Changes in maternal weight from the first to second trimester of pregnancy are associated with fetal growth and infant length at birth

Associations of Diet Quality, Socioeconomic Factors, and Nutritional Status with Gestational Weight Gain among Pregnant Women in Dar es Salaam, Tanzania

Background

Gestational weight gain (GWG) is a modifiable factor associated with maternal and child health outcomes, but the relationship between diet quality and GWG has not been evaluated using metrics validated for low-income and middle-income countries (LMICs).

Objective

This study aimed to investigate relationships between diet quality, socioeconomic characteristics, and GWG adequacy using the novel Global Diet Quality Score (GDQS), the first diet quality indicator validated for use across LMIC.

Methods

Weights of pregnant women enrolled between 12 and 27 wk of gestation (N = 7577) were recorded in Dar es Salaam, Tanzania, from 2001 to 2005 during a prenatal micronutrient supplementation trial. GWG adequacy was the ratio of measured GWG to Institute of Medicine-recommended GWG, categorized into severely inadequate (<70%), inadequate (70 to <90%), adequate (90 to <125%), or excessive (≥125%). Dietary data were collected using 24-h recalls. Multinomial logit models were used to estimate relationships between GDQS tercile, macronutrient intake, nutritional status, and socioeconomic characteristics and GWG.

Results

GDQS scores in the second [relative risk (RR): 0.82; 95% confidence interval (CI): 0.70, 0.97] tercile were associated with lower risk of inadequate weight gain than those in the first tercile. Increased protein intake was associated with higher risk of severely inadequate GWG (RR: 1.06; 95% CI: 1.02, 1.09). Nutritional status and socioeconomic factors were associated with GWG: underweight prepregnancy BMI (in kg/m2) with a higher risk of severely inadequate GWG (RR: 1.49; 95% CI: 1.12, 1.99), overweight or obese BMI with a higher risk of excessive GWG (RR: 6.80; 95% CI: 5.34, 8.66), and a higher education (RR: 0.61; 95% CI: 0.42, 0.89), wealth (RR: 0.68; 95% CI: 0.48, 0.80), and height (RR: 0.96; 95% CI: 0.95, 0.98) with a lower risk of severely inadequate GWG.

Conclusions

Dietary indicators showed few associations with GWG. However, stronger relationships were revealed between GWG, nutritional status, and several socioeconomic factors.This trial was registered at clinicaltrials.gov as NCT00197548.

Maternal Nutrition, Body Composition and Gestational Weight Gain on Low Birth Weight and Small for Gestational Age-A Cohort Study in an Indian Urban Slum

Maternal nutritional status and care during pregnancy are essential for adequate birth weight. In this prospective cohort study (N = 1061) in an urban slum, we investigated the association of maternal anthropometry, body composition, gestational weight gain and dietary intakes with low birthweight (LBW, <2.5 kg). About one-third of the women were short (<150 cm), 35% were underweight (<45 kg), 23% suffered from chronic energy deficiency (CED, BMI < 18.5 kg/m2) and another 30% were overweight/obese. The mean age and BMI were 23 years and 21.7 kg/m2, respectively, and haemoglobin was 10.73 g/dL. The mean birthweight (N = 605) was 2.81 ± 0.5 kg, and the average gestational age was 38 ± 2 weeks. About 15% of infants had LBW, and 48% were small for gestational age (SGA). Maternal body composition was assessed by skinfold thickness (SFT) in all trimesters. In the first trimester (N = 762), we found that mean fat-free mass (FFM), fat mass (FM) and body fat percentage (% BF) were 38.86 kg, 11.43 kg and 21.55%, respectively. Low birthweight was significantly associated with preterm deliveries (p < 0.001) and less fat free mass (p = 0.02) in the third trimester. Among other factors were age (p = 0.017), maternal anthropometry (height: p = 0.031; weight: p = 0.059) and fewer antenatal check-ups (p = 0.037). Small size (SGA) was consistently associated with maternal bodyweight at all trimesters (term I, p = 0.013, term II, p = 0.003 and term III, p < 0.001), fat mass in the third trimester (p < 0.001) and maternal height (p = 0.003).

Birth length is the strongest predictor of linear growth status and stunting in the first 2 years of life after a preconception maternal nutrition intervention: the children of the Women First trial

BACKGROUND

The multicountry Women First trial demonstrated that nutritional supplementation initiated prior to conception (arm 1) or early pregnancy (arm 2) and continued until delivery resulted in significantly greater length at birth and 6 mo compared with infants in the control arm (arm 3).

OBJECTIVES

We evaluated intervention effects on infants' longitudinal growth trajectory from birth through 24 mo and identified predictors of length status and stunting at 24 mo.

METHODS

Infants' anthropometry was obtained at 6, 12, 18, and 24 mo after the Women First trial (registered at clinicaltrials.gov as NCT01883193), which was conducted in low-resource settings: Democratic Republic of Congo, Guatemala, India, and Pakistan. Longitudinal models evaluated intervention effects on infants' growth trajectory from birth to 24 mo, with additional modeling used to identify adjusted predictors for growth trajectories and outcomes at 24 mo.

RESULTS

Data for 2337 (95% of original live births) infants were evaluated. At 24 mo, stunting rates were 62.8%, 64.8%, and 66.3% for arms 1, 2, and 3, respectively (NS). For the length-for-age z-score (LAZ) trajectory, treatment arm was a significant predictor, with adjusted mean differences of 0.19 SD (95% CI: 0.08, 0.30; P < 0.001) and 0.17 SD (95% CI: 0.07, 0.27; P < 0.001) for arms 1 and 2, respectively. The strongest predictors of LAZ at 24 mo were birth LAZ <-2 and <-1 to ≥-2, with adjusted mean differences of -0.76 SD (95% CI: -0.93, -0.58; P < 0.001) and -0.47 SD (95% CI: -0.56, -0.38; P < 0.001), respectively. For infants with ultrasound-determined gestational age (n = 1329), the strongest predictors of stunting were birth LAZ <-2 and <-1 to ≥- 2: adjusted relative risk of 1.62 (95% CI: 1.39, 1.88; P < 0.001) and 1.46 (95% CI: 1.31, 1.62; P < 0.001), respectively.

CONCLUSIONS

Substantial improvements in postnatal growth are likely to depend on improved intrauterine growth, especially during early pregnancy.

Gestational Diabetes Mellitus as an Effect Modifier of the Association of Gestational Weight Gain with Perinatal Outcomes: A Prospective Cohort Study in China

The association of gestational weight gain (GWG) with perinatal outcomes seems to differ between women with and without gestational diabetes mellitus (GDM). Whether GDM is an effect-modifier of the association has not been verified. This study aimed to assess the modifying effect of GDM on the association of GWG with perinatal outcomes. Data on 12,128 pregnant women (3013 with GDM and 9115 without GDM) were extracted from a prospective, multicenter, cohort study in China. The associations of total and trimester-specific GWG rates (GWGR) with perinatal outcomes, including small size for gestational age, large size for gestational age (LGA), preterm birth, cesarean delivery, and gestational hypertension disorders, were assessed. The modifying effect of GDM on the association was assessed on both multiplicative and additive scales, as estimated by mixed-effects logistic regression. As a result, total GWGR was associated with all of the perinatal outcomes. GDM modified the association of total GWGR with LGA and cesarean delivery on both scales (all p < 0.05) but did not modify the association with other outcomes. The modifying effect was observed in the third trimester but not in the first or the second trimester. Therefore, maternal GWG is associated with perinatal outcomes, and GDM modifies the association with LGA and cesarean delivery in the third trimester.

The effects of exercise during pregnancy on placental composition: A systematic review and meta-analysis

INTRODUCTION

Morphological changes to the placenta occur as the demands of the foetus increase throughout gestation. Physical activity during pregnancy is known to benefit both the mother and infant, however the impact of antenatal exercise training on placental development is less known. The aim of this systematic review and meta-analysis was to investigate the effects of exercise training during pregnancy on measures of placental composition.

METHODS

Six electronic databases were searched from inception to June 2021 for studies comparing regular antenatal exercise with either usual maternal care or no exercise for its effect on measures of placental morphological composition. Meta-analyses were performed for placental weight and the placental weight to birthweight (PWBW) ratio.

RESULTS

Seven randomised controlled trials and two cohort studies were included in the systematic review and meta-analysis (n = 9). There was no significant difference in placental weight (mean difference (MD) = -9.07g, p = 0.42) or the PWBW ratio (MD = 0.00, p = 0.32) between exercise and control groups. Parenchymal tissue volume was higher, represented by an increase in villous tissue, and non-parenchymal volume was lower in women who exercised regularly compared to those that were not exercising during pregnancy.

DISCUSSION

Exercise training during pregnancy may not alter placental weight or the PWBW ratio. However, findings from this review indicate that antenatal exercise training can promote advantageous morphological changes to placental tissues.

