Special Article
Outcomes of Pregnancy in a National Sample of Resident Physicians
N Engl J Med 1990; 323:1040-1045October 11, 1990
- Abstract
- Abstract
Background.
Physically demanding, highly stressful work during pregnancy has been reported to cause a variety of adverse outcomes. It has been difficult, however, to separate the effects of work from those of socioeconomic status.
Methods.
By means of a national questionnaire-based survey, we studied the outcomes of pregnancy during residency for 4412 women who graduated from medical school in 1985 and for the wives of 4236 of their male classmates, who served as controls.
Results.
The rate of response to our survey was 87 percent (4412 of 5079) for the women residents and 85 percent (4236 of 4968) for the wives of the male residents. There were no significant differences in the proportion of pregnancies ending in miscarriage (13.8 percent for residents vs. 11.8 percent for their classmates' wives, P = 0.12), ectopic gestations (0.5 percent vs. 0.8 percent, P = 0.69), and stillbirths (0.2 percent vs. 0.5 percent, P = 0.20). There were 989 women residents and 1238 residents' wives whose first pregnancy during residency resulted in the live birth of a singleton infant. Although during each trimester the women residents worked many more hours than the wives of the male residents, the frequency of preterm births (<37 weeks' gestation) was similar: 6.5 percent for residents and 6.0 percent for residents' wives (odds ratio = 1.1; 95 percent confidence interval, 0.7 to 1.5). Infants who were small for gestational age (with birth weights less than the 10th percentile for gestational age) were born to 5.3 percent of the residents and 5.8 percent of the residents' wives (odds ratio = 0.9; 95 percent confidence interval, 0.6 to 1.3). Adjustment for factors that differed between the women residents and the wives of male residents resulted in odds ratios of 1.2 (95 percent confidence interval, 0.8 to 1.7) for preterm delivery and 0.9 (95 percent confidence interval, 0.6 to 1.3) for the delivery of an infant who was small for gestational age. However, the women residents more frequently reported having had preterm labor (11 percent vs. 6 percent), but not preterm delivery (6.5 percent vs. 6.0 percent); preeclampsia was also more common among the women residents (8.8 percent vs. 3.5 percent).
Conclusions.
These results suggest that working long hours in a stressful occupation has little effect on the outcome of pregnancy in an otherwise healthy population of high socioeconomic status. (N Engl J Med 1990; 323: 1040–5.)
Media in This Article
Table 1
Outcome of the First Pregnancy That Began during Residency.Table 2
Characteristics of Women Residents and Wives of Male Residents.Article Activity
- Article
PHYSICALLY strenuous occupations have long been suspected of causing adverse pregnancy outcomes. Occupational factors such as long working hours,1 , 2 night work,1 and lengthy periods of standing1 , 3 have been associated with an increased risk of preterm delivery. Prolonged standing at work has also been associated with reduced intrauterine growth.4 A common criticism of these reports is that women with physically demanding occupations are likely to be of lower socioeconomic status than women with less demanding occupations.5 To address this issue, it is necessary to separate the effects of occupational physical stress and socioeconomic status.
Residency training provides a unique opportunity to make this separation. Medical residents are highly educated, yet they spend long hours during both day and night in work that includes prolonged standing and great emotional stress. Although residency occurs at an age when many women want to have children, most residency programs have no specific policies regarding maternity leave,6 , 7 and many pregnant residents perceive resentment of the pregnancy on the part of other house officers and faculty members.6
It is commonly believed that pregnant residents are at high risk for a variety of adverse outcomes. Pregnant physicians have been reported to have an increased risk of preterm delivery,8 intrauterine growth retardation,9 placental abruption,10 and ppregnancy-induced hypertension.11 However, not one of the previous studies of pregnancy among residents has used a broad sample of residents and had a response rate sufficient to ensure the validity of the results. The present study is the largest to date that has evaluated the outcomes of pregnancy among women residents.
