Cohort profile: the Hlabisa pregnancy cohort, KwaZulu-Natal, South Africa

Maternal exposure to heat and its association with miscarriage in rural KwaZulu-Natal, South Africa: A population-based cohort study

BACKGROUND

We sought to improve the current understanding of how climate change impacts women's reproductive health in sub-Saharan Africa.

OBJECTIVES

We investigated the relationship between maternal heat exposure and miscarriage (pregnancy ending before 20 weeks gestation) in a South African setting.

DESIGN

Population-based cohort study.

METHODS

Our study involved data for pregnancies collected via a health and demographic surveillance system in rural KwaZulu-Natal, South Africa between 2012 and 2016. Data from the South African Weather Service were used to compute maternal exposure to heat during the following time windows for each pregnancy: during the month preceding conception (T1) and during the week preceding the study outcome (either a miscarriage or no miscarriage, T2). Heat exposure was operationalized as a continuous variable and defined as the number of days that a mother was exposed to a mean daily temperature of > 26.6°C (A "hot day," equivalent to a mean daily temperature of > 80°F) during T1 or T2. Binary logistic regression was used to investigate the relationship between maternal heat exposure and miscarriage.

RESULTS

A total of 105/3477 pregnancies included in our analysis ended in miscarriage (3.0%). Each additional hot day during T1 was associated with a 26% higher odds of miscarriage (odds ratio: 1.26; 95% confidence interval: 1.15-1.38). No significant associations were observed between maternal heat exposure during T2 and the odds of miscarriage (odds ratio: 0.94, 95% confidence interval: 0.73-1.20). The relationship between maternal heat exposure during T1 and the odds of miscarriage was J-shaped.

CONCLUSION

There is a clear relationship between maternal heat exposure during the month preceding conception and miscarriage in our sub-Saharan African setting. Given the lack of feasible strategies to reduce pregnancy loss associated with prevailing high temperatures in sub-Saharan Africa, progressive climate change will likely exacerbate existing challenges for women's reproductive health in this region.

Staying, leaving and returning: Trends of prevention of mother-to-child transmission retention among newly diagnosed HIV-positive pregnant and postpartum women

Uptake of services and retention throughout the Prevention of Mother-to-Child Transmission continuum are necessary to achieve the goal of reducing Mother-to-Child Transmission of Human Immunodeficiency Virus (HIV). Adopting a retrospective cohort design, we tracked the uptake of services in a district hospital in Ghana from antenatal booking through to six weeks postnatal when early infant diagnosis was conducted. Of the 1252 pregnant women booked antenatally, 94.1% (n = 1178) received pre-test counselling, 96.3% (1134) opted for HIV testing and 3.8% (n = 43) women tested positive for HIV throughout the continuum. The retention rate at six weeks postpartum was 67.4%. Missed opportunities occurred throughout the programme and the highest disengagement, 58.9% (23/39) occurred antenatally. Instances of re-engagement were also recorded. Establishing measures to promote retention throughout the programme is critical to ensuring HIV-infected mothers maintain their health and their exposed newborns are HIV-free. This phase of the study provided a comprehensive view of retention in the absence of any baseline.

HIV viral load and pregnancy loss: results from a population-based cohort study in rural KwaZulu-Natal, South Africa

OBJECTIVE

With ever-expanding antiretroviral therapy (ART) access among pregnant women in sub-Saharan Africa, it is more than ever important to address the gap in knowledge around ART effectiveness, as measured by HIV viral load, and pregnancy loss.

DESIGN

A population-based cohort study.

METHODS

The study sample consisted of 3431 pregnancies from 2835 women living with HIV aged 16-35 years old. All women participated in a population-based cohort conducted between 2004 and 2018 in rural KwaZulu-Natal, South Africa. Viral load data were collected at prior surveys and an HIV care registry. The closest available viral load to the date that each pregnancy ended was used and classified as either a pre- or postconception viral load. Logistic regression was used to investigate the association between high viral load (log10 viral load >4.0 copies/ml) and pregnancy loss, defined as either a miscarriage or stillbirth.

