Monochorionic Research Articles

The Outcome after Laser Therapy of Monochorionic Twin Pregnancies Complicated by Twin-Twin Transfusion Syndrome with Coexistent Selective Fetal Growth Restriction.

Background: Most previous studies evaluated outcomes of twin-twin transfusion syndrome (TTTS) without considering the coexistence of selective fetal growth restriction (sFGR). The objectives of this study were to compare twin survival and pregnancy complications after laser therapy of TTTS with and without sFGR. Methods: For this purpose, a retrospective cohort study including 98 monochorionic diamniotic twins and three dichorionic triamniotic triplets treated in a single tertiary center was conducted. Results: Overall, 46 twins had selective fetal growth restriction (26 type I, 13 type II, 7 type III). At birth, donor survival (61% vs. 91%), double survival (57% vs. 82%), and overall survival (75% vs. 88%) were significantly lower in the group with coexistent sFGR. Recipient survival (89% vs. 86%), miscarriage (7% vs. 2%), PPROM < 32 weeks (48% vs. 29%), and preterm delivery < 32 weeks (52% vs. 45%) were not significantly higher in the group with coexistent sFGR. Donor twins with sFGR type I (69% vs. 91%) and types II-III (50% vs. 91%) showed significantly lower survival than those without sFGR. Multivariate regression analysis identified sFGR and its subtypes as independent predictors of donor demise. Conclusions: the coexistence of sFGR in TTTS pregnancies was associated with poor donor outcomes and is probably the most important predictor of donor survival.

Monochorionic Twinning in Bioengineered Human Embryo Models.

Monochorionic twinning of human embryos increases the risk of complications during pregnancy. The rarity of such twinning events, combined with ethical constraints in human embryo research, makes investigating the mechanisms behind twinning practically infeasible. As a result, there is a significant knowledge gap regarding the origins and early phenotypic presentation of monochorionic twin embryos. In this study, a microthermoformed-based microwell screening platform is used to identify conditions that efficiently induce monochorionic twins in human stem cell-based blastocyst models, termed "twin blastoids". These twin blastoids contain a cystic GATA3+ trophectoderm-like epithelium encasing two distinct inner cell masses (ICMs). Morphological and morphokinetic analyses reveal that twinning occurs during the cavitation phase via splitting of the OCT4+ pluripotent core. Notably, each ICM in twin blastoids contains its own NR2F2+ polar trophectoderm-like region, ready for implantation. This is functionally tested in a microfluidic chip-based implantation assay with epithelial endometrium cells. Under defined flow regimes, twin blastoids show increased adhesion capacity compared to singleton blastoids, suggestive of increased implantation potential. In conclusion, the development of technology enabling large-scale formation of twin blastoids, coupled with high-sensitivity readout capabilities, presents an unprecedented opportunity for systematically exploring monochorionic twin formation and its impact on embryonic development.

Management and clinical implications of multiple pregnancies: A focus on zygosity, chorionicity, and monochorionic twin complications

Management and clinical implications of multiple pregnancies: A focus on zygosity, chorionicity, and monochorionic twin complications

Heterokaryotypic Monochorionic Twin Pregnancy: New Perspective

AbstractMonozygotic twins are thought to be identical since they are created from a single fertilized egg, yet there may be differences in their congenital defects, birth weight, and genetic makeup. Asymmetric X chromosome inactivation, unequal gene imprinting, and postzygotic mitotic mistakes including nondisjunction and anaphase lag can all result in heterokaryotypic monochorionic twins. We report a monochorionic twin pregnancy that exhibited stigmata associated with trisomy 18 on postnatal examination despite a low risk of common aneuploidy (trisomy 18) on noninvasive prenatal screening. Short tandem repeat markers were used for postnatal examination to confirm high-grade mosaicism. These markers indicated mosaic trisomy 18 in twin II and normal in twin I, ruling out uniparental disomy and establishing monozygosity in both fetuses. Twin sac amniocentesis is a prenatal diagnostic procedure that can be used to identify discrepant monochorionic twins because chorionic villus sampling, single sac amniocentesis, or cordocentesis may not be able to rule out aneuploidy in the second fetus and may yield a false-negative result. For prompt zygosity diagnosis, chromosomal complement, genetic counseling, and referral for selective fetal reduction, twin sac amniocentesis is recommended.

