Energy intake and physical activity during pregnancy in relation to maternal fat accretion and infant birthweight

Physical Activity Volumes during Pregnancy: A Systematic Review and Meta-Analysis of Observational Studies Assessing the Association with Infant's Birth Weight

Objective This study aims to examine the association between different maternal physical activity exposures during pregnancy and infant's birth weight, body composition, and risk of inadequate weight. Methods Two reviewers (M.B. and J.L.G.) identified observational studies reporting total or leisure time activity during pregnancy and birth weight outcomes. Pooled analyses were performed to summarize the risk associated with high or moderate volumes of physical activity on birth weight. Results A total of 54 studies among 4,080 reported the association between physical activity and birth weight (37 studies) or risks of small or large birth weight. The association between physical activity and birth weight was evaluated by physical activity levels (low, moderate, or high). Despite heterogeneity, pooled results (23 studies) suggested that moderate levels of activity are associated with an increased birth weight (mean difference: 61.5 g, 95% confidence interval [CI]: 16.6, 106.5, 15 studies), while high levels were associated with lower birth weight (mean difference: -69.9 g, 95% CI: -114.8, -25.0, 15 studies). Data were insufficient to provide robust estimates for other outcomes. Conclusions The results of observational studies suggest an inverted u-shaped association between physical activity and birth weight, despite methodological variability. These results could help refining physical activity guidelines for pregnancy and provide guidance for future research.

Macronutrient composition and gestational weight gain: a systematic review

BACKGROUND

Abnormal gestational weight gain is associated with unfavorable pregnancy outcomes. Several risk factors have been identified, but the effect of macronutrient intake during pregnancy on gestational weight gain has not been systematically evaluated in both high-income countries and low- and middle-income countries.

OBJECTIVE

We conducted a systematic review of the literature in 8 different databases (until 12 August 2015) to assess whether energy intake and macronutrient intake (i.e., protein, fat, and carbohydrate) during pregnancy were associated with gestational weight gain (following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines).

RESULTS

Of 7623 identified references, we included 56 articles (46 observational studies and 10 trials, 28 of which were in high-income countries and 28 of which were in low- and middle-income countries). Eleven of the included articles were of high quality (20%). Results of 5 intervention and 7 high-quality observational studies suggested that higher energy intake during pregnancy is associated with higher gestational weight gain (n = 52). Results from observational studies were inconsistent for protein intake (n = 29) and carbohydrate intake (n = 18). Maternal fat intake (n = 25) might be associated with gestational weight gain as suggested by observational studies, although the direction of this association might depend on specific types of fat (e.g., saturated fat). Macronutrient intake was not consistently associated with the prevalence of inadequate or excessive gestational weight gain. Associations were comparable for high-income countries and low- and middle-income countries.

CONCLUSIONS

The current literature provides evidence that energy intake is associated with gestational weight gain, but the roles of individual macronutrients are inconsistent. However, there is a need for higher-quality research because the majority of these studies were of low quality.

Understanding health behaviours in a cohort of pregnant women at risk of gestational diabetes mellitus: an observational study

OBJECTIVE

To assess health behaviours, physical activity levels, weight gain and development of gestational diabetes mellitus (GDM) in high-risk women.

DESIGN

An observational sub-study of a larger randomised controlled trial.

SETTING

A large tertiary hospital in Australia.

POPULATION

Ninety-seven women (mean age 31.7 ± 4.5 years; body mass index 30.3 ± 5.9 kg/m(2) ) at risk of developing GDM.

METHODS

Women were identified as at risk of GDM based on a validated screening tool. Baseline measures were completed at 12-15 weeks of gestation and repeated at 26-28 weeks of gestation.

MAIN OUTCOME MEASURES

Anthropometric (weight and height) and physical activity assessment (Yamax pedometer and International physical activity questionnaire), questionnaires (self-efficacy) and GDM screening.

RESULTS

By 28 weeks of gestation, there was a high GDM prevalence of 26% using the recent International Association of Diabetes and Pregnancy Study Group criteria. Weight gain in overweight (body mass index 25-29.9 kg/m(2)) and obese (body mass index >30.0 kg/m(2)) women exceeded minimum total weight gain recommendations set by the Institute of Medicine (P < 0.01). Physical activity levels were low and declined during pregnancy (5437 ± 2951 steps/day to 4096 ± 2438 steps/day, respectively, P < 0.001). Despite reduced activity levels, increased weight gain and high GDM incidence many women did not accurately perceive GDM risk and were confident in their ability to control weight. A significant association with physical activity, weight and GDM outcome was not observed.