RESULTS

Pregnancy loss occurred at a rate of 1.3 (95% confidence interval: 1.0-1.8) per 100 pregnancies. There were 1451 pregnancies (42.3%) with postconception viral load measurements. The median time between the viral load measurement and the pregnancy end date was 11.7 (interquartile range: 5.0-25.4) months. We found a higher likelihood of pregnancy loss in women who had high viral loads prior to the outcome of their pregnancy (adjusted odds ratio: 2.38, 95% confidence interval: 1.10-5.18).

CONCLUSION

Given the significant relationship between high viral load and pregnancy loss, our study lends further credence to ensuring effective ART through enrolment and retention of pregnant women living with HIV in ART programs, treatment adherence interventions, and viral load monitoring during pregnancy.

Trends in the prevalence and incidence of orphanhood in children and adolescents <20 years in rural KwaZulu-Natal South Africa, 2000-2014

BACKGROUND

In South Africa, large increases in early adult mortality during the 1990s and early 2000s have reversed since public HIV treatment rollout in 2004. In a rural population in KwaZulu-Natal, we investigate trends in parental mortality and orphanhood from 2000-2014.

METHODS

Using longitudinal demographic surveillance data for a population of approximately 90,000, we calculated annual incidence and prevalence of maternal, paternal and double orphanhood in children and adolescents (<20 years) and, overall and cause-specific mortality of parents by age.

RESULTS

The proportion of children and adolescents (<20 years) for whom one or both parents had died rose from 26% in 2000 to peak at 36% in 2010, followed by a decline to 32% in 2014. The burden of orphanhood remains high especially in the oldest age group: in 2014, 53% of adolescents 15-19 years had experienced the death of one or both parents. In all age groups and years, paternal orphan prevalence was three-five times higher than maternal orphan prevalence. Maternal and paternal orphan incidence peaked in 2005 at 17 and 27 per 1,000 person years respectively (<20 years) before declining by half through 2014. The leading cause of parental death throughout the period, HIV/AIDS and TB cause-specific mortality rates declined substantially in mothers and fathers from 2007 and 2009 respectively.

CONCLUSIONS

The survival of parents with children and adolescents <20 years has improved in tandem with earlier initiation and higher coverage of HIV treatment. However, comparatively high levels of parental deaths persist in this rural population in KwaZulu-Natal, particularly among fathers. Community-level surveillance to estimate levels of orphanhood remains important for monitoring and evaluation of targeted state welfare support for orphans and their guardians.

Awareness of HIV-positive status and linkage to treatment prior to pregnancy in the "test and treat" era: A national antenatal sentinel survey, 2017, South Africa

Introduction

Knowledge of HIV status in South Africa (SA) is reported to be 90% among people living with HIV. National level estimates could mask population-specific levels, which are critical to monitor program coverage and potential impact. Using data from the 2017 national antenatal sentinel survey, we assessed knowledge of HIV-positive status, initiation of antiretroviral therapy (ART), and socio-demographic characteristics associated with knowledge of HIV-positive status prior to the current pregnancy among women attending antenatal care.

Methods

Between 1 October and 15 November 2017, a nationally representative sample of 32,716 pregnant women were enrolled from 1,595 public health facilities selected from all districts of SA. Data on age, gravidity, knowledge of HIV-positive status and ART initiation prior to pregnancy were extracted from medical records. A blood sample was collected from each woman regardless of prior knowledge of HIV status or ART history, and tested for HIV in the laboratory. All HIV-positive pregnant women enrolled in the survey were eligible for inclusion in the analysis. Multivariable survey logistic regression was used to examine factors associated with knowledge of HIV-positive status prior to the current pregnancy.

