Left ventricular remodeling in twin pregnancy, noninvasively assessed using hemodynamic forces and pressure-volume relation analysis: prospective, cohort study.

This study was designed to prospectively investigate the pattern of intraventricular hemodynamic forces (HDFs) associated with left ventricular (LV) function and remodeling in women with uncomplicated twin pregnancy. Transthoracic echocardiography was performed on 35 women (aged 35.9 ± 4.7-yr old) during gestation (T1, <14 wk; T2, 14-27 wk; T3, >28 wk) and 6-7 mo after delivery (T0). LV HDFs were computed from echocardiography long-axis data sets using a novel technique based on endocardial boundary tracking, both in apex-base (A-B) and latero-septal (L-S) directions. HDF distribution was evaluated by L-S over A-B HDF ratio (L-S:A-B HDF ratio). At T1, L-S:A-B HDF ratio was higher than in T0 (P < 0.05) indicating HDF misalignment. At T2, a slight impairment of cardiac function was then recorded with a reduction of global longitudinal strain (GLS) and left ventricular end-systolic elastance (Ees) at pressure-volume relationship analysis versus T1 (both P < 0.05). Finally, at T3, when HDF misalignment and LV contractility reduction (GLS and Ees) were all restored, a rightward shift of the end-diastolic pressure-volume relationship (EDPVR) with an increase of ventricular capacitance was documented. In twin pregnancy, HDF misalignment in the first trimester precedes the slight temporary decrease in left ventricular systolic function in the second trimester; at the third trimester, a rightward shift of the EDPVR was associated with a realignment of HDF and normalization of ventricular contractility indexes. These coordinated changes that occur in the maternal heart during twin pregnancy suggest the role of HDFs in cardiac remodeling.NEW & NOTEWORTHY These changes indicate that 1) the misalignment of hemodynamic forces (HDFs) precedes a mild reduction in systolic function in twin pregnancy and 2) the positive left ventricular (LV) response to hemodynamic stress is mainly due to an improved diastolic function with enhanced LV cavity compliance.

Changes in cytokine and sequestosome-1 levels during twin pregnancy progression: Association with outcome.

BACKGROUND: Twin pregnancies are associated with complications and adverse outcomes. The number of twin pregnancies has increased in the last decades, due to the use of assisted reproductive techniques and delayed childbearing. Analysis of changes that occur during twin pregnancy progression and their association with outcome will lead to improved clinical interventions. OBJECTIVE: We evaluated if the plasma concentration of select cytokines and the level of sequestosome-1 (p62) in peripheral blood mononuclear cells (PBMCs) during each trimester of twin gestations was predictive of pregnancy outcome. STUDY DESIGN: This prospective, observational study was conducted at Careggi University Hospital, Florence, Italy. Plasma from 82 women with twin pregnancies was collected in each trimester for measurement of interleukin (IL)-1ß, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α. The intracellular PBMC concentration of p62, a protein involved in autophagy, kinase activity and cell differentiation, was also determined. RESULTS: IL-1ß (p < 0.001), IL-6 (p < 0.001), TNF-α (p < 0.001) and p62 (p < 0.05) increased from the 1st to the 2nd to the 3rd trimester. The TNF-α level was correlated with the IL-1ß concentration in the 1st and 3rd trimesters p < 0.01) and with the IL-6 concentration in each of the three trimesters (p < 0.01). The intracellular p62 level in PBMCs was negatively correlated with the concentration of IL-1ß in the 2nd trimester (p < 0.05) and negatively correlated with the IL-6 level in the 3rd trimester (p < 0.05). The TNF-α level was significantly higher in the 2nd (p < 0.05) and 3rd (p < 0.001) trimester in women with a spontaneous preterm delivery. The TNF-α concentrations in the 2nd (p < 0.05) and 3rd (p < 0.01) trimester, respectively, and 3rd trimester IL-6 (p < 0.01), were negatively associated with gestational age at delivery. The concentration of IL-6 was highest in the 2nd (p < 0.05) and 3rd (p < 0.05) trimesters in women who utilized assisted reproductive technologies. An elevated IL-1ß level in the 3rd trimester was associated with gestational diabetes mellitus (p < 0.05). CONCLUSION: Variations in cytokine levels between individual women during the three trimesters of twin gestations are predictive of spontaneous preterm delivery and the onset of gestational diabetes.

Late selective termination in dichorionic twins: comparing late second and third trimester procedures.

RESEARCH QUESTION: Do perinatal outcomes of selective termination performed in the late second versus third trimester differ and what risk factors are associated with subsequent preterm birth? DESIGN: This is a retrospective cohort study of late selective terminations performed in dichorionic twins between 2009 and 2021. Perinatal outcomes were compared between two groups: group A, late second trimester (20.2 to 24.2 weeks, n = 26), and group B, third trimester (≥28.2 weeks, n = 55) selective terminations. Univariate and multivariate analyses were conducted to identify factors associated with post-procedure preterm birth. RESULTS: In total, 81 dichorionic twin pregnancies were included. There were no pregnancy losses but 16% (13/81) of cases experienced complications. Group A had a higher median birthweight centile (36.5th versus 15th centile, P = 0.002) and lower rates of intrauterine growth restriction (IUGR) and Caesarean delivery (11.5% versus 32.7%, P = 0.04; and 26.9% versus 61.8%, P = 0.003) than group B. Preterm birth rates were similar (46.2% versus 63.6%, P = 0.15). Multiple regression revealed that reduction of the presenting twin and cervical length ≤35 mm were independently associated with post-procedure preterm birth (odds ratio [OR] 8.7, P = 0.001, 95% confidence interval [CI] 2.5-29.8; OR 3.8, P = 0.015, 95% CI 1.3-11). CONCLUSIONS: Late second trimester selective termination is associated with a higher birthweight centile and lower rates of IUGR and Caesarean delivery, compared with third trimester selective termination. Cervical length 35 mm or less and reduction of the presenting twin are independent risk factors for post-procedural preterm birth. These findings may help determine the optimal time to perform a late selective termination.