Methods
We surveyed women physicians who graduated from medical school in 1985 (n = 5096) and a random sample of 5000 of the 12,306 male physicians who graduated in 1985. Names and addresses for the physicians were obtained from the American Medical Association (AMA) Physicians' Master File. Physicians were sent a questionnaire, along with a covering letter and a letter of endorsement from the American College of Obstetricians and Gynecologists. Male physicians were instructed to give the questionnaires to their wives for completion, or to complete the questionnaire themselves if giving it to their wives was not possible. Nonrespondents were sent a postcard reminder and subsequently received a second copy of the questionnaire. Those who still had not responded were then contacted by telephone, at which time the questionnaire was completed by professional interviewers if possible.
The questionnaire covered the outcome of each pregnancy, demographic information, and the woman's weight and height. The remainder of the questions concerned the first pregnancy that began during the residency (index pregnancy) and included items on the type of residency (or other work in the case of the wives), the number of hours worked, the amount of time off from work, and the attitudes of the woman's colleagues toward the pregnancy. The analyses in the present report are based on these index pregnancies.
The outcomes of interest, reported by the respondents, were preterm delivery, defined as the delivery of a live-born infant before 37 weeks of gestation, and the delivery of an infant who was small for his or her gestational age, defined as a live-born infant with a birth weight less than the 10th percentile for gestational age.12 The association between the outcome of pregnancy and exposure status was expressed in terms of odds ratios and 95 percent confidence limits.13 A variety of factors known to influence the outcome of pregnancy were compared for women physicians and the wives of male physicians by chi-square tests and t-tests, as appropriate. The odds ratios for adverse pregnancy outcomes according to exposure status were adjusted for age at delivery, parity, height, prepregnancy weight, and race or ethnic group with use of multiple logistic regression.14
Results
The study population initially consisted of 5096 female and 5000 male physicians. Because of errors in the listing of sex in the AMA Master File, the final population we surveyed comprised 5094 women and 5002 men. Physicians who had died, did not enter residency, or had a mailing address outside the United States and its territories (15 women and 34 men) were regarded as ineligible, leaving 5079 women and 4968 men to whom we mailed questionnaires.
The overall rate of response to the survey was 86.1 percent. The response rate was 86.9 percent (4412 of 5079) for female physicians and 85.3 percent (4236 of 4968) for the wives of male physicians; 1.3 percent of the female and 1.5 percent of the male physicians declined to participate, and the remainder of those not included did not respond. Respondents who returned the mailed questionnaire were more likely than respondents contacted by telephone ever to have had a pregnancy. Among those who had been pregnant, however, the frequency of preterm delivery and delivery of an infant who was small for gestational age did not differ between postal and telephone respondents. Among male physicians' wives who had ever been pregnant (n = 2119), 231 were themselves either physicians or medical students. These wives were considered to have been exposed to the same conditions as the women residents and were therefore excluded from further analysis.
