Influence Of Chorionicity Research Articles

Incidence and Perinatal Outcomes of Twin Pregnancy in Tertiary Healthcare Facility, Odisha, India

Background: Assisted reproductive technology has resulted in a progressive rise in the incidence of twin pregnancies, which affect both mother and child in terms of antepartum complications. Objective: To assess the perinatal outcomes of twin pregnancies and the influence of chorionicity on them in a tertiary healthcare facility. Methods: It is a hospital-based cross-sectional study that was carried out in the Obstetrics and Gynecology Department of S.C.B. Medical College Hospital, Cuttack, during the period from 2013 to 2015. All mothers having twin pregnancies (with 28 weeks of completed gestation) admitted to the antenatal (ANC) ward and labor room during this period were taken as a study group, and written informed consent was taken after explaining the details of the study. Results: A total of 150 cases are identified; among them, 98 cases (65.33%) are dichorionic diamniotic, 50 cases (33.33%) are monochorionic diamniotic, and 2 cases (1.33%) are monochorionic and monoamniotic pregnancies. The majority (66%) of the twin pregnancies were between 35-38 wks of gestational age at the onset of labor. It is also observed that macerated births, stillbirths, and neonatal deaths are higher in mono-chorionic twins as compared to dichorionic twins. Conclusions: Twin pregnancies carry a greater risk of adverse outcomes, especially perinatal mortality and neonatal morbidity, in monochorionic twins than dichorionic twins. Good antenatal care, early diagnosis of chorionicity, and antepartum assessment of placentation will prevent mortality and morbidity.

Influence of chorionicity on healthy twin pregnancy outcome

Background/Aim. It is still under debate in what sense and extent can chorionicity impact the pregnancy outcome of twins without gestational complications specific for monochorionicity. The study aimed to evaluate the effect of chorionicity on healthy twin pregnancy outcome. Methods. The study included patients with uncomplicated twin pregnancies after first trimester that were checked-up and delivered at the Clinic of Obstetrics and Gynecology, Clinical Center of Serbia, Belgrade during three years (2010?2013). Data regarding mother?s age, comorbidities, parity, presence and type of gestational complications, chorionicity, mode and time of pregnancy ending, birth-weight and Apgar score of twins were determined. Obtained data were compared and statistically analyzed. Results. The study included 361 women with mean age of 33 years. Regardless of chorionicity, twins were mostly born during the 36th gestational week and received Apgar score ? 8. Only three monochorionic twins were stillborn, two preterm (29 and 32 gestational week) and one in term (35 gestational week) delivery. Contrary, no intrauterine fetal deaths were recorded. Monochorionicity negatively correlated with having live-born twins (OR = 0.023; CI = [0.001?0.609]; p = 0.024), but was not associated with twins condition at birth, i.e. Apgar score (p = 0.345), pregnancy ending time (p = 0.578) or any other twins characteristic. However, premature preterm membrane rupture and earlier gestational week of pregnancy ending were important confounding factors for relationship between chorionicity and pregnancy outcome. Conclusion. Monochorionicity increases risk for adverse pregnancy outcomes even for uncomplicated, healthy twin pregnancy, but has no influence on the condition of twins who survive until term. If appropriate surveillance and therapy are applied, both healthy twins can be delivered at term regardless of chorionicity.

Influence of chorionicity and gestational age at single fetal loss on risk of preterm birth in twin pregnancy: analysis of STORK multiple pregnancy cohort.

