Monochorionic (MC) twins are at an increased risk of developing congenital heart defects (CHDs) compared to singletons and dichorionic twins. The development of acquired CHDs in this specific group of twins is associated with twin–twin transfusion syndrome (TTTS). We performed a systematic review and meta-analysis to provide an overview of the reported birth prevalence of CHDs in liveborn MC twins with and without TTTS. Twelve studies were included in this review. Compared to the reference population, MC twins were 6.3 times more likely to be born with a CHD (59.3 per 1000 liveborn twins; relative risk (RR) 6.3; 95% confidence interval (CI): 4.4–9.1), and TTTS twins had a 12-fold increased risk of having a CHD at birth (87.3 per 1000 live births; RR 12.4, 95% CI: 8.6–17.8). The increased incidence of CHDs can mainly be attributed to the risk of right ventricular outflow tract obstruction (35/1000 TTTS twin live births vs. 0.5/1000 singleton live births). We recommend an expert fetal echocardiogram in all MC twins, follow-up scans in the event of TTTS, and a postnatal cardiac evaluation in all TTTS survivors.

Objective: To investigate whether perioperative fetal hemodynamic changes in twin‐to‐twin transfusion syndrome (TTTS) are associated with neurodevelopmental impairment (NDI) at two years.Methods: Doppler parameters of three sonograms (day before, first day after and 1 week after laser surgery for TTTS) were assessed for correlation with neurodevelopmental outcome at two years (2008‐2016). NDI was defined as: cerebral palsy, deafness, blindness, and/or a Bayley‐III cognitive/motor developmental test‐score > 2SD below the mean.Results: Long‐term outcome was assessed in 492 TTTS survivors. NDI was present in 5% (24/492). After adjustment for severe cerebral injury (present in 4%), associated with NDI were: middle cerebral artery peak systolic velocity (MCA‐PSV) >1.5 multiples of the median (MoM) 1 day after surgery (odds ratio [OR] 4.96; 95% confidence interval [CI]: 1.17‐21.05, P = .03), a change from normal umbilical artery pulsatility index (UA‐PI) presurgery to UA‐PI >p95 postsurgery (OR 4.19; 95% CI: 1.04‐16.87, P = .04), a change from normal to MCA‐PSV >1.5MoM (OR 4.75; 95% CI: 1.43‐15.77, P = .01).Conclusion: Perioperative fetal hemodynamic changes in TTTS pregnancies treated with laser are associated with poor neurodevelopmental outcome. Prospective research on the cerebrovascular response to altered hemodynamic conditions is necessary to further understand the cerebral autoregulatory capacity of the fetus in relation to neurodevelopmental outcome.

This study aimed to investigate the value of echocardiography and Doppler before fetoscopic laser coagulation for twin‐twin transfusion syndrome (TTTS) in the prediction of intrauterine fetal demise (IUFD). We performed a systematic review and meta‐analysis to compare preoperative parameters between fetuses with and without demise after laser surgery. Eighteen studies were included. Recipient twins have an increased risk of demise in case of preoperative absent/reversed flow (A/REDF) in the umbilical artery (odds ratio [OR] 2.76, 95% confidence interval [CI], 1.78‐4.28), absent or reversed a‐wave in the ductus venosus (OR 2.32, 95% CI, 1.70‐3.16), or a middle cerebral artery peak systolic velocity > 1.5 multiples of the median (MoM) (OR 7.59, 95% CI, 2.56‐22.46). In donors, only A/REDF in the umbilical artery (OR 3.40, 95% CI, 2.68‐4.32) and absent or reversed a‐wave in the ductus venosus (OR 1.66, 95% CI, 1.12‐2.47) were associated with IUFD. No association was found between donor‐IUFD and preoperative myocardial performance index (MPI). Two studies found an association between abnormal MPI and recipient demise. With this study, we have identified a set of preoperative Doppler parameters predictive of fetal demise after laser surgery. More research is needed to assess the utility of preoperative echocardiographic parameters such as the MPI in predicting IUFD.

