The Relation of Maternal Birth Weight to African-American and Non-Latina White Twin Pregnancy Outcomes: A Population-Based Study.

Objectives The authors investigated the association between maternal birth weight and adverse birth outcome as measured by rates of low birth weight (<2500 g, LBW), preterm birth (<37 weeks, PTB), and small for gestational age (weight <10th percentile for gestational age, SGA) among African American and White twin pregnancies. Methods Stratified and multivariable regression analyses were performed on the Illinois transgenerational dataset of non-Latina African American and non-Latina White twin pairs (born 1989-1991) and their mothers (born 1956-1976). Results Former LBW (n = 104) and non-LBW (n = 742) African American mothers had LBW rates in both twins of 76 and 56 %, respectively; RR (95 % CI) = 1.4 (1.2-1.6). Former LBW (n = 105) and non-LBW (n = 2136) White mothers had LBW rates in both twins of 41 and 34 %, respectively; RR = 1.2 (0.9-1.5). In multivariable regression models, the adjusted (controlling for maternal age, education, marital status, parity, prenatal care usage, and cigarette smoking) RR of LBW in both twins among former LBW (compared to non-LBW) African American and White mothers equaled 1.4 (1.2-1.6) and 1.2 (0.9-1.5), respectively. Maternal LBW was associated with a modestly increased risk of PTB but not SGA among African American twin pregnancies: adjusted RR = 1.3 (1.1-1.4) and 1.1 (0.8-1.5), respectively. Conclusions In African American twin pregnancies, maternal LBW is a risk factor for LBW in both twins. Further research is needed to determine whether a similar generational association occurs among non-Latina White twin pregnancies.