Postpartum obesity and weight gain among human immunodeficiency virus-infected and human immunodeficiency virus-uninfected women in South Africa

Measurement of body composition in postpartum South African women living with and without HIV infection

Background

While several methodologies are available to measure adiposity, few have been validated in sub-Saharan African (SSA) and none in postpartum African women living with HIV (WLHIV). We compared bioelectrical impendence analysis (BIA) and air displacement plethysmography (ADP) against dual x-ray absorptiometry (DXA) in South African women and examined differences by HIV and body mass index (BMI) status.

Methods

Lin's concordance correlation coefficient (CCC) test was used to examine fat mass (FM), fat free mass (FFM), and total body fat percent (%BF) difference between BIA vs. DXA, and ADP vs. DXA in women living with HIV (n = 57) and without HIV (n = 25). The Bland Altman test was used to assess mean differences and the direction of bias.

Results

The median age was 31 years (IQR, 26-35) and months postpartum were 11 (IQR, 7-16), 44% of the women had obesity. Lin's CCC for BIA and ADP vs. DXA were both 0.80 for %BF and 0.97 for FM, and 0.86 and 0.80 for FFM, respectively. Mean differences (DXA-BIA and ADP estimates) were 0.22 ± 4.54% (p = 0.54) and 3.35 ± 3.27% (p < 0.01) for %BF, -0.82 ± 3.56 kg (p = 0.06) and 1.43 ± 2.68 kg (p = 0.01) for FM, -1.38 ± 3.61 kg (p = 0.01) and - 3.34 ± 2.37 kg (p < 0.01) for FFM, respectively. BIA overestimated %BF in WLHIV and underestimated it in women with obesity.

Conclusion

Body composition measurements using BIA and ADP correlated well with DXA, thereby providing alternative, safe tools for measuring postpartum FM and FFM in SSA women, including WLHIV.

Hypertensive disorders of pregnancy and HIV: analysis of a province-wide cohort during 2018 and 2019

OBJECTIVE

We evaluated the prevalence of de novo hypertensive disorders of pregnancy (dnHDP) in pregnant people with HIV (PPHIV) in the Western Cape Province, South Africa in 2018-2019 by HIV and antiretroviral therapy (ART) status.

METHODS

All people with a pregnancy outcome from 1 January 2018 to 31 December 2019 in the Western Cape Provincial Health Data Centre (WCPHDC) were included. The WCPHDC integrates data from multiple electronic platforms according to unique identifiers. dnHDP was classified by ICD-10 code or first-time prescription of antihypertensive drugs less than 140 days before delivery. Pregnant people with preexisting hypertension without superimposed preeclampsia/eclampsia were not considered to have dnHDP. Adjusted prevalence ratios (aPR) for dnHDP by HIV/ART status were calculated using Poisson regression with robust variance.

RESULTS

Among 180 553 pregnant people studied, 13 677 (7.6%) had dnHDP and 33 978 (18.8%) were PPHIV. Among PPHIV, 11.3% ( N  = 3827) had no evidence of ART, 59.7% ( N  = 20 283) initiated ART preconception and 29.0% ( N  = 9868) had ART initiated during pregnancy. Compared to those without HIV (7.7%), dnHDP prevalence was lower in PPHIV with preconception [6.9%; aPR 0.78; 95% confidence interval (CI) 0.74-0.83] or pregnancy-initiated ART (7.0%; aPR 0.83; 95% CI 0.75-0.92) and higher in PPHIV without ART (9.8%; aPR 1.17; 95% CI 1.06-1.29) adjusted for maternal age, multiparity, multigestation pregnancy and preexisting hypertension. ART duration by delivery of at least 100 weeks versus pregnancy-initiated ART of 20-<40 weeks was protective (aPR 0.88; 95% CI 0.78-0.98).

CONCLUSIONS

In the context of universal ART, these findings are reassuring for most PPHIV. ART was not associated with increased dnHDP prevalence and longer ART duration was protective.

Relationship between pre-pregnancy maternal body mass index and infant weight trajectories in HIV-exposed and HIV-unexposed infants

BACKGROUND

Maternal HIV and antiretroviral therapy (ART) exposure in utero may influence infant weight, but the contribution of maternal y body mass index (BMI) to early life overweight and obesity is not clear.

OBJECTIVE

To estimate associations between maternal BMI at entry to antenatal care (ANC) and infant weight through approximately 1 year of age and to evaluate whether associations were modified by maternal HIV status, maternal HIV and viral load, breastfeeding intensity through 6 months or timing of entry into ANC.