Objectives: This systematic review explores cardiac adaptation in monochorionic (MC) twins with twin–twin transfusion syndrome (TTTS) or selective fetal growth restriction (sFGR) and assesses the risk of congenital heart defects (CHDs).Methods: Adhering to PRISMA guidelines, 63 studies were reviewed (49 on cardiac adaptation, 13 on CHD, one on both). A narrative synthesis of cardiac adaptation patterns was performed. Additionally, a meta‐analysis compared the livebirth prevalence of CHD in TTTS and sFGR against uncomplicated MC twins.Results: In TTTS recipients, cardiac function may be impaired for diastolic, systolic, as well as global functions, while in donors, cardiac function is generally preserved. In sFGR, large twins may show hypertrophic cardiomyopathy, and small twins may show impaired systolic function. Co‐occurrence of TTTS and sFGR magnifies cardiac impact but is often underreported. Meta‐analysis for CHD prevalence revealed a relative risk ratio of 3.5 (95% CI: 2.5–4.9) for TTTS and 2.2 (95%CI: 1.3–3.5) for sFGR compared with uncomplicated MC twins.Conclusions: This study highlights the well‐documented cardiac adaptation in TTTS, contrasting with limited understanding in sFGR. Elevated CHD risks were observed in both conditions. Enhanced cardiovascular surveillance is warranted in complicated MC twin pregnancies. Future research should explore cardiac adaptation in sFGR and its long‐term consequences.

BACKGROUND: Newborns with anemia are at increased risk of persistent pulmonary hypertension of the newborn (PPHN), yet reports on the association between fetomaternal hemorrhage (FMH) and PPHN are rare. To optimize care for pregnancies complicated by FMH, clinicians should be aware of the risks of FMH and the possible diagnostic and therapeutic options. To increase the current knowledge, the incidence of PPHN and short‐term neurologic injury in FMH cases were studied.STUDY DESIGN AND METHODS: We included all FMH cases (≥30 mL fetal blood transfused into the maternal circulation) admitted to our neonatal unit between 2006 and 2018. First, we evaluated the incidence of PPHN and short‐term neurologic injury. Second, we studied the potential effect of intrauterine transfusion (IUT).RESULTS: PPHN occurred in 37.9% of newborns (11 of 29), respectively, 14.3% (one of seven) and 45.5% (10 of 22) in the IUT group and no‐IUT group (p = 0.20). The mortality rate was 13.8% (4 of 29). Severe brain injury occurred in 34.5% (10 of 29), respectively, and 14.3% (one of seven) and 40.9% (nine of 22) in the IUT group and no‐IUT group (p = 0.37).CONCLUSION: Awareness should be raised among perinatologists and neonatologists about the possible life‐threatening consequences of FMH, as more than one‐third of neonates with anemia due to FMH experience PPHN and suffer from severe brain injury. Antenatal treatment with IUT seems to reduce these risks. Specialists should therefore always consider fetal anemia in FMH cases and refer patients to a fetal therapy center. If anemia is present at birth, it should be corrected promptly and neonatologists should be aware of signs of PPHN.

Introduction: Monochorionic twins are at increased risk of congenital heart defects (CHDs). Up to 26% have a birth weight <1,500 g, a CHD requiring neonatal surgery, therefore, poses particular challenges. Objective: The aim of the study was to describe pregnancy characteristics, perinatal management, and outcome of monochorionic twins diagnosed with critical coarctation of the aorta (CoA). Methods: We included monochorionic twins diagnosed with critical CoA (2010–2019) at 2 tertiary referral centers, and we systematically reviewed the literature regarding CoA in monochorionic twins. Results: Seven neonates were included. All were the smaller twin of pregnancies complicated by selective fetal growth restriction. The median gestational age at birth was 32 weeks (28–34). Birth weight of affected twins ranged as 670–1,800 g. One neonate underwent coarctectomy at the age of 1 month (2,330 g). Six underwent stent implantation, performed between day 8 and 40, followed by definitive coarctectomy between 4 and 9 months in 4. All 7 developed normally, except for 1 child with neurodevelopmental delay. Three co-twins had pulmonary stenosis, of whom 1 required balloon valvuloplasty. The literature review revealed 10 cases of CoA, all in the smaller twin. Six cases detected in the first weeks after birth were treated with prostaglandins alone, by repeated transcatheter angioplasty or by surgical repair, with good outcome in 2 out of 6. Conclusions: CoA specifically affects the smaller twin of growth discordant monochorionic twin pairs. Stent implantation is a feasible bridging therapy to surgery in these low birth weight neonates.