The outcomes of pregnancy in the two groups are shown in Table 1Table 1
Outcome of the First Pregnancy That Began during Residency.. There were 1293 residents and 1494 wives who became pregnant during residency; the final study population consisted of the 989 residents and 1239 spouses who gave birth to live-born singleton infants as a result of the first pregnancy that began during the residency. As shown in Table 1, there were no statistically significant differences between residents and residents' wives in terms of the proportion of pregnancies that ended in miscarriage (13.8 percent vs. 11.8 percent, respectively; P = 0.12), ectopic gestation (0.5 percent vs. 0.8 percent, P = 0.69), or stillbirth (0.2 percent vs. 0.5 percent, P = 0.20). The difference in the percentage of pregnancies ending in live birth was a result of a threefold higher rate of voluntary terminations of pregnancy among the women residents (8.0 percent vs. 2.7 percent). Sixty-nine percent of the terminations elected by women residents took place before nine weeks' gestation, making it unlikely that they were due to fetal anomalies.Selected characteristics of the women residents and the wives of male residents are presented in Table 2Table 2
Characteristics of Women Residents and Wives of Male Residents.. The women residents were slightly older and more likely to be black than the wives of male residents; they were also more likely than the wives to be primiparous. The women residents were approximately 2.4 kg heavier. There were no significant differences in height or weight gain during pregnancy; smoking during pregnancy was uncommon in both groups. Twenty-three percent of the employed wives of the male residents were registered nurses, 11 percent were teachers, 5 percent were secretaries, and 3 percent were accountants. The remainder worked in 113 different occupations. The women residents reported working nearly twice as many hours per week throughout the entire pregnancy as did the wives of the male residents. Since the data on hours worked refer only to employed women, the actual differences between residents and spouses in the mean number of hours employed are even greater than those shown in Table 2. The women residents quit work on average 12 days before delivery, as compared with 35 days for the wives (P<0.001). Among the residents, 52 percent worked until the day of the delivery or the day before, as compared with 26 percent of the wives. The women residents perceived significantly less support from both coworkers and supervisors during their pregnancy than did the wives of male residents. Results of the comparisons of hours worked and colleagues' attitudes were not changed when the questionnaires completed by male residents for their wives (n = 416) were eliminated from the analyses.Despite major occupational differences, neither preterm delivery nor delivery of an infant who was small for his or her gestational age was significantly more common among the women residents than among the wives of male residents. The overall frequency of preterm delivery was 6.5 percent for women residents and 6.0 percent for wives (P = 0.64); the corresponding figures for infants small for gestational age were 5.3 percent and 5.8 percent (P = 0.56). The mean birth weight of the children born to the women residents was 3396 g, as compared with 3428 g for the children born to the wives of male residents (P = 0.19). The proportion of infants who weighed less than 2500 g at birth was 4.3 percent for the residents and 3.0 percent for the wives (P = 0.12); the proportion weighing less than 1500 g was 0.4 percent for the residents and 0.6 percent for the wives (P = 0.58).
The associations between the characteristics of the women and the incidence of preterm delivery are presented in Table 3Table 3
Characteristics Associated with Preterm Delivery among Women Residents and Wives of Male Residents.*. Corresponding data for the delivery of infants who were small for their gestational age are presented in Table 4Table 4
Characteristics Associated with the Delivery of Infants Who Were Small for Their Gestational Age among Women Residents and Wives of Male Residents.*. Preterm delivery was significantly more common among the wives of male residents who were less than 25 or more than 35 years of age; a similar but not statistically significant trend was observed among the women residents. Smaller weight gain was significantly associated with preterm delivery in both groups. None of the other factors shown in Table 3 were significantly associated with preterm delivery. The frequency of delivering infants small for gestational age differed significantly according to race or ethnic group among both groups of women. The delivery of infants small for gestational age was more common among primiparous, shorter, and lighter women, and among women who gained less weight during pregnancy. None of the other factors shown in Table 4 were significantly associated with the delivery of an infant who was small for his or her gestational age.The crude and adjusted odds ratios for preterm delivery and delivery of infants small for gestational age are presented in Table 5Table 5
