Maternal activity in relation to birth size in rural India. The Pune Maternal Nutrition Study

Risk of prematurity, low birthweight and pre-eclampsia in relation to working hours and physical activities: a systematic review

BACKGROUND

Occupational activities are suspected of having an adverse impact on outcomes of pregnancy.

AIM

To assess the evidence relating three major adverse outcomes (preterm delivery, low birthweight (LBW) and pre-eclampsia/gestational hypertension) to five common occupational exposures (prolonged working hours, shift work, lifting, standing and heavy physical workload).

METHODS

A systematic search of Medline and Embase (1966-December 2005) using combinations of keywords and medical subject heading terms was conducted. For each relevant paper, standard details were abstracted that were then used to summarise the design features of studies, to rate their methodological quality (completeness of reporting and potential for important bias or confounding) and to provide estimates of effect. For studies with similar definitions of exposure and outcome, pooled estimates of relative risk (RR) in meta-analysis were calculated.

RESULTS

53 reports were identified-35 on preterm delivery, 34 on birth weight and 9 on pre-eclampsia or gestational hypertension. These included 21 cohort investigations. For pre-term delivery, extensive evidence relating to each of the exposures of interest was found. Findings were generally consistent and tended to rule out a more than moderate effect size (RR >1.4). The larger and most complete studies were less positive, and pooled estimates of risk pointed to only modest or null effects. For small-for-gestational age, the position was similar, but the evidence base was more limited. For pre-eclampsia and gestational hypertension, it was too small to allow firm conclusions.

CONCLUSIONS

The balance of evidence is not sufficiently compelling to justify mandatory restrictions on any of the activities considered in this review. However, given some uncertainties in the evidence base and the apparent absence of important beneficial effects, it may be prudent to advise against long working hours, prolonged standing and heavy physical work, particularly late in pregnancy. Our review identifies several priorities for future investigation.

Obesity epidemic in India: intrauterine origins?

The epidemic of ‘obesity’ in India is not appreciated because BMI underestimates the adiposity of Indians. Specific adiposity measurements are necessary for recognition of the adiposity of ‘thin’ Indians. The origin of this adiposity is only beginning to be understood. In addition to a possible genetic predisposition, intrauterine ‘programming’ might be responsible, although in the ‘thrifty phenotype’ hypothesis the adiposity of the ‘thin’ fetus has not been appreciated. Dutch men who faced ‘winter hunger’ during the first trimester of their in utero life have become more obese as adults. Low birth weight predicts central obesity in some studies, including studies in urban children. It has also been shown that small and thin Indian newborns (weight 2·7?kg and ponderal index 2·4?kg\m3) have poor muscle and visceral mass but higher adiposity for a given weight compared with white Caucasian babies. This body composition is influenced by maternal adiposity before pregnancy and by aspects of maternal nutritional intake and circulating nutrient concentrations during pregnancy. There are no strong paternal determinants of adiposity at birth. Adiposity may be an integral part of the orchestrated adjustments made to support ‘brain preservation’ during intrauterine growth, because brain tissue is predominantly fat. Increased nutrition in the face of a genetic predisposition or multigenerational undernutrition increases maternal insulin resistance in late pregnancy and promotes fetal adiposity even in absence of marked hyperglycaemia. Further research is necessary to define the role of specific nutrients and metabolites in the intrauterine processes promoting adiposity before maternal interventions to curtail the epidemic of obesity and diabetes are planned.

Gender differences in body mass index in rural India are determined by socio-economic factors and lifestyle

A survey of the nutritional status of women in 6 villages of the Pune district of Maharashtra, India, found young women to have a significantly lower BMI than their male peers. The purpose of this study was to identify social and economic factors associated with this difference in thinness and to explore the behavior in men and women that might underlie these associations. We compared men and women in 90 families in this part of Maharashtra by taking measurements of the height and weight of the married couple of child-bearing age in each family and assessing their social and economic details, fasting practices, and oil consumption. In this agricultural community, women were thinner in joint land-owning families, where the main occupation was farming, than those in nonfarming families. This was not true of men in this type of family. Men in "cash-rich" families had higher BMI than men in families without this characteristic. There was no corresponding difference in women's BMI. We then examined the lifestyles of men and women in a subset of 45 of these families. Women were more likely to work full time in farming than men, to carry the burden of all household chores, to have less sleep, and to eat less food away from home than men. Women fasted more frequently and more strictly than men. Despite identifying significant differences in behavior between men and women in the same household, we did not find a direct link between behavior and BMI. We conclude that being married into a farming family is an important factor in determining the thinness of a woman in rural Maharashtra.