CONCLUSIONS

Overweight and obese pregnant women at risk for developing GDM demonstrate excessive weight gain and a reduced level of physical activity observed from early pregnancy to 28 weeks of gestation. Results highlight the need for targeted intervention in women at risk for developing GDM.

Maternal behaviors during pregnancy impact offspring obesity risk

This study investigated the effects of maternal changes during pregnancy in diet, exercise, and psychosocial factors on offspring weight parameters at birth and 6 months. In overweight/obese (OW/OB; n = 132) mothers, greater % kcal from sweets early in pregnancy was the strongest, independent predictor of higher weight for age (WFA) (beta = 0.19; P = 0.004), higher odds of macrosomia (OR = 1.1 (1.0-1.2); P = 0.004) and WFA >90th percentile at birth (OR = 1.2 (1.1-1.3); P = 0.002) and higher WFA at 6 months (beta = 0.30; P = 0.002). In normal weight (n = 153) mothers, higher intake of soft drinks was the strongest predictor of higher offspring WFA at birth (beta = 0.16; P = 0.04) but not at 6 months. Prenatal physical activity, depressive symptoms, and sleep-related variables did not significantly predict offspring weight outcomes. Mothers' eating behaviors during pregnancy, especially intake of sweets in OW/OB mothers, may have a lasting effect on child weight.

Measuring physical activity during pregnancy

BACKGROUND

Currently, little is known about physical activity patterns in pregnancy with prior estimates predominantly based on subjective assessment measures that are prone to error. Given the increasing obesity rates and the importance of physical activity in pregnancy, we evaluated the relationship and agreement between subjective and objective physical activity assessment tools to inform researchers and clinicians on optimal assessment of physical activity in pregnancy.

METHODS

48 pregnant women between 26-28 weeks gestation were recruited. The Yamax pedometer and Actigraph accelerometer were worn for 5-7 days under free living conditions and thereafter the International Physical Activity Questionnaire (IPAQ) was completed. IPAQ and pedometer estimates of activity were compared to the more robust and accurate accelerometer data.

RESULTS

Of 48 women recruited, 30 women completed the study (mean age: 33.6 ± 4.7 years; mean BMI: 31.2 ± 5.1 kg/m(2)) and 18 were excluded (failure to wear [n = 8] and incomplete data [n = 10]). The accelerometer and pedometer correlated significantly on estimation of daily steps (ρ = 0.69, p < 0.01) and had good absolute agreement with low systematic error (mean difference: 505 ± 1498 steps/day). Accelerometer and IPAQ estimates of total, light and moderate Metabolic Equivalent minutes/day (MET min(-1) day(-1)) were not significantly correlated and there was poor absolute agreement. Relative to the accelerometer, the IPAQ under predicted daily total METs (105.76 ± 259.13 min(-1) day(-1)) and light METs (255.55 ± 128.41 min(-1) day(-1)) and over predicted moderate METs (-112.25 ± 166.41 min(-1) day(-1)).

CONCLUSION

Compared with the accelerometer, the pedometer appears to provide a reliable estimate of physical activity in pregnancy, whereas the subjective IPAQ measure performed less accurately in this setting. Future research measuring activity in pregnancy should optimally encompass objective measures of physical activity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry Number: ACTRN12608000233325. Registered 7/5/2008.

Weight gain and dietary intake during pregnancy in industrialized countries--a systematic review of observational studies

BACKGROUND

Gestational weight gain (GWG) above the recently recommended ranges is likely to be related to adverse pregnancy outcomes and therefore a challenge in industrialized countries.

AIMS

We conducted a systematic review on observational studies in order to gain more evidence on whether diets with lower caloric/protein content or other diets might be associated with lower GWG.

METHODS

We searched in MEDLINE and EMBASE for observational studies written in English or German reporting associations between diet and GWG in singleton pregnancies of healthy women in industrialized countries.

RESULTS

We identified 12 studies which met the inclusion criteria. Five studies suggested significant positive associations between energy intake and GWG, whereas three found no significant association. Further significant positive associations of GWG were reported with respect to protein intake, animal lipids, energy density and a number of different food servings per day, whereas intake of carbohydrates and vegetarian diet were associated with less GWG.

CONCLUSIONS

We suggest that GWG might be reduced by lower energy intake in pregnancy.