The association between neonatal birthweight discordance and preeclampsia in twin pregnancy.

To investigate the association between neonatal birthweight (NBW) discordance and preeclampsia (PE) in twin pregnancy. This was a single-center retrospective cohort study. Women with two live births in the First Affiliated Hospital of Sun Yat-sen University from January 2011 to June 2020 were eligible. They were classified into four groups based on the quartiles of NBW discordance in monochorionic (MC) and dichorionic (DC) twin pregnancy. The relationship between NBW discordance and the risk of PE was assessed by logistic regression, subgroup analyses was further analyzed. A total of 1566 women were eligible for the final analysis, there were 445 MC cases and 1121 DC cases. No matter in monochorionic or dichorionic pregnancy, higher NBW discordance quartiles were associated with increased risks of PE. Compared with women in the lowest NBW discordance quartile, women in the highest NBW discordance quartile had approximately 3.6 and 6.0 times risk of PE in monochorionic and dichorionic pregnancy respectively. The association between quartiles of NBW discordance and the risk of PE were higher in dichorionic pregnancy than in monochorionic pregnancy. No matter in MC or DC pregnancy, no significant interaction effects were identified for maternal age, pregnancy body mass index, mode of conception and whether complicated with gestational diabetes mellitus. The increased NBW discordance quartile was related to an increased risk of PE. Assessing estimated fetal weight discordance by using ultrasound in clinical practice to predict PE remained to be further researched.

New radiofrequency ablation procedure for selective reduction in complicated monochorionic twin or triplet pregnancy using multistep, incremental expansion technique.

Radiofrequency ablation (RFA) is the preferred approach for selective reduction in complex monochorionic (MC) multiple pregnancies owing to the ease of operation and minimal invasiveness. To optimize the RFA technique and reduce the risk of adverse pregnancy outcome resulting from the heat-sink effect of RFA therapy, we used an innovative RFA method, in which an electrode needle was expanded incrementally and stepwise. This study aimed to assess the efficacy and safety profile of this novel multistep incremental expansion RFA method for selective fetal reduction in MC twin and triplet pregnancies. This was a single-center retrospective cohort study of all MC multiple pregnancies undergoing RFA between March 2016 and October 2022 at our center. The multistep RFA technique involved the use of an expandable needle, which was gradually expanded during the RFA procedure until cessation of umbilical cord blood flow was achieved. The needle used for the single-step RFA method was fully extended from the start of treatment. In total, 132 MC multiple pregnancies underwent selective reduction using RFA, including 50 cases undergoing multistep RFA and 82 cases undergoing single-step RFA. The overall survival rates were not significantly different between the multistep and single-step RFA groups (81.1% vs 72.3%; P = 0.234). Similarly, the rates of preterm prelabor rupture of the membranes within 2 weeks after RFA, procedure-related complications, spontaneous preterm delivery and pathological findings on cranial ultrasound, as well as gestational age at delivery and birth weight, did not differ between the two groups. However, there was a trend towards a prolonged procedure-to-delivery interval following multistep RFA compared with single-step RFA (median, 109 vs 99 days; P = 0.377). Moreover, the fetal loss rate within 2 weeks after RFA in the multistep RFA group was significantly lower than that in the single-step RFA group (10.0% vs 24.4%; P = 0.041). The median ablation time was shorter (5.3 vs 7.8 min; P < 0.001) and the median ablation energy was lower (10.2 vs 18.0 kJ; P < 0.001) in multistep compared with single-step RFA. There were no significant differences in neonatal outcomes following multistep vs single-step RFA. Overall survival rates were similar between the two RFA methods. However, the multistep RFA technique was associated with a lower risk of fetal loss within 2 weeks after RFA. The multistep RFA technique required significantly less ablation energy and a shorter ablation time compared with single-step RFA in selective fetal reduction of MC twin and triplet pregnancies. Additionally, there was a trend towards a prolonged procedure-to-delivery interval with the multistep RFA technique. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early diagnosis and management of inseparable conjoint twins. A low-middle-income country experience