Real-time ultrasound to assist during a vaginal breech delivery.

We report a novel application of intrapartum sonography, herein used to assist the internal podalic version and the vaginal delivery of a transverse-lying second twin. Following the vaginal delivery of the first cephalic twin, the internal podalic version was performed under continuous ultrasound vision, leading to the uncomplicated breech delivery of a healthy neonate.

Greater risk of type 2 diabetes progression in multifetal gestations with gestational diabetes: the impact of obesity.

BACKGROUND: The relationship between gestational diabetes mellitus and adverse outcomes in multifetal pregnancies is complex and controversial. Moreover, limited research has focused on the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus specifically in multifetal pregnancies, resulting in conflicting results from existing studies. OBJECTIVE: This study aimed to assess the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus between singleton and multifetal pregnancies in a large cohort of parturients with a 5-year follow-up. STUDY DESIGN: A retrospective study was conducted on a prospective cohort of pregnant individuals with pregnancies between January 1, 2017, and December 31, 2020, followed up to 5 years after delivery. Glucose levels during pregnancy were obtained from the Meuhedet Health Maintenance Organization laboratory system and cross-linked with the Israeli National Diabetes Registry. The cohort was divided into 4 groups: singleton pregnancy without gestational diabetes mellitus, singleton pregnancy with gestational diabetes mellitus, multifetal pregnancy without gestational diabetes mellitus, and multifetal pregnancy with gestational diabetes mellitus. Gestational diabetes mellitus was defined according to the American Diabetes Association criteria using the 2-step strategy. Univariate analyses, followed by survival analysis that included Kaplan-Meier hazard curves and Cox proportional-hazards models, were used to assess differences between groups and calculate the adjusted hazard ratios with 95% confidence intervals for progression to type 2 diabetes mellitus. RESULTS: Among 88,611 parturients, 61,891 cases met the inclusion criteria. The prevalence of type 2 diabetes mellitus was 6.5% in the singleton pregnancy with gestational diabetes mellitus group and 9.4% in the multifetal pregnancy with gestational diabetes mellitus group. Parturients with gestational diabetes mellitus, regardless of plurality, were older and had higher fasting plasma glucose levels in the first trimester of pregnancy. The rates of increased body mass index, hypertension, and earlier gestational age at delivery were significantly higher in the gestational diabetes mellitus group among patients with singleton pregnancies but not among patients with multifetal pregnancies. Survival analysis demonstrated that gestational diabetes mellitus was associated with adjusted hazard ratios of type 2 diabetes mellitus of 4.62 (95% confidence interval, 3.69-5.78) in singleton pregnancies and 9.26 (95% confidence interval, 2.67-32.01) in multifetal pregnancies (P<.001 for both). Stratified analysis based on obesity status revealed that, in parturients without obesity, gestational diabetes mellitus in singleton pregnancies increased the risk of type 2 diabetes mellitus by 10.24 (95% confidence interval, 6.79-15.44; P<.001) compared with a nonsignificant risk in multifetal pregnancies (adjusted hazard ratio, 9.15; 95% confidence interval, 0.92-90.22; P=.059). Among parturients with obesity, gestational diabetes mellitus was associated with an increased risk of type 2 diabetes mellitus for both singleton and multifetal pregnancies (adjusted hazard ratio, 3.66; [95% confidence interval, 2.81-4.67; P<.001] and 9.31 [95% confidence interval, 2.12-40.76; P=.003], respectively). CONCLUSION: Compared with gestational diabetes mellitus in singleton pregnancies, gestational diabetes mellitus in multifetal pregnancies doubles the risk of progression to type 2 diabetes mellitus. This effect is primarily observed in patients with obesity. Our findings underscore the importance of providing special attention and postpartum follow-up for patients with multifetal pregnancies and gestational diabetes mellitus, especially those with obesity, to enable early diagnosis and intervention for type 2 diabetes mellitus.

Risk of adverse pregnancy outcomes in twin- and singleton-born women: An inter-generational cohort study.

