sections than SC twin pregnancies. The absolute risks of these complications remained relatively low. We also found a slightly higher risk of respiratory distress syndrome (RDS) and congenital malformations in ART-conceived infants compared to the risks in SC infants. Finally, the risk of neonatal intensive care unit (NICU) admissions was significantly higher in ART-conceived infants than in SC infants, but with high heterogeneity. We found associations between DCDA twin pregnancies conceived through ART and increased frequencies of adverse maternal outcomes. However, the absolute risks of these complications remained low, and the benefits of ART for achieving successful pregnancies may well outweigh the potential risks. Additionally, ART-conceived DCDA twin pregnancies may pose higher risks of RDS, congenital malformations and NICU, admissions than SC DCDA twin pregnancies.

Risk factors associated with stillbirth and adverse perinatal outcomes in dichorionic twin pregnancies complicated by selective fetal growth restriction: a cohort study.

The main aim of this study was to investigate the perinatal outcomes of dichorionic twin pregnancies complicated by selective fetal growth restriction (sFGR). Retrospective cohort study. Tertiary reference centre. Dichorionic twin pregnancies complicated by sFGR between 2000 and 2019 in St George's University Hospital. Regression analyses were performed using generalised linear models and mixed-effects generalised linear models where appropriate to account for pregnancy level dependency in variables. Time to event analyses were performed with mixed-effects Cox regression models. Stillbirth, neonatal death or neonatal unit admission with morbidity in one or both twins. A total of 102 (of 2431 dichorionic twin pregnancies) pregnancies complicated by sFGR were included in the study. The Cochrane-Armitage test revealed a significant trend for increased adverse perinatal outcome rates with more severe forms of umbilical artery flow impedance, i.e. reversed, absent, positive with resistant flow and positive flow without resistance. A multivariable model including maternal and conception characteristics had poor predictive accuracy for stillbirth (area under the curve: 0.68, 95% confidence interval [CI] 0.55-0.81) and composite adverse perinatal outcomes (area under the curve: 0.58, 95% CI 0.47-0.70). When umbilical artery Doppler parameters were added to the models, the area under the curve values improved to 0.95 (95% CI 0.89-0.99) and 0.83 (95% CI 0.73-0.92) for stillbirth and composite adverse perinatal outcomes, respectively. In dichorionic twin pregnancies complicated by sFGR, the umbilical artery Z-scores were associated with both intrauterine death and adverse perinatal outcomes.

Pregnancy and perinatal outcomes of early vs late selective termination in dichorionic twin pregnancy: systematic review and meta-analysis.

To evaluate outcomes of dichorionic twin pregnancies undergoing early vs late selective termination of pregnancy (ST). MEDLINE, EMBASE, CINAHL and the Web of Science databases were searched electronically up to March 2022. The primary outcome of this study was pregnancy loss prior to 24 weeks' gestation. The secondary outcomes included preterm birth (PTB) before 37, 34, and 32 weeks, preterm prelabor rupture of membranes (PPROM), gestational age (GA) at delivery, Cesarean delivery, mean birth weight, 5-min Apgar score < 7, overall neonatal morbidity and neonatal survival. Only prospective or retrospective studies reporting data on the outcome of early (before 18 weeks) vs late (at or after 18 weeks) ST in dichorionic twin pregnancies were considered suitable for inclusion. Quality assessment of the included studies was performed using the Newcastle-Ottawa scale for cohort studies. Random-effects head-to-head meta-analysis was used to analyze the data. Seven studies reporting on 649 dichorionic twin pregnancies were included in this systematic review. The risk of pregnancy loss prior to 24 weeks was significantly lower in dichorionic twin pregnancies undergoing early compared with late ST (1% vs 8%; odds ratio (OR), 0.25 (95% CI, 0.10-0.65); P = 0.004). The risk of PTB was significantly lower in dichorionic twin pregnancies undergoing early compared with late ST when considering PTB before 37 weeks (19% vs 45%; OR, 0.36 (95% CI, 0.23-0.57); P < 0.00001), before 34 weeks (4% vs 19%; OR, 0.24 (95% CI, 0.11-0.54); P = 0.0005) and before 32 weeks (4% vs 20%; OR, 0.21 (95% CI, 0.05-0.85); P = 0.03). The mean birth weight was significantly greater in the early-ST group (mean difference (MD), 392.2 g (95% CI, 59.1-726.7 g); P = 0.02), as was the mean GA at delivery (MD, 2.47 weeks (95% CI, 0.04-4.91 weeks); P = 0.049). There was no significant difference between dichorionic twin pregnancies undergoing early compared with late ST in terms of PPROM (P = 0.27), Cesarean delivery (P = 0.38), 5-min Apgar score < 7 (P = 0.35) and neonatal survival of the non-reduced twin (P = 0.54). The risk of pregnancy loss prior to 24 weeks and the rate of PTB before 37, 34 and 32 weeks were significantly higher in dichorionic twin pregnancies undergoing late vs early ST, thus highlighting the importance of early diagnosis of fetal anomalies in twin pregnancies. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of Gestational Diabetes and Hypertension Disorders of Pregnancy on Neonatal Outcomes in Twin Pregnancies Based on Chorionicity.

