Gestational Weight Gain and Long-term Maternal Obesity Risk: A Multiple-Bias Analysis

Placental Bioenergetics and Antioxidant Homeostasis in Maternal Obesity and Gestational Diabetes

Maternal obesity has been associated with short- and long-term risks of pregnancy-perinatal adverse events, possibly due to alterations of placental mitochondrial bioenergetics. However, several detrimental mechanisms occurring in the placentas of women with obesity still need to be clarified. Here, we analyzed placental mitochondrial features and oxidative environment of 46 pregnancies in relation to pre-pregnancy BMI. Seventeen Caucasian normal-weight (NW) and twenty-nine women who were obese (OB) were enrolled. The protein expression of mitochondrial CypD and electron transfer chain complexes (C) I-V were measured, as well as ATP production and oxygen consumption rates (OCRs). The protein levels of the pro/anti-oxidant enzymes TXNIP, SOD2, and PON2 were also analyzed. Despite no differences in CypD expression, OCRs were significantly lower in OB vs. NW women. Accordingly, ATP synthase (CV) levels and ATP content were decreased in OB women, positively correlating with placental efficiency, suggesting a link between ATP deficiency and placental dysfunction. SOD2 expression negatively correlated with maternal BMI, indicating a possible impairment of antioxidant defenses with increasing BMI. These changes were worsened in 10 OB women presenting with gestational diabetes mellitus. Overall, these results suggest alterations of placental bioenergetics in pregnancies of women with obesity, possibly leading to placental dysfunction and altered fetal development and programming.

Validation of Long-term Recall of Pregnancy-related Weight in the Life-course Experiences And Pregnancy Study

BACKGROUND

Prepregnancy body mass index (BMI) and gestational weight gain (GWG) are determinants of maternal and child health. However, many studies of these factors rely on error-prone self-reported measures.

METHODS

Using data from Life-course Experiences And Pregnancy (LEAP), a US-based cohort, we assessed the validity of prepregnancy BMI and GWG recalled on average 8 years postpartum against medical record data treated as alloyed gold standard ("true") values. We calculated probabilities of being classified into a self-reported prepregnancy BMI or GWG category conditional on one's true category (analogous to sensitivities and specificities) and probabilities of truly being in each prepregnancy BMI or GWG category conditional on one's self-reported category (analogous to positive and negative predictive values).

RESULTS

There was a tendency toward under-reporting prepregnancy BMI. Self-report misclassified 32% (95% confidence interval [CI] = 19%, 48%) of those in LEAP with truly overweight and 13% (5%, 27%) with obesity into a lower BMI category. Self-report correctly predicted the truth for 72% (55%, 84%) with self-reported overweight to 100% (90%, 100%) with self-reported obesity. For GWG, both under- and over-reporting were common; self-report misclassified 32% (15%, 55%) with truly low GWG as having moderate GWG and 50% (28%, 72%) with truly high GWG as moderate or low GWG. Self-report correctly predicted the truth for 45% (25%, 67%) with self-reported high GWG to 85% (76%, 91%) with self-reported moderate GWG. Misclassification of BMI and GWG varied across maternal characteristics.

CONCLUSION

Findings can be used in quantitative bias analyses to estimate bias-adjusted associations with prepregnancy BMI and GWG.

Interpregnancy maternal weight change is not associated with offspring weight and obesity at age 2 years

BACKGROUND

Weight retention between pregnancies is associated with increased risk of perinatal complications, but it is unclear whether there is an association with offspring weight status. This study aimed to determine whether maternal interpregnancy weight change is associated with offspring overweight/obesity, controlling for confounding variables.

SUBJECTS/METHODS

Routinely collected linked data from perinatal and child datasets, in Flanders, Belgium were used. Women having their first and second live births between 2009-2018 were included. The association between maternal interpregnancy weight change and overweight/obesity in the second child at 2 years was examined by logistical regression models.

