Advanced maternal age and fetal growth inhibition in triplets.
OBJECTIVE
To determine whether advanced maternal age is associated withfetal growth inhibition in triplets.


METHODS
We conducted a retrospective cohort study on triplet live births in the United States from 1995 through 1998. The outcomes of fetal growth inhibition measured were low birth weight, very low birth weight, preterm birth, very preterm birth and smallnessfor gestational age. We generated adjusted ORs after taking into account intracluster correlations using the generalized estimating equation framework.


RESULTS
As compared to women of younger maternal age (20-29), mature (30-39) and older women (> or =40 years) with triplet gestations tended to have a lower likelihood offetal growth inhibition. Mean birth weight and mean gestational age at delivery increased with increasing maternal age in a dose-dependent pattern (p for trend < 0.0001). As compared to triplets born to younger mothers, those of older women were less likely to have low birth weight (OR=0.51, 95% CI=0.37-0.69) or very low birth weight (OR = 0.58, 95% CI = 0.47-0.72) or to be preterm (OR = 0.39, 95% CI = 0.27-0.56) or very preterm (OR = 0.67, 95% CI = 0.55-0.80). The riskfor small-for-gestational-age infants was comparable.


CONCLUSIONS
Older maternal age is associated with morefavorable triplet fetal growth parameters, although the exact mechanisms of this paradox remain poorly understood.
Salihu
Hamisu M
HM
Department of Maternal and Child Health, University of Alabama at Birmingham, Birmingham, USA. hsalihu@uab.edu
Bagchi
Suparna
S
Aliyu
Zakari Y
ZY
Kirby
Russell S
RS
Alexander
Greg R
GR
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology*; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008423:Maternal Age; D008875:Middle Aged; D016017:Odds Ratio; D011247:Pregnancy; D047928:Premature Birth; D012189:Retrospective Studies; D012307:Risk Factors; D014310:Triplets