Prevalence and determinants of malnutrition among reproductive aged women of rural Bangladesh

Malnutrition among the rural Bangladeshi women of reproductive age is still very high. This high prevalence attributes to a range of adverse health consequences on the women and their offspring. A total of 2341 women aged between 20 and 45 years residing in the study area were interviewed in this cross-sectional study. Information on socioeconomic variables, nutritional status, and pregnancy-related history was obtained using interviewer administered questionnaire. A total of 34% of the reproductive aged rural women suffer from malnutrition. A multivariate analysis shows association between malnutrition and monthly household income, history of taking oral contraceptive, current pregnancy status, and history of breastfeeding. The final regression model shows a statistically significant decreasing trend in malnutrition status with increasing income (P for trend <.001). The economic and health consequences of malnutrition in this group of women are enormous. National nutritional program should target this women group for any intervention with a special priority.

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.

Determination of Maternal Body Composition in Pregnancy and Its Relevance to Perinatal Outcomes

Three models and 10 specific methods for determining maternal body composition are discussed and their perinatal relevance reviewed. English language publications (1950 to January 2004) were searched electronically and by hand. Search terms included "body composition," "human," " pregnancy," "obesity," "adiposity," "regional," "2-, 3-, 4-component," "truncal," "peripheral," "central," "visceral" along with specific techniques and outcomes listed subsequently. Three models of body composition are described: 2-component being fat and fat-free mass; 3-component being fat, water, and protein; and 4-component being fat, water, protein, and osseous mineral. Ten techniques of body composition assessment are described: 1) anthropometric techniques including skinfold thicknesses and waist-hip ratio; 2) total body water (isotopically labeled); 3) hydrodensitometry (underwater weighing); 4) air-displacement plethysmography; 5) bio-impedance analysis (BIA); 6) total body potassium (TBK); 7) dual-energy x-ray absorptiometry (DEXA); 8) computed tomography (CT); 9) magnetic resonance imaging (MRI); and 10) ultrasound (USS). Most methods estimate total adiposity. Regional fat distribution-central (truncal) compared with peripheral (limb) or visceral compared with subcutaneous-is important because of regional variation in adipocyte metabolism. Skinfolds, DEXA, CT, MRI, or USS can distinguish central from peripheral fat. CT, MRI, or USS can further subdivide central fat into visceral and subcutaneous. Perinatal outcomes examined in relation to body composition include pregnancy duration, birth weight, congenital anomalies, gestational diabetes, gestational hypertension, and the fetal origins of adult disease. A few studies suggest that central compared with peripheral fat correlates better with birth weight, gestational carbohydrate intolerance, and hypertension. Means of accurately assessing maternal body composition remain cumbersome and impractical, but may more accurately predict perinatal outcomes than traditional assessments such as maternal weight.

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

OBJECTIVE

To describe the relationship of the mother's physical activity to the birth size of her baby in a rural Indian population.

DESIGN

: Prospective observational study.

SETTING

Six villages near Pune, Maharashtra, India.

SUBJECTS

: A total of 797 women were studied after excluding abortions and termination of pregnancies (112), foetal anomalies (8), multiple pregnancies (3), incomplete pre-pregnancy anthropometry (14) and pregnancies detected later than 21 weeks of gestation (168).

METHOD

An activity questionnaire was developed after focus group discussions and incorporated community-specific activities. It was validated against an observer-maintained diary. Activity scores were derived using published data on energy costs to weight the contributions of various activities. It was then administered to assess physical activity at 18 (+/-2) and 28 (+/-2) weeks of gestation.

OUTCOME MEASURES

Birth outcome, maternal weight gain and neonatal anthropometry.

RESULTS

The activity questionnaire was used to classify women into light, moderate and heavy activity categories. Maternal activity did not influence the incidence of prematurity or stillbirth, or the duration of gestation. It was inversely related to maternal weight gain up to 28 weeks of gestation (P=0.002). Higher maternal activity in early, as well as mid gestation, was associated with lower mean birth weight (P=0.05 and 0.02, respectively ), and smaller neonatal head circumference (P=0.005 and 0.009) and mid-arm circumference (P=0.03 and 0.01) after adjusting for the effect of major confounding factors.

CONCLUSIONS

The Findings suggest that excessive maternal activity during pregnancy is associated with smaller foetal size in rural India, The approach described for developing an activity questionnaire has potential for adoption in other settings.

Associations between reproduction and maternal body weight: examining the component parts of a full reproductive cycle

OBJECTIVE

Many transitional societies currently face both extremes of nutritional status, undernutrition and overnutrition. Women of reproductive age are at high risk of these conditions. The purpose of this review is to consider evidence for relationships between reproduction and nutritional status in women from societies of varying economic development, using body weight or weight-for-height as indicators of maternal nutritional status.

