Chorionicity and neurodevelopmental outcomes in twin pregnancy: a systematic review and meta-analysis

Impact of Chorionicity in Neurodevelopmental Outcomes in Preterm Twins

Introduction Multifetal pregnancies, which account for 2-4% of births worldwide, have increased in recent years. Twin pregnancies carry a higher risk of preterm birth and associated neonatal morbimortality, with monochorionic twins considered at greater risk. This study investigates the influence of chorionicity on neurodevelopmental outcomes in preterm twins. Methods A retrospective cohort study was conducted, including preterm twins born before 32 weeks of gestational age and/or with a birth weight of less than 1500 grams, admitted to a tertiary-hospital neonatal intensive care unit from 2013 to 2021. Neurodevelopmental outcomes were evaluated at 24 months of corrected age using the Griffiths II Mental Development Scales. Moderate to severe neurodevelopmental impairment was determined by the occurrence of one or more of the listed criteria: global development quotient <70, severe visual impairment, cerebral palsy, or profound sensorineural deafness. Results A total of 125 preterm twins were evaluated, of which 45% (n=56) were monochorionic. Overall, 5.6% (n=7) of the infants had moderate to severe neurodevelopmental impairment (NDI), with higher comorbidity rates in this group. No significant differences were found in NDI or other prematurity-related comorbidities between monochorionic and dichorionic twins. Gestational age over 27 weeks and birth weight over 1010 grams were identified as accurate predictors for an absence of moderate to severe NDI in these infants. Conclusion Chorionicity alone does not appear to independently affect neurodevelopmental outcomes in preterm twins when complications are effectively managed. Improved prenatal monitoring and appropriate treatment of twin pregnancies, especially monochorionic, are crucial to mitigate risks associated with moderate to severe neurodevelopmental impairment.

Cerebral palsy as a childhood-onset neurological disorder caused by both genetic and environmental factors

Cerebral palsy (CP) is a clinical term used to describe a spectrum of movement and posture disorders resulting from non-progressive disturbances in the developing fetal brain. The clinical diagnosis of CP does not include pathological or aetiological defining features, therefore both genetic and environmental causal pathways are encompassed under the CP diagnostic umbrella. In this review, we explore several genetic causal pathways, including both monogenic and polygenic risks, and present evidence supporting the multifactorial contributions to CP. Historically, CP has been associated with various risk factors such as pre-term birth, multiple gestation, intrauterine growth restriction (IUGR), maternal infection, and perinatal asphyxia. Thus, we also examine genetic predispositions that may contribute to these risk factors. Understanding the specific aetiology of CP enables more tailored treatments, especially with the increasing potential for early genetic testing.

Chorionicity and Psychomotor Development From Infancy to Childhood: The Japan Environment and Children's Study

Twins lag behind singletons in their early psychomotor development, but little is known about how chorionicity affects this difference. We compared early psychomotor development in singletons, monochorionic (MC) twins and dichorionic (DC) twins. Our longitudinal data from the Japan Environment and Children's Study (JECS; see Appendix) included 98,042 singletons, 577 MC twins and 1051 DC twins representing the general Japanese population. Chorionicity was evaluated by ultrasound images and complemented by postnatal pathological examinations. Five domains of psychomotor development were evaluated at 6 time points from 6 months to 3 years of age using the Ages and Stages Questionnaires (ASQ-3). The data were analyzed using linear regression models. Twins lagged behind singletons in all areas of psychomotor development during infancy. This gap decreased over time but was still noticeable at 3 years of age. More than half of this difference was attributed to twins having lower birth weight and being born earlier in gestation. MC twins showed slightly delayed development compared to DC twins, but this difference was minor compared to the overall gap between twins and singletons. Twins delay singletons in their early psychomotor development, and this delay is not specific to MC twinning.

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.

Two Year Neurodevelopmental Outcome after Fetoscopic Laser Therapy for Twin-Twin Transfusion Syndrome: Comparison with Uncomplicated Monochorionic Diamniotic Twins

BACKGROUND

Twin-twin Transfusion Syndrome (TTTS) represents a significant complication in monochorionic twin pregnancies, caused by an unbalanced shunting of blood through intertwin placental vascular anastomoses. Despite advances in fetoscopic laser surgery, TTTS is still associated with a high rate of cerebral injury. However, there are no studies comparing these pregnancies with uncomplicated monochorionic diamniotic (MCDA) twin pregnancies, establishing the baseline risk of neurodevelopmental impairment. The aim of this study is to evaluate the odds of neurodevelopmental impairment in MCDA twins who undergo fetoscopic laser surgery for twin-twin transfusion syndrome, in comparison to a cohort of uncomplicated MCDA twin pregnancies.

STUDY DESIGN

This is a retrospective cohort study of children born from MCDA twin pregnancies at a single center between 2008 and 2019. A routine, standardized follow-up assessment was conducted at a minimum of 2 years after delivery. The primary outcome of this was a 2 year neurodevelopmental impairment. Neurological, motor, and cognitive development was assessed by using the revised Brunet-Lézine scale.

RESULTS

176 children met the enrolment criteria. Of these, 42 (24%; TTTS group) underwent fetoscopic laser surgery for TTTS during pregnancy, and 134 (76%; uncomplicated MCDA group) were uncomplicated MCDA pregnancies. The primary outcome was found in four children (9.52%) in the TTTS group and ten children (7.46%) in the uncomplicated MCDA group (p = 0.67, aOR 2.82, 95% CI 0.49-16.23). Major neurologic impairment was found in 2.38% after fetoscopic laser surgery and 1.49% in uncomplicated MCDA twins (p = 0.70, aOR 0.97, 95% CI 0.22-4.24). The data were adjusted by birth order, birth weight, and gestational age at birth.

CONCLUSIONS

The outcome in MCDA twins who underwent fetoscopic laser surgery for TTTS is comparable to the outcome in uncomplicated MCDA twins. Our findings emphasize the need for long-term neurodevelopmental follow-ups in all children from monochorionic twin gestations.