OBJECTIVE: To compare the risk of adverse pregnancy outcomes between twin-born and singleton-born women. We also evaluated whether in utero exposure to pre-eclampsia or preterm delivery affected adverse pregnancy outcomes in women's own pregnancies. DESIGN: Population-based cohort study. SETTING: Medical Birth Registry of Norway 1967-2020. POPULATION: 9184 twin-born and 492 894 singleton-born women during 1967-2005, with their later pregnancies registered during 1981-2020. METHODS: Data from an individual's birth were linked to their later pregnancies. We used generalised linear models with log link binomial distribution to obtain exponentiated regression coefficients that estimated relative risks (RRs) with 95% confidence intervals (CIs) for associations between twin- or singleton-born women and later adverse pregnancy outcomes. MAIN OUTCOME MEASURES: Pre-eclampsia, preterm delivery or perinatal loss in twin-born compared with singleton-born women. RESULTS: There was no increased risk for adverse outcomes in twin-born compared with singleton-born women: adjusted RRs for pre-eclampsia were 1.00 (95% CI 0.93-1.09), for preterm delivery 0.96 (95% CI 0.90-1.02) and for perinatal loss 1.00 (95% CI 0.84-1.18). Compared with singleton-born women exposed to pre-eclampsia in utero, twin-born women exposed to pre-eclampsia had lower risk of adverse outcomes in their own pregnancies; the aRR for pre-eclampsia was 0.73 (95% CI 0.58-0.91) and for preterm delivery was 0.71 (95% CI 0.56-0.90). Compared with preterm singleton-born women, preterm twin-born women did not differ in terms of risk of pre-eclampsia (aRR 1.05, 95% CI 0.92-1.21) or perinatal loss (aRR 0.99, 95% CI 0.71-1.37) and had reduced risk of preterm delivery (RR 0.83, 95% CI 0.74-0.94). CONCLUSIONS: Twin-born women did not differ from singleton-born women in terms of risk of adverse pregnancy outcomes. Twin-born women exposed to pre-eclampsia in utero, had a lower risk of pre-eclampsia and preterm delivery compared with singleton-born women exposed to pre-eclampsia.

Longitudinal maternal hemodynamic evaluation in uncomplicated twin pregnancies according to chorionicity: physiological cardiovascular dysfunction in monochorionic twin pregnancy.

OBJECTIVE: Maternal cardiac function plays a crucial role in placental function and development. The maternal hemodynamic changes in twin pregnancy are more pronounced than those in singleton pregnancy, presumably due to a greater plasma volume expansion. In view of the correlation between maternal cardiac and placental function, it is plausible that chorionicity could influence maternal cardiac function. The aim of this study was to compare the longitudinal maternal hemodynamic changes between uncomplicated dichorionic (DC) and monochorionic (MC) twin pregnancies and in comparison to singleton pregnancies. METHODS: Included in the study were 40 MC diamniotic and 35 DC diamniotic uncomplicated twin pregnancies. These were compared with a group of 294 healthy singleton pregnancies from a previous cross-sectional study. All participants underwent a hemodynamic evaluation using an Ultrasound Cardiac Output Monitor (USCOM®), at three different stages in pregnancy (11-15 weeks, 20-24 weeks and 29-33 weeks). The following parameters were recorded: mean arterial pressure (MAP), stroke volume (SV), stroke volume index (SVI), heart rate, cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI), stroke volume variation, Smith-Madigan inotropy index (INO) and potential-to-kinetic-energy ratio (PKR). RESULTS: In the first trimester, DC and MC twin pregnancies showed lower MAP, SVR and PKR and higher CO and SV in comparison to singleton pregnancy. In the second trimester, maternal CO (8.33 vs 7.30 L/min, P = 0.03) and CI (4.52 vs 4.00 L/min/m2 , P = 0.02) were significantly higher in MC compared with DC twin pregnancy. In the third trimester, compared with in singleton pregnancy, women with MC twin pregnancy showed significantly higher PKR (24.06 vs 20.13, P = 0.03) and SVRI (1837.20 vs 1698.48 dynes × s/cm5 /m2 , P = 0.03), and significantly lower SV (78.80 vs 88.80 mL, P = 0.01), SVI (42.79 vs 50.31 mL/m2 , P < 0.01) and INO (1.70 vs 1.87 W/m2 , P = 0.03); these differences were not observed between DC twin and singleton pregnancies. CONCLUSIONS: Maternal cardiovascular function undergoes significant change during uncomplicated twin pregnancy and chorionicity influences maternal hemodynamics. In both MC and DC twin pregnancy, hemodynamic changes are detectable as early as the first trimester, showing higher maternal CO and lower SVR compared with singleton pregnancy. In DC twin pregnancy, the maternal hemodynamics remain stable during the rest of pregnancy. In contrast, in MC twin pregnancy, the rise in maternal CO continues in the second trimester in order to sustain the greater placental growth. There is a subsequent crossover, with a reduction in cardiovascular performance during the third trimester. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Longitudinal evaluation of cervical length and shear wave elastography in women with spontaneous preterm birth.