Results

Of 10,065 eligible HIV-positive women, 60.8% (95% confidence interval (CI):59.9%–61.7%) knew their HIV status prior to the current pregnancy, of whom 91.1% (95% CI: 90.4%–91.7%) initiated ART prior to the current pregnancy. Knowledge of HIV-positive status was lower among adolescent girls and young women (15–24 years) (38.9%) and primigravid women (40.5%) compared with older women (35–49 years) (75.5%) and multigravid women (64.7%). In a multivariable analysis, significant effect modification was found between gravidity and age (P value = 0.047). Being in the age group 15–24 years compared to the age group 35–49 years decreased the odds of knowing HIV-positive status by 80% (adjusted odds ratio (AOR): 0.2, 95% CI:0.1–0.4) among primigravid women and by 60%(AOR: 0.4, 95% CI:0.3–0.4) among multigravid women.

Conclusion

Knowledge of HIV-positive status prior to the current pregnancy fell short of the target of 90% among pregnant women living with HIV. This was especially low among adolescent girls and young women, highlighting the gap in youth friendly reproductive health and HIV testing services.

Persistently high incidence of HIV and poor service uptake in adolescent girls and young women in rural KwaZulu-Natal, South Africa prior to DREAMS

BACKGROUND

Adolescent girls and young women (AGYW) bear the brunt of the HIV epidemic in South Africa. 'DREAMS' aims to reduce HIV incidence through multi-level combination prevention. We describe HIV incidence and uptake of HIV and sexual reproductive health (SRH) by AGYW in KwaZulu-Natal (KZN), prior to DREAMS.

METHODS

Longitudinal and cross-sectional analysis of women (15-24 year old) in a population-based HIV incidence cohort within a demographic surveillance site in KZN. Observation time for HIV incidence was person-years at risk while resident. "Current use of contraceptives" and "having an HIV test in the past 12 months" was compared between 2011 and 2015.

RESULTS

In 2015, HIV prevalence was 11.0% and 34.1% and HIV incidence (2011-2015) was 4.54% (95%CI:3.89-5.30) and 7.45% (95%CI:6.51-8.51) per year in 15-19 and 20-24 year olds respectively, with no significant decline compared to 2006-2010. In 2015, 90.7% of 20-24-year-olds were unemployed, 36.4% and 51.7% of 15-19 and 20-24 year olds reported recent migration; 20.9% and 72.6% of 15-19 and 20-24 year olds had ever been pregnant. In 2015, less than 50% reported condom-use at last sex, 15.0% of 15-19 year olds and 48.9% of 20-24 year olds were currently using contraception and 32.0% and 66.7% of 15-19 and 20-24 year olds had tested for HIV in the past 12 months. There had been no improvement compared to 2011. Factors associated with AGYW testing for HIV in the past 12 months were, survey year-2011 more likely than 2015 (aOR = 0.50), number of partners (aOR = 3.25), ever been pregnant (aOR = 2.47) and knowing where to find ART (aOR = 1.54). Factors associated with contraception use were being older (aOR = 4.83); ever been pregnant (aOR = 12.62); knowing where to get ART (aOR = 1.79) and having had an HIV test in past 12 months (aOR = 1.74).

CONCLUSION

Prior to DREAMS, HIV incidence in AGYW was high. HIV and SRH service uptake did not improve and was suboptimal. Findings highlight the need for combination HIV prevention programmes for AGYW in this economically vulnerable area.

Preterm delivery and small-for-gestation outcomes in HIV-infected pregnant women on antiretroviral therapy in rural South Africa: Results from a cohort study, 2010-2015

Objectives

Increasingly more women conceive on antiretroviral therapy (ART) with non-nucleoside reverse transcriptase-based regimens. This study assessed the effect of preconception tenofovir disoproxil fumarate (TDF)-lamivudine (3TC)/emtricitabine (FTC)-efavirenz (EFV) and post-conception TDF-(3TC/FTC)-EFV (versus other regimens) on preterm delivery (PTD) and small-for-gestational age (SGA) births.

