Weight Loss Prior to Pregnancy and Early Gestational Glycemia: Prepare, a Randomized Clinical Trial

Effective interventions in preventing gestational diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Lifestyle choices, metformin, and dietary supplements may prevent GDM, but the effect of intervention characteristics has not been identified. This review evaluated intervention characteristics to inform the implementation of GDM prevention interventions.

METHODS

Ovid, MEDLINE/PubMed, and EMBASE databases were searched. The Template for Intervention Description and Replication (TIDieR) framework was used to examine intervention characteristics (who, what, when, where, and how). Subgroup analysis was performed by intervention characteristics.

RESULTS

116 studies involving 40,940 participants are included. Group-based physical activity interventions (RR 0.66; 95% CI 0.46, 0.95) reduce the incidence of GDM compared with individual or mixed (individual and group) delivery format (subgroup p-value = 0.04). Physical activity interventions delivered at healthcare facilities reduce the risk of GDM (RR 0.59; 95% CI 0.49, 0.72) compared with home-based interventions (subgroup p-value = 0.03). No other intervention characteristics impact the effectiveness of all other interventions.

CONCLUSIONS

Dietary, physical activity, diet plus physical activity, metformin, and myoinositol interventions reduce the incidence of GDM compared with control interventions. Group and healthcare facility-based physical activity interventions show better effectiveness in preventing GDM than individual and community-based interventions. Other intervention characteristics (e.g. utilization of e-health) don't impact the effectiveness of lifestyle interventions, and thus, interventions may require consideration of the local context.

Prepregnancy dieting and obstetrical and neonatal outcomes: Findings from a national surveillance project in the United States

PROBLEM AND BACKGROUND

Women with overweight or obesity are recommended to lose weight before pregnancy. Dieting is one of the most used weight control strategies. However, the health implications of dieting before pregnancy remain unclear.

AIM

To evaluate the associations of dieting during the year before pregnancy with obstetrical and neonatal outcomes, including gestational weight gain (GWG), gestational diabetes, low birthweight, macrosomia, small-for-gestational-age infants (SGA), large-for-gestational-age infants (LGA), and preterm birth.

METHODS

This study analyzed data from the Pregnancy Risk Assessment Monitoring System (PRAMS), which is a surveillance project in the United States that collects data on maternal health before, during, and after pregnancy. Women who participated in PRAMS phase 7 with a prepregnancy body mass index ≥25 kg/m2 and a singleton birth were eligible. Statistical analyses included logistic regressions and post-hoc mediation analysis (Sobel Test).

FINDINGS

A total number of 51,399 women were included in the analysis. Women who self-reported prepregnancy dieting (42.8 %) had lower odds of SGA (adjusted odds ratio [aOR]: 0.87; 95 % CI: 0.79-0.97), and higher odds of excessive GWG vs adequate GWG (aOR: 1.42; 95 % CI: 1.32-1.52), gestational diabetes (aOR: 1.12; 95 % CI: 1.02-1.22), and LGA (aOR: 1.18; 95 % CI: 1.08-1.28). Furthermore, the association between prepregnancy dieting and LGA was mediated by excessive GWG (Sobel Test z-value = 5.72, p < 0.01).

DISCUSSION AND CONCLUSION

This analysis revealed that prepregnancy dieting was associated with several adverse consequences, including excessive GWG, gestational diabetes, and LGA infants. Findings contribute to an improved understanding of the perinatal implications of prepregnancy dieting.

Prepregnancy weight loss and maternal metabolic and inflammatory biomarkers during pregnancy: An analysis of National Health and Nutrition Examination Survey

AIM

Women with overweight or obesity are recommended to lose weight before conception to optimize pregnancy outcomes. However, the obstetrical implications of prepregnancy weight loss have been minimally examined. The objective of this study was to investigate the association between prepregnancy weight loss and maternal metabolic and inflammatory profiles during a subsequent pregnancy.

METHODS

This study was a retrospective analysis of National Health and Nutrition Examination Survey data (2003-2018). Participants were women who were pregnant at the time of assessment. Prepregnancy weight loss was described as percent weight change based on self-reported baseline (1 year before pregnancy) and prepregnancy weight. Metabolic (e.g., blood pressure [BP]) and inflammatory biomarkers (i.e., high-sensitivity C-reactive protein [hs-CRP]) were determined by standard medical tests. Statistical analyses included linear regressions with appropriate imputation, weighting, and variance estimation techniques.