OBJECTIVE: To evaluate longitudinal changes in cervical length (CL) and mean cervical shear wave elastography (CSWE) score in women with a singleton or twin pregnancy who undergo spontaneous preterm birth (sPTB) compared with those who deliver at term. METHODS: This was a prospective longitudinal study of unselected women with a singleton or twin pregnancy attending a dedicated research clinic for screening for sPTB at four timepoints during pregnancy: 11 + 0 to 15 + 6 weeks, 16 + 0 to 20 + 6 weeks, 21 + 0 to 24 + 6 weeks and 28 + 0 to 32 + 6 weeks. At each visit, a transvaginal ultrasound scan was conducted to measure the CL and the CSWE scores in six regions of interest (ROI) (inner, middle and external parts of anterior and posterior cervical lips). The mean CSWE score from the six ROIs was calculated for analysis. Log10 transformation was applied to data to produce a Gaussian distribution prior to statistical analysis. A multilevel mixed-effects analysis was performed to compare longitudinally CL and CSWE between the sPTB and term-delivery groups. RESULTS: The final cohort consisted of 1264 women, including 1143 singleton pregnancies, of which 57 (5.0%) were complicated by sPTB, and 121 twin pregnancies, of which 33 (27.3%) were complicated by sPTB. Compared to those who delivered at term, women with sPTB had a lower CL across gestation when controlling for history of cervical surgery, number of fetuses, gestational age (GA) at cervical assessment and the interaction between GA at cervical assessment and sPTB (P < 0.001). Specifically, CL in the sPTB group was significantly lower at 21 + 0 to 24 + 6 weeks (P = 0.039) and 28 + 0 to 32 + 6 weeks (P < 0.001). Twin pregnancies had significantly greater CL throughout pregnancy compared with singleton pregnancies (regression coefficient, 0.01864; P < 0.001). After adjusting for maternal age, weight, height, body mass index and GA at cervical assessment, CSWE score in the sPTB group was significantly lower compared with that in the term-delivery group across gestation (P = 0.013). However, on analysis of individual visits, CSWE score in the sPTB group was significantly lower than that in the term-delivery group only at 11 + 0 to 15 + 6 weeks (P = 0.036). There was no difference in CSWE score between singleton and twin pregnancies throughout gestation (regression coefficient, -0.00128; P = 0.937). CONCLUSIONS: Women with sPTB have a shorter and softer cervix across gestation compared with those who deliver at term. A shorter cervix in the sPTB group is observed from the late second trimester onwards, while lower cervical stiffness in the sPTB group is observed primarily in the first trimester. CL is significantly lower in singleton pregnancies compared with twin pregnancies, while cervical stiffness does not differ between the two. Our findings indicate that the cervix tends to undergo a softening process prior to shortening in sPTB cases. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Incidence of neonatal morbidity in small-for-gestational-age twins based on singleton and twin charts.

OBJECTIVE: To compare morbidity, as measured by length of stay in the neonatal intensive care unit (NICU), in twin and singleton gestations classified as small-for-gestational age (SGA) according to estimated fetal weight < 10th percentile on twin or singleton growth charts. METHODS: NICU length of stay was compared in 1150 twins and 29 035 singletons that underwent ultrasound assessment between 35 + 0 and 36 + 6 weeks' gestation. Estimated fetal weight was obtained from measurements of head circumference, abdominal circumference and femur length using the Hadlock formula. Gestational age was derived from the first-trimester crown-rump length measurement, using the larger of the two twins. Singletons and twins were compared in terms of NICU admission rate and length of stay according to classification as SGA by the Fetal Medicine Foundation singleton and twin reference distributions. RESULTS: The overall proportions of twins and singletons admitted to NICU were similar (7.3% vs 7.4%), but twins tended to have longer lengths of stay in NICU (≥ 7 days: 2.4% vs 0.8%; relative risk (RR), 3.0 (95% CI, 1.6-4.4)). Using the singleton chart, a higher proportion of twins were classified as SGA compared with singletons (37.6% vs 7.0%). However, the proportion of SGA neonates entering NICU was similar (10.2% for twins and 10.1% for singletons) and the proportion of SGA neonates spending ≥ 7 days in NICU was substantially higher for twins compared with singletons (3.7% vs 1.4%; RR, 2.6 (95% CI, 1.4-4.7)). CONCLUSIONS: When singleton charts are used to define SGA in twins and in singletons, there is a greater degree of growth-related neonatal morbidity amongst SGA twins compared with SGA singletons. Consequently, singleton charts do not inappropriately overdiagnose fetal growth restriction in twins and they should be used for monitoring fetal growth in both twins and singletons. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Medicine Foundation charts for fetal growth in twins.

OBJECTIVE: To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons. METHODS: Gestational-age- and chorionicity-specific reference distributions for singleton percentiles and EFW were fitted to data on 4391 twin pregnancies with two liveborn fetuses from four European centers, including 3323 dichorionic (DC) and 1068 monochorionic diamniotic (MCDA) twin pregnancies. Gestational age was derived using the larger of the two crown-rump length measurements obtained during the first trimester of pregnancy. EFW was obtained from ultrasound measurements of head circumference, abdominal circumference and femur length using the Hadlock formula. Singleton percentiles were obtained using the Fetal Medicine Foundation population weight charts for singleton pregnancies. Hierarchical models were fitted to singleton Z-scores with autoregressive terms for serial correlations within the same fetus and between twins from the same pregnancy. Separate models were fitted for DC and MCDA twins. RESULTS: Fetuses from twin pregnancies tended to be smaller than singletons at the earliest gestational ages (16 weeks for MCDA and 20 weeks for DC twins). This was followed by a period of catch-up growth until around 24 weeks. After that, both DC and MCDA twins showed reduced growth. In DC twins, the EFW corresponding to the 50th percentile was at the 50th percentile of singleton pregnancies at 23 weeks, the 43rd percentile at 28 weeks, the 32nd percentile at 32 weeks and the 22nd percentile at 36 weeks. In MCDA twins, the EFW corresponding to the 50th percentile was at the 36th percentile of singleton pregnancies at 24 weeks, the 29th percentile at 28 weeks, the 19th percentile at 32 weeks and the 12th percentile at 36 weeks. CONCLUSIONS: In DC and, to a greater extent, MCDA twin pregnancies, fetal growth is reduced compared with that observed in singleton pregnancies. Furthermore, after 24 weeks, the divergence in growth trajectories between twin and singleton pregnancies becomes more pronounced as gestational age increases. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Neurodevelopmental outcome in complicated twin pregnancy: prospective observational study.