Odds Ratios for Preterm Delivery and Delivery of Infants Who Were Small for Their Gestational Age among Women Residents as Compared with Wives of Male Residents.*. Odds ratios were adjusted for factors that differed significantly between residents and wives and were associated with either preterm delivery or delivery of an infant small for gestational age; these variables included age, race or ethnic group, parity, height, and prepregnancy weight. This adjustment had a limited effect on the odds ratios; none of the crude or adjusted odds ratios for preterm delivery or delivery of an infant small for gestational age among the women residents were statistically or clinically different from those for the residents' wives. When male residents completed the questionnaire, their wives' mean reported height was 0.8 cm greater (P = 0.08) and their mean weight was 1.1 kg less (P = 0.02) than the height and weight of the wives who completed the questionnaire themselves. Elimination of data from questionnaires completed by male residents resulted in odds ratios of 1.2 for preterm delivery and 1.0 for delivery of an infant small for gestational age. The vast majority of the women (76 percent of wives and 100 percent of residents) worked at some time during their pregnancy. To account for the possibility that unemployed wives might bias the results (because health problems might have prevented their employment), we excluded unemployed wives from the analysis. The resulting odds ratios were 1.1 for preterm delivery and 1.0 for the delivery of an infant small for gestational age.We investigated the possibility that working longer hours and more nights was related to the incidence of preterm delivery or the delivery of an infant small for gestational age. This analysis was limited to women residents, because of the variety of occupations held by the wives and the large difference in hours worked between women residents and the wives of male residents. The 143 residents who worked 100 hours or more per week during the first trimester of pregnancy had a 9.8 percent risk of preterm delivery, as compared with 4.6 percent for the 818 residents who worked less than 100 hours per week (P = 0.012). The corresponding figures for the second trimester were 8.8 percent and 4.9 percent, respectively (P = 0.07). There was no indication that increasing numbers of hours worked up to 100 per week were associated with preterm delivery. Working 100 or more hours per week was not associated with the delivery of an infant who was small for gestational age. Residents who did not work during the third trimester (n = 53) had a 77 percent incidence of pregnancy complications; the rate of preterm delivery among such women was correspondingly elevated. After we excluded the 53 women who did not work, the residents who worked 100 hours or more per week during the third trimester were found to be at increased risk of preterm delivery (10.3 percent) as compared with those who worked less than 100 hours (4.8 percent, P = 0.04). The average number of nights on call per month ranged from six to seven and did not differ in any trimester between the residents who delivered preterm infants and those whose infants were delivered at term or between those who delivered infants small for gestational age and those who delivered infants who were not small for gestational age.
Women in surgical specialties (surgeons and obstetrician—gynecologists) reported working the most hours during each trimester; it is likely that they spent more time standing than other residents. The mean weight of the infants born to the residents in surgical specialties was 3334 g, as compared with 3408 g for the infants born to the other residents (P = 0.13). The odds ratios for the delivery of preterm infants, infants who were small for their gestational age, and low-birth-weight infants were 1.6 (P = 0.12), 0.8 (P = 0.63), and 0.8 (P = 0.72) for surgeons and obstetrician—gynecologists as compared with the other residents. This suggests that employment in these particularly strenuous specialties has only a modest effect on the outcome of pregnancy.
Among women whose residency normally lasts three years (those in pediatrics, internal medicine, and family practice), the rates of preterm delivery for women in postgraduate years 1, 2, and 3 were 8.4 percent, 3.2 percent, and 5.6 percent, respectively (P = 0.46 for the trend). The corresponding rates of delivery of infants small for gestational age were 4.2 percent, 5.7 percent, and 6.1 percent (P = 0.53). Because the number of hours worked and the number of nights on call usually decrease as training in these three specialties progresses, these data provide additional evidence against a strong effect of workload on pregnancy outcome.
The incidence of pregnancy complications among the women residents and the wives of male residents is presented in Table 6Table 6
Frequency of Complications of Pregnancy among Women Residents and Wives of Male Residents.. In spite of the lack of difference in the rate of preterm delivery, premature labor requiring bed rest or hospitalization was nearly twice as common among the women residents as among the residents' wives. Preeclampsia or eclampsia was more than twice as common among the residents; this association did not change after adjustment for parity. Placental abruption was less likely to occur among the residents (P = 0.054). None of the other complications differed in incidence between the two groups.Discussion
Medical residency provides a unique opportunity to study occupationally related physical activity and pregnancy outcome without the confounding effect of socioeconomic status. It would be difficult to assemble a cohort of women who work longer hours, suffer more sleep deprivation, and are under more stress than residents. As most residency programs have no specific contingency plans for pregnancy leave, the majority of pregnant residents take no time off before the birth of their babies.6 However, in spite of their physically demanding occupation, residents are usually of high socioeconomic status.