Phenomenology Study of Stunting Nutrition for Babies in the Work Area of Pante Kuyun Health Center, Aceh Jaya District

BACKGROUND: Stunting causes organs not to grow and develop optimally. One of the factors that indirectly influence stunting in children is the mother’s parenting style. Parenting includes the family’s ability to provide time, attention, and support in meeting the physical, mental and social needs of children growing in the family. AIM: This is to find out the nutrition parenting patterns of children who are stunted in the working area of the Health Center Pante Kuyun, Aceh Jaya Regency. METHODS: This study uses qualitative methods with a phenomenological approach. This research was conducted in the working area of Pante Kuyun Health Center, Aceh Jaya Regency. The research was carried out for 1 month, starting from August to September. The choice of research location was due to the high incidence of stunting in the area. The number of samples was determined 15 people consisting of 10 children under five who were stunted, two people as the head of the Health Center, and two community leaders from various elements. This study uses recording devices, video recording devices (camcorders), tape recorders, group discussion guidelines, and field notes. Data analysis techniques used in qualitative research include transcript analysis of interview results, data reduction, analysis, data interpretation, and triangulation. RESULTS: Stunting is closely related to the social construction of society. There are differences in social constructs that shape the parenting styles’ understanding for toddlers who are stunted. During pregnancy, most mothers follow the restrictions recommended by their parents and in-laws. The number of taboo foods to be consumed during pregnancy to breastfeeding generally comes from the food group of animal protein sources such as squid, shrimp, crab, shellfish, and so on. These foods are believed to cause the, etc., become sticky, making it difficult for the delivery process, and milk is difficult to pass. It turns out that the customs, culture, and hereditary habits that continue to be carried out influence stunting in children under five. The pattern of nutrition parenting during the postpartum, postpartum period also causes stunting. During postpartum, the culture in society prohibits food other than white rice, and the fish is only anchovies. It turns out that the lack of intake during the postpartum period up to 40 days has an impact on the health of the postpartum, postpartum mother, especially only a little breast milk, dry skin, weakness, dizziness, and even sickness. Community beliefs also influence nutritional care patterns. For infants aged 0–6 months, none of the informants’ toddlers receive exclusive; breastfeeding. Exclusive breastfeeding is not given to children due to the mother’s lack of knowledge about exclusive breastfeeding benefits. The eating habit prioritizes elders’ advice such as parents, in-laws, and religious leaders are still related to myths about health and nutrition in pregnant women and toddlers. The pattern of nutrition parenting performed by mothers for infants >6 months is not under the Indonesian Ministry of Health recommendations. In the Aceh Jaya district, mothers habitually give instant noodles as a substitute for the rice to consume toddlers. However, their mothers also have parenting styles, whereas if the working mothers provide food for toddlers, they are older siblings, grandmothers, or nieces. Inadequate care, such as improper feeding from infancy to toddlerhood, causes toddlers to suffer from illness more often due to disruption of digestion because the baby’s intestines are still vulnerable. CONCLUSION: Parenting affects toddlers who experience stunting in the working area of Pante Kuyun Community Health Center, Aceh Jaya Regency.

Biomarkers of environmental enteric dysfunction are not consistently associated with linear growth velocity in rural Zimbabwean infants

BACKGROUND

Child stunting remains a poorly understood, prevalent public health problem. Environmental enteric dysfunction (EED) is hypothesized to be an important underlying cause.

OBJECTIVES

Within a subgroup of 1169 children enrolled in the SHINE (Sanitation Hygiene Infant Nutrition Efficacy) trial in rural Zimbabwe, followed longitudinally from birth to 18 mo of age, we evaluated associations between the concentration of 11 EED biomarkers and linear growth velocity.

METHODS

At infant ages 1, 3, 6, 12, and 18 mo, nurses measured child length and collected stool and blood; the lactulose-mannitol urine test was also conducted at all visits except at 1 mo. Stool neopterin, α-1 antitrypsin, myeloperoxidase, and regenerating gene 1β protein; urinary lactulose and mannitol; and plasma kynurenine, tryptophan, C-reactive protein, insulin-like growth factor-1 (IGF-1), soluble CD14, intestinal fatty acid binding protein, and citrulline were measured. We analyzed the change in relative [∆ length-for-age z score (LAZ)/mo] and absolute (∆ length/mo) growth velocity during 4 age intervals (1-3 mo; 3-6 mo; 6-12 mo; and 12-18 mo) per SD increase in biomarker concentration at the start of each age interval.

RESULTS

In fully adjusted models, we observed only 3 small, statistically significant associations: kynurenine:tryptophan ratio at 12 mo was associated with decreased mean LAZ velocity during the 12-18 mo interval (-0.015 LAZ/mo; 95% CI: -0.029, -0.001 LAZ/mo); mannitol excretion at 6 mo was associated with increased LAZ velocity during the 6-12 mo interval (0.013 LAZ/mo; 95% CI: 0.001, 0.025 LAZ/mo), and plasma IGF-1 at 1 mo was associated with increased LAZ velocity during the 1-3 mo interval (0.118 LAZ/mo; 95% CI: 0.024, 0.211 LAZ/mo). Results for absolute growth velocity were similar, except IGF-1 was also associated with growth during the 12-18 mo interval. We found no other associations between any EED biomarker and linear growth velocity.

CONCLUSIONS

None of 11 biomarkers of EED were consistently associated with linear growth among Zimbabwean children.This trial was registered at clinicaltrials.gov as NCT01824940.

Gestational diabetes mellitus, pre-pregnancy body mass index and gestational weight gain predicts fetal growth and neonatal outcomes

BACKGROUND

Gestational diabetes mellitus (GDM), body mass index (BMI) and gestational weight gain (GWG) are salient predictors of pregnancy-outcomes. However, findings on the association between GDM, BMI, and GWG with fetal growth measures are limited.

OBJECTIVE

The aim of this study was to investigate the effect of GDM on fetal growth measures and birth outcomes.

METHODS

All participants came from Tongji Maternal and Child health cohort, in which pregnant women were enrolled before 16 weeks of gestation and had their weights measured regularly during antenatal visits. GDM was diagnosed by oral glucose tolerance test (OGTT) during 24-28 weeks of gestation. Ultrasound measurements of fetal bi-parietal diameters (BPD), head circumferences (HC), abdominal circumferences (AC) and femur length (FL) before birth were collected and neonate outcomes were obtained from the hospital records. Odds ratios were calculated using logistic regression to assess the association of GDM, pre-pregnancy BMI, and GWG with fetal growth measures of ultrasound and birth outcomes, while controlling confounding.

RESULTS

Of 3253 singleton pregnant women, 293 (9.0%) were diagnosed with GDM, 357 (11.0%) were overweight before pregnancy, and 1995 (61.3%) had excessive GWG. GDM was associated with decreased intrauterine fetal growth measurements including BPD and AC. Maternal pre-pregnancy overweight was associated with increased fetal HC and neonatal birth weight and length, women gained excessive GWG had increased fetal growth measurements of BPD, HC, AC, FL, neonatal birth weight and length. Offspring of GDM women had increased odds of cesarean section 1.31 (1.03, 1.66) and preterm birth 2.02 (1.05, 3.91) in unadjusted models, but these associations disappeared after adjustment. Compared with neonate born to mothers with normal pre-pregnancy weight, those born to underweight mother had higher risk of SGA, and lower risk of cesarean section, LGA and macrosamia, whereas those born to overweight mother had increased risk of cesarean section, LGA and macrosamia. Compared with neonate born to mothers of adequate GWG, neonate of women with excessive GWG had elevated risk of cesarean section, LGA and macrosamia, but lower risk of preterm birth and SGA.

CONCLUSION

Pre-pregnancy BMI, GWG and GDM all associated with fetal growth and birth outcomes. The effect of GDM decreased after adjusting pre-pregnancy BMI and GWG. Early screening and management of GDM, preventing excessive GWG could help protect fetuses of GDM mothers from adverse birth outcomes.

Stunting at birth and associated factors among newborns delivered at the University of Gondar Comprehensive Specialized Referral Hospital

Background

Stunting at birth is a chronic form of undernutrition majorly attributable to poor prenatal nutrition, which could persist in children’s later life and impact their physical and cognitive health. Although multiple studies have been conducted in Ethiopia to show the magnitude of stunting and factors, all are concentrated on children aged between 6 to 59 months. Therefore, this study was done to determine the prevalence and associated factors of stunting at birth among newborns delivered at the University of Gondar Comprehensive Specialized Referral Hospital, Northwest, Ethiopia.

Methods

An institution-based cross-sectional study was conducted from February 26^th to April 25^th/2020. A systematic random sampling technique was used, to select a total of 422 newborn-mother pairs. The binary logistic regression was employed to identify factors associated with stunting and all independent variables were entered into the multivariable logistic regression model to adjust for confounders. Variables that had significant association were identified based on p-value < 0.05 and the adjusted odds ratio with its respective 95% confidence interval was applied to determine the strength as well as the direction of the association.

Results

About 30.5% (95% CI: 26.3%, 35.1%) of newborns were stunted at birth. Being male [Adjusted odds ratio (AOR) = 2.9(1.62, 5.21)], newborns conceived in Kiremt(rainy season) [AOR = 2.7(1.49, 4.97)], being low birth weight [AOR = 3.1(1.64, 6.06)] were factors associated with stunting at birth. Likewise, newborns born to short stature mothers [AOR = 2.8(1.21, 6.62)] and chronically malnourished mothers [AOR = 15.3(8.12, 29.1)] were at greater risk of being stunted.

Conclusion

Just under a third of newborns are stunted at birth, implying a pressing public health problem. Newborns born to chronically malnourished and short stature mothers were more stunted. Besides, stunting was prevalently observed among male neonates, newborns conceived in Kiremet, and being low birth weight. Thus, policymakers and nutrition programmers should work on preventing maternal undernutrition through nutrition education to reduce the burden of low birth weight and stunting. Further, paying due attention to newborns conceived in Kiremet season to improve nutritional status is recommended.

Low lung function in the developing world is analogous to stunting: a review of the evidence

Background: Low vital capacity, one of the consequences of restricted lung growth, is a strong predictor of cardiovascular mortality. Vital capacity is lower in the developing world than the developed world, even after adjusting for height, weight and gender. This difference is typically dismissed as ethnic variation, adjusted for by redefining normal. Whether this is a consequence of stunted lung growth, rather than just genetically smaller lungs, has not been investigated in detail. Therefore, we sought to compare factors implicated in both stunting and lung development, particularly in the developing world.

