Physical work load, fetal development and course of pregnancy (original) (raw)

The effect of work activity in pregnancy on the risk of fetal growth retardation

Acta Obstetricia et Gynecologica Scandinavica, 1996

The relationship between physical activity at work and risk of fetal growth restriction is controversial. For the most part, previous studies investigated the effect of work activity on birthweight alone. We evaluated the impact of type of occupation and physical effort at work on the risk of ultrasonographically confirmed fetal growth retardation among nulliparous women. Methods. We compared the characteristics of work and the intensity of occupational fatigue (work posture, weekly working hours, physical effort at work) in 349 patients with ultrasonographically confirmed fetal growth retardation and 698 control pregnancies with appropriate fetal growth. Physical demands at work were evaluated by interview at birth. Logistic regression analysis was used to evaluate the association of employment status, type of occupation, and intensity of occupational fatigue with the risk of fetal growth retardation, correcting for potential confounders (maternal age, pre-pregnancy body mass index, mean weight gain in pregnancy, education, partner's social status, smoking in pregnancy, alcohol use, illicit drug use, time of stopping work, and hypertension). Results. After adjusting for confounding, the risk of fetal growth retardation was similar between unemployed and formally employed women at the beginning of pregnancy (OR=l.26; 95% confidence interva1=0.86-1.83). However, manual workers were at slightly higher risk of IUGR than not formally employed women (OR=1.81; 95% CI=1.15-2.85). Among formally employed women, standing or walking at work, and working 230 hours a week were not significantly associated with IUGR. Finally, the risk of IUGR was significantly higher (OR=2.4; 95% CI=1.36421) among women reporting moderate-to-heavy as compared to light physical effort at work. Conclusion. Formal employment at the beginning of pregnancy is not associated with an increased risk of IUGR. However, moderate-to-heavy physical effort at work seems to increase the risk of sonographically confirmed fetal growth retardation.

Work-related physical exertion and risk of preterm, low birthweight delivery

Paediatric and Perinatal Epidemiology, 1990

Although many women work during pregnancy, the effect of maternal job experience on pregnancy outcome is controversial. We investigated whether work-related physical exertion increases a woman's risk of delivering a preterm, low birthweight infant. We studied 773 employed, pregnant women included in the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), a nationally representative sample of young adults. Data concerning work status, job title during pregnancy, and other factors affecting the outcome of pregnancy were obtained from the NLSY. Assessment of physical exertion was based on job title, using an established catalogue of occupational characteristics. Women in jobs characterised by high physical exertion experienced a higher rate of preterm, low birthweight delivery, defined as maternal report of delivery more than 3 weeks early and birthweight under 2500 g (adjusted RR=5.1, 95% CI=1.5, 17.7). These findings support a policy of limiting work-related physical exertion during pregnancy.

Effect of Maternal Work Activity on Preterm Birth and Low Birth Weight

American Journal of Epidemiology, 1990

The association of the prolonged standing required by certain jobs with the rate of preterm births and low birth weight deliveries was examined in New Haven, Connecticut, between 1980 and 1982. In a sample of 1,206 women, the rate of preterm births (births occurring <37 weeks from the last menstrual period) was higher among women with jobs requiring prolonged standing (7.7%) compared with those with sedentary (4.2%) or active jobs (2.8%). The odds of preterm delivery in the standing group was 2.72 (95% confidence interval of 1.24-5.95). A significant association between standing on the job and preterm birth was demonstrated when adjustment was made for the following variables in a logistic regression model: parity, smoking, education, caffeine use, marijuana use, race, gestational age at interview, and marital status. The low birth weight (<2,500 g) rate was higher among those in the standing group (5.5%) compared with those in the sedentary (4.0%) and active groups (4.0%), but this association was not significant when confounding factors were controlled. birth weight; occupations; pregnancy

Birth complications, overweight, and physical inactivity

Acta Obstetricia et Gynecologica Scandinavica, 2009

Facsimile: +47 23 07 26 50 2 Birth complications, overweight and physical inactivity Abstract. Maternal life style factors are potential predictors of pregnancy complications.

Working conditions and adverse pregnancy outcome: a meta-analysis

Obstetrics & Gynecology, 2000

To evaluate the association between working conditions and adverse pregnancy outcomes by performing a meta-analysis of published studies. Data Sources: We searched the English-language literature in MEDLINE through August 1999 using the terms standing, posture, work, workload, working conditions, shift, occupational exposure, occupational diseases, lifting, pregnancy complications, pregnancy, small for gestational age (SGA), fetal growth retardation (FGR), preterm, and labor. Methods of Study Selection: We included observational studies evaluating the effect of one or more of the following work-related exposures on adverse pregnancy outcome: physically demanding work, prolonged standing, long work hours, shift work, and cumulative work fatigue score. Outcomes of interest were preterm birth, hypertension or preeclampsia, and SGA. We conducted a meta-analysis based on 160,988 women in 29 studies to evaluate the association of physically demanding work, prolonged standing, long working hours, shift work, and cumulative work fatigue score with preterm birth. Also analyzed were the associations of physically demanding work with hypertension or preeclampsia and SGA infants. The data were analyzed using the Peto-modified Mantel-Haenszel method to estimate the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Tabulation, Integration, and Results: Physically demanding work was significantly associated with preterm birth (OR 1.22, 95% CI 1.16, 1.29), SGA (OR 1.37, 95% CI 1.30, 1.44), and hypertension or preeclampsia (OR 1.60, 95% CI 1.30, 1.96). Other occupational exposures significantly associated with preterm birth included prolonged standing (OR 1.26, 95% CI 1.13, 1.40), shift and night work (OR 1.24, 95% CI 1.06, 1.46), and high cumulative work fatigue score (OR 1.63, 95% CI 1.33, 1.98). We found no significant association between long work hours and preterm birth (OR 1.03, 95% CI 0.92, 1.16). Conclusion: Physically demanding work may significantly increase a woman's risk of adverse pregnancy outcome.

The effect of physical activity during pregnancy on preterm delivery and birth weight

American Journal of Obstetrics and Gynecology, 1990

The relationship between physical activity during pregnancy, preterm birth, and gestational age-adjusted birth weight was investigated prospectively in a cohort of 7101 women. This study is one of few to evaluate both employment-and non-employment-related physical activity. Prolonged periods of standing were associated with a modestly increased risk of preterm delivery (adjusted odds ratio for 2:8 hours/day of standing == 1.31). Heavy work or exercise was not associated with preterm delivery (adjusted odds ratio for 2:4 hours per day of heavy work == 1.04). The proportion of infants born preterm did not differ among women working in predominantly standing, active, and sedentary occupations. Physical activity was not associated with gestational age-adjusted birth weight after controlling for confounding variables. These data suggest that unmeasured socioeconomic differences among women reporting different levels of activity may account for previously described associations between physical activity and pregnancy butcome. Most pregnant women who report increased levels of physical activity are not at increased risk of preterm delivery or reduced intrauterine growth. However, these data do not address the role of activity restriction in the management of selected women at high risk for adverse pregnancy outcome. (AM J The effect of physical activity during pregnancy on preterm delivery and fetal growth has been controversial. Mamelle et al. I stated that as the number of fatigue factors among women employed during pregnancy increased from 0 to 5, the rate of premature birth increased from 2.3% to 11.1%. Among hospital workers, work-related factors (long periods of standing, carrying heavy loads, and performing heavy cleaning tasks) were observed to be associated with preterm delivery! Compared with women whose occupations entailed varied amounts of physical activity, women employed in occupations requiring long periods of standing were found to be 2.7 times as likely to be delivered before