The choice of the wives of male residents as controls for this unique population has several advantages. Such women are similar in socioeconomic status and age to the women residents. The wives of male residents are likely to receive prenatal care from the same sources as the women residents. In addition, the wives in this study were employed in a variety of occupations, so that any adverse effect of one particular occupation would be minimized. Many of the wives of male residents had medical backgrounds, and those who did not had ready access to medical consultation — a factor that could be expected to increase greatly the reliability of the self-reported pregnancy outcomes.
We found no significant differences in the rates of miscarriage, ectopic gestation, and stillbirth, or in either fetal growth or duration of pregnancy between the women residents and the wives of male residents. Moreover, both groups of women had rates of delivery of low-birth-weight infants that were lower than that in the general U.S. population and similar to that in women of comparable education.15 These findings cast doubt on previously reported associations between employment in physically demanding occupations and an increased risk of adverse pregnancy outcomes.1 2 3 4 In addition, our results do not support the widely held belief that women residents are at high risk for adverse outcomes of pregnancy.16 The use of a nationally representative sample of recent medical graduates and the high response rate (more than 85 percent for both study groups) increase the validity of the conclusions.
Preterm labor was significantly more common among women residents than among the residents' wives, although preterm delivery was not. This finding is in agreement with those of some other studies,8 , 17 but it suggests that attending obstetricians may have a lower threshold for diagnosing early labor in a group of women who are known to work extremely long hours and are widely believed to be at high risk,8 9 10 , 16 or that pregnant physicians may be more likely to report symptoms to their obstetricians. Alternatively, preterm labor triggered by work-related stress could be more reversible than that due to other causes.
The excess risk of reported preeclampsia among the residents could also be due to a difference in diagnostic vigilance. Major adverse effects of preeclampsia are the delivery of infants who are small for gestational age, preterm delivery, and stillbirth. Among women in whom preeclampsia developed, 24 percent of the residents and 41 percent of the wives had one or more of these outcomes (P = 0.048). This suggests that the residents had milder cases of preeclampsia than the wives, that medical management was more effective among the residents, or that obstetricians were more vigilant in diagnosing preeclampsia among women residents.
Our results differ from those of Miller et al.,8 who noted that 60 women physicians who received care in a university group practice were 2.3 times more likely to deliver preterm infants than a group of control women who had at least 16 years of education. Grunebaum et al.9 reported that the delivery of low-birth-weight infants was 3 to 4 times more common, and the delivery of infants small for gestational age was 7.5 times more common, in pregnancies among obstetrical residents than in pregnancies among the same women before or after their residencies. Neither of these studies used a large, scientifically selected sample of physicians; moreover, Grunebaum et al. reported a response rate under 50 percent, raising the issue of biased response. Our results are in general agreement with those of several small17 and uncontrolled10 , 11 surveys, which found women physicians to be at low risk of delivering preterm infants, infants who are small for gestational age, or low-birth-weight infants.
These results call into question the association between stressful occupations requiring long hours of physical activity and the incidence of preterm delivery. Several studies have found occupational factors — such as high number of working hours per week,1 , 2 night work,1 and long periods of standing1 , 3 — to be associated with an increased risk of preterm delivery. "Preventive rest periods" for fatigue in the absence of specific obstetrical disorders were shown in one study to result in a reduced occurrence of preterm delivery.18 The degree to which unmeasured socioeconomic factors account for these results has been unclear, since women with physically demanding occupations are usually of lower socioeconomic status than those with less demanding occupations. We found that pregnant residents, who worked long hours and were likely to work until delivery, did not have significantly higher rates of most adverse outcomes than a control group of women of similar socioeconomic status but with jobs that demanded fewer hours of work. Among women residents, a larger number of hours worked per week and a larger number of nights on call were not strongly associated with adverse pregnancy outcomes; only extremely long workweeks appeared hazardous. Therefore, the previously reported associations between occupational stress and adverse pregnancy outcome may be attributable to unmeasured socioeconomic factors.
