TY - JOUR

T1 - Job loss and fetal growth restriction

T2 - identification of critical trimesters of exposure

AU - Gailey, Samantha

AU - Mortensen, Laust H.

AU - Bruckner, Tim A.

N1 - Publisher Copyright: © 2022 Elsevier Inc.

PY - 2022

Y1 - 2022

N2 - Purpose: Previous research suggests that job loss in a household during pregnancy may perturb fetal growth. However, this work often cannot rule out unmeasured confounding due to selection into job loss. Recent work using data on exogenous job loss (due to a plant closure) finds that a father's unexpected job loss during his spouse's pregnancy increases the risk of a low weight birth. Using a unique set of linked registries in Denmark, we build on this work and examine whether associations between a father's unexpected job loss and low birthweight differ by trimester of in utero exposure. We additionally examine trimester-specific associations of job loss with small-for-gestational-age, a proxy for restricted fetal growth, which may cause low birthweight. Methods: We apply a sibling control design to over 1.4 million live births in Denmark, 1980 to 2017, to examine whether this plausibly exogenous form of job loss corresponds with increased risk of low weight or small-for-gestational-age births, depending on the timing of displacement in the first, second, or third trimester. Results: Results indicate an elevated risk of low birthweight (OR = 1.80, 95% CI: 1.24, 2.62) and small-for-gestational-age (OR = 1.40, 95% CI: 1.02, 1.93) among gestations exposed to job loss in the second trimester of pregnancy. Sensitivity analyses using continuous outcome measures (e.g., birthweight in grams, birthweight for gestational age percentile) and maternal fixed effects analyses produce substantively similar inference. Conclusions: Findings support the notion that unexpected job loss may affect fetal growth and that the second trimester in particular appears sensitive to this external stressor.

AB - Purpose: Previous research suggests that job loss in a household during pregnancy may perturb fetal growth. However, this work often cannot rule out unmeasured confounding due to selection into job loss. Recent work using data on exogenous job loss (due to a plant closure) finds that a father's unexpected job loss during his spouse's pregnancy increases the risk of a low weight birth. Using a unique set of linked registries in Denmark, we build on this work and examine whether associations between a father's unexpected job loss and low birthweight differ by trimester of in utero exposure. We additionally examine trimester-specific associations of job loss with small-for-gestational-age, a proxy for restricted fetal growth, which may cause low birthweight. Methods: We apply a sibling control design to over 1.4 million live births in Denmark, 1980 to 2017, to examine whether this plausibly exogenous form of job loss corresponds with increased risk of low weight or small-for-gestational-age births, depending on the timing of displacement in the first, second, or third trimester. Results: Results indicate an elevated risk of low birthweight (OR = 1.80, 95% CI: 1.24, 2.62) and small-for-gestational-age (OR = 1.40, 95% CI: 1.02, 1.93) among gestations exposed to job loss in the second trimester of pregnancy. Sensitivity analyses using continuous outcome measures (e.g., birthweight in grams, birthweight for gestational age percentile) and maternal fixed effects analyses produce substantively similar inference. Conclusions: Findings support the notion that unexpected job loss may affect fetal growth and that the second trimester in particular appears sensitive to this external stressor.

KW - Birth outcomes

KW - Fetal growth

KW - Job loss

KW - Sibling comparison designs

KW - Unemployment

U2 - 10.1016/j.annepidem.2022.05.003

DO - 10.1016/j.annepidem.2022.05.003

M3 - Journal article

C2 - 35605768

AN - SCOPUS:85133241188

VL - 76

SP - 174

EP - 180

JO - Annals of Epidemiology

JF - Annals of Epidemiology

SN - 1047-2797

ER -