Methods: We conducted a manual screen of articles identified through Google Scholar and assessed risk of bias. No language restrictions were applied, so long as there was an associated English abstract. We queried VizHub (Global Burden of Disease Visualization Tool) and Google Dataset search engines for disease burden and genome wide association studies.  The scope of the article and the heterogeneity of the outcome measures reported required a narrative review of available evidence. To the extent possible, the review follows PRISMA reporting guidelines.

Results: Early life influences operate in synergism with genetic, environmental and nutritional factors to influence lung growth and development in children.  Low lung function and stunting have common anthropometric, environmental and nutritional correlates originating during early development. Similar anthropometric correlates shared chronic inflammatory pathways, indicated that the two conditions were analogous.

Conclusion: The analogy between poor lung function and stunting is conspicuous in the developing world, with malnutrition at the center of non -achievement of growth potential, susceptibility to infectious diseases and intrauterine programming for metabolic syndrome. This counter the idea of redefining the normal for lung function measurements, since observed inter-ethnic variations are likely a mix of natural genetic differences as well as differences in nurture such that reduced lung function reflects early life adversities.

Evaluation of a Package of Behaviour Change Interventions (Baduta Program) to Improve Maternal and Child Nutrition in East Java, Indonesia: Protocol for an Impact Study

BACKGROUND

Over the past decade, the prevalence of stunting has been close to 37% in children aged <5 years in Indonesia. The Baduta program, a multicomponent package of interventions developed by the Global Alliance for Improved Nutrition, aims to improve maternal and infant nutrition in Indonesia.

OBJECTIVE

This study aims to assess the impact of the Baduta program, a package of health system strengthening and behavior change interventions, compared with the standard village health services on maternal and child nutrition.

METHODS

The impact evaluation uses a cluster randomized controlled trial design with 2 outcome assessments. The first uses cross-sectional surveys of mothers of children aged 0-23 months and pregnant women before and after the interventions. The second is a cohort study of pregnant women followed until their child is 18 months from a subset of clusters. We will also conduct a process evaluation guided by the program impact pathway to assess coverage, fidelity, and acceptance. The study will be conducted in the Malang and Sidoarjo districts of East Java, Indonesia. The unit of randomization is the subdistricts. As random allocation of interventions to only 6 subdistricts is feasible, we will use constrained randomization to ensure balance of baseline covariates. The first intervention will be health system strengthening, including the Baby-Friendly Hospital Initiative, and training on counseling for appropriate infant and young child feeding (IYCF). The second intervention will be nutrition behavior change that includes Emo-Demos; a national television (TV) advertising campaign; local screening TV spots; a free, text message service; and promotion of low-cost water filters and hygiene practices. The primary study outcome is child stunting (low length-for-age), and secondary outcomes include length-for-age Z scores, wasting (low weight-for-length), anemia, child morbidity, IYCF indicators, and maternal and child nutrient intakes. The sample size for each cross-sectional survey is 1400 mothers and their children aged <2 years and 200 pregnant women in each treatment group. The cohort evaluation requires a sample size of 340 mother-infant pairs in each treatment group. We will seek Gatekeeper consent and written informed consent from the participants. The intention-to-treat principle will guide our data analysis, and we will apply Consolidated Standards of Reporting Trials guidelines for clustered randomized trials in the analysis.

RESULTS

In February 2015, we conducted a baseline cross-sectional survey on 2435 women with children aged <2 years and 409 pregnant women. In February 2017, we conducted an end-line survey on 2740 mothers with children aged <2 years and 642 pregnant women. The cohort evaluation began in February 2015, with 729 pregnant women, and was completed in December 2016.

CONCLUSIONS

The results of the program evaluation will help guide policies to support effective packages of behavior change interventions to prevent child stunting in Indonesia.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/18521.

Maternal Anthropometric Factors and Circulating Adipokines as Predictors of Birth Weight and Length

Pregnancy is a period of serial metabolic and hormonal changes in the woman's body. Factors such as circulating adipokines affect the fetal period and may cause long-term changes in metabolic pathways at the cellular, tissue, or organ level. The nutritional status of the pregnant woman affects the course of pregnancy, delivery, and confinement, as well as the health of the offspring following birth and in subsequent years. Adipokine hormones essential for modulating metabolism during pregnancy include adiponectin and leptin. This study aimed to assess maternal anthropometric parameters and plasma concentrations of specific adipokines as predictive measures of newborn birth weight, birth length, and ponderal index. Anthropometric measurements (prepregnancy body weight and height) were obtained from 168 surveyed Polish women. Data related to the birth parameters of 168 newborns (body length and mass) were derived from clinical records. Circulating maternal adiponectin and leptin levels at birth were determined. Significant correlations between newborn birth weight and maternal prepregnancy body mass index (p < 0.05) or maternal weight gain during pregnancy (p < 0.05) were observed. Women with below normal weight gain during pregnancy were more likely to give birth to newborns with significantly lower birth weight than women with excessive weight gain during pregnancy (p < 0.05). Maternal plasma concentrations of leptin were significantly related to prepregnancy maternal body mass index (p < 0.05), and concentrations of adiponectin and leptin were significantly related to weight gain during pregnancy (p < 0.05). However, they did not affect the birth parameters of the newborn.

Low lung function in the developing world is analogous to stunting: a review of the evidence

Background: Low vital capacity, one of the consequences of restricted lung growth, is a strong predictor of cardiovascular mortality. Vital capacity is lower in the developing world than the developed world, even after adjusting for height, weight and gender. This difference is typically dismissed as ethnic variation, adjusted for by redefining normal. Whether this is a consequence of stunted lung growth, rather than genetically smaller lungs, has not been investigated in detail. Therefore, we sought to compare factors implicated in both stunting and lung development, particularly in the developing world. Methods: We conducted a manual screen of articles identified through Google Scholar and assessed risk of bias. No language restrictions were applied, so long as there was an associated English abstract. We queried VizHub (Global Burden of Disease Visualization Tool) and Google Dataset search engines for disease burden and genome wide association studies.  The scope of the article and the heterogeneity of the outcome measures reported required a narrative review of available evidence. To the extent possible, the review follows PRISMA reporting guidelines. Results: Early life influences operate in synergism with environmental and nutritional factors to influence lung growth and development in children.  Low lung function and stunting have common anthropometric, environmental and nutritional correlates originating during early development. Similar anthropometric correlates and shared chronic inflammatory pathways indicated that the two conditions were analogous. Conclusion: The analogy between poor lung function and stunting is conspicuous in the developing world, where malnutrition lies at the center of non -achievement of growth potential, susceptibility to infectious diseases and intrauterine programming for metabolic syndrome. The common pathological mechanisms governing stunting and lung function deficits counter the idea of redefining the normal for lung function measurements.

Maternal nutritional status mediates the linkage between household food insecurity and mid-infancy size in rural Bangladesh

Household food insecurity (HFI) is a major concern in South Asia. The pathways by which HFI may reduce child growth remain inadequately understood. In a cohort study of 12 693 maternal-infant dyads in rural Bangladesh, we examined association and likely explanatory pathways linking HFI, assessed using a validated nine-item perception-based index, to infant size at 6 months. Mothers were assessed early in pregnancy for anthropometric status, dietary diversity and socio-economic status. Infants were assessed for weight, length, and arm, chest and head circumferences and breast and complementary feeding status at birth and 6 months of age. Extent of HFI shared a negative, dose-response association with all measures of infant size at 6 months and odds of wasting and stunting; 57-89 % of variances in the unadjusted models were explained by prenatal factors (maternal nutritional status and dietary diversity), and birth size adjusted for gestational age. Postnatal infant breast and complementary feeding and morbidity exposures explained the remaining fraction of the significant association between HFI and differences in infant arm and chest circumferences and odds of underweight. Contextual (i.e. socio-economic) factors finally brought remaining non-significant fractions of the food insecurity-related mid-infancy growth deficit to practically zero. Improving food security prior to pregnancy and during gestation would likely improve infant growth the most in rural Bangladesh.

A Fortified Food Can Be Replaced by Micronutrient Supplements for Distribution in a Mexican Social Protection Program Based on Results of a Cluster-Randomized Trial and Costing Analysis

BACKGROUND

Despite positive nutrition impacts, the prevalence of malnutrition among beneficiaries of Mexico's conditional cash transfer (CCT) program remains high. Greater nutrition impact may have been constrained by the type of nutritional supplements provided.

OBJECTIVE

The objective of this study was to inform a potential modification to the supplements distributed to pregnant and lactating women and children.

METHODS

Impact was assessed using 2 cluster-randomized trials (pregnant women, children) run simultaneously. Communities (n = 54) were randomly assigned to the fortified foods provided by the program (Nutrivida women, Nutrisano children) or alternatives: tablets (women), syrup (children), or micronutrient powders for women (MNP-W) and children (MNP-C). Each supplement for women/children contained the same micronutrients based on the formulations of Nutrivida and Nutrisano, respectively. Pregnant women (aged >18 y) were recruited before 25 weeks of gestation and followed to 3 mo postpartum. Children aged 6-12 mo were recruited and followed to age 24 mo. Primary outcomes were anemia for women and length growth for children. Statistical analyses appropriate for cluster-randomized designs were used, and structural equation modeling to estimate dose-response effects. Supplement costs per beneficiary (daily dose for 18 mo) were estimated for production and distribution.

RESULTS

There was no significant difference in change of anemia prevalence between supplement groups in women, or in length growth between groups in children. One daily dose of any supplement was associated with 0.8 cm greater length growth. From baseline to age 24 mo, the prevalence of anemia in the Nutrisano, syrup, and MNP-C groups decreased by 36.7, 40.8, and 37.9 percentage points, respectively (within-group, P < 0.05; between groups, P > 0.05). Costs per beneficiary ranged from $12.1 (MNP-C) to $94.8 (Nutrivida).

CONCLUSIONS

The CCT program could distribute alternative supplements at lower cost per beneficiary without compromising potential for impact. Acceptance among beneficiaries should also be considered in choice of alternatives. This trial was registered at www.clinicaltrials.gov as NCT00531674.

