Diabetes Care, Vol 22, Issue 7 1059-1062, Copyright © 1999 by American Diabetes Association
Birth weight of women with gestational diabetes
RG Moses, J Moses and S Knights
Illawarra Area Health Service, Wollongong, New South Wales, Australia. robert_moses@uow.edu.au
OBJECTIVE: Epidemiological observations have suggested a relationship
between type 2 diabetes and a low birth weight. However, there are many
confounding variables and problems with retrospective data collection.
Women with gestational diabetes mellitus (GDM), who are likely to develop
type 2 diabetes in the future, may help clarify these observations.
RESEARCH DESIGN AND METHODS: Consecutive women with GDM (n = 138) were
included in the study if they had a singleton pregnancy delivered between
37 and 41 weeks of gestation, if they had themselves been born in the local
hospital, and if their own delivery data were available. With respect to
their own births, a matched group was obtained by considering the next
female delivery of the same gestational age. RESULTS: For women with GDM,
the mean (+/- 1 SD) birth weight was 3,293 +/- 493 g and the ponderal index
was 27.0 +/- 2.4. Their values were not significantly different from the
matched group, which had a birth weight of 3,315 +/- 460 g and a ponderal
index of 27.0 +/- 2.5. After adjusting for the gestational age of delivery,
the birth weight of women with GDM did not show a U-shaped distribution.
CONCLUSIONS: After adjustment for the gestational age of delivery, women
with GDM do not themselves have either a lower or higher birth weight than
a matched group. These data suggest that women with GDM are either not a
good surrogate for investigating the relationship between birth weight and
type 2 diabetes or that correction for the gestational age of delivery
removes the most important confounding variable. It is also possible that
modern dietary changes may have altered the relationship.