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The relationship between maternal birthweight and gestational age in twins and singletons and those of their offspring in Norway
Author(s) -
Glinianaia Svetlana,
Magnus Per,
Skjæven Rolv,
Bakketeig Leiv
Publication year - 1997
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1046/j.1365-3016.1997.d01-188.x
Subject(s) - offspring , singleton , medicine , gestational age , obstetrics , birth weight , pregnancy , population , demography , biology , genetics , environmental health , sociology
In order to elucidate whether maternal plurality affects offspring intrauterine growth, the relationship between birthweight and gestational age of twins and singletons and those of their first singleton liveborn children in Norway was studied using data from the Medical Birth Registry. The population‐based sample consisted of 49 698 mother–offspring pairs (48 842 with singleton and 856 with twin‐mothers). In bivariate analyses, no significant differences in mean birthweight and gestational age of offspring of twin and singleton mothers were found, although the mean birthweight and gestational age of the twin‐mothers themselves were significantly lower than those of singletons (819 g and 14 days respectively). In multiple regression analysis, the expected birthweight of offspring was 230.3 g (95% CI: 193.2–267.4 g) higher when the mother was a twin than when the mother was a singleton, when controlling for non‐standardised maternal birthweight. When adjusting for relative maternal birthweight ( z ‐score), the association between maternal plurality and offspring birthweight was not statistically significant. The results suggest that being born as a twin has no substantial consequences on offspring growth in utero and show that mean differences in birthweight between twins and singletons should be standardised when both groups are included in multivariate studies.