Why are rural Indian women so thin? Findings from a village in Maharashtra

OBJECTIVE

To identify social, behavioural and cultural factors that explain the thinness of young women relative to their men in rural Maharashtra, India.

DESIGN

Twelve focus group discussions were conducted to explore the villagers' understanding of why women in their area might be thinner than men.

SETTING

Pabal village and surrounding hamlets, in the Pune district of Maharashtra, India.

SUBJECTS

Samples of young mothers and fathers, grandmothers and grandfathers were selected from families in the village with children below 10 years of age.

RESULTS

Four factors were identified that the villagers felt contributed to the disparity in thinness. First, marriage isolated girls from their own families and villages, and brought the expectation of early motherhood. Young brides were often unable to relax and eat adequately. Second, marriage increased the workload of young women. They were expected to do the heaviest household chores as well as farm work in this predominantly agricultural community. Third, women had no financial autonomy or freedom of movement, and were therefore denied access to supplementary food sources available to men. Fourth, young women felt responsible for their household's health and success. They were encouraged to fast regularly to ensure this. Despite feeling responsible, young women had no control over factors that might affect the household's well being. This made them anxious and worried a great deal of the time.

CONCLUSIONS

Interventions to improve the nutritional status of young women in this region need to recognise the roles and responsibilities taken up by young brides.

A Review of Physical Activity Patterns in Pregnant Women and Their Relationship to Psychological Health

Regular physical activity contributes positively to physical and psychological health. Adverse consequences of inactivity may be an especially important problem among pregnant women. Up to 60% are inactive during pregnancy. This review found consistent evidence that physical activity is reduced during pregnancy; however, few investigators have sought to quantify physical activity patterns among pregnant women using well validated measures. Some of the barriers to physical activity during pregnancy, such as depression, anxiety and fatigue, have been shown to be attenuated by regular exercise performed by non-pregnant samples. There is a need to better understand the relationships between these factors and physical activity during pregnancy. Available retrospective and prospective results suggest that both leisure time and work-related physical activities are decreased across pregnancy. Intensity and duration decrease both during pregnancy compared with pre-pregnancy and in the third trimester compared with the first. There is a need for well designed longitudinal investigations that document pregnancy-related changes in physical activity at frequent intervals during pregnancy using validated and more precise measures of physical activity. Reductions in physical activity and a worsening mood are common during pregnancy. If the relationship between physical inactivity and mood disturbances is indeed observed and maintained during pregnancy, then decreases in physical activity in the third trimester would be expected to result in a worsening mood. In recent years, increased attention has been paid to antenatal mood disturbances, and this research has yielded a host of important findings. Prior correlational and experimental research with non-pregnant samples has demonstrated a consistent relationship between physical inactivity and mood disturbances. Whether this relationship occurs among pregnant women and/or is maintained as women progress during pregnancy is uncertain. Prior investigations have revealed that there is higher rate of mood disturbance during pregnancy than following pregnancy but little is known about the mechanisms that cause these mood disturbances. It is important to better understand changes in mood with pregnancy because mood disturbances can have major negative consequences for a pregnant woman. The major adverse consequences of depression among pregnant women are largely the same as those of non-pregnant individuals. Only six investigations have quantified the relationship between changes in physical activity and changes in mood during pregnancy. The available evidence suggests that inactivity is associated with worse mood. Additional research into this topic is warranted due to the limited number of published papers and the design and methodology limitations of these investigations.

Increasing maternal parity predicts neonatal adiposity: Pune Maternal Nutrition Study

OBJECTIVE

This study was undertaken to study the effect of parity on maternal and neonatal characteristics.

STUDY DESIGN

Maternal anthropometry, diet, micronutrient status, biochemistry, and physical activity were measured during pregnancy and detailed neonatal size recorded in 770 pregnancies in rural Maharashtra, India.

