Growth percentiles of singleton and twin newborns: Analysis of births in Germany

Objective: There is no consensus whether twin gestations require different normal values for anthropometric measurements than singleton pregnancies. S ome authors have recommended developing twin-specific growth curves whereas others prefer singleton standards. Part of the uncertainty results from th e small size of databases on twins. The objective of the present study was to compare percentiles of birth weight, length, and head circumference of t win and singleton newborns according to gestational age between 21 and 43 w eeks' gestation and sex in a large database. Methods: We analyzed 81,986 twin, births and 563,483 singleton births with cumulative frequencies and percentiles. Results: After 30 weeks' gestation, percentile values for both male and fem ale twins were below those for singletons. Conclusion: These data suggest that current standards for singletons are no t applicable to twins and that normograms for twins should be developed. An thropometric measurements of twins and data on perinatal morbidity and mort ality require further study.