The Long-Lasting Influenza: The Impact of Fetal Stress During the 1918 Influenza Pandemic on Socioeconomic Attainment and Health in Sweden, 1968-2012

The 1918 influenza pandemic had not only a massive instant death toll but also lasting effects on its survivors. Several studies have shown that children born in 1919, and thus exposed to the H1N1 virus in utero, experienced worse health and socioeconomic outcomes in older ages than surrounding birth cohorts. This study combines several sources of contemporary statistics with full-population individual-level data for Sweden during 1968-2012 to examine the influence of fetal exposure to the Spanish flu on health, adulthood income, and occupational attainment. For both men and women, fetal exposure resulted in higher morbidity in ages 54-87, as measured by hospitalization. For males, exposure during the second trimester also affected mortality in cancer and heart disease. Overall, the effects on all-cause mortality were modest, with about three months shorter remaining life expectancy for the cohorts exposed during the second trimester. For socioeconomic outcomes, results fail to provide consistent evidence supporting any long-term consequences of fetal exposure. We conclude that although the immediate health effects of exposure to the 1918 pandemic were huge, the long-term effects were modest in size.

A review of child stunting determinants in Indonesia

Child stunting reduction is the first of 6 goals in the Global Nutrition Targets for 2025 and a key indicator in the second Sustainable Development Goal of Zero Hunger. The prevalence of child stunting in Indonesia has remained high over the past decade, and at the national level is approximately 37%. It is unclear whether current approaches to reduce child stunting align with the scientific evidence in Indonesia. We use the World Health Organization conceptual framework on child stunting to review the available literature and identify what has been studied and can be concluded about the determinants of child stunting in Indonesia and where data gaps remain. Consistent evidence suggests nonexclusive breastfeeding for the first 6 months, low household socio-economic status, premature birth, short birth length, and low maternal height and education are particularly important child stunting determinants in Indonesia. Children from households with both unimproved latrines and untreated drinking water are also at increased risk. Community and societal factors-particularly, poor access to health care and living in rural areas-have been repeatedly associated with child stunting. Published studies are lacking on how education; society and culture; agriculture and food systems; and water, sanitation, and the environment contribute to child stunting. This comprehensive synthesis of the available evidence on child stunting determinants in Indonesia outlines who are the most vulnerable to stunting, which interventions have been most successful, and what new research is needed to fill knowledge gaps.

Association of Timing of Weight Gain in Pregnancy With Infant Birth Weight

IMPORTANCE

Gestational weight gain is a determinant of infant birth weight, but it is unclear whether its timing in pregnancy may hold implications in this regard. Previous studies have yielded conflicting findings on the association of maternal weight gain in early pregnancy with birth weight. However, as these studies have typically recruited women during the first trimester, they are inherently limited by a reliance on self-reported pregravid weight.

OBJECTIVE

To evaluate the associations of directly measured maternal pregravid weight and the timing of subsequent weight gain across pregnancy with infant birth weight.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective, preconception, observational cohort study, 1164 newly married women in Liuyang, China, underwent pregravid evaluation at a median of 19.9 weeks before a singleton pregnancy during which they underwent serial weight measurements. The study was conducted from February 1, 2009, to November 4, 2015. Data analysis was performed between September 1, 2016, and May 6, 2017.

EXPOSURE

Maternal weight gain was calculated for the following 10 gestational intervals: from pregravid to less than 14, 14 to 18, 19 to 23, 24 to 28, 29 to 30, 31 to 32, 33 to 34, 35 to 36, 37 to 38, and 39 to 40 weeks.

MAIN OUTCOMES AND MEASURES

Associations of pregravid weight and weight gain within each of the 10 gestational intervals with the outcome of infant birth weight.

RESULTS

The mean (SD) age of the 1164 women included in the study was 25.3 (3.1) years. Pregravid weight was consistently associated with infant birth weight. However, among the 10 gestational intervals, only weight gain from pregravid to 14 weeks and from 14 to 18 weeks was associated with birth weight. Birth weight increased by 13.6 g/kg (95% CI, 3.2-24.1 g/kg) of maternal weight gain from pregravid to 14 weeks and by 26.1 g/kg (95% CI, 3.8-48.4 g/kg) of maternal weight gain from 14 to 18 weeks.

CONCLUSION AND RELEVANCE

Maternal weight only in the first half of gestation is a determinant of infant birth weight. Before pregnancy and early gestation may be a critical window for intervention to affect subsequent birth weight.

The importance of public health, poverty reduction programs and women's empowerment in the reduction of child stunting in rural areas of Moramanga and Morondava, Madagascar

BACKGROUND

Malnutrition accounts for 45% of mortality in children under five years old, despite a global mobilization against chronic malnutrition. In Madagascar, the most recent data show that the prevalence of stunting in children under five years old is still around 47.4%. This study aimed to identify the determinants of stunting in children in rural areas of Moramanga and Morondava districts to target the main areas for intervention.

METHODS

A case-control study was conducted in children aged from 6 to 59.9 months, in 2014-2015. We measured the height and weight of mothers and children and collected data on child, mother and household characteristics. One stool specimen was collected from each child for intestinal parasite identification. We used a multivariate logistic regression model to identify the determinants of stunting using backwards stepwise methods.

RESULTS

We included 894 and 932 children in Moramanga and in Morondava respectively. Stunting was highly prevalent in both areas, being 52.8% and 40.0% for Moramanga and Morondava, respectively. Stunting was most associated with a specific age period (12mo to 35mo) in the two study sites. Infection with Trichuris trichiura (aOR: 2.4, 95% CI: 1.1-5.3) and those belonging to poorer households (aOR: 2.3, 95% CI: 1.6-3.4) were the major risk factors in Moramanga. In Morondava, children whose mother had activities outside the household (aOR: 1.7, 95% CI: 1.2-2.5) and those perceived to be small at birth (aOR: 1.6, 95% CI: 1.1-2.1) were more likely to be stunted, whereas adequate birth spacing (≥24months) appeared protective (aOR: 0.4, 95% CI: 0.3-0.7).

CONCLUSION

Interventions that could improve children's growth in these two areas include poverty reduction, women's empowerment, public health programmes focusing on WASH and increasing acceptability, and increased coverage and quality of child/maternal health services.

Gestational Weight Gain and Fetal-Maternal Adiponectin, Leptin, and CRP: results of two birth cohorts studies

Gestational weight gain (GWG) is an important modifiable factor known to influence fetal outcomes including birth weight and adiposity. Unlike behaviors such as smoking and alcohol consumption, the effect of GWG throughout pregnancy on fetal development and other outcomes has not been extensively studied. The aim of this study was to investigate the relationship of GWG with endocrine factors such as adiponectin, leptin, and C-reactive protein which may be associated with inflammatory response, fetal growth, and adiposity later in life. Data were obtained from the Ulm Birth Cohort Study (UBCS) and the Ulm SPATZ Health Study, two methodologically similar birth cohort studies including newborns and their mothers recruited from 11/2000–11/2001 and 04/2012–05/2013. In the two included birth cohorts we consistently observed statistically significant positive associations between GWG beginning as early as the second trimester with fetal cord blood leptin and stronger association beginning as early as the first trimester with post-delivery maternal serum leptin. Total weight gain exceeding commonly accepted recommended guidelines was consistently associated with higher leptin levels in both cord blood and post-delivery maternal serum. These results suggest a potential pathomechanistic link between fetal environment and surrogate markers of long-term health.

Timing of Gestational Weight Gain on Fetal Growth and Infant Size at Birth in Vietnam

OBJECTIVE

To examine the importance of timing of gestational weight gain during three time periods: 1: ≤ 20 weeks gestation), 2: 21-29 weeks) and 3: ≥ 30 weeks) on fetal growth and infant birth size.

METHODS

Study uses secondary data from the PRECONCEPT randomized controlled trial in Thai Nguyen province, Vietnam (n = 1436). Prospective data were collected on women starting pre-pregnancy through delivery. Maternal conditional weight gain (CWG) was defined as window-specific weight gains, uncorrelated with pre-pregnancy body mass index and all prior body weights. Fetal biometry, was assessed by ultrasound measurements of head and abdomen circumferences, biparietal diameter, and femoral length throughout pregnancy. Birth size outcomes included weight and length, and head, abdomen and mid upper arm circumferences as well as small for gestational age (SGA). Adjusted generalized linear and logistic models were used to examine associations.

RESULTS

Overall, three-quarters of women gained below the Institute of Medicine guidelines, and these women were 2.5 times more likely to give birth to a SGA infant. Maternal CWG in the first window (≤ 20 weeks), followed by 21-29 weeks, had the greatest association on all parameters of fetal growth (except abdomen circumference) and infant size at birth. For birth weight, a 1 SD increase CWG in the first 20 weeks had 3 times the influence compared to later CWG (≥ 30 weeks) (111 g vs. 39 g) and was associated with a 43% reduction in SGA risk (OR (95% CI): 0.57 (0.46-0.70).

CONCLUSION

There is a need to target women before or early in pregnancy to ensure adequate nutrition to maximize impact on fetal growth and birth size.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01665378.

Linear growth trajectories in Zimbabwean infants

BACKGROUND

Undernutrition in early life underlies 45% of child deaths globally. Stunting malnutrition (suboptimal linear growth) also has long-term negative effects on childhood development. Linear growth deficits accrue in the first 1000 d of life. Understanding the patterns and timing of linear growth faltering or recovery during this period is critical to inform interventions to improve infant nutritional status.

OBJECTIVE

We aimed to identify the pattern and determinants of linear growth trajectories from birth through 24 mo of age in a cohort of Zimbabwean infants.

