Skip to main content

Can Birthweight Discordancy Within Monozygotic Twin Pairs Be Used as an Indicator of Chorionicity?

  • Marij Gielen (a1), Catherine Derom (a2), Robert Derom (a3), Robert Vlietinck (a4) and Maurice P. Zeegers (a5)...

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.

Corresponding author
*Address for correspondence: Marij Gielen, Department of Complex Genetics, Cluster of Genetics and Cell Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Universiteitssingel 50 Box 616, 6200 MD Maastricht, The Netherlands.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Twin Research and Human Genetics
  • ISSN: 1832-4274
  • EISSN: 1839-2628
  • URL: /core/journals/twin-research-and-human-genetics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed