Occupational Hazard? Birth Outcomes Among Physician Mothers

The Issue:

Stress and other environmental factors experienced during pregnancy have been shown to impact the health and long-term well-being of children. Physicians are subject to long hours, stressful work environments, night shifts, and 24-hour on call periods, all of which could lead to adverse birth outcomes such as low gestational age and preterm delivery. Each year women make up an increasing share of practicing physicians. Accordingly, questions of whether the physically demanding aspects of the occupation are associated with measurable impacts on pregnant physicians and their neonatal children – as well as how to mitigate the potential effects of a strenuous occupation – have become more pressing.

Can long hours, altered sleep, long periods of standing and stress have measurable impacts on the pregnancy outcomes of physicians?

The Facts:

• Physically demanding jobs and stress have been associated with adverse pregnancy outcomes including lower birth weight and shorter pregnancies. As the share of women in the workforce has grown, with most women working through their reproductive years, a growing body of research examines the health and safety risks to pregnant workers. A review of many studies conducted between 1966 and 2011 found that long work hours (more than 40 per week), shift work, and long periods of standing (over 4 hours per day) were associated with a small increase in the likelihood of having a preterm birth (delivery before 37 weeks of gestation). Strenuous work requirements – physically demanding work, prolonged standing, long work hours, shift work, and cumulative work fatigue – have also been linked to increased rates of hypertension or preeclampsia in pregnancy. In addition, a review of studies published between 1970-2012 illustrated that high levels of maternal prenatal stress are associated with lower birth weights and shorter gestational ages. The definition of maternal stress used in the studies varied widely ranging from measures of maternal anxiety about pregnancy to experiencing a stressful event such as the loss of a loved one. Events during a person’s early development can have long term effects. Low birth weight, which tends to be an indicator for poor fetal nutrition, has been linked to coronary artery disease, hypertension, obesity, and insulin resistance later in life. 
• While the level depends on their specialty, physicians are subject to physically demanding job requirements. Medicine was once a completely male-dominated industry, but in the last 40 years, the share of physicians that are women has increased with about 37% of all active physicians identifying as female in 2021. Most physicians work between 40 and 60 hours a week and are often on call for around 3 other days a month. Being on call combines two strenuous work environments: long hours and night work, both of which are related to increased stress levels and poor sleep. Conditions are especially demanding for those in training (residents) and for surgeons who reported being required to stand for longer periods of time (around 4 hours on average). Surgical residents reported a median 78 total patient care hours per week in a 2023 study. Further, physicians often experience high spikes of stress when treating patients in emergency situations.
• It is difficult to establish the extent to which work conditions cause negative pregnancy outcomes, as other factors such as income and education can also be associated with both work conditions and pregnancy outcomes. Adjusting for those other factors can allow economists to try to isolate the effect that work conditions have on pregnancy outcomes. There are potential pathways that could explain a causal relationship between work conditions and pregnancy outcomes. Strenuous work could affect blood flow to the uterus and long hours of standing can increase the pressure on the uterus. Additionally, maternal stress may increase production of certain hormones to dangerous levels which can then impede fetal growth. Maternal stress can also impact fetal health if it leads to worse sleep, changes in diet, and a reduction in physical activity (see here, here and here). 
• When comparing physicians to lawyers, a demographically and behaviorally similar group, we find that physicians tend to have lower birth weights and slightly shorter pregnancies. We argue that, since individuals with similar levels of education and income tend to go into both occupations, one major difference between physicians and lawyers is the increased physical demands required of physicians. Specifically, after taking into account several maternal characteristics, we find that physicians have 2.3% lower birth weights (about 75.84 grams or 2.68 ounces) and slightly shorter pregnancies. These findings are similar in magnitude to the estimated effects of air pollution experienced during pregnancy on infant health as identified in other studies (see here and here). Our results are driven primarily by physicians in surgical specialties who, in general, tend to have the most strenuous job requirements. 
• Because physicians are highly informed about the benefits and costs of health care treatments, in theory their behavior and outcomes could differ greatly from that of the rest of the public. Given their expertise, one could expect that physicians’ birth outcomes would be better than those of comparably educated mothers. If so, our results could understate any potential detrimental impacts of adverse working conditions on the birth outcomes of physicians. However, there is mixed evidence as to whether physicians use their medical knowledge to improve their own health. Physicians are less likely to give birth via c-section, which aligns with the growing medical consensus that too many mothers are undergoing a c-section. However, when looking across many types of procedures, one study showed that physician patients adhere to care guidelines at about the same rate or only slightly more than non-physician patients. Similarly, another study found that physicians (and those with access to medical knowledge) are 7 percent less likely to adhere to prescription drug guidelines.
• Changes in working conditions for medical residents have yielded mixed results. In 2003 the Accreditation Council for Graduate Medical Education (ACGME) limited the number of hours that residents could work to 80 hours per week. The work reform was intended to address the public concern that long duty hours led to a decrease in patient safety and resident well-being. Following the change, residents reported decreased levels of burnout, better quality of life, and an increase in motivation without experiencing any change in the quality of their training or education. The work reform also led to a change in who entered certain specialties with women entering into specialties that were previously more time-intensive such as neurosurgery or urology. In 2011 the ACGME instituted an additional work reform by limiting the number of hours that a first-year resident could consecutively work to 16 hours. Despite first-year residents reducing the number of hours they worked, they did not report a change in how many hours they slept, their well-being scores, or the presence of depressive symptoms. Moreover, there was an increase in self-reported errors. In our research we found that the 2011 reform could not have closed the gap we found in birth outcomes between physicians and lawyers. In 2017 the ACGME reversed the 2011 duty hour work reform, meaning that first-year residents could go back to working 24 consecutive hours.