DESIGN

We performed a secondary analysis of longitudinal data from a subset of 3338 HIV-unexposed infants in the Zimbabwe Vitamin A for Mothers and Babies trial. We used k-means clustering for longitudinal data to identify linear growth trajectories and multinomial logistic regression to identify covariates that were associated with each trajectory group.

RESULTS

For the entire population, the mean length-for-age z score declined from -0.6 to -1.4 between birth and 24 mo of age. Within the population, 4 growth patterns were identified that were each characterized by worsening linear growth restriction but varied in the timing and severity of growth declines. In our multivariable model, 1-U increments in maternal height and education and infant birth weight and length were associated with greater relative odds of membership in the least-growth restricted groups (A and B) and reduced odds of membership in the more-growth restricted groups (C and D). Male infant sex was associated with reduced odds of membership in groups A and B but with increased odds of membership in groups C and D.

CONCLUSION

In this population, all children were experiencing growth restriction but differences in magnitude were influenced by maternal height and education and infant sex, birth weight, and birth length, which suggest that key determinants of linear growth may already be established by the time of birth. This trial was registered at clinicaltrials.gov as NCT00198718.

Associations of Early and Late Gestational Weight Gain with Infant Birth Size

OBJECTIVES

Associations of gestational weight gain (GWG) during specific periods of pregnancy with infant birth size have been inconsistent. Infant sex-specific differences in these associations are unknown

METHODS

Information on GWG (kg) [total, early (<20 weeks gestation), and late (≥20 weeks gestation)] and indices of infant birth size including birthweight (BW), ponderal index (PI), crown-heel length (CHL), and head circumference (HC) was collected from 3,621 pregnant women. We calculated adjusted mean differences and 95 % confidence intervals (CIs) relating total, early and late GWG to infant birth size using multivariable linear regression procedures. We used stratified analyses and interaction terms to test whether associations differed by infant sex.

RESULTS

One-kg increases in total, early or late GWG were associated with BW increases of 17.2 g (95 % CI 13.8-18.9), 14.1 g (95 % CI 10.3-18.0), and 21.0 g (95 % CI 16.7-25.4), respectively. Early GWG-BW and late GWG-BW associations were different (p = 0.026). Sex-stratified total GWG-BW associations were similar to overall results. There were sex-specific differences in early GWG-BW and late GWG-BW associations. Among females, early GWG-BW (12.0 g, 95 % CI 6.7-17.2) and late GWG-BW (24.2 g, 95 % CI 18.2-30.3) associations differed (p = 0.0042); the corresponding associations did not differ among males. Total, early, and late GWG were associated with CHL and HC, but not with PI. Associations did not differ for early or late GWG.

CONCLUSIONS FOR PRACTICE

For comparable GWG, late-GWG-related BW increase is greater than early-GWG-related BW increase, particularly among female infants.

Impact of demographic, genetic, and bioimpedance factors on gestational weight gain and birth weight in a Romanian population: A cross-sectional study in mothers and their newborns: the Monebo study (STROBE-compliant article)

The present study had 2 objectives, first, to investigate possible relationships between increased gestational weight gain and demographic, clinical, paraclinical, genetic, and bioimpedance (BIA) characteristics of Romanian mothers, and second, to identify the influence of predictors (maternal and newborns characteristics) on our outcome birth weight (BW).We performed a cross-sectional study on 309 mothers and 309 newborns from Romania, divided into 2 groups: Group I-141 mothers with high gestational weight gain (GWG) and Group II-168 mothers with normal GWG, that is, control group.The groups were evaluated regarding demographic, anthropometric (body mass index [BMI], middle upper arm circumference, tricipital skinfold thickness, weight, height [H]), clinical, paraclinical, genetic (interleukin 6 [IL-6]: IL-6 -174G>C and IL-6 -572C>G gene polymorphisms), and BIA parameters.We noticed that fat mass (FM), muscle mass (MM), bone mass (BM), total body water (TBW), basal metabolism rate (BMR) and metabolic age (P < 0.001), anthropometric parameters (middle upper arm circumference, tricipital skinfold thickness; P < 0.001/P = 0.001) and hypertension (odds ratio = 4.65, 95% confidence interval: 1.27-17.03) were higher in mothers with high GWG. BW was positively correlated with mothers' FM (P < 0.001), TBW (P = 0.001), BMR (P = 0.02), while smoking was negatively correlated with BW (P = 0.04). Variant genotype (GG+GC) of the IL-6 -572C>G polymorphism was higher in the control group (P = 0.042).We observed that high GWG may be an important predictor factor for the afterward BW, being positively correlated with FM, TBW, BMR, metabolic age of the mothers, and negatively with the mother's smoking status. Variant genotype (GG+GC) of the IL-6 -572C>G gene polymorphism is a protector factor against obesity in mothers. All the variables considered explained 14.50% of the outcome variance.

Stunting at birth: recognition of early-life linear growth failure in the western highlands of Guatemala

OBJECTIVE

Measurements of length at birth, or in the neonatal period, are challenging to obtain and often discounted for lack of validity. Hence, classical 'under-5' stunting rates have been derived from surveys on children from 6 to 59 months of age. Guatemala has a high prevalence of stunting (49.8%), but the age of onset of growth failure is not clearly defined. The objective of the study was to assess length-for-age within the first 1.5 months of life among Guatemalan infants.

DESIGN

As part of a cross-sectional observational study, supine length was measured in young infants. Mothers' height was measured. Length-for-age Z-scores (HAZ) were generated and stunting was defined as HAZ <-2 using WHO growth standards.

SETTING

Eight rural, indigenous Mam-Mayan villages (n 200, 100% of Mayan indigenous origin) and an urban clinic of Quetzaltenango (n 106, 27% of Mayan indigenous origin), Guatemala.

SUBJECTS

Three hundred and six newborns with a median age of 19 d.

RESULTS

The median rural HAZ was -1.56 and prevalence of stunting was 38%; the respective urban values were -1.41 and 25%. Linear regression revealed no relationship between infant age and HAZ (r = 0.101, r(2) = 0.010, P = 0.077). Maternal height explained 3% of the variability in HAZ (r = 0.171, r(2) = 0.029, P = 0.003).

CONCLUSIONS

Stunting must be carried over from in utero growth retardation in short-stature Guatemalan mothers. As linear growth failure in this setting begins in utero, its prevention must be linked to maternal care strategies during gestation, or even before. A focus on maternal nutrition and health in an intergenerational dimension is needed to reduce its prevalence.

[DOHaD: epidemiological researches]

Epidemiological researches in the field of DOHaD are in favor of a role of early environment, including chemical (pesticides), physical (air pollution), nutritional or psychosocial environment, on child and adult health. Disentangling the different factors of environment that may affect health, especially over time, and identifying critical periods of exposure remains a major challenge. The biological mechanisms involved remain elusive in human beings. Nevertheless, it seems that whatever the nature of the exposure, epigenetic mechanisms are currently discussed to explain how the environment may alter biological systems over time.

A retrospective cohort study of factors relating to the longitudinal change in birth weight

BACKGROUND

Recent reports have shown a decrease in birth weight, a change from prior steady increases. Therefore we sought to describe the demographic and anthropometric changes in singleton term fetal growth.

METHODS

This was a retrospective cohort analysis of term singleton deliveries (37-42 weeks) from January 1, 1995 to January 1, 2010 at a single tertiary obstetric unit. We included all 43,217 neonates from term, singleton, non-anomalous pregnancies. Data were grouped into five 3-year intervals. Mean and median birth weight (BW), birth length (BL), and Ponderal Index (PI) were estimated by year, race and gestational age. Our primary outcome was change in BW over time. The secondary outcomes were changes in BL and PI over time.

RESULTS

Mean and median BW decreased by 72 and 70 g respectively (p < 0.0001) over the 15 year period while BL also significantly decreased by 1.0 cm (P < 0.001). This contributed to an increase in the neonatal PI by 0.11 kg/m(3) (P < 0.001). Mean gestational age at delivery decreased while maternal BMI at delivery, hypertension, diabetes, and African American race increased. Adjusting for gestational age, race, infant sex, maternal BMI, smoking, diabetes, hypertension, and parity, year of birth contributed 0.1 % to the variance (-1.7 g/year; 26 g) of BW, 1.8% (-0.06 cm/year; 0.9 cm) of BL, and 0.7% (+0.008 kg/m(3)/year; 0.12 kg/m(3)) of PI. These findings were independent of the proportional change in race or gestational age.

CONCLUSIONS

We observed a crude decrease in mean BW of 72 g and BL of 1 cm over 15 years. Furthermore, once controlling for gestational age, race, infant sex, maternal BMI, smoking, diabetes, hypertension, and parity, we identified that increasing year of birth was associated with a decrease in BW of 1.7 g/year. The significant increase in PI, despite the decrease in BW emphasizes the limitation of using birth weight alone to define changes in fetal growth.

Gender perceptions predict sex differences in growth patterns of indigenous Guatemalan infants and young children

BACKGROUND

Nearly one-half of Guatemalan children experience growth faltering, more so in indigenous than in nonindigenous children.

OBJECTIVES

On the basis of ethnographic interviews in Totonicapán, Guatemala, which revealed differences in maternal perceptions about food needs in infant girls and boys, we predicted a cumulative sex difference in favor of girls that occurred at ∼6 mo of age and diminished markedly thereafter. We examined whether the predicted differences in age-sex patterns were observed in the village, replicated the examination nationally for indigenous children, and examined whether the pattern in nonindigenous children was different.

DESIGN

Ethnographic interviews (n = 24) in an indigenous village were conducted. Anthropometric measurements of the village children aged 0-35 mo (n = 119) were obtained. National-level growth patterns were analyzed for indigenous (n = 969) and nonindigenous (n = 1374) children aged 0-35 mo with the use of Demographic and Health Survey (DHS) data.

