478 - The age-related patterns of small-for-gestational age infants among US-born and foreign-born Latinx women in the US: the effect of Black race

Poster Number: 478
Publication Number: 478.129

Wendi Gu, NewYork-Presbyterian Morgan Stanley Children's Hospital, New York, NY, United States; Janardhan Mydam, John H Stroger Jr. Hospital of Cook County Chicago ,IL ; Rush Medical College, Chicago ,IL., Buffalo Grove, IL, United States; James Collins, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States

Background: In the US, race is a strong determinant of the age-related patterns of small for gestational age (weight < 10th percentile for gestational age, SGA) rates. Among non-Latinx White women, SGA rates decrease with advancing age. In stark contrast, African-American women experience a “weathering” pattern of rising SGA rates with increasing age (Love, MCHJ, 2010). Most pertinent, a prior study found that Black race was a risk factor for low birth weight ( < 2500g) among US-born Latinx women (Mydam et al, MCHJ, 2016). The relationship between race, age, and SGA rates among US-born and foreign-born Latinx women is unknown.

Objective: To determine the extent to which race modifies the association of age and SGA rates among US-born and foreign-born Latinx women.

Design/Methods: Stratified analyses were performed on the 2016-2019 National Center for Health Statistics linked birth-death certificate files of singleton infants born to US-born and foreign-born Latinx women who self-identified as Black or White. Race-specific SGA rates were calculated according to age among US-born and foreign-born Latinx women.

Results: US-born Black Latinx women (Nf69,419) had a greater SGA rate than US-born White Latinx women (Nf1,440,244): 14.3% vs 10.5%, RR = 1.4 (1.3, 1.4). The racial disparity narrowed among the foreign-born Latinx subgroup: Black women (Nf25,259) had an SGA rate of 11.0% compared to 9.5% for White women (Nf1,116,528); RR = 1.2 (1.1, 1.2). Among US-born and foreign-born women, race-specific SGA rates declined with advancing age (Figure 1). The distribution of selected high-risk characteristics (i.e. no/inadequate prenatal care, cigarette smoking, and paternal non-acknowledgement) was greater among Black (compared to White) US-born and foreign-born Latinx women (Table 1). Most striking, the pattern of decreasing SGA rates with increasing age persisted among each high-risk subgroup, including US-born Black Latinx women who smoked cigarettes (Figure 2).Conclusion(s): Black race, or something closely related to it, is a stronger risk factor of SGA birth among US-born (compared to foreign-born) Latinx women. In stark contrast to the “weathering phenomenon” experienced by African-American women, SGA rates decrease with advancing age among US-born and foreign-born Black Latinx women. Further research is needed to ascertain the age-related patterns of SGA rates among established (i.e. two or more generations of US residence) Black Latinx women.
Figure 1Small for gestation (SGA) rates among births to US-born and foreign-born Latinx women by maternal age and race, United States, 2016-2019 (Singleton live births to mothers with self-identified race).
Table 1. Distribution of risk factors among 4 race-nativity groups.The P-value of χ2 test of association between race-nativity (four groups of women) and risk factors is < 0.0001 for all risk factors.