Single intrauterine death (sIUD) in twin pregnancy is associated with a significant risk of cotwin demise and preterm birth (PTB), especially in monochorionic (MC) twins. However, it is yet to be established whether the gestational age at loss may influence the pregnancy outcome. The aim of this study was to explore the risk of PTB according to the gestational age at diagnosis of sIUD. This was a cohort study of all twin pregnancies booked for antenatal care in a large regional network of nine hospitals over a 10-year period. Ultrasound data were matched to hospital delivery records and to a mandatory national register for stillbirth and neonatal loss provided by the Centre for Maternal and Child Enquires. Cases with double fetal loss at the time of the scan and cases of sIUD occurring at or after 34 weeks of gestation were not included in the analysis. The relative risk (RR) of PTB at < 34, < 32 and < 28 weeks of gestation in twin pregnancies complicated by sIUD was assessed and compared with that in twin pregnancies without fetal loss. The risk of PTB at < 34 weeks was stratified according to the gestational age at diagnosis of sIUD. The risk of PTB in twin pregnancy after sIUD according to the gestational age at death was also explored. The analysis included 3013 twin gestations (2469 dichorionic (DC) and 544 MC). Median gestational age at birth was lower in the pregnancies complicated by sIUD compared with those that were not (32.0 weeks: interquartile range (IQR), 29.0-34.3 weeks vs 36.7 weeks: IQR, 35.0-37.6; P < 0.001) and this difference persisted when stratifying the data according to chorionicity (P < 0.0001 for both MC and DC pregnancies). The risk of PTB at < 34 weeks (RR, 4.3 (95% CI, 3.5-5.2)), < 32 weeks (RR, 6.1 (95% CI, 4.6-8.1)) and < 28 weeks (RR, 12.4 (95% CI, 6.9-22.2)) of gestation was higher in pregnancies complicated by sIUD compared with those which did not experience fetal loss. This association was observed both in MC and DC twin gestations. When compared with DC pregnancies, MC twins affected by sIUD were not at significantly increased risk of PTB before either 34, 32 or 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred at a later gestational age (chi-square test for trend, P < 0.001). Twin pregnancies complicated by sIUD, regardless of the chorionicity, have a significantly higher risk of PTB at < 34, < 32 and < 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred in the second half of the pregnancy. Large prospective multicenter studies with shared protocols for prenatal management are needed to ascertain the actual risk of spontaneous PTB in twin pregnancies affected by sIUD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Re: Influence of chorionicity and gestational age at single fetal loss on risk of preterm birth in twin pregnancy: analysis of STORK multiple pregnancy cohort. F. D'Antonio, B. Thilaganathan, T. Dias and A. Khalil, on behalf of the Southwest Thames Obstetric Research Collaborative (STORK). Ultrasound Obstet Gynecol 2017; 50: 723-727.

Linked Comment: Ultrasound Obstet Gynecol 2017; 50: 723–727

The role of ultrasound in the prediction of birth weight discordance in twin pregnancies: are we there yet?

To analyze the accuracy of ultrasound prediction of birth weight discordance (BWD) and the influence of chorionicity and fetal growth restriction (FGR) on ultrasound performance. Retrospective analysis of 176 twin pregnancies at a Portuguese tertiary center, between 2008 and 2014. Last ultrasound biometry was recorded. Cases with delivery before 24 weeks, fetal malformations, interval between last ultrasound and deliver >3 weeks, twin-to-twin transfusion syndrome and monoamniotic pregnancies were excluded. The accuracy of prediction of BWD was assessed using the area under the receiver-operating characteristics curve (AUC). BWD ≥20% was present in 21.6% of twin pregnancies. EBW had the best predictive performance for BWD (AUC 0.838, 95%CI 0.760-0.916), with a negative predictive value of 86.9% and a positive predictive value of 51.3%. Chorionicity did not influence ultrasound performance. None of the biometric variables analyzed was predictive of BWD in pregnancies without FGR. The accuracy of ultrasound in the prediction of BWD is limited, particularly in pregnancies without fetal growth restriction. Clinical decisions should not rely on BWD alone.

OP11.08: The influence of chorionicity on miscarriage and fetal loss in triplet pregnancies

The aim of this study was to compare fetal loss rates between trichorionic (TC) triplet pregnancies and those with mixed chorionicity. This was a retrospective cohort study of all triplet pregnancies managed at a single tertiary center over ten year period. Triplet pregnancies which underwent selective reduction were not included in the analysis. Cumulative fetal loss rates for TC and dichorionic (DC) triplet pregnancies from 11 to 36 weeks gestation were analysed using Kaplan-Meier survival curves to assess the difference in mortality between TC and DC twins. Logistic regression analysis was performed to investigate pregnancy and ultrasound characteristics independently associated with the risk of fetal loss. 94 triplet pregnancies (35 trichorionic and 59 mixed chrionicity) were included in the analysis. The total fetal loss rate in TC and in triplet with mixed chorionicity was 3.81% (4/105 fetuses) and 31.0% (55/177), respectively (OR 3.49, 95% CI 1.2 to 10.4). The trend in total fetal loss rate was significantly higher in triplets with mixed chorionicity in all gestation (log rank test, p < 0.0001). The results of the logistic regression analysis showed that mixed chorionicity was independently associated with the occurrence of feta loss in triplets (OR: 1.87, 95% CI 1.5-2.9). The rate of fetal loss remained significantly higher in triplets with mixed chorionicity even afetr exclusion of cases complicated by twin–twin transfusion syndrome (p00.002). Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Influence of chorionicity in intra-partum management of twin deliveries

Objective: To analyze morbidity and mortality in twin pregnancies as a function of the type of delivery and chorionicity. Design: Retrospective cohort study. Methods: Analysis of the type of delivery, intertwin time interval, and perinatal variables of >1000 twin deliveries during a 10-year period. Main outcome measure: Influence of delivery type and chorionicity on perinatal outcome. Results: The rate of cesarean sections was 42.4%. No differences were found as a function of chorionicity or as a function of presentation of the second twin. Cesarean sections were performed after vaginal delivery of the first twin in 1.8% of cases, being more common if the second baby was in a non-cephalic presentation (6.9% vs. 0.4%, p < 0.05). The average twin-to-twin delivery time interval was longer in the cases where the second had a cephalic presentation (8.26 ± 7.75 min vs. 6.81 ± 5.97 min, p < 0.05). The umbilical artery pH was lower the longer the interval between the birth of the twins, both in monochorionic and dichorionic. Conclusions: According to the results, vaginal delivery is as safe as elective caesarean section in twin pregnancies where the first twin is in cephalic presentation and the intrapartum management should not vary due to chorionicity.