The objective of this study was to investigate the impact of the co-existence of gestational diabetes (GDM) and hypertension disorders of pregnancy (HDP) on neonatal outcomes in twin pregnancies based on chorionicity. A retrospective study of 1398 women with twin pregnancies was performed between January 2016 and December 2021. The effects of GDM and HDP on neonatal outcomes were assessed by logistic regression models. An additional stratified analysis was conducted to estimate the effects based on chorionicity (monochorionic (MC) and dichorionic (DC)). The incidence of the co-existence of GDM and HDP was 3.8%. The presence of GDM increased the likelihood of HDP only in women with MC twin pregnancies (OR, 2.13; 95% CI 1.08-4.19). After adjustments, co-existence of GDM and HDP was positively associated with gestational age (β, 1.06; 95% CI 0.43-1.69) and birthweight (β, 174.90; 95% CI 8.91-340.89) in MC twin pregnancies, while no associations were found between co-existence of GDM and HDP and neonatal outcomes in DC twin pregnancies. However, HDP was negatively associated with birthweight (β, -156.97; 95% CI (-257.92, -56.02)) and positively associated with small-for-gestational-age (SGA) (OR, 2.03; 95% CI 1.02-4.03) and discordant twins (OR, 2.83; 95% CI 1.78-4.48) in DC twin pregnant women without GDM. Our results suggested that GDM leads to an increased risk of HDP only in MC twin pregnancies, but GDM seemed to attenuate the adverse effects of HDP on perinatal outcomes in both MC and DC twin pregnancies. Further investigation is needed to explain these intriguing findings.

Maternal and perinatal outcomes in twin pregnancies conceived spontaneously and by assisted reproductive techniques: cross-sectional study.

Data vary on maternal and perinatal outcomes of twin pregnancies conceived through assisted reproductive technology compared with spontaneous conception. This study compared maternal, perinatal and obstetric outcomes of dichorionic twin pregnancies conceived spontaneously with twin pregnancies conceived through assisted reproductive technology. This was a cross-sectional study of dichorionic twins delivered at the Maternity Teaching Hospital, Erbil, Kurdistan Region, Iraq from 1 November 2016 to 31 December 2017. Twin pregnancies were classified into two groups: spontaneously conceived (n = 121) and conceived through assisted reproductive technology (n = 79). Maternal and perinatal outcomes were compared between the two groups. The chi-squared test was used to compare categorical variables and the Student t-test to compare means. Logistic regression analysis was used to assess factors associated with admission to the neonatal intensive care unit. Pregnancy-induced hypertension, gestational diabetes and preterm rupture of membranes were more common in mothers in the assisted reproductive technology group (P < 0.05). Preterm birth, low neonatal birth weight and congenital malformation were also more common in the assisted reproductive technology group (P < 0.001). Gestational age < 33 weeks and conception through assisted reproductive technology were significantly associated with admission to the neonatal intensive care unit for both twins. Studies are needed to assess the reasons for the differences in perinatal and maternal outcomes between twin pregnancies conceived spontaneously and through assisted reproductive technology.