RESULTS

Mothers reported that, compared with female infants, male infants were hungrier, were not as satisfied with breastfeeding alone, and required earlier complementary feeding. An anthropometric analysis confirmed the prediction of healthier growth in indigenous girls than in indigenous boys throughout the first year of life, which resulted in a 2.98-cm height-for-age difference (HAD) between sexes in the village and a 1.61-cm HAD (P < 0.001) in the DHS data between 6 and 17 mo of age in favor of girls. In both data sets, the growth sex differences diminished in the second year of life (P < 0.05). No such pattern was seen in nonindigenous children.

CONCLUSIONS

We propose that the differences in the HAD that first favor girls and then favor boys in the indigenous growth patterns are due to feeding patterns on the basis of gendered cultural perceptions. Circumstances that result in differential sex growth patterns need to be elucidated, in particular the favorable growth in girls in the first year of life.

Weight Loss Instead of Weight Gain within the Guidelines in Obese Women during Pregnancy: A Systematic Review and Meta-Analyses of Maternal and Infant Outcomes

Background

Controversy exists about how much, if any, weight obese pregnant women should gain. While the revised Institute of Medicine guidelines on gestational weight gain (GWG) in 2009 recommended a weight gain of 5–9 kg for obese pregnant women, many studies suggested even gestational weight loss (GWL) for obese women.

Objectives

A systematic review was conducted to summarize pregnancy outcomes in obese women with GWL compared to GWG within the 2009 Institute of Medicine guidelines (5–9 kg).

Design

Five databases were searched from 1 January 2009 to 31 July 2014. The Cochrane Handbook for Systematic Reviews of Interventions and the PRISMA Statement were followed. A modified version of the Newcastle-Ottawa scale was used to assess individual study quality. Small for gestational age (SGA), large for gestational age (LGA) and preterm birth were our primary outcomes.

Results

Six cohort studies were included, none of which assessed preterm birth. Compared to GWG within the guidelines, women with GWL had higher odds of SGA <10^th percentile (adjusted odds ratio [AOR] 1.76; 95% confidence interval [CI] 1.45–2.14) and SGA <3^rd percentile (AOR 1.62; 95% CI 1.19–2.20) but lower odds of LGA >90^th percentile (AOR 0.57; 95% CI 0.52–0.62). There was a trend towards a graded relationship between SGA <10^th percentile and each of three obesity classes (I: AOR 1.73; 95% CI 1.53–1.97; II: AOR 1.63; 95% CI 1.44–1.85 and III: AOR 1.39; 95% CI 1.17–1.66, respectively).

Conclusion

Despite decreased odds of LGA, increased odds of SGA and a lack of information on preterm birth indicate that GWL should not be advocated in general for obese women.

Longitudinal changes in gestational weight gain and the association with intrauterine fetal growth

OBJECTIVE

Total pregnancy weight gain has been associated with infant birthweight; however, most prior studies lacked repeat ultrasound measurements. Understanding of the longitudinal changes in maternal weight gain and intrauterine changes in fetal anthropometrics is limited.

STUDY DESIGN

Prospective data from 1314 Scandinavian singleton pregnancies at high-risk for delivering small-for-gestational-age (SGA) were analyzed. Women had ≥1 (median 12) antenatal weight measurements. Ultrasounds were targeted at 17, 25, 33, and 37 weeks of gestation. Analyses involved a multi-step process. First, trajectories were estimated across gestation for maternal weight gain and fetal biometrics [abdominal circumference (AC, mm), biparietal diameter (BPD, mm), femur length (FL, mm), and estimated fetal weight (EFW, g)] using linear mixed models. Second, the association between maternal weight changes (per 5 kg) and corresponding fetal growth from 0 to 17, 17 to 28, and 28 to 37 weeks was estimated for each fetal parameter adjusting for prepregnancy body mass index, height, parity, chronic diseases, age, smoking, fetal sex, and weight gain up to the respective period as applicable. Third, the probability of fetal SGA, EFW <10th percentile, at the 3rd ultrasound was estimated across the spectrum of maternal weight gain rate by SGA status at the 2nd ultrasound.

RESULTS

From 0 to 17 weeks, changes in maternal weight were most strongly associated with changes in BPD [β=0.51 per 5 kg (95%CI 0.26, 0.76)] and FL [β=0.46 per 5 kg (95%CI 0.26, 0.65)]. From 17 to 28 weeks, AC [β=2.92 per 5 kg (95%CI 1.62, 4.22)] and EFW [β=58.7 per 5 kg (95%CI 29.5, 88.0)] were more strongly associated with changes in maternal weight. Increased maternal weight gain was significantly associated with a reduced probability of intrauterine SGA; for a normal weight woman with SGA at the 2nd ultrasound, the probability of fetal SGA with a weight gain rate of 0.29 kg/w (10th percentile) was 59%, compared to 38% with a rate of 0.67 kg/w (90th percentile).

CONCLUSION

Among women at high-risk for SGA, maternal weight gain was associated with fetal growth throughout pregnancy, but had a differential relationship with specific biometrics across gestation. For women with fetal SGA identified mid-pregnancy, increased antenatal weight gain was associated with a decreased probability of fetal SGA approximately 7 weeks later.

Fetal growth in relation to gestational weight gain in women with type 2 diabetes: an observational study

AIMS

To evaluate fetal growth in relation to gestational weight gain in women with Type 2 diabetes.

METHODS

A retrospective cohort study of 142 consecutive pregnancies in 28 women of normal weight, 39 overweight women and 75 obese women with Type 2 diabetes (pre-pregnancy BMI < 25, 25-29.9, ≥ 30 kg/m2, respectively). Gestational weight gain was categorized as excessive (exceeding the US Institute of Medicine recommendations) or as non-excessive (within or below the Institute of Medicine recommendations).

RESULTS

Excessive and non-excessive gestational weight gain were seen in 61 (43%) and 81 women (57%) with a median (range) gestational weight gain of 14.3 (9-32) vs. 7.0 (-5-16) kg (P < 0.001), respectively. Infants of women with excessive gestational weight gain were characterized by higher birth weight (3712 vs. 3258 g; P = 0.001), birth weight z-score (1.14 vs. -0.01, P = 0.001) and prevalence of large-for-gestational-age infants (48 vs. 20%; P < 0.001). In normal weight, overweight and obese women with non-excessive gestational weight gain, the median weight gain in the first half of pregnancy was 371, 114 and 81 g/week, and in the second half of pregnancy 483, 427 and 439 g/week, respectively. In multiple linear regression analysis, gestational weight gain was associated with a higher infant birth weight z-score independent of pre-pregnancy BMI, smoking, HbA1c and insulin dose at last visit, ethnicity and parity [β=0.1 (95% CI 0.06-0.14), P < 0.001].

CONCLUSIONS

Infant birth weight was almost 0.5 kg higher in women with Type 2 diabetes and excessive gestational weight gain than in women with Type 2 diabetes and non-excessive weight gain.

The stunting syndrome in developing countries

Linear growth failure is the most common form of undernutrition globally. With an estimated 165 million children below 5 years of age affected, stunting has been identified as a major public health priority, and there are ambitious targets to reduce the prevalence of stunting by 40% between 2010 and 2025. We view this condition as a 'stunting syndrome' in which multiple pathological changes marked by linear growth retardation in early life are associated with increased morbidity and mortality, reduced physical, neurodevelopmental and economic capacity and an elevated risk of metabolic disease into adulthood. Stunting is a cyclical process because women who were themselves stunted in childhood tend to have stunted offspring, creating an intergenerational cycle of poverty and reduced human capital that is difficult to break. In this review, the mechanisms underlying linear growth failure at different ages are described, the short-, medium- and long-term consequences of stunting are discussed, and the evidence for windows of opportunity during the life cycle to target interventions at the stunting syndrome are evaluated.

Preconception maternal nutrition: a multi-site randomized controlled trial

BACKGROUND

Research directed to optimizing maternal nutrition commencing prior to conception remains very limited, despite suggestive evidence of its importance in addition to ensuring an optimal nutrition environment in the periconceptional period and throughout the first trimester of pregnancy.

METHODS/STUDY DESIGN

This is an individually randomized controlled trial of the impact on birth length (primary outcome) of the time at which a maternal nutrition intervention is commenced: Arm 1: ≥ 3 mo preconception vs. Arm 2: 12-14 wk gestation vs. Arm 3: none.192 (derived from 480) randomized mothers and living offspring in each arm in each of four research sites (Guatemala, India, Pakistan, Democratic Republic of the Congo). The intervention is a daily 20 g lipid-based (118 kcal) multi-micronutient (MMN) supplement. Women randomized to receive this intervention with body mass index (BMI) <20 or whose gestational weight gain is low will receive an additional 300 kcal/d as a balanced energy-protein supplement. Researchers will visit homes biweekly to deliver intervention and monitor compliance, pregnancy status and morbidity; ensure prenatal and delivery care; and promote breast feeding. The primary outcome is birth length. Secondary outcomes include: fetal length at 12 and 34 wk; incidence of low birth weight (LBW); neonatal/infant anthropometry 0-6 mo of age; infectious disease morbidity; maternal, fetal, newborn, and infant epigenetics; maternal and infant nutritional status; maternal and infant microbiome; gut inflammatory biomarkers and bioactive and nutritive compounds in breast milk. The primary analysis will compare birth Length-for-Age Z-score (LAZ) among trial arms (independently for each site, estimated effect size: 0.35). Additional statistical analyses will examine the secondary outcomes and a pooled analysis of data from all sites.

DISCUSSION

Positive results of this trial will support a paradigm shift in attention to nutrition of all females of child-bearing age.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01883193.

Newborn length predicts early infant linear growth retardation and disproportionately high weight gain in a low-income population

BACKGROUND

Stunting is prevalent by the age of 6 months in the indigenous population of the Western Highlands of Guatemala.