In spite of working longer hours, working later in their pregnancies, and working with reportedly less supportive coworkers and supervisors, women residents have a risk of adverse pregnancy outcome that is similar to that for the wives of male residents. However, residents who work more than 100 hours per week (15 percent during the first trimester, decreasing to 8 percent during the third) may be at increased risk for preterm delivery. This increase suggests that the New York State law limiting residents to 80 hours of work per week19 is well advised with respect to pregnant residents. That pregnant residents as a group are at low risk of adverse outcome does not mean that residency programs should not make appropriate provisions for pregnant residents (the extent to which such provisions existed in this study is unknown). Nor would it be appropriate to conclude that jobs involving other types of strenuous physical labor might not affect pregnancy outcome. With the possible exception of those with extremely long workweeks, however, our findings refute the belief that pregnant residents are a high-risk group in terms of pregnancy outcome, and they call into question the relation of occupational stress and fatigue to outcome in otherwise healthy women of high socioeconomic status.
Supported by a contract (N01-HD-9–2923) with the National Institutes of Health.
Presented at the annual meeting of the Society for Pediatric Epidemiologic Research, Snowbird, Utah, June 12, 1990.
We are indebted to Rita Stone and Robin Krug of Westat, Inc., for their exceptional work in carrying out the survey; to the American College of Obstetricians and Gynecologists for their endorsement; and, most of all, to the medical school class of 1985 and their families for participating in the survey.
Source Information
From the Division of Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Md. (M.A.K.); the Center for the Future of Children, David and Lucile Packard Foundation, Los Altos, Calif. (P.H.S.); and the Department of Environmental and Community Medicine, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway (G.G.R.). Address reprint requests to Dr. Klebanoff at the Division of Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, EPN 640, Bethesda, MD 20892.
- References
References
1
Mamelle
Web of Science | Medline2
McDonald
Medline3
Saurel-Cubizolles
CrossRef | Web of Science | Medline4
Naeye
Web of Science | Medline5
Fabro 6
Sayres
Full Text | Web of Science | Medline7
Sinal
Medline8
Miller
Web of Science | Medline9
Grunebaum
Web of Science | Medline10
Schwartz
Web of Science | Medline11
Phelan
Web of Science | Medline12
Williams
Web of Science | Medline13
Woolf
CrossRef | Medline14
Kleinbaum DG, Kupper LL, Morgenstern H. Epidemiologic research: principles and quantitative methods. Belmont, Calif.: Lifetime Learning Publications, 1982.
15
Kleinman
Web of Science | Medline16
Katz
Medline17
Osborn 18
Mamelle
CrossRef | Medline19
Bergman
CrossRef | Web of Science | Medline
- Citing Articles (41)
Citing Articles
1
A. MacKenzie, L. Roberts. (2011) Personal maternal care reflections of general practice physicians. Family Practice
CrossRef2
Ahmet Ursavas. 2011. Sleep Disorders and Pregnancy. , 185-205.