HIGHLIGHTS Conjoined twins have captivated mankind for centuries due to the rarity of this birth type; nonetheless, physicians have constantly encountered difficulties in dealing with conjoined twins. Early diagnosis of conjoined twins during prenatal examination is critical for ascertaining the prognosis of the fetus, guiding parental counseling over appropriate courses of action, and potentially enabling the termination of the pregnancy. First-trimester ultrasonography and MRI are complementary modalities in determining the diagnosis and prognosis of conjoined twins in early pregnancy. ABSTRACT Objectives: To discuss the crucial early diagnosis of conjoined twins to determine the type and prognosis. Case Report: A 27-year-old woman was referred to the type A referral hospital with suspicion of congenital abnormalities at 17 weeks of pregnancy. Ultrasound results showed intrauterine monochorionic monoamniotic twins with babies fused on their heads to the urogenital part. The MRI showed a craniopagus, suspected meningomyelocele, and severe bilateral hydronephrosis in the second baby. Due to non-separable cases and a bad prognosis for the fetus, the pregnancy was terminated using misoprostol induction and inserting a balloon catheter. The fetus is born weighing 400 g and 20 cm in length. Conjoined twins obtained the rostral type: a fused head with two faces, a fused thorax until the lower abdomen with one umbilicus, and two pairs of hands and feet. The diagnosis of conjoint twins becomes a problem in early pregnancy, mostly in developing countries. Early diagnosis of conjoined twins during prenatal examination is critical for ascertaining the prognosis of the fetus, guiding parental counseling over appropriate courses of action, and potentially enabling the termination of the pregnancy to prevent maternal stress and complications. Conclusion: Conjoined twins should be identified as soon as feasible to establish the best course of management for both mother and fetus. Ultrasonography and MRI are modalities for determining the diagnosis and prognosis of conjoined twins.

Fetoscopic Laser Photocoagulation for Twin-Twin Transfusion Syndrome in a Dizygotic Monochorionic Twins

Fetoscopic Laser Photocoagulation for Twin-Twin Transfusion Syndrome in a Dizygotic Monochorionic Twins

Pregnancy and obstetric outcomes of dichorionic triamniotic triplet pregnancies with selective foetal reduction after assisted reproductive technology

BackgroundIt is generally beneficial and recommended that dichorionic triamniotic (DCTA) triplet pregnancies be reduced to monochorionic (MC) twin or singleton pregnancies after assisted reproductive technology (ART). However, some infertile couples still have a firm desire to retain twins. For this reason, the best foetal reduction strategies need to be available for infertile couples and clinicians. Given that data on the elective reduction of DCTA triplet pregnancies to twin pregnancies are scarce, we investigated the outcomes of elective reduction of DCTA triplet pregnancies through the retrospective analysis of previous data.MethodPatients with DCTA triplet pregnancies who underwent elective foetal reduction between January 2012 and June 2020 were recruited. A total of 67 eligible patients with DCTA triplet pregnancies were divided into two groups: a DCTA-to-dichorionic diamniotic (DCDA) twin group (n = 38) and a DCTA-to-monochorionic diamniotic (MCDA) twin group (n = 29); the basic clinical data of the two groups were collected for comparison.ResultsCompared with the DCDA-to-MCDA twin group, the DCTA-to-DCDA twin group had lower rates of complete miscarriage (7.89% versus 31.03%, p = 0.014), early complete miscarriage (5.26% versus 24.14%, p = 0.034), late preterm birth (25.71% versus 65.00%, p = 0.009) and very low birth weight (0 versus 11.11%, p = 0.025). In addition, the DCTA-to-DCDA twin group had higher rates of full-term delivery (65.71% versus 25.00%, p = 0.005), survival (92.11% versus 68.97%, p = 0.023), and taking the babies home (92.11% versus 68.97%, p = 0.023) than did the DCTA-to-MCDA twin group. In terms of neonatal outcomes, a significantly greater gestational age (38.06 ± 2.39 versus 36.28 ± 2.30, p = 0.009), average birth weight (3020.77 ± 497.33 versus 2401.39 ± 570.48, p < 0.001), weight of twins (2746.47 ± 339.64 versus 2251.56 ± 391.26, p < 0.001), weight of the larger neonate (2832.94 ± 320.58 versus 2376.25 ± 349.95, p < 0.001) and weight of the smaller neonate (2660.00 ± 345.34 versus 2126.88 ± 400.93, p < 0.001) was observed in the DCTA-to-DCDA twin group compared to the DCTA-to-MCDA twin group.ConclusionThe DCTA-to-DCDA twin group had better pregnancy and neonatal outcomes than the DCTA-to-MCDA twin group. This reduction approach may be beneficial for patients with dichorionic triamniotic triplet pregnancies who have a strong desire to have DCDA twins.