AIM

The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy.

STUDY DESIGN AND SUBJECTS

One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 months. Maternal measurements were also obtained.

RESULTS

Mean ± SD length-for-age Z-score (LAZ) declined from newborn -1.0 ± 1.01 to -2.20 ± 1.05 and -2.26 ± 1.01 at 3 and 6 months respectively. Stunting rates for newborn, 3 and 6 months were 47%, 53% and 56% respectively. A multiple regression model (R(2) = 0.64) demonstrated that the major predictor of LAZ at 3 months was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education∗maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from -0.44 to +1.28 from birth to 3 months. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ.

CONCLUSION

The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions.

Rate and pattern of weight gain in Indian women from the upper income group during pregnancy and its effect on pregnancy outcome

Maternal weight gain and pattern of weight gain during pregnancy influence the ultimate outcome of pregnancy. Pregravid body mass index (BMI), maternal dietary intake, maternal height and age all determine the weight gain during pregnancy. The study was taken up with an objective to observe maternal weight gain and its pattern in pregnancy in women from an upper income group and to find out their association with pregnancy outcome. 180 normal primiparous pregnant Indian women (20-35 years) from an upper income group were recruited between the 10th and 14th weeks of pregnancy and were followed up throughout their pregnancy to record total and trimester-wise weight gain. Neonatal birth weights were recorded. The results showed that mothers with high pregravid BMI gained more weight during pregnancy than the recommended weight gain; in addition, weight gain in the first trimester was significantly correlated with birth weight of the neonates (P = 0.019). Significant correlation was found between weight gain in the third trimester and birth weight of the neonate irrespective of maternal BMI. The rate of weight gain was significantly correlated with neonatal birth weights irrespective of maternal pregravid BMI (P = 0.022) and as per its categories (P = 0.027). Thus, overall it can be concluded that adequate maternal nutrition before and during pregnancy is important for adequate weight gain by the mother and can result in better outcome of pregnancy. The rate of weight gain is also an important contributing factor.

Specific role of maternal weight change in the first trimester of pregnancy on birth size

The specific role of weight change in the first weeks of gestation in fetal growth has not been fully explored in humans. Our aims were to investigate: (1) the specific association between weight change in the first trimester of pregnancy (WCT1) and size at birth in term pregnancies; and (2) the role of placental weight in this relationship. From 2002 women included in the French EDEN study, 1744 mother-child pairs reached term, had pre-pregnancy weight available and at least five measures of weight in pregnancy. We extrapolated women's weight at each week of gestation with a three-degree polynomial model and estimated weight change during each trimester of gestation. We used a multivariate linear model to investigate the associations between WCT1 and birth size after taking into account potential confounders (age, parity, BMI, tobacco use, educational level, length of gestation, newborn gender, weight change after the first trimester and centre of study). Then, we performed path analysis to investigate whether the relation between WCT1 and birth size could be mediated by placental weight. After taking into account weight gain in later gestation, WCT1 was positively associated with birthweight. Results of path analysis showed that there was no direct association between WCT1 and birth size, but that this association was mediated by placental weight. Weight change during the first weeks of pregnancy may impact on fetal growth independently of weight change later in pregnancy through its effects on placental growth and function.

Reliability and validity of birth certificate prepregnancy weight and height among women enrolled in prenatal WIC program: Florida, 2005

To investigate the reliability and validity of weight, height, and body mass index (BMI) from birth certificates with directly measured values from the Women, Infants, and Children (WIC) Program. Florida birth certificate data were linked and compared with first trimester WIC data for women with a live birth during the last quarter of calendar year 2005 (n = 23,314 women). Mean differences for weight, height, and BMI were calculated by subtracting birth certificate values from WIC values. Reliability was estimated by Pearson's correlation. Validity was measured by sensitivity and specificity using WIC data as the reference. Overall mean differences plus or minus standard error (SE) were 1.93 ± 0.04 kg for weight, -1.03 ± 0.03 cm for height, and 1.07 ± 0.02 kg/m(2) for BMI. Pearson's correlation ranged from 0.83 to 0.95, which indicates a strong positive association. Compared with other categories, women in the second weight group (56.7-65.8 kg), the highest height group (≥167.6 cm), or BMI < 18.5 had the greatest mean differences for weight (2.2 ± 0.08 kg), height (-2.4 ± 0.05 cm), and BMI (1.5 ± 0.06), respectively. Mean differences by maternal characteristics were similar, but statistically significant, likely in part from the large sample size. The sensitivity for birth certificate data was 77.3% (±1.42) for underweight (BMI < 18.5) and 76.4% (±0.51) for obesity (BMI ≥ 30). Specificity was 96.8% (±0.12) for underweight and 97.5% (±0.12) for obesity. Birth certificate data had higher underweight prevalence (6 vs. 4%) and lower obesity prevalence (24 vs. 29%), compared with WIC data. Although birth certificate data overestimated underweight and underestimated obesity prevalence, the difference was minimal and has limited impact on the reliability and validity for population-based surveillance and research purposes related to recall or reporting bias.

Prepregnancy weight, gestational weight gain, and risk of growth affected neonates

BACKGROUND

In 2009, the Institute of Medicine published revised gestational weight gain (GWG) guidelines with changes notable for altered body mass index (BMI) categorization as per World Health Organization criteria and a stated range of recommended gain (11-20 pounds) for obese women. The goal of this study was to evaluate associations between maternal BMI-specific GWG adherence in the context of these new guidelines and risk of small for gestational age (SGA) and large for gestational age (LGA) neonates.

METHODS

Subjects were a retrospective cohort of 11,203 live birth singletons delivered at 22-44 weeks at a Massachusetts tertiary care center between April 2006 and March 2010. Primary exposure was GWG adherence (inadequate, appropriate, or excessive) based on BMI-specific recommendations. SGA and LGA were defined as <10th and ≥90th percentiles of U.S. population growth curves, respectively. The association between GWG adherence and SGA and LGA was examined in polytomous logistic regression models that estimated adjusted odds ratios (AOR) stratified by prepregnancy weight status, controlling for potential confounders.

RESULTS

Before pregnancy, 3.8% of women were underweight, 50.9% were normal weight, 24.6% were overweight, and 20.6% were obese. Seventeen percent had inadequate GWG, and 57.2% had excessive GWG. Neonates were 9.6% SGA and 8.7% LGA. Inadequate GWG was associated with increased odds of SGA (AOR 2.51, 95% confidence interval [CI] 1.31-4.78 for underweight and AOR 1.78, 95% CI 1.42-2.24 for normal weight women) and decreased odds of LGA (AOR 0.5, 95% CI 0.47-0.73 for normal weight and AOR 0.56, 95% CI 0.34-0.90 for obese women). Excessive GWG was associated with decreased odds of SGA (AOR 0.59, 95% CI 0.47-0.73 for normal weight and AOR 0.64, 95% CI 0.47-0.89 for overweight women) and increased odds of LGA (AOR 1.76, 95% CI 1.38-2.24 for normal weight, AOR 2.99, 95% CI 1.92-4.65 for overweight, and AOR 1.55, 95% CI 1.10-2.19 for obese women).

CONCLUSIONS

Efforts to optimize GWG are essential to reducing the proportion of SGA and LGA neonates, regardless of prepregnancy BMI.

The influence of maternal body composition on birth weight

OBJECTIVE

To identify the maternal body composition parameters that independently influence birth weight.

STUDY DESIGN

A longitudinal prospective observational study in a large university teaching hospital. One hundred and eighty-four non-diabetic caucasian women with a singleton pregnancy were studied. In early pregnancy maternal weight and height were measured digitally in a standardised way and the body mass index (BMI) was calculated. At 28 and 37 weeks' gestation maternal body composition was assessed using segmental multifrequency bioelectrical impedance analysis. At delivery the baby was weighed and the clinical details were recorded.

RESULTS

Of the women studied, 29.2% were overweight and 34.8% were obese. Birth weight did not correlate with maternal weight or BMI in early pregnancy. Birth weight correlated with gestational weight gain (GWG) before the third trimester (r=0.163, p=0.027), but not with GWG in the third trimester. Birth weight correlated with maternal fat-free mass, and not fat mass at 28 and 37 weeks gestation. Birth weight did not correlate with increases in maternal fat and fat-free masses between 28 and 37 weeks.

CONCLUSIONS

Contrary to previous reports, we found that early pregnancy maternal BMI in a non-diabetic population does not influence birth weight. Interestingly, it was the GWG before the third trimester and not the GWG in the third trimester that influenced birth weight. Our findings have implications for the design of future intervention studies aimed at optimising gestational weight gain and birth weight.

CONDENSATION

Maternal fat-free mass and gestational weight gain both influence birth weight.

Sex differences in fetal growth responses to maternal height and weight

Sex differences in fetal growth have been reported, but how this happens remains to be described. It is unknown if fetal growth rates, a reflection of genetic and environmental factors, express sexually dimorphic sensitivity to the mother herself. This analysis investigated homogeneity of male and female growth responses to maternal height and weight. The study sample included 3,495 uncomplicated singleton pregnancies followed longitudinally. Analytic models regressed fetal and neonatal weight on tertiles of maternal height and weight, and modification by sex was investigated (n = 1,814 males, n = 1,681 females) with birth gestational age, maternal parity, and smoking as covariates. Sex modified the effects of maternal height and weight on fetal growth rates and birth weight. Among boys, tallest maternal height influenced fetal weight growth before 18 gestational weeks of age (P = 0.006), and prepregnancy maternal weight and body mass index subsequently had influence (P < 0.001); this was not found among girls. Additionally, interaction terms between sex, maternal height, and maternal weight identified that males were more sensitive to maternal weight among shorter mothers (P = 0.003) and more responsive to maternal height among lighter mothers (P < or = 0.03), compared to females. Likewise, neonatal birth weight dimorphism varied by maternal phenotype. A male advantage of 60 g occurred among neonates of the shortest and lightest mothers (P = 0.08), compared to 150 and 191 g among short and heavy mothers, and tall and light-weight mothers, respectively (P = 0.01). Sex differences in response to maternal size are under-appreciated sources of variation in fetal growth studies and may reflect differential growth strategies.