Pregnancy and perinatal outcomes of first-trimester crown-rump length discordant IVF dichorionic twin pregnancies - a retrospective cohort study.

This study aimed to evaluate the association between discordance in crown-rump length (CRL) and adverse pregnancy and perinatal outcomes in dichorionic twin pregnancies. This was a retrospective cohort study of dichorionic twin pregnancies after IVF that showed two live fetuses at the first ultrasound scan between 6 +5 and 8 weeks gestational age from 1 January 2015 to 31 December 2016. Study groups were defined by the presence or absence of 20% or more discordance in CRL. The primary outcomes were early fetal loss of one or both fetuses before 12 weeks and birthweight discordance. Secondary outcomes included fetal anomalies, fetal loss between 12 and 28 weeks, stillbirth, small for gestational age (SGA) at birth, low birthweight (LBW), very low birthweight (VLBW), admission to the neonatal intensive care unit (NICU) and preterm delivery (PTD). CRL-discordant twin pregnancies were more likely to end in the loss of one fetus before 12 weeks' gestation (odds ratio [OR] 15.877, 95% confidence interval [CI] 10.495-24.019). Discordant twin pregnancies with twin deliveries had a significantly higher risk of birthweight discordance (OR 1.943, 95% CI 1.032-3.989). There was no significant difference in perinatal outcomes including fetal anomalies, PTD, LBW, VLBW, SGA, neonatal death and admission to NICU between singleton or twin deliveries. Discordant twin pregnancies were at increased risk of one fetal loss prior to 12 weeks' gestation. Except for birthweight discordance, there was no significant difference between CRL discordance and other adverse perinatal outcomes.

Correlation between second trimester weight gain and perinatal outcomes in dichorionic twin pregnancies: The LoTiS cohort study

PurposeTo investigate how second trimester gestational weight gain relates to perinatal outcomes in twin pregnancies of the LoTiS cohort in Chongqing, China. MethodsA cohort study was conducted among women with dichorionic twin pregnancies; pregnancies that culminated in delivery at ≥20 gestational weeks were included in the analysis (n = 177). Data were collected through the Longitudinal Twin Study (LoTiS). The second trimester was divided into two periods: 12–20 and 21–28 gestational weeks. Correlations between maternal weight gain and perinatal outcomes were estimated using linear or logistic regression models; the crude OR and adjusted OR were calculated. ResultsThe average total gestational weight gain for the whole pregnancy was 17.71 ± 4.98 kg and average gestational weight gains during 12–20 gestational weeks and 20–28 gestational weeks were 5.11 ± 1.81 kg and 5.84 ± 2.05 kg, respectively. Insufficient gestational weight gain was associated with higher risk of preterm birth (OR = 0.92, 95% CI 0.86-0.99) and spontaneous preterm birth (OR = 0.89, 95% CI 0.82–0.97). Reduced gestational weight gain during 12–20 gestational weeks was associated with higher risk of small for gestational age. Additionally, the mean birth weight of a twin pair increased by 45.78 g or 13.03 g when gestational weight gain during 12–20 weeks or total gestational weight gain increased by 1 kg. ConclusionMaternal weight gain in the early second trimester was correlated with birth weight in dichorionic twins.

Association Between Gestational Weight Gain and Pregnancy Complications or Adverse Delivery Outcomes in Chinese Han Dichorionic Twin Pregnancies: Validation of the Institute of Medicine (IOM) 2009 Guidelines.

