Third Generation Consequences of Small for Gestational Age Births

Area of Science:

• Reproductive Health
• Perinatal Epidemiology
• Transgenerational Health Studies

Background:

• Small for gestational age (SGA) is a significant indicator of adverse perinatal outcomes.
• Understanding intergenerational health patterns can inform preventative strategies.
• Previous research has explored familial links in birth outcomes, but transgenerational SGA transmission requires further investigation.

Purpose of the Study:

• To determine if US-born women who were themselves born small for gestational age (SGA) exhibit higher rates of SGA in their grandchildren compared to non-SGA women.
• To investigate the potential transgenerational influence of maternal SGA status on grandchild birth outcomes.

Main Methods:

• Utilized a multi-step linkage strategy connecting vital records of Chicago-born infants (2005-2017) to their mothers (1989-1991) and maternal grandmothers (1956-1976).
• Defined SGA based on sex-specific weight-for-gestational age percentiles using population-based references.
• Employed stratified and multivariable log binomial regression analyses, calculating Population Attributable Risk (PAR).

Main Results:

• Women born SGA had a higher incidence of SGA births in their grandchildren (23.3%) compared to non-SGA women (17.6%), with a relative risk (RR) of 1.30.
• Adjusted analysis, controlling for covariates, showed an increased RR of 1.22 for grandchildren SGA among former SGA women.
• Maternal grandmother's SGA status accounted for 4.3% of SGA births among African Americans.

Conclusions:

• In the US, women born SGA have a modestly increased frequency of SGA births in their grandchildren.
• The findings suggest a transgenerational component to SGA, particularly notable in African American populations.
• A small proportion of SGA births can be attributed to the SGA status of the maternal grandmother.