Can birth weight discordancy within monozygotic twin pairs be used as an indicator of chorionicity?

Research output: Contribution to journalArticlepeer-review

Authors

External organisations

  • Department for Human Genetics, Faculty of Medicine, Catholic University of Leuven, Belgium
  • Association for Scientific Research in Multiple Births, Destelbergen, Belgium
  • Department Complex Genetics, Cluster of Genetics and Cell Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, the Netherlands
  • Department Complex Genetics, Cluster of Genetics and Cell Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, the Netherlands

Abstract

Both zygosity and chorionicity provide important information in twin research. The East Flanders Prospective Twin Survey (EFPTS) determines zygosity and chorionicity at birth and therefore provides a gold standard for the testing of diagnostic parameters that can be used to determine chorionicity. The aim of the present study was to investigate whether birthweight discordancy can be used as an indicator of chorionicity. The study sample consisted of 4,060 live-born twin pairs from the EFPTS. We studied MZ twins, using univariate and multivariate logistic regression analyses to calculate odds ratios (OR) and 95% confidence intervals (CI) of being MC in relation to discordancy level. Diagnostic parameters, including sensitivity and specificity, were calculated. A two-fold cross-validation was carried out and a bootstrap distribution with 10,000 samples was created to estimate the standard deviations. For discordancy levels of below 10%, 10-15%, 15-20%, 20-25% and above 25%, the ORs (95% CI) were 1.16 (0.91-1.47), 1.38 (1.05-1.80), 2.13 (1.51-3.01), 2.73 (1.73-4.29) and 2.81 (2.81-4.35) respectively. There were no gender differences. Sensitivity was 42.2% (SD 5.6%), specificity was 72.8% (SD 6.3%), positive predictive value was 72.8% (1.5%) and the negative predictive value was 39.2% (0.7%). In conclusion, although a higher discordancy level resulted in higher ORs of being an MC twin, birthweight discordancy level can only be used to some weak extent as a proxy for chorionicity, highlighting the need to assess and record chorionicity data in obstetrical units.

Details

Original languageEnglish
Pages (from-to)169-174
Number of pages6
JournalTwin Research and Human Genetics
Volume12
Issue number02
Publication statusPublished - Apr 2009