RESULTS

A total of 33,172 women were included. 52.7% (n = 17478) had a stable interpregnancy BMI, 24.1% (n = 8024) and 8.5% (n = 2821) had moderate and substantial BMI increases respectively. At 2 years, 91.6% (n = 30383) of the second offspring had a healthy weight, 0.6% (n = 210), 7.0% (n = 2312) and 0.8% (n = 267) were in the underweight, overweight and obesity BMI categories respectively. Multivariate analysis showed no statistical evidence that maternal interpregnancy BMI change is independently associated with overweight/obesity in the second child. The strongest independent factors were the first child (sibling) being in the obesity category at 2 years (odds ratio [OR] 7.2, [95% CI, 5.49-9.45] and being born Large for Gestational Age (LGA) (2.13 [1.92-2.37]). The following variables were also independently associated with the outcome measure: maternal African origin (1.90 [1.59-2.26]), maternal obesity at start of first pregnancy (1.33 [1.16-1.53]), excessive gestational weight gain in the second pregnancy (1.15 [1.04-1.28]), being born after a < 1-year interpregnancy time interval (1.17 [1.05-1.30]) and not being exclusively breastfed at 12 weeks old (1.29 [1.10-1.52]).

CONCLUSION

Sibling obesity and being born LGA were most strongly independently associated with overweight/obesity at 2 years. This supports the need for family interventions and to address risk factors for development of LGA infants. There was no independent association with interpregnancy weight gain, contrary to what was hypothesised.

Gestational weight gain and adverse birth outcomes in South African women with HIV on antiretroviral therapy and without HIV: a prospective cohort study

INTRODUCTION

Outside of pregnancy, evidence shows that persons with HIV initiating or switching to dolutegravir (DTG)-based antiretroviral therapy (ART) experience greater weight gain compared to those on other ART classes. However, there are few data on the impact of DTG-based ART on gestational weight gain (GWG) in sub-Saharan Africa where HIV is most common. According to the National Academy of Medicine (NAM), GWG below and above NAM guidelines is associated with adverse birth outcomes. Therefore, the objective of this study was to describe GWG by HIV status and ART regimen, and examine the associations with adverse birth outcomes.

METHODS

We enrolled pregnant women with HIV (WHIV) and without HIV (≥18 years) in a peri-urban primary healthcare facility in Cape Town, South Africa between 2019 and 2022. GWG was study-measured at 24-28 (baseline) and 33-38 weeks gestation and converted to GWG rate (kg/week) in accordance with NAM guidelines. GWG z-scores were generated using the INTEGROWTH-21 and US standards to account for differing lengths of gestation. Birth outcome data were obtained from medical records. Associations of GWG z-score with adverse birth outcomes were assessed using multivariable linear or log-binomial regression.

RESULTS

Among 292 participants (48% WHIV), median age was 29 years (IQR, 25-33), median pre-pregnancy body mass index (BMI) was 31 kg/m2 (IQR, 26-36) and 20% were primiparous at baseline. The median weekly rate of GWG was 0.30 kg/week (IQR, 0.12-0.50), 35% had GWG below NAM standards (59% WHIV) and 48% had GWG above NAM standards (36% WHIV). WHIV gained weight more slowly (0.25 vs. 0.37 kg/week, p<0.01) than women without HIV. Weekly rate of GWG did not differ by ART regimen (DTG-based ART 0.25 vs. efavirenz-based ART 0.27 kg/week, p = 0.80). In multivariable analyses, GWG z-score was positively associated with continuous birth weight (mean difference = 68.53 95% CI 8.96, 128.10) and categorical high birth weight of >4000 g (RR = 2.18 95% CI 1.18, 4.01).

CONCLUSIONS

Despite slower GWG among WHIV, nearly half of all women gained weight faster than recommended by the NAM. GWG was positively associated with infant birth weight. Interventions to support healthy GWG in sub-Saharan Africa are urgently needed.

Sex-Specific Obesity and Cardiometabolic Disease Risks in Low- and Middle-Income Countries: A Meta-Analysis Involving 3 916 276 Individuals

CONTEXT

There is limited knowledge about the disparities between the sexes in obesity prevalence and associated cardiovascular complications in low- and middle-income countries (LMICs).