CrossRef3
Bilgay Izci-Balserak, Grace W Pien. (2010) Sleep-disordered breathing and pregnancy: potential mechanisms and evidence for maternal and fetal morbidity. Current Opinion in Pulmonary Medicine 16:6, 574-582
CrossRef4
Reginald Quansah, Jouni J. Jaakkola. (2010) Occupational Exposures and Adverse Pregnancy Outcomes Among Nurses: A Systematic Review and Meta-Analysis. Journal of Women's Health 19:10, 1851-1862
CrossRef5
Jen Jen Chang, Grace W. Pien, Stephen P. Duntley, George A. Macones. (2010) Sleep deprivation during pregnancy and maternal and fetal outcomes: Is there a relationship?. Sleep Medicine Reviews 14:2, 107-114
CrossRef6
Lisa L. Willett, Melissa F. Wellons, Jason R. Hartig, Lindsey Roenigk, Mukta Panda, Angela T. Dearinger, Jeroan Allison, Thomas K. Houston. (2010) Do Women Residents Delay Childbearing Due to Perceived Career Threats?. Academic Medicine 85:4, 640-646
CrossRef7
Marlos Rodrigues Domingues, Alicia Matijasevich, Aluísio J.D. Barros. (2009) Physical Activity and Preterm Birth. Sports Medicine 39:11, 961-975
CrossRef8
Reginald Quansah, Mika Gissler, Jouni J. K. Jaakkola. (2009) Work as a physician and adverse pregnancy outcomes: a Finnish nationwide population-based registry study. European Journal of Epidemiology 24:9, 531-536
CrossRef9
Lori B. Lerner, Kelly L. Stolzmann, Vanessa D. Gulla. (2009) Birth Trends and Pregnancy Complications among Women Urologists. Journal of the American College of Surgeons 208:2, 293-297
CrossRef10
Sunyoung Kim, Jin Kyoung Kim, Ji In Chung, Jung Kwon Lee. (2009) Results of a Survey of Residents Who Experience Pregnancy and Delivery. Korean Journal of Medical Education 21:2, 175
CrossRef11
F. Goffinet. 2009. Épidémiologie. , 11-21.
CrossRef12
A. Croteau. (2006) Work Activity in Pregnancy, Preventive Measures, and the Risk of Delivering a Small-for-Gestational-Age Infant. American Journal of Public Health 96:5, 846-855
CrossRef13
E K Rousham, P E Clarke, H Gross. (2006) Significant changes in physical activity among pregnant women in the UK as assessed by accelerometry and self-reported activity. European Journal of Clinical Nutrition 60:3, 393-400
CrossRef14
Joseph S. Ross, Beverly A. Forsyth, Julie R. Rosenbaum. (2006) BRIEF REPORT: Housestaff Adherence to Cervical Cancer Screening Recommendations. Journal of General Internal Medicine 21:1, 68-70
CrossRef15
Alison M. Heru. (2005) Pink-collar medicine: Women and the future of medicine. Gender Issues 22:1, 20-34
CrossRef16
Lisa A. Pompeii, David A. Savitz, Kelly R. Evenson, Bonnie Rogers, Michael McMahon. (2005) Physical Exertion at Work and the Risk of Preterm Delivery and Small-for-Gestational- Age Birth. Obstetrics & Gynecology 106:6, 1279-1288
CrossRef17
Charles L. Baum. (2005) THE EFFECTS OF EMPLOYMENT WHILE PREGNANT ON HEALTH AT BIRTH. Economic Inquiry 43:2, 283-302
CrossRef18
Danielle J. Jacobs, Sophie A. Vreeburg, Gus A. Dekker, Adrian R. Heard, Kevin R. Priest, Annabelle Chan. (2003) Risk factors for hypertension during pregnancy in South Australia. The Australian and New Zealand Journal of Obstetrics and Gynaecology 43:6, 421-428
CrossRef19
Sanjay M Bhananker, Bruce F Cullen. (2003) Resident work hours. Current Opinion in Anaesthesiology 16:6, 603-609
CrossRef20
ARYEH D. STEIN, JUANITA M. RIVERA, JAMES M. PIVARNIK. (2003) Measuring Energy Expenditure in Habitually Active and Sedentary Pregnant Women. Medicine & Science in Sports & Exercise 35:8, 1441-1446
CrossRef21
David C. Warltier, Steven K. Howard, Mark R. Rosekind, Jonathan D. Katz, Arnold J. Berry. (2002) Fatigue in Anesthesia. Anesthesiology 97:5, 1281-1294
CrossRef22