RESULTS

Participants (N = 236) reported a mean percent weight loss of 4.6% (standard error [SE] = 0.3%) during the year before pregnancy. Regression models showed that prepregnancy weight loss was inversely associated with levels of total cholesterol (β = -1.24, p = 0.01), low-density lipoprotein-cholesterol (β = -0.79, p < 0.01), and high-density lipoprotein-cholesterol (β = -0.18, p < 0.01). The effect of prepregnancy weight loss on BP, insulin sensitivity, and hs-CRP was not significant, although there was a trend toward higher levels of diastolic BP (β = 0.24, p = 0.07) and hs-CRP (β = 0.10, p = 0.08).

CONCLUSIONS

This study found favorable changes in lipid profiles following prepregnancy weight loss. Due to limitations such as a relatively small sample size, self-reported weight measures, and missing data on several outcome variables, future studies are needed to confirm study findings.

Randomized controlled trial of prepregnancy lifestyle intervention to reduce recurrence of gestational diabetes mellitus

BACKGROUND

Preconception lifestyle intervention holds potential for reducing gestational diabetes mellitus, but clinical trial data are lacking.

OBJECTIVE

This study aimed to determine the effects of a prepregnancy weight loss intervention on gestational diabetes mellitus recurrence in women with overweight/obesity and previous gestational diabetes mellitus.

STUDY DESIGN

A 2-site, randomized controlled trial comparing a prepregnancy lifestyle intervention with educational control was conducted between December 2017 and February 2022. A total of 199 English- and Spanish-speaking adults with overweight/obesity and previous gestational diabetes mellitus were randomized to a 16-week prepregnancy lifestyle intervention with ongoing treatment until conception or educational control. The primary outcome was gestational diabetes mellitus recurrence. Analyses excluded 6 participants who conceived but did not have gestational diabetes mellitus ascertained by standard methods.

RESULTS

In the 63 (33%) women who conceived and had gestational diabetes mellitus ascertained (Ns=38/102 [37%] intervention vs 25/91 [28.0%] control; P=.17), those in the intervention group had significantly greater weight loss at 16 weeks compared with controls (4.8 [3.4-6.0] vs 0.7 [-0.9 to 2.3] kg; P=.001) and a greater proportion lost ≥5% of body weight (50.0% [17/34] vs 13.6% [3/22]; P=.005). There was no significant difference in the incidence of gestational diabetes mellitus recurrence between the intervention (57.9% [ns=23/38]) and the control group (44.0% [ns=11/25]; odds ratio, 1.8 [0.59-5.8]). Independent of group, greater prepregnancy weight loss predicted 21% lower odds of gestational diabetes mellitus recurrence (odds ratio, 0.79 [0.66-0.94]; P=.008). A ≥5% weight loss before conception reduced the odds of gestational diabetes mellitus recurrence by 82% (odds ratio, 0.18 [0.04-0.88]; P=.03).

CONCLUSION

Lifestyle intervention produced considerable prepregnancy weight loss but did not affect gestational diabetes mellitus rates. Given that the conception rate was 50% lower than expected, this study was underpowered.

Pregnancy as an Early Cardiovascular Moment: Peripartum Cardiovascular Health

Pregnancy is commonly referred to as a window into future CVH (cardiovascular health). During pregnancy, physiological adaptations occur to promote the optimal growth and development of the fetus. However, in approximately 20% of pregnant individuals, these perturbations result in cardiovascular and metabolic complications, which include hypertensive disorders of pregnancy, gestational diabetes, preterm birth, and small-for-gestational age infant. The biological processes that lead to adverse pregnancy outcomes begin before pregnancy with higher risk of adverse pregnancy outcomes observed among those with poor prepregnancy CVH. Individuals who experience adverse pregnancy outcomes are also at higher risk of subsequent development of cardiovascular disease, which is largely explained by the interim development of traditional risk factors, such as hypertension and diabetes. Therefore, the peripartum period, which includes the period before (prepregnancy), during, and after pregnancy (postpartum), represents an early cardiovascular moment or window of opportunity when CVH should be measured, monitored, and modified (if needed). However, it remains unclear whether adverse pregnancy outcomes reflect latent risk for cardiovascular disease that is unmasked in pregnancy or if adverse pregnancy outcomes are themselves an independent and causal risk factor for future cardiovascular disease. Understanding the pathophysiologic mechanisms and pathways linking prepregnancy CVH, adverse pregnancy outcomes, and cardiovascular disease are necessary to develop strategies tailored for each stage in the peripartum period. Emerging evidence suggests the utility of subclinical cardiovascular disease screening with biomarkers (eg, natriuretic peptides) or imaging (eg, computed tomography for coronary artery calcium or echocardiography for adverse cardiac remodeling) to identify risk-enriched postpartum populations and target for more intensive strategies with health behavior interventions or pharmacological treatments. However, evidence-based guidelines focused on adults with a history of adverse pregnancy outcomes are needed to prioritize the prevention of cardiovascular disease during the reproductive years and beyond.