OBJECTIVE: Twin pregnancy is associated with increased perinatal mortality and morbidity, but long-term neurodevelopmental outcome remains underinvestigated. The primary objective of this study was to investigate the incidence of adverse neurodevelopment after 1 year of age in complicated monochorionic diamniotic (MCDA) twin pregnancies compared with uncomplicated twin pregnancies. METHODS: This was a prospective cohort study conducted at St George's University Hospital NHS Foundation Trust, London, UK. Women with a twin pregnancy culminating in at least one surviving child, aged between 12 and 60 months (corrected for prematurity) at the time of assessment, were invited to complete the relevant Ages and Stages Questionnaire® version 3 (ASQ-3) test. The two study groups were: (1) complicated MCDA twin pregnancies, including those with twin-twin transfusion syndrome, twin anemia-polycythemia sequence, selective fetal growth restriction, twin reversed arterial perfusion sequence and/or single intrauterine demise; and (2) uncomplicated MCDA and dichorionic diamniotic twin pregnancies. The primary outcome measure was an abnormal ASQ-3 score, defined as a score of more than 2 SD below the mean in any one of the five domains. Mixed-effects multivariable logistic regression analysis was performed to determine whether a complicated MCDA twin pregnancy was associated independently with an abnormal ASQ-3 score. RESULTS: The study included 174 parents who completed the questionnaire for one or both twins; therefore, 327 ASQ-3 questionnaires were available for analysis. Of those, 117 (35.8%) were complicated MCDA twin pregnancies and 210 (64.2%) were controls. The overall rate of an abnormal ASQ-3 score in children born of a complicated MCDA twin pregnancy was nearly double that of those from uncomplicated twin pregnancies (14.5% vs 7.6%; P = 0.056). Children born of a complicated MCDA twin pregnancy had a significantly higher rate of impairment in the gross-motor domain compared with the control group (8.5% vs 2.9%; P = 0.031). Complicated MCDA twin pregnancies that underwent prenatal intervention had a significantly higher rate of abnormal ASQ-3 score compared with those that did not undergo prenatal intervention (28.1% vs 1.7%; P < 0.001). On multilevel logistic regression analysis, complicated MCDA twin pregnancy was an independent predictor of abnormal ASQ-3 score (adjusted odds ratio, 3.28 (95% CI, 3.27-3.29); P < 0.001). CONCLUSIONS: This study demonstrates that survivors of complicated MCDA twin pregnancies have a higher rate of adverse neurodevelopmental outcome, independently of prematurity. Long-term neurodevelopmental follow-up in these pregnancies can ensure timely and optimal management of those affected. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Validation of Fetal Medicine Foundation charts for fetal growth in twins: nationwide Danish cohort study.

OBJECTIVE: To assess the validity of the Fetal Medicine Foundation (FMF) chorionicity-specific models for fetal growth in twin pregnancy. METHODS: This was an external validation study of the FMF models using a nationwide Danish cohort of twin pregnancies. The cohort included all dichorionic (DC) and monochorionic diamniotic (MCDA) twin pregnancies with an estimated delivery date between 2008 and 2018, which satisfied the following inclusion criteria: two live fetuses at the first-trimester ultrasound scan (11-14 weeks' gestation); biometric measurements available for the calculation of estimated fetal weight (EFW) using the Hadlock-3 formula; and delivery of two liveborn infants. Validation involved assessing the distributional properties of the models and estimating the mean EFW Z-score deviations. Additionally, the models were applied to pregnancies that delivered preterm and attended non-scheduled visits (complicated pregnancies). RESULTS: Overall, 8542 DC and 1675 MCDA twin pregnancies met the inclusion criteria. In DC twins, 17 084 fetuses were evaluated at a total of 95 346 ultrasound scans, of which 44.5% were performed at scheduled visits in pregnancies carried to 37 + 0 weeks or later. The median number of growth scans per DC twin fetus from 20 + 0 weeks onwards was four. The model showed good agreement with the validation cohort for scheduled visits in DC twins delivered at 37 + 0 weeks or later (mean EFW Z-score, -0.14 ± 1.05). In MCDA twins, 3350 fetuses underwent 31 632 eligible ultrasound scans, of which 59.5% were performed at scheduled visits in pregnancies carried to 36 + 0 weeks or later. The median number of growth scans per MCDA twin fetus from 16 + 0 weeks onwards was 10. The model showed favorable agreement with the validation cohort for scheduled visits in MCDA twins delivered at 36 + 0 weeks or later (mean EFW Z-score, -0.09 ± 1.01). Non-scheduled visits and preterm delivery before 37 + 0 weeks for DC twins and before 36 + 0 weeks for MCDA twins corresponded with smaller weight estimates, which was consistent with the study's definition of complicated pregnancy. CONCLUSIONS: The FMF models provide a good fit for EFW measurements in our Danish national cohort of uncomplicated twin pregnancies assessed at routine scans. Therefore, the FMF models establish robust criteria for subsequent investigations and potential clinical applications. Future research should focus on exploring the consequences of clinical implementation, particularly regarding the identification of twins that are small-for-gestational age, as they are especially susceptible to adverse perinatal outcome. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The association of preconceptional folic acid supplementation with gestational age and preterm birth risk in twin pregnancies: a prospective cohort study in China.

