Infant Mortality and the Risk of Small Size for Gestational Age in the Subsequent Pregnancy: A Retrospective Cohort Study

To examine the association between prior infant mortality and subsequent risk for small for gestational age (SGA). This population-based,
retrospective cohort study used the Missouri maternally linked, longitudinal dataset (1989–2005). Analyses were restricted
to women who had two singleton pregnancies during the study period. Logistic regression was conducted to obtain adjusted odds
ratios (AOR) and 95 % confidence intervals (CI) for the association between infant mortality in the first pregnancy and SGA
in the second pregnancy. Women with a prior occurrence of infant death were more likely to be black and obese and had lower
educational levels and had higher rates of pregnancy-related complications (p < 0.01). White women with previous infant mortality were at 1.46 times greater risk for SGA in the subsequent pregnancy (AOR = 1.46,
95 % CI = 1.24–1.71). For black women with prior infant death, the risk for SGA increased to 2.77 times (AOR = 2.77, 95 %
CI = 2.19–3.51). White mothers who experienced infant mortality coupled with SGA in the first pregnancy had a nearly threefold
heightened risk for SGA in the second pregnancy (AOR = 2.89, 95 % CI = 2.21–3.78), whereas black women with this history were
more than four times as likely to have an infant with SGA (AOR = 4.60 95 % CI = 3.05–6.96). Prior occurrence of infant mortality
is associated with increased risk for subsequent SGA. This finding has important implications for health professionals, as
targeted inter-conception strategies for women who have experienced infant death, as well as SGA, may be warranted.