Maternal BMI in the preconception period, and association with child zBMI growth rates

BACKGROUND

Elevated body mass index (BMI) and rapid growth in early childhood are important predictors of obesity risk. The association between maternal preconception BMI and child growth rates is unclear.

OBJECTIVES

To assess the association between measured maternal preconception BMI and child age- and sex- standardized WHO BMI z-score (zBMI) growth rates and mean zBMI, in children aged 0-10 years old.

METHODS

A longitudinal cohort study was conducted with children (n = 499) enrolled in The Applied Research Group for Kids (TARGet Kids!) primary care practice-based research cohort. Maternal BMI was measured during the preconception period, defined as the 2 years prior to pregnancy. Repeated measures of child weight and height were obtained between 0 and 10 years of age. Linear mixed models were used to evaluate the association between maternal BMI and child zBMI growth rates and mean zBMI.

RESULTS

Maternal preconception BMI was associated with child zBMI growth rate during some growth periods, with the strongest association from age 0 to 4 months; a 5 kg/m2 higher maternal BMI was associated with 0.031 zBMI SD unit/mo higher growth rate (p = 0.004), and 0.186 SD unit higher mean child zBMI (p = 0.0002).

CONCLUSIONS

Maternal preconception BMI was associated with growth rate and mean zBMI in early childhood. The preconception period may be an important target for health interventions to promote healthy child growth rate and weight outcomes.

Maternal Mortality in the United States: Trends and Opportunities for Prevention

Maternal mortality is unusually high in the United States compared to other wealthy nations and is characterized by major disparities in race/ethnicity, geography, and socioeconomic factors. Similar to other developed nations, the United States has seen a shift in the underlying causes of pregnancy-related death, with a relative increase in mortality resulting from diseases of the cardiovascular system and preexisting medical conditions. Improved continuity of care aimed at identifying reproductive-age women with preexisting conditions that may heighten the risk of maternal death, preconception management of risk factors for major adverse pregnancy outcomes, and primary care visits within the first year after delivery may offer opportunities to address gaps in medical care contributing to the unacceptable rates of maternal mortality in the United States.

Obesity and reproduction

PURPOSE OF REVIEW

The objective of this review is to highlight the recent literature on how obesity affects reproductive capacity in men and women.

RECENT FINDINGS

The relationship between fertility and obesity is complex and involves the hypothalamic-pituitary-ovarian axis, neuroendocrine systems and adipose tissue. The exact pathophysiology of how obesity lowers fertility rates is unknown, but is likely multifactorial involving anovulation, insulin resistance and alterations in gonadotropins. In addition, there is controversy on whether oocyte quality or endometrial receptivity plays a larger role in obese infertile women. Data on effects of bariatric surgery and weight loss on obese infertile men and women are mixed.

SUMMARY

Obesity alters the hormonal profile, gonadotropin secretion, embryo development and in-vitro fertilization outcomes in both men and women.

Maternal Diet During Pregnancy and Lactation and Child Food Preferences, Dietary Patterns, and Weight Outcomes: a Review of Recent Research

PURPOSE OF REVIEW

Efforts to promote children's preferences for healthy foods hold much potential for improving diet quality and preventing obesity. The purpose of this review was to summarize recent evidence for associations between maternal diet during pregnancy and lactation and child food preferences, dietary patterns, and weight outcomes.

RECENT FINDINGS

Recent research illustrates greater maternal vegetable intakes during pregnancy and lactation predict greater child preferences for and intakes of vegetables. Recent randomized clinical trials to improve maternal weight outcomes during the perinatal period via behavioral lifestyle interventions that included dietary components have yielded mixed findings for effects on child weight outcomes. There is strong evidence that maternal diet during pregnancy and lactation shapes flavor preferences during infancy; more research is needed to understand factors that facilitate versus hinder the translation of these preferences to later dietary patterns and weight outcomes.