BackgroundExcessive or insufficient gestational weight gain (GWG) is associated with increased risks of pregnancy complications and adverse delivery outcomes in dichorionic twin pregnancies. The provisional Institute of Medicine (IOM) 2009 guidelines suggested the optimal GWG based on limited epidemiological data collected from Western populations. However, such a recommendation has not yet been validated in a Chinese Han population, the world’s largest ethnic group. The objective of this study was to assess the effect of IOM guidelines by determining the neonatal and maternal outcomes associated with gaining weight below, within, and above the IOM provisional guidelines on GWG in Chinese Han twin pregnancies.Material/MethodsA historical cohort study of 350 twin-conceiving Han women in Chongqing Women and Children’s Health Center delivering liveborn twin infants between January 2015 and November 2016 was conducted. The participants were divided into 3 groups according to the 2009 Institute of Medicine recommendations of GWG: a low GWG group, an adequate GWG group, and a high GWG group. The incidence of pregnancy complications and the delivery outcomes were compared between the groups, and the correlation of GWG and pregnancy complications or delivery outcome was investigated by logistic regression analysis.ResultsIn Han Chinese people, the gestational age (GA) at delivery was significantly different among various GWG groups, and low maternal GWG is associated with shorter GA. Although low GWG increased the incidence of VPTD, it did not impact PTD in twin pregnancies. Moreover, GWG was negatively correlated with the incidence of PPROM and was positively correlated with GHP development in twin pregnancies.ConclusionsThe recommendations of the 2009 IOM guidelines about GWG is beneficial in reducing the incidence of VPTD and PPROM in Han Chinese dichorionic twin pregnancies, but failed to eliminate the development of PTD, PROM, GDM, PE, ICP, and SGA.

Pregnancy and perinatal outcomes of first-trimester crown-rump length discordance in dichorionic twin pregnancies after in vitro fertilization

To evaluate the association between first- trimester crown-rump length discordance and adverse pregnancy and perinatal outcomes in dichorionic twin pregnancies. This was a retrospective cohort study of women with dichorionic twin pregnancies after in vitro fertilization (IVF) at our fertility center with two live fetus scanned between 6+5 and 8 weeks’ gestation during the period 1st January 2015 and 1st January 2017. Study groups were defined by the presence or absence of ≥20% crown-rump length (CRL) discordance at the first-trimester ultrasound scans. Pregnancy outcomes including spontaneous abortion, stillbirth and live birth were compared between discordant and concordant twin pregnancies. Perinatal outcomes (preterm delivery, [PTD], low birth weight [LBW], very low birth weight [VLBW], birthweight discordant, neonatal death and admission in neonate intensive care unit [NICU]) were also assessed. Singleton live deliveries and twin deliveries were analyzed separately. Moreover, fetal anomalies were also evaluated. During the study period we identified 1687 dichorionic twin pregnancies on first-trimester ultrasound, of which1504 met the inclusion criteria. Of the 1504 dichorionic twin pregnancies included, 129 (8.58%) patients were identified as having CRL discordance of at least 20%. CRL discordant twin were more likely to end in one fetal loss before 12 weeks’ gestation (Relative risk= 15.073,95% confidence interval, 10.128-22.431) than were concordant dichrionic twin pregnancies. Discordant twin pregnancies with twin deliveries were at significant higher risk of birthweight discordance (Relative risk=2.192,95% confidence interval, 1.054-4.558). There was no significant difference in perinatal outcomes including PTD, LBW, VLBW, neonatal death and admission to NICU in singleton or twin deliveries. No fetal anomalies were observed in discordant twin pregnancies. Dichorionic twin pregnancies were at increased risk for one fetal loss prior to 12 weeks’ gestation and birthweight discordance, but were not associated with adverse perinatal outcomes and fetal anomalies.

Pravastatin and-L-arginine combination improves umbilical artery blood flow and neonatal outcomes in dichorionic twin pregnancies through an nitric oxide-dependent vasorelaxant effect