OC22.02: The influence of chorionicity on miscarriage and early perinatal loss in twin pregnancies: the STORK multiple pregnancy cohort

Arch Dis Child Fetal Neonatal Ed 2012;97(Supp 1):A1–A125 A107 PP.02 THE INFLUENCE OF CHORIONICITY ON MISCARRIAGE AND EARLY PERINATAL LOSS IN TWIN PREGNANCIES: THE STORK MULTIPLE PREGNANCY COHORT M Nanni, T Dias, A Bhide, B Thilaganathan Fetal Medicine Unit, St George’s Hospital NHS Trust, London, United Kingdom 10.1136/fetalneonatal-2012-301809.349 Background Monochorionic (MC) twins are at increased risk of fetal loss in early pregnancy as a consequence of twin-twin transfusion syndrome (TTTS). Previous studies estimated that the cumulative MC loss rate was >12% by 24 weeks’ gestation in an era prior to routine fetoscopic laser treatment for TTTS. The aim of this study is to compare current fetal loss rates between MC and DC twins. Methods A retrospective study of all twin pregnancy births of known chorionicity from a regional of 9 hospitals over ten year period. Ultrasound data was matched to hospital delivery records and a mandatory national register for perinatal losses (CMACE). Cumulative fetal and perinatal loss rates for MC and DC twins from 14 to 26 weeks gestation were analysed using Kaplan-Meier survival curves. Results 3133 twin pregnancies (599 MC and 2534 DC) were included in the analysis. The total fetal loss rate in MC and DC twins were 6.3% (75/1198) and 0.9% (44/5068), respectively (OR 0.14, 95% CI 0.09 to 0.20). The cumulative rate of loss in MC twins rose signifi cantly from 0.5% at 14 weeks’ gestation up to a plateau of 6.3% at 24-26 weeks’ gestation, whereas there was no signifi cant change in DC pregnancy loss rate (0.5%) over this period. Conclusion Cumulative fetal loss rate before 26 weeks’ gestation in MC twins has almost halved compared to the rates available in the published literature. Early detection and prompt treatment of complications in MC twins is likely to have contributed to this improvement in twin pregnancy outcomes. 02_fetalneonatal-2012-301809.indd Sec1:107 3/25/2012 6:05:09 PM

The influence of chorionicity on miscarriage and early perinatal loss in twin pregnancies: the stork multiple pregnancy cohort

BackgroundMonochorionic (MC) twins are at increased risk of fetal loss in early pregnancy as a consequence of twin-twin transfusion syndrome (TTTS). Previous studies estimated that the cumulative MC loss rate...

Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies

Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies

Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies

To assess outcome in twin pregnancies according to chorionicity. A cohort was retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising all twin pregnancies with two live fetuses scanned between weeks 11 and 14 in the period 1 January 2004 to 31 December 2006. Outcome data were retrieved from the National Board of Health. Among 2038 twin pregnancies, 1757 (86.2%) were dichorionic (DC) and 281 (13.8%) were monochorionic diamniotic (MC). In MC pregnancies, the rate of spontaneous fetal loss in both second and third trimesters was more than threefold higher than the comparable rate in DC pregnancies: 6.0% vs. 1.9% for at least one fetus in the second trimester (P < 0.001) and 2.1% vs. 0.7% in the third trimester (P = 0.03). In 98.4% of DC pregnancies and in 91.1% of MC pregnancies, at least one infant was liveborn. Amongst pregnancies with two live fetuses at 24 weeks, the proportion with two live infants at 28 days after delivery was 97.5% and 95.1%, respectively. The increased incidence of fetal loss in MC pregnancies compared with DC pregnancies predominantly occurs before 24 weeks' gestation. After this stage, although the risk of intrauterine fetal death is still higher in MC than in DC pregnancies, if both fetuses are alive at 24 weeks, the chance of a woman having two live infants 1 month after delivery is similar in MC and DC pregnancies.