Measurement error for ultrasound fetal biometry performed by paramedics in rural Bangladesh

OBJECTIVES

To document the accuracy and precision of sonographic fetal biometry performed by nine paramedics from rural Bangladesh.

METHODS

Paramedics underwent intensive training (6 weeks) including hands-on practice then underwent a series of standardization exercises. Measurements of each fetus were taken by a highly-trained medical doctor (study supervisor) and the nine paramedics. Crown-rump length (CRL) in fetuses of less than 10 weeks' gestation, and biparietal diameter (BPD), occipitofrontal diameter, head and abdominal circumference (AC) and femur diaphysis length (FL) were measured twice using standard procedures by each paramedic and the medical doctor for each fetus, with at least 20 min between them. Precision was quantified using variance components analysis; the intraobserver error for each of the paramedics was calculated by comparing repeat measurements taken on the same participant, and the measurements obtained by each individual paramedic were also compared with those taken by the others (interobserver error). Accuracy was estimated by comparing the mean of the two measures taken by each paramedic to those taken by the study supervisor using paired t-tests. Bland-Altman plots were used to visually assess the relationship between precision of repeat measurements (intraobserver error) and fetal size.

RESULTS

A total of 180 women, at 7 to 31 weeks' gestation, participated in the study. Intraobserver error of the measurements obtained by the paramedics, expressed as the mean SD, ranged from 0.97 mm for BPD in the first trimester to 7.25 mm for AC in the third trimester, and was larger than the interobserver error (i.e. accounting for a greater proportion of total variance) for most measurements. Interobserver error ranged from 0.00 mm for FL to 3.36 mm for AC, both in the third trimester. For all measurements except CRL, intraobserver error increased with increasing fetal size. The measurements obtained by the paramedics did show some statistically significant differences from those obtained by the study supervisor, but these were relatively small in magnitude.

CONCLUSIONS

Both inter- and intraobserver measurement errors were within the range reported in the literature for studies conducted by technical staff and medical doctors. With intense training, paramedics with no prior exposure to ultrasonography can provide accurate and precise measures of fetal biometry.

Health workers, quality of care, and child health: simulating the relationships between increases in health staffing and child length

OBJECTIVE

One in three children globally is stunted in growth. Many of the conditions that promote child stunting are amenable to quality care provided by skilled health workers.

METHODS

The study uses household and facility data from the Indonesian Family Life Surveys in 1993 and 1997. The first set of multivariate regression models evaluate whether the number of medical doctors (MDs), nurses, and midwives predict quality of care as measured by adherence to clinical guidelines. The second set explains the relationships between quality and length among children less than 36 months. Using the information generated from these two sets of regressions, we simulate the effect of increasing the number of MDs, nurses, and midwives on child length and stunting.

RESULTS

Increases in the number of MDs and nurses predict increases in the quality of care. Higher quality care is associated with child length in centimeters and stunting. Simulations suggest that large health gains among children under 24 months of age result by placing MDs where none are available.

CONCLUSIONS

Improvements in child health could be made by increasing the number of qualified health staff. The returns to investing in improvements in human resources for health are high.

Effects of maternal dioxin exposure on newborn size at birth among Japanese mother-infant pairs

OBJECTIVE

Maternal exposure to dioxins [polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (DFs)] during pregnancy is known to affect infant growth and neurodevelopment in humans and animals. The aim of this study was to investigate the relationship between newborn size and the concentration of dioxin isomers in breast milk and to subsequently evaluate the potential toxicity of each dioxin isomer among mothers living in sea coast areas who are at a high risk of contamination due to a high consumption of fish.

METHODS

A total of 75 milk samples were obtained within 1 month of delivery from Japanese mothers living in the coastal areas of the Japan Sea. The relationships between the levels of seven dioxins and ten furan isomers in maternal breast milk, measured by high-resolution-gas chromatography/mass spectrometry, and the birth size of newborns, which is related to fetal growth, were investigated after adjustment for confounding factors.

RESULTS

The concentrations of 1,2,3,6,7,8-HxCDD (hexachlorodibenzo-p-dioxin), 2,3,4,7,8-PeCDF (pentachlorodibenzofuran), 2,3,4,6,7,8-HxCDF, and three dioxin toxic equivalent (TEQ) levels (PCDDs-TEQ, PCDFs-TEQ, and total-TEQ) in maternal breast milk were inversely correlated to newborn length even after adjustment for gestational weeks, infant sex, and maternal age and height. These isomers were abundant among the 17 isomers tested and reflected the TEQ levels. Only 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), the most toxic isomer, was negatively correlated with newborn head circumference, even after adjustment for gestational weeks, infant birth weight, and other confounding factors.

CONCLUSIONS

Based on our results, fetal growth may be influenced by maternal total exposure to dioxins, but only exposure to 2,3,7,8-TCDD would appear to possibly affect fetal head size during pregnancy.

Tradeoffs between oxygen and energy in tibial growth at high altitude

Some studies of high altitude populations argue that stature reduction results from caloric, rather than hypoxic, stress. However, tradeoff models of oxygen and glucose metabolism predict that in hypoxemia, glucose metabolism will be downregulated. We used tradeoff assumptions in two hypotheses: First, that hypoxia targets leg segment growth differentially, and second, that proportions of leg segments partition the impact of high altitude into hypoxemic and energetic components. A group of 113 Han and Tibetan middle school children at 3100 m aged 8 to 11 were measured for segment anthropometries, skinfolds, vital capacity, blood oxygen saturation, and percent body fat. MANOVA showed that Tibetan children were significantly larger and fatter than Han children. Independent of ethnicity or caloric status, absolute and relative tibia length was significantly reduced in children with lower blood oxygen saturation. Height, chest circumference, sitting height, tibia length, and ankle diameter were greatest in fatter children, independent of ethnicity or blood oxygen. For children of either ethnicity with the lowest blood oxygen, size as well as proportion was impacted. These results support the tradeoff model. Caloric reserves and ethnicity independently affect total skeletal size. Oxygen saturation and ethnicity affect leg proportions. In hypoxemia, body fat has less impact on growth than when ample oxygen is present. Therefore, we should qualify the claim that size in high altitude populations stems from nutritional stress. The findings also suggest that decanalization may have different meanings and outcomes depending on which body segments contribute to the effect.

Pre-pregnancy body mass index, gestational weight gain, and other maternal characteristics in relation to infant birth weight

OBJECTIVES

Infant birth weight is influenced by modifiable maternal pre-pregnancy behaviors and characteristics. We evaluated the relationship among pre-pregnancy body mass index (BMI), gestational weight gain, and infant birth weight, in a prospective cohort study.

METHODS

Women were enrolled at < or =20 weeks gestation, completed in-person interviews and had their medical records reviewed after delivery. Infant birth weight was first analyzed as a continuous variable, and then grouped into Low birth weight (LBW) (<2,500 g), normal birth weight (2,500-3,999 g), and macrosomia (> or =4,000 g) in categorical analysis. Pre-pregnancy BMI and gestational weight gain were categorized based on Institute of Medicine BMI groups and gestational weight gain guidelines. Associations among infant birth weight and pre-pregnancy BMI, gestational weight gain, and other factors were evaluated using multivariate regression. Risk ratios were estimated using generalized linear modeling procedures.

RESULTS

Pre-pregnancy BMI was independently and positively associated with infant birth weight (beta = 44.7, P = 0.001) after adjusting for confounders, in a quadratic model. Gestational weight gain was positively associated with infant birth weight (beta = 19.5, P < 0.001). Lower infant birth weight was associated with preterm birth (beta = -965.4, P < 0.001), nulliparity (beta = -48.6, P = 0.015), and female babies (beta = -168.7, P < 0.001). Less than median gestational weight gain was associated with twice the risk of LBW (RR = 2.04, 95% CI 1.34-3.11). Risk of macrosomia increased with increasing pre-pregnancy BMI and gestational weight gain (P for linear trend <0.001).

CONCLUSIONS

These findings support the need to balance pre-pregnancy weight and gestational weight gain against the risk of LBW and macrosomia among lean and obese women, respectively.

How should gestational weight gain be assessed? A comparison of existing methods and a novel method, area under the weight gain curve

BACKGROUND

Gestational weight gain is important to assess for epidemiological and public health purposes: it is correlated with infant growth and may be related to maternal outcomes such as reproductive health and chronic disease risk. Methods commonly used to assess weight gain incorporate assumptions that are usually not borne out, such as a linear weight gain, or do not account for differential length of gestation.

METHODS

We introduce a novel method to assess gestational weight gain, the area under the weight gain curve. This is easily interpretable as the additional pound-days carried due to pregnancy and avoids many flaws in alternative assessments. We compare the performance of the simple difference, weekly gain, Institute of Medicine categories and the area under the weight gain curve in predicting birthweight and maternal weight retention at 6, 12, 24 and 36 months postpartum. The analytic sample comprises 2016 participants in Project Viva, an observational prospective cohort study of pregnant women in Massachusetts.

RESULTS

For birthweight outcomes, none of the weight gain measures is a meaningfully superior predictor. For 6-month postpartum weight retention the simple difference is superior, while for 12-, 24- and 36-month weight retention the area under the weight gain curve is superior.

CONCLUSIONS

These findings are plausible biologically: the same amount of weight gained early vs later in the pregnancy may reflect increased maternal fat stores. The timing of weight gain is reflected best in the area under the weight gain curve. Different methods of measuring gestational weight gain may be appropriate depending on the context.