Judith A. Owens. (2001) Sleep loss and fatigue in medical training. Current Opinion in Pulmonary Medicine 7:6, 411-418
CrossRef23
E. Petridou, H. Salvanos, A. Skalkidou, N. Dessypris, M. Moustaki, D. Trichopoulos. (2001) Are there common triggers of preterm deliveries?. BJOG: An International Journal of Obstetrics and Gynaecology 108:6, 598-604
CrossRef24
Y Melamed. (2000) Differences in preterm delivery rates and outcomes in Jews and Bedouins in southern Israel. European Journal of Obstetrics & Gynecology and Reproductive Biology 93:1, 41-46
CrossRef25
Susan P. Walker, John R. Higgins, Michael Permezel, Shaun P. Brennecke. (1999) Maternal Work and Pregnancy. The Australian and New Zealand Journal of Obstetrics and Gynaecology 39:2, 144-151
CrossRef26
Kristin R. Kardel, Trygve Kase. (1998) Training in pregnant women: effects on fetal development and birth. American Journal of Obstetrics and Gynecology 178:2, 280-286
CrossRef27
Ros Bramwell. (1997) Studying the impact of the psychosocial work environment on pregnancy outcome: A review of methodological issues. Journal of Reproductive and Infant Psychology 15:3-4, 257-269
CrossRef28
Steven G. Gabbe, L.Paige Turner. (1997) Reproductive hazards of the American lifestyle: Work during pregnancy. American Journal of Obstetrics and Gynecology 176:4, 826-832
CrossRef29
Lucie Capek, Dorothy E. Edwards, Susan E. Mackinnon. (1997) Plastic Surgeons: A Gender Comparison. Plastic & Reconstructive Surgery 99:2, 289-299
CrossRef30
K M Brett, D S Strogatz, D A Savitz. (1997) Employment, job strain, and preterm delivery among women in North Carolina.. American Journal of Public Health 87:2, 199-204
CrossRef31
Arsenio Spinillo, Ezio Capuzzo, Laura Colonna, Gaia Piazzi, Sabrina Nicola, Federica Baltaro. (1995) The Effect of Work Activity in Pregnancy on the Risk of Severe Preeclampsia. The Australian and New Zealand Journal of Obstetrics and Gynaecology 35:4, 380-385
CrossRef32
C. Höß. (1995) Frauenärztin und akademische Karriere. Archives of Gynecology and Obstetrics 257:1-4, 704-709
CrossRef33
Gertrud S. Berkowitz, Emile Papiernik. (1995) Working conditions, maternity legislation, and preterm birth. Seminars in Perinatology 19:4, 272-278
CrossRef34
Maureen A. Kelley, Joyceen S. Boyle. (1995) How Much Is too Much? A Study of Pregnant Women in Service Industry Jobs. Journal of Obstetric, Gynecologic, <html_ent glyph="@amp;" ascii="&"/> Neonatal Nursing 24:3, 269-275
CrossRef35
Debra E. Irwin, David A. Savitz, Kenneth A. St. André, Irva Hertz-Picciotto. (1994) Study of occupational risk factors for pregnancy-induced hypertension among active duty enlisted navy personnel. American Journal of Industrial Medicine 25:3, 349-359
CrossRef36
Jeanne F. Deloseph. (1993) Redefining Women's Work During Pregnancy: Toward a More Comprehensive Approach. Birth 20:2, 86-93
CrossRef37
H. I. J. Wildschut, L. M. Harker, C. J. Riddoch. (1993) The potential value of a short self-completion questionnaire for the assessment of habitual physical activity in pregnancy. Journal of Psychosomatic Obstetrics & Gynecology 14:1, 17-29
CrossRef38
Neil Chernoff, John M. Rogers, Robert Kavet. (1992) A review of the literature on potential reproductive and developmental toxicity of electric and magnetic fields. Toxicology 74:2-3, 91-126
CrossRef39
(1991) Outcomes of Pregnancy in Resident Physicians. New England Journal of Medicine 324:9, 629-631
Full Text40
Anja Poerksen, Diana B. Petitti. (1991) Employment and low birth weight in black women. Social Science & Medicine 33:11, 1281-1286
CrossRef41
Little, A. Brian, . (1990) Why Can't a Woman Be More like a Man?. New England Journal of Medicine 323:15, 1064-1065
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