To construct monochorionic (MC) twin-specific longitudinal Doppler references for umbilical artery pulsatility index (UA-PI), middle cerebral artery (MCA) PI and peak systolic velocity (PSV) and ductus venosus (DV) PI derived from a strictly selected cohort of uncomplicated MC twins. The secondary aim of the study was to compare our findings with singleton reference charts. A retrospective evaluation was made of all consecutive uncomplicated MC twin pregnancies referred to our Unit from 2010 to 2018. Fortnightly serial examinations were performed of UA-PI, MCA-PI, MCA-PSV and DV-PI, according with the clinical protocol, from 20 to 37 weeks of gestation. We included cases with at least four ultrasound examinations, delivery at our hospital and complete neonatal follow up. A two-step method was used to trace the estimated centile curves: estimation of the median was performed with appropriate fractional polynomials by a multilevel model and estimation of the external centiles through the residuals (quantile regression). The comparison with singletons was made by plotting the references derived from the present study on the referred charts commonly used for singletons. The study group comprised 150 uncomplicated MC twin pairs. Estimated centiles (3^rd, 5^th, 10^th, 50^th, 90^th, 95^th, 97^th) of UA-PI, MCA-PI, MCA-PSV and DV-PI in function of the gestational age are presented. The comparison with singletons showed substantial differences, with higher UA-PI and lower MCA-PI and PSV median values in MC twins. Median DV PI values were similar to the values for singletons, while the upper centiles were higher in MC twins. This study sets out MC twin-specific longitudinal references for UA-PI, MCA-PI, MCA-PSV and DV-PI derived from the largest series of uncomplicated MC twin pregnancies presently available. The comparison with singleton reference values underscores the deviation from physiology that is intrinsic to these unique pregnancies and supports the need for MC twin-specific charts.

Introduction: We aimed to identify maternal and fetal complications and investigate postnatal and long-term outcomes of fetal hydrothorax (FHT) treated with pleuro-amniotic shunting (shunt). Methods: Single-center retrospective observational cohort of shunt cases performed from 2000 to 2021. Risk factors for maternal complications, fetal demise, neonatal death (NND), and postnatal outcomes were identified. Results: Out of 88 cases, 70 (79.5%) were complicated by hydrops, with an average gestational age (GA) at diagnosis of 27 weeks (range 16–34). In 16 cases, definitive etiology of FHT was identified; five cases of Noonan syndrome and three cases of monogenic disorders diagnosed by whole-exome sequencing (EPHB4, VEGFR3, RASA1). Shunt was performed at an average GA of 28 weeks (20–34), with a dislodgement in 10 cases (11.4%). Maternal: Complications occurred in three cases; survival rate was 76.1% (67/88). Follow-up data were available for 57/67 (85.1%) children. Incidence of severe neurodevelopmental impairment and pneumopathy (broncho dysplasia, persistent pulmonary hypertension of newborn, and asthma) was 5.3% and 8.8%, respectively. Post-treatment persistence of hydrops, FHT associated with genetic syndromes, and GA at birth were risk factors for fetal demise, NND, and postnatal complications. Conclusion: In truly isolated FHT, whenever indicated, pleuro-amniotic shunting is a safe procedure associated with good survival rate and long-term outcome.

Pregnancies complicated by severe polyhydramnios are associated with a high rate of underlying fetal anomaly. Amnioreduction may be offered to alleviate maternal symptoms. This is a retrospective study of amnioreductions performed on singleton and twin gestations complicated by symptomatic polyhydramnios between 2010 and 2023 at our tertiary referral center. The indications, procedural techniques and pregnancy and neonatal outcomes were retrieved from an archive database and reviewed with the use of the maternal and child medical record chart, the hospital electronic clinical discharge report and telephone recalls. Our study comprised 86 pregnancies, 65 singletons and 21 twin pregnancies. Fetal anomalies were identified in 79% of cases, mainly gastrointestinal obstructive anomalies; 9.3% of cases were idiopathic. The median gestational age at first amnioreduction was 32.5 weeks, and peri-procedural complications were rare (1 case of placental abruption and 2 cases of preterm delivery). The median gestational age at delivery was 36.5 weeks, with a median prolongation of the pregnancy from the time of first drain until birth of 30 days. Preterm labor < 37 weeks occurred in 48.8% of procedures, with 26.7% of patients delivering before 34 weeks and pPROM < 36 weeks recorded in 23.2% of cases. In conclusion, amnioreduction offered to alleviate maternal symptoms is a reasonably safe procedure with a low complication rate. These pregnancies necessitate management in a tertiary referral center because of their need for a multidisciplinary approach both prenatally and postnatally.

Right ventricular outflow tract anomalies (RVOTAs), such as pulmonary stenosis (PS), pulmonary atresia (PA), and pulmonary insufficiency (PI), are typical cardiac anomalies in monochorionic twins, and they are complicated by twin-to-twin transfusion syndrome (TTTS). The aim of this study was to conduct a long-term postnatal cardiological evaluation of prenatal RVOTAs in monochorionic diamniotic twin pregnancies complicated by TTTS and treated with fetoscopic laser surgery (FLS) and to analyze possible prenatal predictors of congenital heart disease (CHD). Prenatal RVOTAs were retrospectively retrieved from all TTTS cases treated with FLS in our unit between 2009 and 2019. Twenty-eight prenatal cases of RVOTAs (16 PI, 10 PS, 2 PA) were observed out of 335 cases of TTTS. Four cases did not reach the postnatal period. CHD was present in 17 of the remaining 24 cases (70.8%), with 10 being severe (58.8%; 10/17); nine cases of PS required balloon valvuloplasty, and one case required biventricular non-compaction cardiomyopathy. The risk of major CHD increased with prenatal evidence of PS and decreased with the gestational age at the time of TTTS and with the prenatal normalization of blood flow across the pulmonary valve. Despite treatment with FLS, the majority of monochorionic diamniotic twin pregnancies complicated by TTTS with prenatal RVOTAs had CHD at long-term follow-up.