The increase in fetal and neonatal morbidity and mortality associated with twin pregnancies correlates with an increased risk of preterm delivery, low birth weight, and intrauterine growth restriction (IUGR). Although the pathogenesis of IUGR is unclear and thus management remains a major challenge, feto-placental blood vessels are compromised, and altered umbilical blood flow is observed. In this pilot observational study we investigated the effects of pravastatin plus l-arginine on umbilical artery (umb art) blood flow. Between 2013 and 2016, five women received daily doses l-arginine and pravastatin when an umb art pulsatility index above limits for gestational age was observed and concerns about selective growth restrictions arose. All patients showed selective absent or reversed end-diastolic umbilical artery Doppler flow (AREDV) associated with increased perinatal mortality. Pravastatin (PRAV) plus l-arginine (l-Arg) treatment diminished umb art resistance significantly and allowed pregnancy to continue. No signs of acidosis or hypoxia, normal cardiotocography tracing, normal fetal movement and fetal weight gain were observed in the twins that showed abnormal umb art Dopplers. All neonates were born around 33 weeks (median 33 weeks, IQR [31.4–33.0]), thus diminishing substantially the chances for any prematurity-associated adverse neonatal outcomes. The infants now show normal growth and development. In in vitro studies, pravastatin induced relaxation of aortic rings. Murine studies identified were performed to investigate the mechanism behind PRAV+L-Arg beneficial effects. A nitric oxide (NO)-dependent synergistic vasorelaxant effect of PRAV+L-Arg was demonstrated using aortic rings. Increased levels of placental NO and increased synthesis of eNOS in placental endothelial cells were observed in mice treated with PRAV+L-Arg compared to untreated mice and mice treated with PRAV- or L-Arg alone.This study suggests that PRAV plus L-Arg might be a good therapeutic option to improve blood flow in umbilical arteries prolonging pregnancy and improving pregnancy outcomes in twins. A RCT should be organized to confirm these results.

Doppler velocimetry in dichorionic twin pregnancies and its correlation with various fetal outcome

Aim: This study was to evaluate the applicability of Doppler velocimetry to determine its correlation with fetal outcome in dichorionic twin pregnancies. Material and methods: Doppler examination of the umbilical artery (UA) and middle cerebral artery (MCA) was performed in 57 twin pairs. Abnormal values of the umbilical artery pulsatility index (PI), umbilical artery Resistive index (RI) were above the 95th percentile and below 5th percentile for the Middle cerebral artery pulsatility index (MCA PI) and Middle cerebral artery resistivity index (MCA RI) for gestational week. The difference of UA PI ≥0.5 in twin pairs was considered abnormal. Results: 33 subjects had a fetal discordance of greater than 15%. Birth weight was found to be significantly lower in subjects with Umbilical artery PI greater than 95th percentile for gestational age (p=0.014). Abnormal MCA RI (P=0.018) and Umbilical artery RI values above 95th percentile was significantly associated with increased risk of IUGR (intra uterine growth restriction) (P=0.036) and NICU (Neonatal intensive care unit) admission (P=0.005). Increased Umbilical artery PI values above 95th percentile was significantly associated with IUGR (P=0.003). Increased Umbilical Artery systolic/diastolic ratio above 95th percentile was significantly associated with IUGR (P=0.002), NICU admission (P=0.026) and still birth (P=0.026). Abnormal cerebra-umbilical ratio ( 0.5) was significantly correlated with increased degree of birth weight discordance of the twins, IUGR (P=0.001) and still birth (P=0.001). Conclusion: Abnormal Doppler values in discordant twin fetus are more likely to be associated with abnormal fetal outcome.

Observational study of associations between gestational weight gain and perinatal outcomes in dichorionic twin pregnancies.

To evaluate relationships between gestational weight gain (GWG) and adverse events during pregnancy among patients of normal weight with twin pregnancies. The present observational study included patients with dichorionic twin pregnancies with a pre-gravid body mass index of 18.5-24.99kg/m2 who underwent delivery at no earlier than 22weeks of pregnancy between January 1, 2007, and June 30, 2016, at the Medical University of Warsaw, Warsaw, Poland. The GWG ratio was categorized as low (<0.45kg/wk), adequate (0.45-0.66kg/wk), or high (>0.66kg/wk), and pregnancy outcomes were compared between the GWG ratio groups. Associations between GWG ratio and pregnancy outcomes were estimated using generalized additive models. There were 201 patients included in the study. No differences in rates of preterm delivery, very preterm delivery (VPTD), small for gestational age fetus, pre-eclampsia, gestational diabetes, preterm premature rupture of membranes, or intrauterine fetal demise were observed between the patient groups. Linear relationships with GWG ratio were recorded for VPTD (P=0.019) and spontaneous VPTD (P=0.003); non-linear relationships with GWG ratio were recorded for pre-eclampsia (P=0.023) and perinatal mortality (P=0.015). A GWG ratio of 0.55-0.56kg/wk appeared optimal in terms of twin pregnancy outcomes. The incidence of VPTD, pre-eclampsia, and perinatal mortality during dichorionic twin pregnancy were associated with GWG ratio.