DESIGN

The conceptual framework guiding this review is that the duration of the reproductive cycle varies as a function of its component parts, which include (i) pregnancy, (ii) lactation, (iii) the non-pregnant/non-lactating (NP/NL) interval or, possibly, (iv) an overlap between lactation and next pregnancy. All component parts of the complete cycle vary in length and are associated with changes in nutritional status. A variety of factors ('proximal and distal determinants') influence the duration of the component parts of the reproductive cycle. This framework is used to examine current knowledge of changes in maternal nutritional status during each of these parts.

RESULTS

Women in affluent societies retain some weight with each pregnancy, beyond that of non-pregnant women. Women in less affluent societies retain less weight with each pregnancy. During lactation, women in both affluent and less affluent societies experience only modest weight loss. During the NP/NL interval, women in affluent societies tend to gain weight, whereas weight of women in less affluent societies is likely to fluctuate.

CONCLUSIONS

We conclude that there is a dearth of information on certain parts of the cycle, particularly the periods of overlap of lactation with pregnancy and the NP/NL interval.

Trends in eating patterns, physical activity and socio-demographic factors in relation to postpartum body weight development

'The Stockholm Pregnancy and Weight Development Study' was conducted to identify risk factors for postpartum weight retention, such as dietary habits, physical activity and socio-demographic factors. The body weight development of 1423 pregnant women was studied prospectively from the beginning of the pregnancy until 1 year postpartum. Data were collected from routine pregnancy records and from questionnaires 6 and 12 months postpartum. Mean weight retention 1 year postpartum was 0.5 kg compared with the prepregnancy body weight. A 'trend method' was constructed to identify a number of pre-defined major patterns of behaviour. The weight retention 1 year postpartum was greater in women who (a) increased their energy intake during and after pregnancy, (b) increased their snack eating after pregnancy to three or more snacks/d, and (c) decreased their lunch frequency starting during or after the pregnancy. Women who had retained > or = 5 kg 1 year postpartum were more seldom physically active in their leisure time throughout the study period compared with women with a smaller weight gain. Postpartum weight retention correlated negatively with the degree of physical activity in the second half year postpartum. These results indicate that postpartum weight retention is more affected by a change in lifestyle during, and above all after, pregnancy than by factors before pregnancy.

Energy intake and activity pattern during pregnancy in relation to infant birth weight

The study was designed to determine if the activity pattern of pregnancy women on an intake of energy lower than that recommended will affect fetal growth. Subjects who volunteered were either attending public or private hospitals. Pregnant women in the "private" group were significantly older (p < 0.001) weighed somewhat less and significantly taller (p < 0.001) when compared to the "public" group. Differences in energy intake during the second and third trimesters between the "public" and "private" groups were small; 1608 +/- 334, 1726 +/- 271 kcal and 1627 +/- 367, 1778 +/- 260 kcal, respectively. However, daily activity patterns revealed that the "public" group was more active as reflected by the higher energy expenditure of 1412 +/- 74 kcal and 1578 +/- kcal during the second and third trimesters respectively. There was a significant difference (p < 0.01) in birth weight between the "public" and "private" groups; 2951 +/- 377 g and 3173 +/- 357 g respectively. This study indicates that energy intakes lower than recommended and sedentary lifestyles have no direct influence on birth weights of babies.

Effects of early maturation on fetal growth

While the association of young maternal age with low birthweight (LBW) is well known, the contribution of early menarche to this association has never been studied. We examined the effects of early menarche (less than or equal to 11 years) on LBW and its two major underlying causes: pre-term delivery and smallness-for-gestational-age (SGA). Results represent a narrow chronological age range, 17-18 years, of a larger geographically based cohort of 2789 pregnant adolescents. Adjusted odds ratios (AOR) indicated that early menarche was significantly associated with an increased risk of LBW which was specific to SGA. The attributable risk of SGA with early menarche exceeded 20%. Early age at menarche is also correlated with an earlier onset of sexual activity, pregnancy, and childbearing. Consequently, adolescents with early menarche are over-represented in a sample limited to young gravidae or a sample that contains a stratum of young gravidae. This may have previously obscured the effects or early menarche on foetal growth and attributed them to a more frequently measured characteristic, young maternal age. Thus, effects of secular change in age at menarche may not be wholly benign. Improvements in maternal fertility and nutritional status appear to be offset by intrauterine growth retardation in the offspring.