Risks of pelvic girdle pain and job loss from heavy lifting in pregnancy

The risks of pelvic girdle pain (PGP) and employment cessation are increased among pregnant workers experiencing heavy lifting and postural load, according to a recent study published in the American Journal of Obstetrics & Gynecology.

Musculoskeletal health declines during pregnancy, increasing risks of multiple immediate and long-term consequences.Up to 70% of pregnancies are impacted by mild musculoskeletal pain and up to 20% have severe musculoskeletal pain persisting into the postpartum period.

While physically demanding work has been linked to musculoskeletal disorders among a general working population, there is little data evaluating this association in pregnant individuals. More data is also needed about the link between workplace exposure in pregnancy with outcomes such as fatigue, analgesic use, and employment outcomes.

To evaluate the association between lifting and postural load during pregnancy with musculoskeletal disorders and associated outcomes, investigators conducted a systematic review.

Literature was obtained through searches of the Embase, Medline, Cumulative Index to the Nursing and Allied Health Literature, National Institute for Occupational Safety and Health Technical Information Center, and Ergonomics Abstracts databases. Included studies were published after 1990 to reflect more modern working conditions.

Nonrandomized comparative studies of employed pregnant or postpartum workers were assessed for prevalence, incidence, and associations. Studies not restricting the sample to or including a subgroup analysis for employed patients were excluded from the analysis.

Exposures were evaluated during pregnancy or up to 6 months postpartum. Studies reporting only crude or composite physical job demand measures were excluded, as well as those that did not distinguish between occupational and nonoccupational physical demands. Relevant outcomes included fatigue, analgesic use, and employment outcomes.

Two independent investigators performed title and abstract screening, while 2 of 5 independent investigators screened full texts. Data was extracted by 1 investigator, then verified by a second investigator.

Extracted data included study name, citation information, study years, study design, country, funding source, research objectives, enrollment source, sample size, and sample population. Exposure characteristics and outcome characteristics were also extracted.

There were 16 studies included in the final analysis, 11 of which used a cohort design, 2 a nested case-control design, and 3 a cross-sectional design. Most studies were conducted in northern Europe and half were published since 2010. Data was obtained from the Danish National Birth Cohort in 3 studies, while the remaining 13 had unique study samples.

Exposures to both occupational lifting and postural load were assessed in 56% of studies, while 6 only assessed postural load and 1 only lifting. Additionally, musculoskeletal or employment outcomes were assessed during pregnancy in 88% of studies and postpartum in 2 studies.

The prevalence or incidence of musculoskeletal disorders among occupationally exposed pregnant workers was not identified in any of the studies, nor were associations reported between relevant exposures and upper or lower extremity musculoskeletal disorders.

Two studies reported an association between frequent occupational heavy lifting and the occurrence of low back pain (LBP), with one also finding an association with LBP severity and the other an association with PGP. PGP functionality outcomes were inconsistent between studies, with one reporting elevated risk while another had null findings.

While no associations were reported between occupational lifting exposure and postpartum LBP or PGP, a consistent pattern of null findings was identified for associations between standing or standing and walking with back pain or LBP. Associations were also found for other postural load conditions such as uncomfortable postures and LBP or PGP.

An association was also found between postural load exposure at 30 weeks’ gestation and PGP within 12 weeks postpartum. However, no association was reported between postural load and postpartum LBP.

For outcomes associated with musculoskeletal disorders, a link was only reported for employment outcomes, with robust consistency between studies. One study indicated an impact from the timing or duration during exposure with an over 3-fold risk of antenatal leave of 14 days or more from persistent exposure to heavy lifting through 27 weeks’ gestation.

The risk of employment cessation was also increased by exposure to heavy lifting and prolonged standing through 27 weeks’ gestation. However, elevated risk was not reported from exposure at only 12 weeks’ gestation.

These results indicated increased risks of PGP and adverse employment outcomes from heavy lifting and postural load during pregnancy. Investigators concluded guidelines addressing physical job demands during pregnancy may be necessary.

Reference

MacDonald LA, Johnson CY, Lu M, et al. Physical job demands in pregnancy and associated musculoskeletal health and employment outcomes: a systematic review. American Journal of Obstetrics & Gynecology. 2024; 230(6):583-599.E16. doi:10.1016/j.ajog.2023.12.014