Abstract
BackgroundThe rate of twinning continues to increase due to the combined effect of a rise in parental age and increased use of assisted reproductive technology. The risk of congenital anomalies in twins is higher than in singletons, but it is less well reported in relation to growth patterns. We focused to the auxological outcome of twin pregnancies when one or both of twins are affected by one or more malformations.MethodsWe conducted a retrospective observational study reviewing the clinical charts of twins admitted in the period between January 2003 and December 2018 at the University Hospital of Palermo. The associations between malformations and anthropometric variables at birth were analyzed by comparison within each twin pair and regarding each variable as ordered difference between the two twins.ResultsWe studied data of 488 neonates (52% females) from 244 pregnancies. The rate of major congenital anomalies was 11%, affecting significantly the smaller twin (p = .00018; Odds ratio 3.21; 95% CI 1.65 6.59). Malformation class distribution was as following: genitourinary (24%), gastrointestinal (20%), cardiovascular (18.5%), musculoskeletal (11%), central nervous system (9%), syndromic (9%), ocular (5.5%) and diaphragmatic hernia (2%). The most predictive value, the Birthweight (BW) difference mean ratio in malformed versus not malformed neonates (− 0.31 vs 0.02; p = .0016) was distributed equally lower than zero in all malformed twins, except for those with congenital heart defects (p = .0000083).Microcephaly (head circumference < 2 standard deviation, SD) was present in 3% of symmetrically smaller twin, and severe microcephaly (< 3 SD) was present in 0.6%. We found that an intertwin BW discordance of 18% or greater identified 50% of neonates with microcephaly, but only 11% of malformed twins.ConclusionsIn case of one twin with a BW < 10th centile, a concomitant intertwin BW discordance ≥18% could reveal an increased risk for microcephaly but not for malformation. Lower values of BW, Ponderal index, Body mass index but above all negative value of BW difference mean ratio are associated with malformations in twin pairs.
Highlights
The rate of twinning continues to increase due to the combined effect of a rise in parental age and increased use of assisted reproductive technology
fetal growth restriction (FGR) considered as BW < 3rd centile occurred in 36/ 488 (7.4%) of neonates, and in 44/488 (9.0%) of neonates when a BW < 10th centile and concomitant BW discordance of 18% or greater were considered
Sex was concordant in all MC monoamniotic (MCMA) and MC diamniotic (MCDA) pregnancies, and in 32.5% of DC diamniotic (DCDA) pregnancies
Summary
The rate of twinning continues to increase due to the combined effect of a rise in parental age and increased use of assisted reproductive technology. The risk of congenital anomalies in twins is higher than in singletons, but it is less well reported in relation to growth patterns. In relation to modernization of societies and consequent advanced parental age, we assisted to a progressive falling in fertility rate. Spontaneous twinning rates are increased with advanced parental age and urban residence confirming an environmental influence [6]. Fetal growth restriction (FGR); defined as intrauterine growth restriction, and the condition of small for gestational age (SGA), frequently used interchangeably, are more frequent in case of multiple pregnancy, with a higher global complication rate affecting monozygotic (MZ) twins [7, 8]. FGR, variably defined in scientific literature, cannot be frequently predicted by maternal risk factors [8], and contribute to the well documented higher prevalence of neurodevelopmental impairment in selected categories of twins compared to singletons [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