OBJECTIVE

We undertook a systematic review and meta-analysis to assess sex-specific disparities in the prevalence of obesity and cardiometabolic diseases in LMICs, the burden in women, and variations by region, country's income status, setting, and time.

METHODS

We searched major databases from inception to March 2023. Two independent reviewers selected the studies, assessed their quality, and extracted data. We used DerSimonian and Laird random-effects models to obtain pooled estimates of odds ratios and 95% CI for the association between sex and obesity and cardiometabolic diseases, and multilevel random-effects logistic regression models to estimate the prevalence of relevant outcomes (PROSPERO CRD42019132609).

RESULTS

We included 345 studies (3 916 276 individuals). The odds of obesity were 2.72-fold higher in women than men (OR 2.72; 95% CI, 2.54-2.91). The sex-specific disparities varied by region, with the greatest disparities in Sub-Saharan Africa (OR 3.91; 95% CI, 3.49-4.39). Among women in LMICs, 23% (95% CI, 21%-25%) had obesity, 27% (95% CI, 24%-29%) had hypertension, and 7% (95% CI, 6%-9%) had type 2 diabetes. The prevalence of obesity and type 2 diabetes in women varied by region, country's income, and setting, with the highest prevalence in the Middle East and North Africa, upper-middle-income countries and urban settings. The odds of hypertension (OR 2.41; 95% CI, 1.89-3.08) and type 2 diabetes (OR 2.65; 95% CI, 1.76-3.98) were doubled in women with vs without obesity.

CONCLUSION

There is an urgent need for a women-centred and region-stratified approach to tackle obesity awareness, treatment, and prevention in women in LMICs.

Association between gestational weight gain and chronic disease risks in later life

To assess the association between gestational weight gain (GWG) and the risk of developing chronic diseases in later life, this historical cohort study of 318 non-overweight women was conducted between April 2017 and November 2020 at a hospital in Tokyo. Data about GWG in the last pregnancy and the development of any chronic diseases of the subjects were retrieved from the women's Maternal and Child Health Handbooks and through a questionnaire survey, respectively. The outcomes were chronic diseases, such as diabetes mellitus (DM), hypertension, hyperlipidemia, and being overweight (body mass index [BMI] ≥ 25 kg/m2). Association between GWG and outcomes were assessed using a logistic regression analysis.There were significant positive linear associations between GWG and the risks of developing DM, hypertension, and being overweight (P = 0.013, 0.050, and 0.017, respectively). After adjusting for later-life BMI, a significant association between GWG and DM (P = 0.025) remained, but the association between GWG and hypertension disappeared. GWG was significantly associated with DM, hypertension, and being overweight later in life. Although the association between GWG and DM was partially independent of BMI later in life, the association between GWG and hypertension was influenced by being overweight later in life.

"We adjusted for race": now what? A systematic review of utilization and reporting of race in American Journal of Epidemiology and Epidemiology, 2020-2021

Race is a social construct, commonly used in epidemiologic research to adjust for confounding. However, adjustment of race may mask racial disparities, thereby perpetuating structural racism. We conducted a systematic review of articles published in Epidemiology and American Journal of Epidemiology between 2020 and 2021 to (1) understand how race, ethnicity, and similar social constructs were operationalized, used, and reported; and (2) characterize good and poor practices of utilization and reporting of race data on the basis of the extent to which they reveal or mask systemic racism. Original research articles were considered for full review and data extraction if race data were used in the study analysis. We extracted how race was categorized, used-as a descriptor, confounder, or for effect measure modification (EMM)-and reported if the authors discussed racial disparities and systemic bias-related mechanisms responsible for perpetuating the disparities. Of the 561 articles, 299 had race data available and 192 (34.2%) used race data in analyses. Among the 160 US-based studies, 81 different racial categorizations were used. Race was most often used as a confounder (52%), followed by effect measure modifier (33%), and descriptive variable (12%). Fewer than 1 in 4 articles (22.9%) exhibited good practices (EMM along with discussing disparities and mechanisms), 63.5% of the articles exhibited poor practices (confounding only or not discussing mechanisms), and 13.5% were considered neither poor nor good practices. We discuss implications and provide 13 recommendations for operationalization, utilization, and reporting of race in epidemiologic and public health research.