Fetal diagnosis and management of pulmonary artery sling: Acase series.

Pulmonary artery sling is a rare congenital anomaly accounting for 2% of all patients with vascular anomalies that cause airway obstruction. In the normal heart, the left (LPA) and right (RPA) pulmonary arteries arise in the intrapericardial space. However, in the pulmonary artery sling, the LPA trunk arises in the extrapericardial space from the posterior aspect of the mid RPA and courses posterior to the trachea causing tracheal compression and, at times, bronchial compression. While a full spectrum of congenital cardiac pathology can be identified before birth, only a few case reports document the prenatal diagnosis of an Left pulmonary artery sling (LPAS). We retrospectively identified all cases of prenatal LPAS from three Canadian fetal cardiology centers (2015-2022). Using the 3-vessel-tracheal view via fetal echocardiography (FE), four fetuses from three pregnancies demonstrated abnormal origin of the LPA from RPA and echogenic trachea. In one of two affected monochorionic twins coronal imaging demonstrated a significant narrowing of the large airways consistent with significant airway obstruction. Prenatal detection of LPAS by FE is possible and should prompt an evaluation for airway obstruction in the coronal view. Investigating associated lesions and genetic testing are recommended for informed shared decision making.

Is There a Cumulative Effect for Congenital Heart Defects in Monochorionic Twins after Assisted Reproduction? - A Retrospective Analysis at a Tertiary Referral Center.

The aim of our study was to compare maternal, chorionicity and neonatal complications in monochorionic (MC) twins between spontaneously conceived (SC) and assisted reproductive technologies (ART) pregnancies. This was a retrospective cohort study between January 2010 to December 2019 at a tertiary referral University center. All consecutive pregnancies with MC twins that delivered at our University hospital were included. Maternal, chorionicity and neonatal complications were recorded and compared between SC and ART pregnancies. 393 MC pregnancies were included for final analysis, including 353 (89.8%) SC and 40 (10.2%) pregnancies conceived after ART. Hypothyroidism was the only maternal condition seen significantly more often in ART pregnancies (35.0% vs 12.5%, p=0.001). There were no significant differences in chorionicity complications, such as twin-twin transfusion syndrome, selective fetal growth restriction and twin anemia-polycythemia sequence (40.0% in ART pregnancies vs 31.6% in SC pregnancies, p=0.291). At least one congenital anomaly in one twin was seen significantly more often in ART pregnancies (18.8% vs 8.1%, p=0.004), especially congenital heart defects (16.3% vs 6.2%, p=0.005). There were no other significant differences in neonatal outcomes between both groups, however, there were non-significant trends in gestational age at delivery (34 weeks in ART pregnancies vs 35 weeks, p=0.078) and birthweight (1951g±747 in ART pregnancies vs 2143g±579, p=0.066). This is the largest cohort study to date comparing maternal, chorionicity and neonatal complications between MC twin pregnancies after ART and after SC. Hypothyroidism was the only maternal condition occurring more frequently in pregnancies conceived after ART. There were no significant differences in chorionicity complications, in contrast to previously reported studies. While MC twins and ART pregnancies per se are known to be at risk for congenital heart defects, there seems to be a cumulative effect in MC pregnancies conceived after ART.

Prevalence, Risk Factors, and Perinatal Outcomes of Velamentous Umbilical Cord Insertion in Twin Pregnancies: A Single-Center Retrospective Study.

