Physically demanding work in pregnant women ups risk of adverse pregnancy outcomes

Pregnant women who engage in physically demanding work are at increased risk of adverse pregnancy outcomes, according to a study.

The investigators searched five electronic databases and three gray literature sources up to 15 March 2019 for studies (except case studies and reviews) containing information on the relevant population (women who engaged in paid work during pregnancy), occupational exposures (heavy lifting, prolonged standing, prolonged walking, prolonged bending and heavy physical workload), comparator (no exposure to the listed physical work demands), and outcomes (preterm birth, low birthweight, small for gestational age, miscarriage, gestational hypertension, pre-eclampsia, gestational diabetes mellitus, stillbirth and intrauterine growth restriction).

Eighty observational studies involving 853,149 women met the inclusion criteria. Based on low-to-very low certainty evidence, pregnant women lifting objects ≥11 kg had a 31-percent higher risk of miscarriage (95 percent confidence interval [CI], 1.08–1.58; I², 79 percent) and 35-percent increased odds of pre-eclampsia (95 percent CI, 1.07–1.71; I², 0 percent). Furthermore, lifting objects for a combined weight of ≥100 kg per day correlated with an increased risk of preterm delivery (odds ratio [OR], 1.31, 95 percent CI, 1.11–1.56; I², 0 percent) and having a low birthweight neonate (OR, 2.08, 95 percent CI, 1.06–4.11; I², 73 percent).

Prolonged standing was also associated with a higher risk of preterm delivery (OR, 1.11, 95 percent CI, 1.02–1.22; I², 30 percent) and having a small-for-gestational-age neonate (OR, 1.17, 95 percent CI, 1.01–1.35; I², 41 percent). In addition, pregnant women with a heavy physical workload had a 23-percent higher risk of preterm delivery (95 percent CI, 1.07–1.41; I², 32 percent) and 79-percent increased odds of having a low birthweight neonate (95 percent CI, 1.11–2.87; I², 87 percent). All other associations were not statistically significant.

In dose-response analysis, women standing for >2.5 hours per day, compared with no standing, had a 10-percent increased risk of having a preterm delivery.