Social Isolation and Depressive Symptoms Among Older Adults: A Multiple Bias Analysis Using a Longitudinal Study in Japan

PURPOSE

Despite the potential burden of social isolation on mental health, it is unclear which component of social isolation (living alone, lack of social support, and lack of social participation) is mostly associated with depression among older adults and whether it varies by gender. Moreover, previous observational studies have suffered from several systematic biases such as confounding, misclassification, and selection bias. We thus aimed to investigate the risk of social isolation on subsequent depressive symptoms among older men and women, fully taking account of such systematic biases simultaneously.

METHODS

This study included 15,311 adults from a nationwide longitudinal cohort study of older adults aged ≥65 years in Japan. We employed modified Poisson regression models to estimate the adjusted risk ratio (aRR) of elevated depressive symptoms (the Geriatric Depression Scale: ≥5 vs. <5) in 2016 according to the social isolation index (SII) score (0-5 points) in 2013. Non-probabilistic multiple bias analyses with weighting approach and bounding factor were conducted to adjust for possible confounding, exposure misclassification, and selection biases.

RESULTS

The mean age (SD) of participants was 72.1 (4.9) years. Adults with the SII score ≥2 showed an increased risk of elevated depressive symptoms than those with the SII score <2 (aRR [95% CI] = 1.57 [1.41-1.76]). All components of SII were associated with elevated depressive symptoms except living alone for women. Our multiple bias analysis showed that an unmeasured confounder needed to have at least moderate relationship (RR=2.0-3.0) with both exposure and outcome to explain away the observed association particularly when social isolation status was independently and non-differentially misclassified.

CONCLUSION

Among older adults in Japan, social isolation was associated with an increased risk of elevated depressive symptoms, even after taking account of systematic biases simultaneously. Increasing social connection may mitigate the risk of depression, which should be the subject of future research.

Addressing Obesity in Preconception, Pregnancy, and Postpartum: A Review of the Literature

PURPOSE OF REVIEW

Reproductive-aged women (aged 19 to 50 years) are a key population warranting focused research for the prevention of overweight and obesity. This review highlights the importance of addressing weight before, during and after pregnancy.

RECENT FINDINGS

Obesity decreases fertility during the preconception period; increases the risk of adverse pregnancy outcomes including gestational diabetes, pre-eclampsia and caesarean section and postpartum weight retention; and increases the long-term health risks for both the mother and offspring. Despite overwhelming efficacy evidence on solutions, there are significant implementation gaps in translating this evidence into pragmatic models of care and real-world solutions. Interventions during preconception, pregnancy and postpartum are likely to be cost-effective or cost-saving, with future investigation needed in the preconception and postpartum period. International clinical guidelines and public health policies are needed for a concerted effort to prevent unhealthy weight gain in these life stages and to reverse the significant adverse health outcomes for women and the next generation.

Effect of the e-health supported INTER-ACT lifestyle intervention on postpartum weight retention and body composition, and associations with lifestyle behavior: A randomized controlled trial

We investigated whether a postpartum lifestyle intervention reduced postpartum weight retention (PPWR) and improved body composition, and whether improved lifestyle was associated with less PPWR and improved body composition. A total of 1075 women with excessive gestational weight gain were randomized into the intervention (N = 551) or control (N = 524) group. A completion rate of 76% was reached. Anthropometrics and lifestyle data were collected at 6 weeks and 6 months postpartum. The e-health supported intervention consisted of 4 face-to-face coaching's, focusing on nutrition, exercise and mental wellbeing and using motivational interviewing and behavior change techniques. In the intervention group we observed; larger decrease in weight in women who reduced their energy intake (mean ± SD: 3.1 ± 4.2 kg vs. 2.2 ± 3.8 kg, P = 0.05) and decreased uncontrolled eating (3.5 ± 4.2 kg vs. 1.9 ± 3.7 kg, P ≤0.001) by the end of the intervention; larger decrease in fat percentage in women who reduced energy intake (2.3% ± 2.9 vs. 1.4% ± 2.7, P = 0.01), enhanced restrained eating (2.2% ± 3 vs. 1.4% ± 2.6, P = 0.02) and decreased uncontrolled eating (2.3% ± 2.9 vs. 1.5% ± 2.7, P = 0.01) and larger decrease in waist circumference in women who reduced energy intake (4.6 cm ± 4.8 vs. 3.3 cm ± 4.7, P = 0.01), enhanced restrained eating (4.5 cm ± 4.8 vs. 3.4 cm ± 4.8, P = 0.05) and decreased uncontrolled eating (4.7 cm ± 4.8 vs. 3.3 cm ± 4.8, P = 0.006), compared to those who did not. Improved energy intake, restrained eating and uncontrolled eating behavior were associated with more favorable outcomes in weight and body composition. ClinicalTrials.gov identifier:NCT02989142.