METHODS

We followed HIV-uninfected and -infected pregnant women initiating efavirenz-based ART from first antenatal visit through 12 months postpartum. Infant weight was assessed via World Health Organization BMI and weight-for-length z-scores (WLZ) at 6 weeks, 3, 6, 9 and 12 months. We used multivariable linear mixed-effects models to estimate associations between maternal BMI and infant z-scores over time.

RESULTS

In 861 HIV-uninfected infants (454 HIV-exposed; 407 HIV-unexposed), nearly 20% of infants were overweight or obese by 12 months of age, regardless of HIV exposure status. In multivariable analyses, increasing maternal BMI category was positively associated with higher infant BMIZ and WLZ scores between 6 weeks and 12 months of age and did not differ by HIV exposure status. However, HIV-exposed infants had slightly lower BMIZ and WLZ trajectories through 12 months of age, compared with HIV-unexposed infants across all maternal BMI categories. Differences in BMIZ and WLZ scores by HIV exposure were not explained by timing of entry into ANC or maternal viral load pre-ART initiation, but z-scores were slightly higher for HIV-exposed infants who were predominantly or exclusively versus partially breastfed.

CONCLUSIONS

These findings suggest maternal BMI influences early infant weight gain, regardless of infant HIV exposure status. Intervention to reduce maternal BMI may help to address growing concerns about obesity among HIV-uninfected children.

High blood pressure at entry into antenatal care and birth outcomes among a cohort of HIV-uninfected women and women living with HIV initiating antiretroviral therapy in South Africa

OBJECTIVE

To examine associations between high blood pressure (BP) when entering antenatal care (ANC) and birth outcomes in a cohort of pregnant HIV- and women living with HIV (WLHIV) initiating antiretroviral treatment (ART).

STUDY DESIGN

Prospective cohort study.

MAIN OUTCOME MEASURES

Cesarean delivery, preterm birth (<37 weeks' gestation), low birthweight (LBW, <2500 g), small-for-gestational age (SGA, <10th percentile), and large-for-gestational age (LGA, >10th percentile for GA).

RESULTS

Of 1116 women (median GA 20 weeks; WLHIV 53%), 48% (53% WLHIV; 43% HIV-) entered ANC with high BP, defined as elevated (120-129 or < 80 mmHg), stage 1 (>130-139 or 80-89) or stage 2 hypertension (≥140 / or ≥ 90). WLHIV were more likely to have high BP (RR 1.32; 95%CI 1.12-1.57), controlling for pre-pregnancy body mass index and additional confounders. In multivariable analysis, there was no evidence that high BP increased the risk of cesarean delivery (RR 1.10, 95% CI 0.92-1.30), preterm birth (RR 1.15, 95% CI 0.81-1.62), LBW (RR 1.16, 95% CI 0.84-1.60) or SGA (RR 1.02, 0.72-1.44), overall or when stratified by HIV-status. High BP was associated with an increased risk of LGA (RR 1.43; 95% CI 1.00-2.03).

CONCLUSION

In this setting, half of women had high BP at entry into ANC, with WLHIV at increased risk of high BP. There was no strong evidence that high BP increased the risk of adverse birth outcomes overall, or by HIV-status, with the exception of LGA. WLHIV may be at high risk of high BP during pregnancy and should be monitored closely.

Postpartum obesity and weight gain among human immunodeficiency virus-infected and human immunodeficiency virus-uninfected women in South Africa

In South Africa, up to 40% of pregnant women are living with human immunodeficiency virus (HIV), and 30-45% are obese. However, little is known about the dual burden of HIV and obesity in the postpartum period. In a cohort of HIV-uninfected and HIV-infected pregnant women initiating antiretroviral therapy in Cape Town, South Africa, we examined maternal anthropometry (weight and body mass index [BMI]) from 6 weeks through 12 months postpartum. Using multinomial logistic regression, we estimated associations between baseline sociodemographic, clinical, behavioural, and HIV factors and being overweight-obese I (BMI 25 to <35), or obese II-III (BMI >35), compared with being underweight or normal weight (BMI <25), at 12 months postpartum. Among 877 women, we estimated that 43% of HIV-infected women and 51% of HIV-uninfected women were obese I-III at enrollment into antenatal care, and 51% of women were obese I-III by 12 months postpartum. On average, both HIV-infected and HIV-uninfected women gained, rather than lost, weight between 6 weeks and 12 months postpartum, but HIV-uninfected women gained more weight (3.3 kg vs. 1.7 kg). Women who were obese I-III pre-pregnancy were more likely to gain weight postpartum. In multivariable analyses, HIV-infection status, being married/cohabitating, higher gravidity, and high blood pressure were independently associated with being obese II-III at 12 months postpartum. Obesity during pregnancy is a growing public health concern in low- and middle-income countries, including South Africa. Additional research to understand how obesity and HIV infection affect maternal and child health outcomes is urgently needed.