The effect of velamentous cord insertion (VCI) on perinatal outcomes in twin pregnancies is unclear due to conflicting findings. This retrospective study aimed to examine VCI prevalence and related risk factors in twin pregnancies and its association with adverse perinatal outcomes. Women with twin pregnancies who delivered between January 2012 and December 2021 in a single tertiary hospital were included. The participants were divided into dichorionic (DC) and monochorionic diamniotic (MCDA) groups, and their maternal and fetal characteristics and VCI rates were compared. Logistic regression models were used to identify risk factors for VCI and VCI-related perinatal outcomes. Among the 694 twin pregnancies included in this study, the VCI rate was significantly higher in MCDA than in DC twins. Body mass index and MCDA twins were significant risk factors for VCI, whereas assisted reproductive technology pregnancy was a significant protective factor against VCI. In DC twins, VCI did not affect perinatal outcomes. In MCDA twins, VCI was a significant risk factor for fetal growth restriction, twin-to-twin transfusion syndrome, and preterm birth at <36 weeks. VCI was a prominent risk factor for adverse perinatal outcomes only in MCDA twins. Antenatal sonographic assessment of the umbilical cord insertion site would be beneficial.

The changing Doppler patterns and perinatal outcomes of monochorionic diamniotic twins with selective fetal growth restriction.

To investigate the clinical outcomes and Doppler patterns changes in monochorionic diamniotic (MCDA) twins with selective fetal growth restriction (sFGR). We retrospectively analyzed 362 sFGR cases from January 2010 to May 2016 at a single tertiary referral center. The Doppler waveforms of umbilical artery end-diastolic flow were collected, and all neonates were subjected to an early neonatal brain scan. A total of 66/100 (66 %) type I cases were stable, whereas 25/100 (25 %) cases changed to type II and 9/100 (9 %) changed to sFGR complicated twin-twin transfusion syndrome (TTTS). A total of 48.9 % (22/45) sFGR cases were complicated with polyhydramnios and 30.4 % (7/23) sFGR cases were complicated with oligohydramnios, both of which were progressed to sFGR with TTTS. Mild cerebral injury was significantly associated with Doppler flow abnormalities, earlier gestational age at delivery and type of sFGR diagnosis. Severe cerebral injury was significantly associated with gestational age at delivery (31.6 vs. 34.1, p=0.002) and larger birthweight discordance (43.9 vs. 29.3 %, p=0.011). Doppler patterns in sFGR can gradually change, with important consequences with regard to management and outcomes. Along with abnormal Doppler findings, earlier occurrence of sFGR and delivery are associated with subsequent neonatal cerebral injury.

Prenatal phthalate exposure and neurodevelopmental differences in twins at 2 years of age

BackgroundPrevious studies of singletons evaluating prenatal phthalate exposure and early neurodevelopment reported mixed results and the associations could be biased by parental, obstetrical, and genetic factors.MethodsA co-twin control design was employed to test whether prenatal phthalate exposure was associated with children’s neurocognitive development. We collected information from 97 mother-twin pairs enrolled in the Wuhan Twin Birth Cohort between March 2016 and October 2018. Fourteen phthalate metabolites were measured in maternal urine collected at each trimester. Neurodevelopmental differences in twins at the age of two were examined as the outcome of interest. Multiple informant model was used to examine the covariate-adjusted associations of prenatal phthalate exposure with mental development index (MDI) and psychomotor development index (PDI) scores assessed at 2 years of age based on Bayley Scales of Infant Development (Second Edition). This model also helps to identify the exposure window of susceptibility.ResultsMaternal urinary levels of mono-2-ethyl-5-oxohexyl phthalate (MEOHP) (β = 1.91, 95% CI: 0.43, 3.39), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) (β = 1.56, 95% CI: 0.33, 2.79), and the sum of di-(2-ethylhexyl) phthalate metabolites (∑DEHP) (β = 1.85, 95% CI: 0.39, 3.31) during the first trimester showed the strongest and significant positive associations with intra-twin MDI difference. When stratified with twin chorionicity, the positive associations of monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), individual DEHP metabolites, and ∑DEHP exposure during pregnancy with intra-twin neurodevelopmental differences were more significant in monochorionic diamniotic (MCDA) twins than those in dichorionic diamniotic (DCDA) twins.ConclusionsNeurodevelopmental differences in MCDA twins were strongly associated with prenatal phthalate exposure. Our findings warrant further confirmation in longitudinal studies with larger sample sizes.