Growth discrepancy in twins in the first trimester of pregnancy

The prevalence and significance of intertwin growth discrepancy in the first trimester of pregnancy are controversial. The aim of this study was to refine the incidence and outcome of this discrepancy in relation to dating of the pregnancy and other biometric parameters. This prospective study of twin pregnancies initially evaluated at 11-14 weeks' gestation was conducted between 2001 and 2004. Differences in crown-rump length (CRL) and estimated gestational age (GA) were calculated for each twin pair and their distribution was analyzed according to chorionicity and mode of conception (spontaneous or following assisted reproductive technologies). CRL-based GA and actual GA were compared. Other biometric parameters were also compared for each twin pair. The distribution of discrepancies was analyzed according to pregnancy outcome. A total of 182 twin pregnancies was included. The mean+/-SD discrepancy in CRL was 3.4+/-3.18 mm or 5.1+/-4.69% and the 95th centile was 9.8 mm or 14.3%. There was no influence of chorionicity (P=0.44), mode of conception (P=0.18) and no relation with outcome (P=0.54). In conceptions resulting from assisted technology, the measured CRL of the smaller twin was closer to the actual GA. Cephalic and abdominal biometric measurements were significantly greater in the twin with the smaller CRL (P<0.05). The two cases with a discrepancy>15 mm were affected by trisomy 18 and triploidy, respectively. CRL discrepancy in twin pregnancies in the first trimester is a frequent finding. Discrepancy>95th centile indicates major growth delay of one twin, which could indicate the presence of aneuploidy. For milder degrees of discordance the CRL of the smaller fetus is a more accurate estimate of the actual GA.

The impact of chorionicity on umbilical cord acid–base values in twin gestations

Objective: To evaluate the impact of chorionicity on inter-twin differences in acid–base status at birth.Methods: Records for twin pregnancies delivered at ⩾ 24 weeks' gestation from 1 January 1990 to 31 June 2000 were reviewed. Collected data included maternal demographics, gestational age, fetal presentation, anesthesia, delivery mode, inter-twin interval, umbilical artery (UA) and venous (UV) acid–base values, Apgar scores and birth weights. The influence of chorionicity on umbilical cord biochemistry was evaluated. (p < 0.05 was considered significant.)Results: Analysis was carried out in 87 twin pairs (29 monochorionic, MC; and 58 dichorionic, DC). MC and DC twins were similar in maternal age (25.5 vs. 28.2 years), estimated gestational age (33.7 vs. 33.6 weeks), Cesarean delivery (55.2 vs. 52.6%), delivery interval (10 v s.5 min) and respective birth weights (twin A,1882 vs. 1981; and twin B,1828 vs. 1872 g). MC first twins had a higher UA pH (7.31 ± 0.05 vs. 7.26 ± 0.08; p = 0.0005) than DC first twins. MC first and second twins had higher UA and UV bicarbonate levels than their DC counterparts (ΔpH = 21.7 ± 5.1 vs. 18.5 ± 3.1 mmol/l and 22.0 ± 3.5 vs. 19.6 ± 2.5 mmol/l, respectively; p = 0.003). MC twins were more discordant in UA pH than DC twins (ΔpH = 0.043 ± 0.09 vs. 0.003 ± 0.07; p = 0.009). MC and DC twins had a similar venous pH (ΔpH = 0.01 ± 0.06 vs. 0.02 ± 0.06; p = 0.5).Conclusions: There is a significant association between placental chorionicity and umbilical cord biochemistry in twins. Although it is possible that the mechanism of this finding is related to placental angioarchitecture, it is unlikely to be a result of simple mixing of blood volumes between twins. The physiology of underlying processes requires further study.

Influence of chorionicity on the heritability estimates of blood pressure: a study in twins.

A basic assumption of the twin design is that environmental influences including prenatal experiences are equal across twin types. However, the intra-uterine environment may differ according to the chorionicity of the monozygotic twins, which may have biased previous heritability estimates of blood pressure. The aim of the present study was to assess whether the heritability of blood pressure, derived from measurements in monozygotic and dizygotic twins, differs according to the chorionicity of the monozygotic twins. Conventional and 24-h ambulatory blood pressures were measured in 125 dizygotic twin pairs and in 97 dichorionic and 128 monochorionic monozygotic twin pairs at the age of 18-34 years. The twin sample was drawn from the East Flanders Prospective Twin Survey, in which perinatal data were collected at birth. Intra-pair correlation coefficients were calculated and compared between both types of monozygotic twin pairs. Heritability was estimated from model-fitting and path analysis, based on the dizygotic twins and, respectively, all monozygotic twins and the two subtypes. Intra-pair correlation coefficients for the various blood pressures, after adjustment for body mass index, ranged from 0.45 to 0.71 in the monozygotic twin pairs and did not differ significantly according to chorionicity. Heritability estimates of blood pressure were between 52 and 64%, and were similar when calculated from dizygotic twins and, respectively, dichorionic and monochorionic monozygotic twins. Heritability estimates of conventional and ambulatory blood pressure do not differ significantly according to the chorionicity of the monozygotic twins.