Doctors who give birth tend to have smaller babies than lawyers do, and the gap is largest for surgeons. An analysis of Texas birth records found physician mothers were 15.8% more likely than lawyer mothers to have a low birthweight infant.
The study is by Anupam Jena of Harvard Medical School and David Slusky and Lilly Springer of the University of Kansas. It was released as NBER Working Paper No. 31955 in December 2023 and revised in June 2024.
Medical training is notoriously punishing. Residents in many specialties routinely work up to 80 hours a week, often on their feet, during the same years many of them start families.
Doctors compared with lawyers, and surgeons with other doctors
The researchers used Texas birth records from 2007 to 2014 for mothers aged 26 to 45 who listed their job as physician or lawyer. Lawyers served as a comparison group with similar education but less physically demanding work. The models adjusted for maternal age, race, ethnicity, prenatal visits and other risk factors.
Compared with lawyers, physicians had a 1.5 percentage point (15.8%) higher rate of low birthweight babies and a 1.9 point (17.9%) higher rate of babies small for their gestational age. They were 10.2% more likely to deliver preterm. Their babies weighed about 80 grams less on average, and pregnancies were slightly shorter. Physicians were also 10.1% less likely to deliver by Caesarean.
Surgeons drove most of the gap. Compared with non-surgeon physicians, surgeon mothers had a 3.5 percentage point (32.4%) higher incidence of low birthweight and were 30.2% more likely to give birth preterm. The authors say these differences are similar in size to effects of air pollution on infant health reported in earlier studies.
A shift limit seemed to help young doctors
In 2011 the Accreditation Council for Graduate Medical Education barred first-year residents from working more than 16 hours in a row. The team compared young physicians with young lawyers before and after the change.
Among mothers aged 26 to 30, the reform was linked to a 6.2 percentage point (56.3%) drop in small for gestational age babies, with suggestive improvements in birthweight. Older physicians aged 34 to 45, who were past training and not covered by the rule, showed no change. The improvement among young doctors was slightly larger for surgeons, who also saw fewer low birthweight babies and Caesarean deliveries.
The sample included 6,062 births to physician mothers before the reform and 3,777 after it. The reform did not change how many physicians gave birth.
What the numbers can and cannot say
The authors stress that the doctor versus lawyer comparison is descriptive, not causal. Occupations were self-reported on birth records, and the data cover one state. They also note that physicians generally have good health habits, so if anything the true toll of the job may be understated.
An earlier version of the paper found no effect of the 2011 reform; the June 2024 revision, which focuses on trainees, finds the improvement for younger physicians. The 16-hour limit for first-year residents was later reversed, and they were again allowed 24-hour shifts plus up to four hours for handovers and teaching.
Study Details:
- Title: Occupational Hazard? An Analysis of Birth Outcomes Among Physician Mothers
- Authors: Anupam Jena, David Slusky, Lilly Springer
- Journal: NBER Working Paper No. 31955
- Publication Date: December 2023
- DOI: 10.3386/w31955