PURPOSE: This study aims to explore the association of maternal preconceptional folic acid (FA) supplementation with gestational age and preterm birth in twin pregnancies, and whether the association varies by chorionicity or conception mode. METHODS: From November 2018 to December 2021, the information of FA supplementation and pregnancy outcomes were collected in twin pregnant women. The linear regression models and the logistic regression were used to test the association of preconceptional FA supplementation with gestational age at delivery and preterm birth and premature rupture of membranes (PROM). RESULTS: A total of 416 twin pregnancies were included. Compared with no use in twins, maternal preconceptional FA use was associated with a 0.385-week longer gestational age (95% CI 0.019-0.751) and lower risk of preterm birth < 36 weeks (adjusted OR 0.519; 95% CI 0.301-0.895) and PROM (adjusted OR 0.426; 95% CI 0.215-0.845). The protective effect on preterm birth < 36 weeks and PROM is similar whether taking FA supplements alone or multivitamins. However, the associations varied by chorionicity and conception mode of twins or compliance with supplementation. The positive associations between preconceptional FA use and gestational age only remained significant among twins via assisted reproductive technology or dichorionic diamniotic twins. Significant protective effects on preterm birth < 36 weeks and PROM were only found among women who took FA at least 4 times a week before conception. CONCLUSION: Maternal preconceptional FA supplementation was associated with longer gestation duration and lower risk of preterm birth < 36 weeks and PROM in twin pregnancies. To improve the success of their pregnancies, reproductive women should start taking FA supplements well before conception and with good compliance.

Twin pregnancy and postpartum haemorrhage: a systematic review and meta-analysis.

BACKGROUND: Postpartum haemorrhage (PPH) continues to stand as the primary cause of maternal morbidity and mortality post-delivery, with twin pregnancies carrying a heightened risk of PPH compared to singleton deliveries. OBJECTIVES: To investigate the incidence of primary PPH among twin pregnancies and report on maternal and peripartum characteristics within this population. METHODS: A literature search was conducted using data from PubMed, EMBASE, Cochrane, Scopus, and Web of Science. The search aimed to identify studies concerning mothers with twin pregnancies and postpartum haemorrhage (PPH) from the inception of each respective database to June 8th, 2023. Pooled means and proportions were analyzed using the generic inverse variance method. This review was registered prospectively with PROSPERO (CRD42023427192). RESULTS: A total of 21 studies involving 23,330 twin pregnant patients were included. Incidence of PPH for vaginal delivery and Caesarean delivery (CS) was found to be 10.9% (95% CI: -0.017, 0.235, I2 = 96%) and 27.0% (95% CI: 0.180, 0.359, I2 = 99%) respectively. In vitro fertilization (IVF) was the most common conception method at 62.0% (95% CI: 0.448, 0.792, I2 = 100%) with 81.1% (95% CI: 0.708, 0.915, I2 = 100%) of twins being dichorionic diamniotic. CONCLUSION: This meta-analysis demonstrated more than one in ten vaginal deliveries and over one in four cesarean sections result in PPH for twin pregnancies. IVF is the predominant method of conception in this patient group and seems to contribute to subsequent PPH risk in specific mothers. While preliminary, these findings underscore the necessity for further well-designed and high-quality studies to validate these results.

Prevalence and adverse outcomes of twin pregnancy in Eastern Africa: a systematic review and meta-analysis.

INTRODUCTION: Multiple pregnancies are much more common today than they were in the past. Twin pregnancies occur in about 4% of pregnancies in Africa. Adverse pregnancy outcome was more common in twin pregnancy than in singleton pregnancy. There is no pooled evidence on the burden and adverse pregnancy outcome of twin pregnancy in eastern Africa. Thus, this systematic review and meta-analysis were conducted to assess the prevalence and adverse pregnancy outcomes of twin pregnancies. METHODS: This systematic review and meta-analysis covers published and unpublished studies searched from different databases (PubMed, CINAHL (EBSCO), EMBASE, DOAJ, Web of Sciences, MEDLINE, Cochrane Library, SCOPUS, Google Scholar, and Google search). Finally, 34 studies were included in this systematic review and meta-analysis. JBI checklist was used to assess the quality of included papers. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. Data synthesis and statistical analysis were conducted using STATA Version 14 software. Heterogeneity and publication bias were assessed. A forest plot was used to present the pooled prevalence using the random effect model. RESULTS: The prevalence of twin pregnancy in eastern Africa was 3% [95% CI: 2, 3]. The adverse pregnancy outcomes like neonatal intensive care unit admission (78%), low birth weight (44%), low APGAR score (33%), prematurity (32%), stillbirth (30%), neonatal mortality (12%) and maternal complications like hypertensive disorder of pregnancy (25%), postpartum hemorrhage (7%), Cesarean section (37%), premature rupture of membrane (12%) and maternal mortality are more common among twin pregnancy than singleton pregnancy. CONCLUSION: One in every 33 children born a twin in east Africa; admission to neonatal intensive care unit, low birth weight, low APGAR score, prematurity, stillbirth, neonatal mortality and maternal complications are its associated adverse birth outcomes. Since twin pregnancy is a high-risk pregnancy, special care is needed during pregnancy, labor and delivery to reduce adverse pregnancy outcomes.