RESULTS

Increasing parity was associated with larger offspring birth weight, skinfold thicknesses, and abdominal circumference, but not head circumference and length. Compared with primiparous women, multiparous women were older, less adipose, and more physically active but had similar education, socioeconomic status, nutritional intake, and weight gain during pregnancy. They had lower circulating concentrations of hemoglobin, albumin, ferritin, glucose, and insulin and lower total leucocyte counts at 18 and 28 weeks' gestation. There was no difference in their husbands' body size. The relationship between maternal parity and neonatal weight and adiposity was significant independent of the difference in maternal characteristics.

CONCLUSION

Increasing maternal parity predicts increasing adiposity in the newborn infant. This may result from maternal nutritional, cardiovascular, or immunologic factors.

Rapid assessment of maternal activity among rural Indian mothers (Pune Maternal Nutrition Study)

OBJECTIVE

To develop an activity questionnaire for objective and rapid assessment of maternal habitual physical activity with the aim of describing its relationship with birth size.

DESIGN

Prospective observational study.

SETTING

Six villages near Pune, Maharashtra, India.

SUBJECTS

Seven hundred and ninety-seven rural Indian mothers were studied after excluding abortions and termination of pregnancies, foetal anomalies, etc.

METHOD

Principal components analysis (PCA) was used to identify a few leading questions from an elaborate questionnaire involving 36 questions related to 14 typical maternal activities.

RESULTS

On the basis of high loading (>0.8), PCA identified three activities, i.e. farming, fetching water and washing clothes. Questions and sub-questions related to these activities only were considered for defining an activity score for rapid assessment. Validation of this new activity score, with the score based on the elaborate questionnaire, showed 70% sensitivity as well as specificity. New activity scores showed strong inverse relationships similar to those observed using the elaborate questionnaire, at early as well as late gestation, with neonatal head circumference (P=0.001 and 0.055) and mid-arm circumference (P=0.02 and 0.03).

CONCLUSIONS

Simple questionnaires, based on leading activities identified by PCA, can be as informative as longer and detailed questionnaires. This method has potential for adaptation, especially in rural communities in developing countries.

Strenuous work, nutrition and adverse pregnancy outcomes: a brief review

This brief review explores the available epidemiologic data to investigate the question of whether strenuous work by women during pregnancy in developing countries influences micronutrient status and thereby increase risks of adverse pregnancy outcomes. Some data exist on the potential relationship between strenuous work or physical activity and nutrient compromise, strenuous work or physical activity and adverse reproductive outcomes and micronutrient intakes or status and adverse reproductive outcomes. No substantial body of data exists that has directly investigated the potential causal path of whether strenuous work during pregnancy alters micronutrient status leading to adverse reproductive outcome. Search of the literature identified only a few papers from developing countries that provided even remotely related data on the topic. Thus, the available data are insufficient for drawing firm inferences that strenuous work, in a developing country, alters a pregnant woman's nutritional status and therefore affects her risk of an adverse pregnancy outcome. Effects on nutritional status, micronutrients in particular, of pregnant women from strenuous physical activities at work or in other lifestyle events require further study in developing countries.

Micronutrients and fetal growth

Fetal undernutrition affects large numbers of infants in developing countries, with adverse consequences for their immediate survival and lifelong health. It manifests as intrauterine growth retardation (IUGR), defined as birth weight <10th percentile, which probably underestimates the number failing to achieve full growth potential. Birth weight is a crude measure of the dynamic process of fetal growth and does not capture effects of fetal undernutrition on body composition and the development of specific tissues. The link between maternal nutrition and fetal nutrition is indirect. The fetus is nourished by a complex supply line that includes the mother's diet and absorption, endocrine status and metabolism, cardiovascular adaptations to pregnancy and placental function. Micronutrients are essential for growth, and maternal micronutrient deficiency, frequently multiple in developing countries, may be an important cause of IUGR. Supplementation of undernourished mothers with micronutrients has several benefits but there is little hard evidence of improved fetal growth. However, this has been inadequately tested. Most trials have only used single micronutrients and many were inconclusive because of methodological problems. Several food-based studies (some uncontrolled) suggest benefits from improving maternal dietary quality with micronutrient-dense foods. One trial of a multivitamin supplement (HIV-positive mothers, Tanzania) showed increased birth weight and fewer fetal deaths. Well-conducted randomized controlled trials of adequate sample size and including measures of effectiveness are needed in populations at high risk of micronutrient deficiency and IUGR and should include food-based interventions and better measurements of fetal growth, maternal metabolism, and long-term outcomes in the offspring.