Assisted reproductive technology and risk of adverse obstetric outcomes in dichorionic twin pregnancies: a systematic review and meta-analysis

To examine whether dichorionic twin pregnancies after assisted reproductive technology (ART) were at higher risk of adverse obstetric outcomes compared with those conceived naturally. Meta-analysis. University-affiliated teaching hospital. Dichorionic twin pregnancies conceived with ART and naturally. Studies comparing obstetric outcomes in dichorionic twin pregnancies conceived by ART and naturally were identified by searching PubMed, Google Scholar, Cochrane Libraries, and Chinese databases through July 2015 with no restrictions. Either a fixed-effects or a random-effects model was used to calculate the overall combined risk estimates. Subgroup analysis was performed to explore potential heterogeneity moderators. Maternal complications and adverse pregnancy outcomes. Fifteen cohort studies involving 6,420 dichorionic twins after ART and 13,650 dichorionic twins conceived naturally were included. Most of maternal complications were similar in both groups, but placenta previa (relative risk [RR] = 2.99, 95% confidence interval [CI] 1.51-5.92; I(2) = 0) was significantly more common in the ART group. For neonatal outcomes, the ART group experienced higher risk of preterm birth (RR = 1.13, 95% CI 1.00-1.29; I(2) = 75%), very preterm birth (RR = 1.39, 95% CI 1.07-1.82; I(2) = 71%), low birth weight (RR = 1.11, 95% CI 1.00-1.23; I(2) = 61%), and congenital malformations (RR = 1.26, 95% CI 1.09-1.46; I(2) = 26%). In addition, the ART group had a higher proportion of elective cesarean sections (RR = 1.79, 95% CI 1.49-2.16; I(2) = 60%), but had a similar proportion for emergency cesarean sections. Relevant heterogeneity moderators have been identified by subgroup analysis. No evidence of publication bias was observed. The rates of placenta previa, elective cesarean section, preterm birth, very preterm birth, low birth weight, and congenital malformations were significantly higher in dichorionic twin pregnancies after ART.

The Relationship Between Intertwin Membrane Separation and Pregnancy Outcome.

To evaluate the association of intertwin membrane separation and pregnancy outcome. This is a retrospective cohort study of women with dichorionic twins who were diagnosed with spontaneous intertwin membrane separation between 2004 and 2013 at a large tertiary care maternity hospital. Control participants were selected as the next two sets of dichorionic twins that delivered at the study institution after a case participant delivered and that did not have an intrauterine procedure. Maternal, fetal, and delivery characteristics were compared using Wilcoxon rank-sum tests. Logistic regressions were used to assess the association of membrane separation and preterm delivery. Among the 27 cases of spontaneous intertwin membrane separation, the median gestational age at diagnosis was 28 weeks (interquartile range 25.5-28.8) and the median gestational age at delivery was 37 weeks (interquartile range 35.3-37.0). The rate of preterm delivery, our primary outcome, was 48% for the case group and 76% for the control group (odds ratio [OR] 0.29, P=.01). The rate of spontaneous preterm delivery was also lower for the case group (19% compared with 44%; OR 0.25, P=.26) as was the rate of neonatal intensive care unit admission (37% compared with 61%; OR 0.37, P=.04). Our retrospective cohort study demonstrates that intertwin membrane separation is not associated with adverse outcomes in dichorionic twin pregnancies. Thus, it is reasonable to manage these pregnancies expectantly. II.

2.2 Abnormal cerebroplacental ratio predicts adverse outcomes in dichorionic twins

ObjectiveTo evaluate the significance of an abnormal cerebroplacental ratio (CPR) in twin pregnancies.Study designIn the prospective multicenter ESPRiT study, twin pregnancies underwent serial sonographic evaluation including multi-vessel Doppler studies. CPR...

Degree and rate of growth discordance in dichorionic twins conceived by in vitro fertilization.

