Association between job control and time to pregnancy in a preconception cohort.

OBJECTIVE

To evaluate associations between low job control (operationalized as job independence and freedom to make decisions) and time to pregnancy. Low job control, a form of workplace stress, is associated with adverse health outcomes ranging from cardiovascular disease to premature mortality; few studies have specifically examined its association with reproductive outcomes.

DESIGN

We used data from Pregnancy Study Online, an internet-based preconception cohort study of couples trying to conceive in the United States and Canada. We estimated fecundability ratios (FRs) and 95% confidence intervals (CIs) via proportional probability regression models, adjusting for sociodemographic and behavioral characteristics.

SETTING

Not applicable (Web-based study).

PATIENTS

Participants self-identified as female, were aged 21-45 years, and reported ≤6 cycles of pregnancy attempt time at enrollment (2018-2022).

EXPOSURE

We assessed job control by matching participants' baseline self-reported occupation and industry with standardized occupation codes from the National Institute for Occupational Safety and Health's Industry and Occupation Computerized Coding System, then linking codes to O∗NET job exposure scores for job independence and freedom to make decisions.

MAIN OUTCOME MEASURE

Our main outcome measure was fecundability. Participants completed self-administered questionnaires at baseline and every 8 weeks for up to 12 months or until reported pregnancy, whichever occurred first.

RESULTS

Among 3,110 participants, lower job independence was associated with reduced fecundability. Compared with the fourth (highest) quartile, corresponding to the most job independence, FRs (95% CI) for first (lowest), second, and third quartiles were 0.92 (0.82-1.04), 0.84 (0.74-0.95), and 0.99 (0.88, 1.11), respectively. Lower freedom to make decisions was associated with slightly reduced fecundability (first vs. fourth quartile: FR = 0.92; 95% CI: 0.80-1.05).

CONCLUSION

Lower job control, a work-related stressor, may adversely influence time to pregnancy. Because job control is a condition of work (i.e., not modifiable by individuals), these findings may strengthen arguments for improving working conditions as a means of improving worker health, including fertility.