Methods

We analysed data of 2549 HIV-infected women attending antenatal clinics in KwaZulu-Natal from 2010 through 2015 in this retrospective cohort study. Preconception, TDF-(3TC/FTC)-EFV was compared to nevirapine (NVP)-based regimens and other 3-drug EFV-based regimens. Post-conception, TDF-(3TC/FTC)-EFV was compared to NVP-based ART and zidovudine (ZDV) prophylaxis. Outcomes included PTD <37 weeks and SGA births. Generalized linear mixed effects were used to fit logistic regression models to account for repeat pregnancies.

Results

Among 2549 singleton live births, 10.4% (n = 264) were PTD and 10.4% (n = 265) SGA. PTD declined from 16.3% in 2010 to 9.3% in 2015 and SGA remained stable from 9.9% in 2010 to 10% in 2015.

Preconception NVP-based regimens [adjusted odds ratio (aOR) 0.66; 95% CI 0.27–1.63] and other 3-drug EFV-based regimens (aOR 0.72; 95% CI 0.24–2.12) were not associated with PTD versus TDF-(3TC/FTC)-EFV. NVP-based (aOR 0.75; 95% CI 0.40–1.42) and other 3-drug EFV-based regimens (aOR 1.55; 95% CI 0.76–3.16) were not associated with SGA births versus TDF-(3TC/FTC)-EFV.

Post-conception NVP-based ART (1.77; 95% CI 0.89–3.51) and ZDV (1.03; 95% CI 0.68–1.58) were not associated with PTD versus TDF-(3TC/FTC)-EFV. NVP-based ART (1.55; 95% CI 0.66–3.61) and ZDV (0.89; 95% CI 0.53–1.47) were not associated with SGA versus TDF-(3TC/FTC)-EFV.

Conclusions

Preconception TDF-(3TC/FTC)-EFV and post-conception TDF-(3TC/FTC)-EFV were not associated with PTD or SGA, compared with other regimens. Increasing ART use merits further study of the optimum ART regimen for safe birth outcomes.

Viraemia before, during and after pregnancy in HIV-infected women on antiretroviral therapy in rural KwaZulu-Natal, South Africa, 2010-2015

OBJECTIVES

Pregnancy and post-partum viral load suppression is critical to prevent mother-to-child HIV transmission and ensure maternal health. We measured viraemia risk before, during and after pregnancy in HIV-infected women.

METHODS

Between 2010 and 2015, 1425 HIV-infected pregnant women on lifelong antiretroviral therapy (ART) for at least six months pre-pregnancy were enrolled in a cohort study in rural KwaZulu-Natal, South Africa. Odds ratios were estimated in multilevel logistic regression, with pregnancy period time-varying.

RESULTS

Over half of 1425 women received tenofovir-based regimens (n = 791). Median pre-pregnancy ART duration was 2.1 years. Of 988 women (69.3%) with pre-pregnancy viral loads, 82.0%, 6.8% and 11.2% had VL <50, 50-999 and ≥1000 copies/ml, respectively. During pregnancy and at six, 12 and 24 months, viral load was ≥1000 copies/ml in 15.2%, 15.7%, 17.8% and 16.6% respectively; viral load <50 was 76.9%, 77%, 75.5% and 75.8%, respectively. Adjusting for age, clinical and pregnancy factors, viraemia risk (viral load ≥50 copies/ml) was not significantly associated with pregnancy [adjusted OR (aOR) 1.31; 95% CI 0.90-1.92], six months (aOR 1.30; 95% CI 0.83-2.04), 12 months (aOR 0.96; 95% CI 0.58-1.58) and 24 months (aOR 1.40; 95% CI 0.89-2.22) post-partum. Adjusting for ART duration-pregnancy period interaction, viraemia risk was 1.8 during pregnancy and twofold higher post-partum.

CONCLUSIONS

While undetectable viral load before pregnancy through post-partum was common, the UNAIDS goal to suppress viraemia in 90% of women was not met. Women on preconception ART remain vulnerable to viraemia; additional support is required to prevent mother-to-child HIV transmission and maintain maternal health.