Objective. Our objective was to estimate degree and rate of discordant growth and its impact on perinatal outcome in dichorionic twin pregnancies conceived by in vitro fertilization (IVF) compared to those conceived spontaneously. Study Design. Growth discordance was defined as 90th percentiles for the study population. Adverse perinatal outcome was defined as 5-minute Apgar score <7 and/or admission to neonatal intensive care unit. Results. In the total study population of dichorionic twins (176 conceived by IVF and 215 spontaneously), 30% discordant growth represented the 90th percentile. After adjusting for gestational age, discordant twins conceived by IVF or spontaneously were at higher risk for adverse perinatal outcome (hazard ratio 4.4; 95% CI 2.4–8.3, P < 0.0001; hazard ratio 2.5; 95% CI 1.5–4.4, P = 0.001, resp.). Similar rates of 5-minute Apgar score <7, admission to neonatal intensive care unit, and delivery <34 weeks were found between discordant twins conceived by IVF and those conceived spontaneously. Conclusion. Dichorionic twins conceived by IVF are at similar risk for the rate and degree of discordant growth and adverse perinatal outcome compared to dichorionic twins conceived spontaneously.

359: Crown-rump length discordance and adverse pregnancy outcomes in dichorionic twins

Growth discordance in twin pregnancy is considered a risk factor for adverse perinatal outcomes. However, data is conflicting regarding the significance of first trimester growth discordance. Our objective was to determine the association of first trimester growth discordance and adverse pregnancy outcomes in dichorionic twin pregnancies.

Prediction of outcome in dichorionic twin pregnancies at 6-10 weeks' gestation

The objective of the study was to predict the outcome of dichorionic (DC) twin pregnancies at 6-10 weeks' gestation from intertwin discordance in crown-rump length (CRL), heart rate (HR), and gestational sac diameter (GSD). Intertwin discordance in CRL, HR, and GSD, was compared in 3 groups of DC twin pregnancies with 2 live embryos at 6-10 weeks. In one group, there were 2 live births (n = 174), in another 1 live birth (n = 24), and in a third group there were no live births (n = 33). Regression analysis was used to determine the predictors of outcome. Significant contributors to the prediction of 1 intrauterine death were discordance in CRL and GSD. The only predictor of 2 deaths was discordance in CRL. Detection rates of screening for single or double death, at 10% false-positive rate, were 79.2% and 27.3%, respectively. In DC twins, intertwin discordance in CRL and GSD at 6-10 weeks can predict outcome.

Obstetric and Perinatal Outcomes of Dichorionic Twin Pregnancies According to Methods of Conception: Spontaneous Versus In-Vitro Fertilization

We have observed the inconsistent findings from various studies on twin pregnancy outcomes obtained by assisted reproductive technology and spontaneous conception. In most studies, however, the concrete chorionicity, regarded as a confounding factor for predicting the perinatal outcomes of twin pregnancies, has not been determined. The purpose of this study was to compare obstetric and perinatal outcomes of only the dichorionic twin pregnancies according to the methods of conception: spontaneous and in-vitro fertilization (IVF). The twin pairs with dichorionicity reported from 1995 to 2008 were investigated and we divided them into two groups which consisted of 286 and 134 twins by spontaneous conception and IVF, respectively. Odds ratios for associations between IVF and pregnancy outcomes were analyzed after adjustment for maternal age and parity. There were no risk differences between the two groups regarding the obstetric complications, which include preterm delivery, preterm labor, preterm premature rupture of membranes, preeclampsia, placenta previa, and abruption. Any differences were not shown in the two groups for the risk estimates of perinatal outcomes, such as low birthweight, very low birthweight, small for gestational age, Apgar scores of < 7 at 5 minutes, discordance in birthweights, congenital anomalies and mortality. However, twins conceived after IVF were less likely to be admitted to the neonatal intensive care unit than those conceived spontaneously (adjusted OR 0.488; 95% confidence interval 0.261-0.910). In the cases of dichorionic twins, IVF may not be associated with adverse perinatal and obstetric outcomes compared with spontaneous conception.