Serum lipid reference values recommended during a twin pregnancy and evaluating its association with perinatal outcomes.

BACKGROUND: Maternal lipid metabolism fluctuations have been shown to increase the risk of adverse pregnancy outcomes. However, there is no consensus over what constitutes normal maternal lipid values during twin pregnancy. Therefore, the aim of this study was to establish a serum lipid reference range for a twin pregnancy. METHODS: A retrospective survey was conducted, from 2011 to 2021, at the Peking University Third Hospital. A total of 881 twin pregnancies, with lipid data from early and middle pregnancies, were included. After excluding those with adverse pregnancy outcomes, we performed a descriptive analysis of total cholesterol (TC), triglycerides (TG), high-density lipid cholesterol (HDL-C), and low-density lipid cholesterol (LDL-C) levels, using the mean and standard deviation to determine appropriate percentiles. We later determined the lipid reference range in early and middle pregnancy based on the initial results. We evaluated Inappropriate lipid levels associations with pregnancy outcomes, including gestational diabetes, pregnancy-induced hypertension, small for gestational age. RESULTS: (1) Serum levels of TC, TG, LDL-C, and HDL-C increased significantly from early to late pregnancy, where the greatest increase was observed in TG. (2) Based on the results, we recommend that TC, TG, and LDL-C serum reference values during early and middle pregnancy should be less than the 95th percentile. On the other hand, HDL-C should be greater than the 5th percentile. During early pregnancy, the values recommended are TC < 5.31 mmol/L, TG < 2.25 mmol/L, HDL > 1.02 mmol/L and LDL < 3.27 mmol/L, and those during middle pregnancy are TC < 8.74 mmol/L, TG < 4.89 mmol/L, HDL > 1.25 mmol/L and LDL < 5.49 mmol/L, while the values during late pregnancy are TC < 9.11 mmol/L, TG < 6.70 mmol/L, HDL > 1.10 mmol/L and LDL < 5.81 mmol/L. Higher levels of blood lipids were associated with GDM, PE, SGA. CONCLUSIONS: We suggested a reference ranges for blood lipids during the twin pregnancy in a Chinese population. The reference ranges recommended by this study can be used to identify women with twin pregnancies using unfavorable lipid values. Higher levels of blood lipids were associated with adverse pregnancy outcomes.

The association of early pregnancy dyslipidemia with preterm birth in twin pregnancies: a retrospective cohort study.

BACKGROUND: Maternal lipid metabolism has been implicated in elevating the risk of adverse pregnancy outcomes, which is a particularly significant concern in twin pregnancies. However, the precise relationship between early pregnancy dyslipidemia and the risk of preterm birth (PTB) in twin pregnancies remains unclear. METHODS: This retrospective cohort study included women with twin pregnancies between January 2018 and December 2023. Early pregnancy blood lipid profiles, including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C), were examined. Dyslipidemia was diagnosed based on the diagnostic criteria outlined in the 2016 guidelines for the prevention and treatment of dyslipidemia in Chinese adults. PTB was defined as birth occurring before 37 weeks of pregnancy. Logistic regression models were used to evaluate the association of early pregnancy dyslipidemia with PTB in twin pregnancies. RESULTS: A total of 613 women with twin pregnancies were included, and 141 women were complicated with dyslipidemia. The incidence of PTB < 37 weeks was significantly higher in the dyslipidemia group compared to the group without dyslipidemia (64.5% vs. 50.4%, P = 0.003). After adjusting for confounding factors, dyslipidemia was positively associated with PTB < 37 weeks (adjusted odds ratio: 1.71; 95% confidence interval: 1.13-2.58). However, these associations varied depending on the chorionicity and mode of conception of the twins. The positive associations between early pregnancy dyslipidemia and PTB < 37 weeks remained significant only in spontaneously conceived (SC) or dichorionic diamniotic (DCDA) twin pregnancies. No statistically significant associations were observed between dyslipidemia and the other secondary outcomes. CONCLUSION: Early pregnancy dyslipidemia was positively associated with PTB < 37 weeks in twin pregnancies, and this association remained significant in SC or DCDA twin pregnancies. Comprehensive lipid profile assessment in the first trimester may be beneficial for patients' monitoring and implementing interventions to mitigate adverse pregnancy outcomes.

Prognosis of remaining fetus in twin pregnancy after demise of one fetus according to its location.