Predictors of Poor Outcomes in Monochorionic Diamniotic Twin Pregnancies Complicated by Selective Fetal Growth Restriction

Introduction: The aim of the study was to identify predictors of poor outcomes in monochorionic diamniotic twin (MCDA) pregnancies with selective fetal growth restriction (sFGR), irrespective of the umbilical artery (UA) Doppler abnormalities. Methods: Single-center retrospective analysis of MCDA twins diagnosed with sFGR that opted for expectant management between 2010 and 2021. The presence of any of the following variables in the growth-restricted fetus: low amniotic fluid volume (DVP ≤2 cm), lack of a cycling bladder, absent or reversed flow in the ductus venosus (DV) with atrial contraction, and elevated middle cerebral artery peak systolic velocity (MCA-PSV) defined as ≥1.50 multiples of the median was categorized as complicated. sFGR cases were classified as simple in the absence of the above-mentioned variables. Results: Overall, 63.3% of cases qualified as simple, and 36.7% were complicated. Intertwin EFW discordance was higher in the complicated category (26 vs. 33%, p = 0.0002). The median gestational age at delivery was earlier (33 weeks vs. 30.5 weeks, p = 0.002), and the likelihood of survival was lower in the complicated category (p < 0.0001). The likelihood of two survivors to discharge was lower in type I complicated cases (70% in complicated type I vs. 97.1% in simple type I, p = 0.0003). On logistic regression analysis, an increase in the “complicated” score negatively correlated with two survivors to discharge (p < 0.0001). An ROC curve was created, and the AUC was 0.79. Increasing intertwin EFW discordance also decreased the probability of two survivors to discharge. Conclusion: The presence of oligohydramnios, lack of a cycling bladder, abnormal DV Doppler, and elevated MCA-PSV in the growth restricted fetus is associated with poor perinatal outcomes and a lower likelihood of having two survivors to discharge. The addition of intertwin EFW discordance to these variables helped improve the survival predictability.

Increased Nuchal Translucency in Fetuses with Normal Karyotype

BACKGROUND: Increased nuchal translucency (NT) is associated with a high risk of chromosomal abnormalities and genetic syndromes. In fetuses with normal karyotype, thickened NT increases the likelihood of congenital heart malformations, spontaneous abortions, and stillbirths, especially in thickness &gt; 3.5 mm. It was found that in the absence of accompanying structural abnormalities and a normal result of amniocentesis, the postnatal neurological development of the newborns did not differ from the general population. CASE PRESENTATION: The authors describe a case of sIUGR of monochorionic twins with second trimester selective umbilical cord ablation and livebirth of a healthy singleton. CONCLUSION: Abnormal NT thickness on early fetal morphology scan in euploid fetuses, especially in twin pregnancies, increase the suspicion for late complications of the pregnancy.

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

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. 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). 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 vs50.31 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. 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.

Fetal Medicine Foundation charts for fetal growth in twins.

To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons. 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. 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. 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.

Outcomes of monochorionic twins with twin reversed arterial perfusion sequence: interstitial laser versus cord occlusion

Outcomes of monochorionic twins with twin reversed arterial perfusion sequence: interstitial laser versus cord occlusion

Long-Term Neurodevelopmental Outcome After Selective Fetoscopic Laser Therapy for Stage I Twin-Twin Transfusion Syndrome.

Twin-twin transfusion syndrome (TTTS) is a serious complication in monochorionic (MC) pregnancies. Fetoscopic laser surgery (FLS) is the primary treatment for advanced TTTS, but managing Quintero stage I TTTS is still controversial. We conducted an observational study evaluating the 2-year neurodevelopment of fetuses, which underwent FLS for stage I TTTS, compared with advanced TTTS and uncomplicated monochorionic diamniotic twins (MCDTs). The study included 156 children: 14 in stage I TTTS group, 28 in advanced TTTS group, and 114 in uncomplicated twin group. In stage I TTTS, 92.9% showed normal neurodevelopment, with no severe neurological impairments observed. These results were comparable with uncomplicated twins (92.1% normal neurodevelopment, P = .921, adjusted odds ratio [aOR] = 1.56, 95% confidence interval [CI] = 0.42-5.79; 1.8% severe impairment, P = .617). Advanced TTTS had a non-significant lower rate of normal neurodevelopment (89.3%, P = .710, aOR = 1.31, 95% CI = 0.12-14.87). In conclusion, FLS for stage I TTTS shows favorable long-term neurodevelopmental outcomes, similar to uncomplicated MC pregnancies.