Excessive Gestational Weight Gain and Long-Term Maternal Cardiovascular Risk Profile: The Study of Women's Health Across the Nation

Background: Excessive gestational weight gain (GWG) is consistently linked with maternal risk of obesity. However, the literature on its long-term cardiovascular risk is minimal and conflicting. We evaluated whether excessive GWG is associated with a high-risk cardiovascular profile among parous women in midlife. Materials and Methods: Participants were women in the multiethnic cohort Study of Women's Health Across the Nation with a history of live birth(s). Excessive GWG was defined according to Institute of Medicine guidelines and collected by self-recall. Outcomes were the atherosclerotic cardiovascular disease (ASCVD) risk score and C-reactive protein (CRP), measured at the study baseline when mean age was 47 years, and at 10 follow-up visits (1996-2017). We estimated the association of excessive GWG with outcomes through linear mixed model regression. Results: The analytic sample included 1318 women with 3049 singleton births. Over 40% (536) reported one or more pregnancies with excessive GWG. Longitudinal models estimated that at a mean age of 67, women with a history of excessive GWG had a 9.8% (9.2, 10.5) 10-year ASCVD risk, compared to 9.5% (8.9, 10.1) for those without, and mean CRP of 2.20 mg/L (1.89, 2.57) versus 1.85 mg/L (1.61, 2.14), respectively, adjusted for participant characteristics. Conclusions: In this multiethnic cohort of parous women, a history of excessive GWG was associated with a small, but statistically significant difference in ASCVD risk, and a moderate, statistically significant difference in CRP across midlife. More research is necessary to understand the mechanistic pathway between excessive GWG and long-term maternal cardiovascular health.

Prepregnancy weight change associated with high gestational weight gain

OBJECTIVE

Gestational weight gain (GWG) above recommendations is a risk factor for adverse maternal, perinatal, and long-term outcomes. This study hypothesized that prepregnancy weight gain may portend excess GWG.

METHODS

Among 1,126 women (51% of whom were of Black race) in the Coronary Artery Risk Development in Young Adults (CARDIA) study with post-baseline births, the prepregnancy annual rate of BMI change per woman was estimated (slope; 5 years before pregnancy) and was related to the risk of GWG above Institute of Medicine recommendations using mixed-effects models (binary) and GWG z score (continuous), adjusting for confounders, and stratified by prepregnancy overweight/obesity status.

RESULTS

A total of 626 women (56%) had excess GWG. Each standard deviation increase in prepregnancy BMI (0.16 kg/m² per year) was associated with an 18% increased risk of excess GWG (95% CI: 1.13-1.23), adjusted for covariates. Stratified results showed an association for women without overweight or obesity (adjusted relative risk = 1.71 [95% CI: 1.38-2.13]) but not among those with overweight or obesity (adjusted relative risk = 0.98 [95% CI: 0.91-1.05]). When evaluated as a z score, prepregnancy weight gain was associated with higher GWG among women with and without overweight or obesity (mean = 0.24 [0.10] and 0.28 [0.12] z score, respectively).

CONCLUSIONS

Weight gain before pregnancy is associated with higher GWG during pregnancy. Assessment of prepregnancy weight changes may identify those at risk for high GWG.