BACKGROUND: To investigate the prognosis of the remaining fetus in twin pregnancy after experiencing one fetal demise in the first trimester according to the location of the demised fetus. METHODS: This was a retrospective study of twin pregnancies with one fetal demise after the first trimester (14 weeks of gestation) delivered between September 2004 and September 2022. The study population was divided into two groups based on the location of the demised fetus as determined by the last recorded ultrasonography results: Group 1 included twin pregnancies where the presenting fetus was demised (n = 36) and Group 2 included twin pregnancies where the non-presenting fetus was demised (n = 44). The obstetric and neonatal outcomes were also reviewed. RESULTS: A total of 80 pregnant women were included. The median gestational age for the diagnosis of fetal demise was 24.1 weeks. The gestational age of the demised fetus was not different between Groups 1 and 2; however, the gestational age of the remaining fetus at delivery was significantly earlier in Group 1 than it was in Group 2 (33.8 vs. 37.3 weeks, P = .004). The rate of preterm birth before 28 weeks was almost five times higher in Group 1 than in Group 2 (22.2% vs. 4.5%, P = .037). Regression analysis demonstrated significant differences between Groups 1 and 2. Respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus, retinopathy of prematurity, and jaundice were more common in Group 1 than in Group 2; however, the association was not significant after adjusting for gestational age at delivery. CONCLUSIONS: When the presenting fetus is demised in a twin pregnancy, the remaining fetus tends to be delivered earlier than when the non-presenting fetus is demised.

Emergency cervical cerclage in delayed-interval delivery of twin pregnancies: a scoping review.

BACKGROUND: The protocol for delayed-interval delivery of the second twin in twin pregnancies has not been standardized. Cervical cerclage is often performed, but its use is debated. To conduct a scoping review on cervical cerclage for prolonging the intertwin delivery interval and improving second twin survival and maternal outcomes after preterm delivery or spontaneous abortion of the first twin in twin pregnancies. METHODS: Seven Chinese and English language databases were searched from inception to March 1, 2023, including PubMed, The Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP Chinese Science Journal Database, and Sinomed. Relevant observational studies that assessed the effectiveness of the use of cervical cerclage in delayed-interval delivery of twins were screened and selected, and raw data were extracted, and descriptive statistics and chi-square analysis were performed. RESULTS: A total of 102 articles were retrieved. After screening and exclusion of duplicate and irrelevant articles, 22 articles meeting the inclusion criteria were obtained. Studies in which cerclage was performed reported longer intertwin delivery intervals than those that did not perform cerclage, and the difference was statistically significant. The cerclage group also tended to have lower rates of chorioamnionitis and maternal complications, but the difference between the two groups was not statistically significant. CONCLUSION: After excluding patients with contraindications, emergency cervical cerclage can be considered in cases of spontaneous abortion of the first twin in twin pregnancies to prolong the gestation and improve the prognosis of the remaining fetus until it becomes viable and increases its birth weight.

Predictive value of maternal serum placental growth factor levels for discordant fetal growth in twins: a retrospective cohort study.

BACKGROUND: Accurate prenatal recognition of discordant fetal growth in twins is critical for deciding suitable management strategies. We explored the predictive value of the level of maternal second-trimester placental growth factor (PLGF) as a novel indicator of discordant fetal growth. METHODS: A total of 860 women pregnant with twins were enrolled, including 168 women with monochorionic twins (31 cases of discordant fetal growth and 137 without) and 692 with dichorionic twins (79 cases of discordant fetal growth and 613 without). Maternal second-trimester PLGF concentrations were measured via immunofluorescence. RESULTS: Maternal second-trimester PLGF levels were significantly lower in women pregnant with twins who subsequently developed discordant fetal growth than in those who did not (monochorionic twin pregnancy: P < 0.001; dichorionic twin pregnancy: P < 0.001). A 3-4 fold difference in median PLGF concentrations was detected between the two groups with both monochorionic and dichorionic twin pregnancies. Maternal second-trimester PLGF levels were significantly correlated with birth weight differences (monochorionic twin pregnancy: r = - 0.331, P < 0.001; dichorionic twin pregnancy: r = - 0.234, P < 0.001). A receiver operating characteristic curve was used to evaluate the predictive efficiency. In monochorionic twin pregnancies, the area under the curve (AUC) was 0.751 (95% confidence interval [CI]: 0.649-0.852), and the cutoff value was 187.5 pg/mL with a sensitivity of 77.4% and specificity of 71.0%. In dichorionic twin pregnancies, the AUC was 0.716 (95% CI; 0.655-0.777), and the cutoff value was 252.5 pg/mL with a sensitivity of 65.1% and specificity of 69.6%. Based on the above cutoff values, univariate and multivariate logistic regression analyses were performed to calculate the odds ratios (OR) for the PLGF levels. After adjustment for potential confounding factors, low PLGF concentrations still significantly increased the risk of discordant fetal growth (monochorionic twin pregnancy: adjusted OR: 7.039, 95% CI: 2.798-17.710, P < 0.001; dichorionic twin pregnancy: adjusted OR: 4.279, 95% CI: 2.572-7.120, P < 0.001). CONCLUSIONS: A low maternal second-trimester PLGF level is considered a remarkable risk factor and potential predictor of discordant fetal growth. This finding provides a complementary screening strategy for the prediction of discordant fetal growth and offers a unique perspective for the subsequent research in this field.