The effect of physical activity during pregnancy on preterm delivery and birth weight (original) (raw)

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

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.

Physical work load, fetal development and course of pregnancy

Scandinavian Journal of Work, Environment & Health, 1989

NURMINEN T, LUSA S, ILMARINEN J , KURPPA K. Physical work load , fetal development and course of pregnancy. Scand J Work Environ Health 1989; 15:404-414. The effects of physical work load during pregnancy were anal yzed in connection with a nationwide case-refere nt study that screened for associations between selected st ruc tural malformations a nd occ upationa l expos ures . The stra in of the occ upational acti vities o f 1475 mo thers of malformed infant s and an equa l number of mothers o f noncase bab ies was assessed from a descript ion of the work tasks by an expert using a standa rdized method reflecting energy expenditure. The non case mothers' experience revealed a relat ion between physical load and gro wth retardation that has also been suggested by other epid emiologic studies. No relation was found between an increase in mean physical load and the occurrence of threatened abortion; yet work involving much standing had an increased risk. Mothers whose work included occasional high physical load s had more pregnancy-induced hypertension . The data showed unexpe cted associations between physical load and structural malformations .

Relationship between maternal physical activities and preterm birth

Environmental Health and Preventive Medicine, 2001

A cross-sectional study was conducted in three Municipal Health Centers located in Aichi prefecture, central Japan. The main purpose of this study was to verify the interaction between maternal leisure-time physical activities prior to and/or during pregnancy and preterm birth and also, to determine the risk factors related to preterm birth. In this study of the 2,682 questionnaires delivered within one year to mothers or relatives at the Municipal Health Centers, 1,714 questionnaires were analyzed. In a univariate analysis the results showed that mothers who had a previous low birthweight or a premature baby, or who were hospitalized during pregnancy before the 37 th week of gestation, or had an occupational activity, or carried out their household chores, or were sick, or received much medical advice and did not exercise were more likely to have a preterm baby. In multivariable logistic regression analyses, maternal hospitalization before the 37 th week of gestation and occupational activities were significant determinants associated with preterm birth. Thus, it was verified that maternal leisure-time physical activities prior to and/or during pregnancy were not related to preterm birth.

The Effect of Work Activity in Pregnancy on the Risk of Severe Preeclampsia

The Australian and New Zealand Journal of Obstetrics and Gynaecology, 1995

The aim of this study was to evaluate the impact of type of employment and level of physical activity at work on the risk of severe preeclampsia. For this purpose, we carried out a case control study of 160 nulliparous pregnant women with severe preeclampsia and 320 normotensive nulliparous controls who received prenatal care from members of one medical staff. The type of employment and the level of physical activity sustained at work were ascertained at birth through an interview based on a standard questionnaire. The degree of physical activity at work was assessed by a 4-level activity score based on type of work, physical intensity, posture at work, and weekly working hours. In logistic regression analysis, after adjustment for potential confounders (maternal age, time of stopping work, prepregnancy body mass index, social status of the partner, history of previous abortion, and prepregnancy smoking status), clerical workers had a significantly lower risk of severe preeclampsia than women who were unemployed at the beginning of pregnancy (OR 0.53, 95% CI 0.30, 0.96). In multivariate analysis, there was a significant linear trend relating the degree of physical activity at work, to the risk of preeclampsia (likelihood chi-square = 9.38,3 df, p = 0.002). We then restricted the analysis to women who had ever worked in pregnancy (n = 339) also adjusting for confounders, and found that clerical workers were still at significantly lower risk of severe preeclampsia than women not formally employed (OR 0.2,95% CI 0.08.0.49). In addition, moderatelhigh physical activity at work was associated with a 2-fold increase in the risk of severe preeclampsia compared to mild activity (OR 2.08, 95% CI 1.11,3.88). We conclude that moderate to high physical activity at work seems to increase the risk of severe preeclampsia.