Date of Award


Degree Name

Master of Science


Public Health


Mary Margaret Weigel


Background & Significance. Evidence has accumulated over the past two decades suggesting that healthy pregnant women who engage in regular moderate physical activity (PA) may reduce their risk for certain adverse pregnancy and postnatal health outcomes. The U.S. Department of Health and Human Services (DHHS)/Centers for Disease Control and Prevention (CDC) recently issued the 2008 Physical Activity Guidelines for Americans which recommends at least 150 minutes/week of moderate-intensity aerobic PA for pregnant women. The American College of Obstetricians and Gynecologists (ACOG, 2002) recommends 30 min of moderate-intensity PA, specified as derived from recreational or leisure activities on most or all days of the week. The World Health Organization (WHO) does not yet published prenatal PA recommendations. Recent findings suggest that U.S. and European women decrease their PA during the second and third trimesters of gestation. However, most of these focused on recreation-derived PA and so may have underestimated the amount of moderate PA from other sources. Published information on the prenatal PA patterns and predictors in Latin American populations is scant. The population prevalence of overweight/obesity throughout Latin America has been rising rapidly among women. Likewise, type 2 diabetes, hypertension, cardiovascular conditions, and other preventable chronic conditions are becoming increasingly more prevalent in Latin American populations. Thus, the examination of prenatal PA patterns and their determinants in Latin America and other less developed countries is important. These may be distinct due to differences in sociodemographic characteristics, lifestyle and environmental conditions. Data on these are needed to help develop country-specific as well as international prenatal PA recommendations.

Objectives and Hypotheses. The major objectives of the current study were to examine the trimestral PA patterns of urban Ecuadorian women, identify major prenatal PA predictors, and compare reported physical activity with DHHS/CDC (2008) and ACOG (2002) recommendations. It was hypothesized that PA would be similar during 1st and 2nd trimesters but decrease in the 3rd trimester because of increased body mass making movement more difficult. Another a priori hypothesis was that women with more children and those employed outside the home will have higher overall PA but less recreation-derived PA compared to other pregnant women Also, physical activity would be reduced in women affected by morning sickness and other common early prenatal complaints. It was also hypothesized that women will not meet the ACOG (2002) recommendation for moderate-intensity leisure time physical activity but will accumulate an equivalent amount from other activities and will meet the DHSS/CDC (2008) recommendations for pregnant women from the Physical Activity Guidelines for Americans.

Methods. The prospective cohort study was conducted in the prenatal clinics of a municipal hospital in Quito, Ecuador. A cohort of 849 apparently healthy women was followed from the 1st through 3rd trimesters. Data on sociodemographic, reproductive/obstetric, lifestyle, common somatic symptoms, and living conditions were collected using a structured questionnaire with open- and closed-ended questions that was administered during the 1st and 2nd trimesters. Repeated 24-hour PA recall data were collected from subjects at their 1st, 2nd, and 3rd trimester. The recall instrument was designed to capture a full range of activities encountered in daily life such as sleeping, resting, housework, childcare, employment, transportation, recreational, and other activities. Subjects were asked to recall the reported context, intensity, and duration of time in 15-minute increments spent engaged in different types of activities during the prior 24-hour period. The intensity or metabolic equivalents (METs) of the different reported activities were obtained from the updated Compendium of Physical Activities which provided an estimate of overall energy expenditure per 24-hour period. Metabolic equivalent hours (MET-hours), a measure of both intensity and duration of specific activities were calculated. These were time/24 hours spent sleeping and resting (0.9 METs) or in very low-intensity activities (1.0-1.9 METs), low-intensity activities (2.0-2.9 METs), moderate-intensity activities (3.0-5.9 METs), and high-intensity activities (> 6 METS). Descriptive, bivariate and multivariate analytical methods were used to examine the data.

Results. Most subjects were aged < 30 years, married, and had completed at least some middle or high school education. Four-tenths were primiparas and only 45% said their current pregnancy was planned. Fewer than 10% reported periconceptual use of tobacco (1.4%) or alcohol (9.8%). Common early prenatal somatic complaints included morning sickness (77%), fatigue (90.1%), dizziness (45.7%), increased irritability (79.6%), breast tenderness (79.4%) and uterine heaviness (79.6%). No statistically significant differences were identified for total mean MET's across trimesters 1-3 (37.4 + 4 vs. 37.4 + 3.9 vs. 37.0 + 4; F=1.1; 3.3). However, mean MET's expenditures from specific activity categories differed. For example, the amount spent sleeping/resting were higher in the 1st trimester compared to 2nd and 3rd trimesters (9.3 + 2.0 vs. 8.9 + 1.6 vs. 9.0 + 1.7; F= 9.3; P=0.002). In contrast, the contribution of very low intensity activities increased from the 1st to 3rd trimester (10.4 + 4.4 vs. 11.3 + 4.4 vs. 11.8 + 4.3; F=17.6; P= 0.001) while those from low intensity activity decreased (14.3 + 7.4 vs. 14.1 + 6.9 vs. 13.2 + 7.1; F= 4.8; P=0.03) suggesting that women were less physically active as pregnancy progressed. No statistically significant trimestral differences were recorded for moderate and high intensity activities which were less frequent. Seventy percent of women's daily time across all three trimesters was spent in resting/sleeping or in self-care, eating, bathing, dressing, watching TV, reading, and other very low and low intensity activities. Household-related activities (~16-17%) conducted within the home (e.g., cleaning, cooking), time spent on buses or other transportation (~6%), household activities performed outside the home such as shopping (2.4%), outside employment (~2-3%), and caregiving (~1.1-1.8%) accounted for most of the remainder of time. It was noteworthy that very few women engaged in moderate-vigorous intensity leisure PA during the 1st (8/849), 2nd (3/420), or 3rd trimesters (0/398). Predictors identified for total MET's for all three trimesters were maternal age, marital status, occupation, and no. of dependents living inside the home. Maternal education, dizziness, and morning sickness were significant predictors of total MET's only during the first trimester. Neither body mass index, other somatic symptoms, other sociodemographic characteristics, nor lifestyle indicators were significant MET expenditure predictors. None of the study women met the ACOG (2002) recommendations for pregnant women due to the reduced recreational opportunities but 40%, 45%, and 44%, respectively met DHHS/CDC (2008) recommendations during the 1st, 2nd, and 3rd trimesters by accumulating moderate intensity PA from other activities.

Conclusion. Overall level of PA and activity energy expenditure remained relatively constant over gestation but the amount contributed by different activity categories varied by trimester. Most daily MET expenditures were contributed by lower intensity activities. Only a small handful of women engaged in any recreational PA during the first two trimesters and none during the final trimester. However when contribution of other moderate-intensity activities is taken into account, around 40% of women were able to meet the DHHS/CDC (2008) prenatal PA recommendations. It is unclear why so few women engage in leisure time activity but could be due to lack of time due to other responsibilities or the lack of a culture of PA for women in Ecuadorian society. Future studies should be conducted to explore this issue.




Received from ProQuest

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67 pages

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Rights Holder

Erika Gonzalez Beltran