Cohort profile: Prematurity Immunology in Mothers living with HIV and their infants Study (PIMS)

An observational cohort study to investigate the impact of dolutegravir in pregnancy and its obesogenic effects on the metabolic health of women living with HIV and their children: Study protocol

INTRODUCTION

Dolutegravir (DTG)-based antiretroviral therapy is the World Health Organization's preferred first-line regimen for all persons with HIV, including pregnant women. While DTG has been implicated as an obesogen associated with greater weight gain compared to other antiretrovirals, there is a paucity of data in pregnant women and their children. The Obesogenic oRigins of maternal and Child metabolic health Involving Dolutegravir (ORCHID) study is investigating associations between DTG, weight gain, and metabolic outcomes in the context of HIV.

MATERIALS & METHODS

ORCHID is a prospective observational study taking place in Cape Town, South Africa (NCT04991402). A total of 1920 pregnant women with and without HIV infection are being followed from ≤18 weeks gestational age to 24 months postpartum with their children. Participants attend eleven study visits: 3 antenatal, delivery, and 7 postnatal visits. Several embedded sub-studies address specific scientific aims. Primary outcome measurements in mothers include anthropometry, blood pressure, body composition, dysglycemia, insulin resistance (IR), and dyslipidemia. Other maternal measures include demographics, resting energy expenditure, viral load, physical activity, dietary intake, hepatic steatosis, and repository specimens. Sub-study measurements include markers of adipose inflammation, gut integrity, and satiety/hunger, subcutaneous adipose tissue morphology and mitochondrial function, and metabolomics. Primary outcome measurements in children include anthropometry, adipose tissue mass, dysglycemia, IR, and dyslipidemia. Other variables include fetal growth, birth outcomes, medical/breastfeeding history, caloric intake, neurodevelopment, and repository specimens. Sub-study measurements include metabolites/lipid subspecies in umbilical cord blood, as well as breast milk composition and DTG exposure.

DISCUSSION

ORCHID will play a pivotal role in defining obesogenic mechanisms and clinical consequences of DTG use in pregnancy in women with HIV and their children. It will provide insights into metabolic disease risk reduction in the context of HIV/DTG, identify intervention targets, and inform public health approaches to diminish chronic metabolic co-morbidities for women and children.

Pregnancy outcomes in women living with HIV and HIV-negative women in South Africa: Cohort analysis based on bias-corrected gestational age

BACKGROUND

Antiretroviral therapy (ART) use during pregnancy may be associated with adverse outcomes, but findings have been inconsistent, at least in part due to unreliably estimated gestational age.

OBJECTIVE

To quantify the association between HIV status, ART initiation timing and adverse birth outcomes, with reliably assessed gestational age at booking, in a public sector primary care facility in Cape Town, South Africa.

METHODS

Pregnant women, HIV-negative or living with HIV (WLHIV), were enrolled at first antenatal care visit and followed through delivery. Ultrasound-assessed gestational age was deemed the gold standard. Based on quantitative bias analysis for outcome misclassification, gestational age by non-ultrasound assessment was corrected using multiple overimputation, which deals with missing data and measurement error simultaneously. Using bias-corrected gestational age, birth outcomes were compared between WLHIV and HIV-negative women, and among WLHIV who initiated ART before versus during pregnancy, further divided into trimesters.

RESULTS

Of 3952 women enrolled, 37% were WLHIV (mostly using tenofovir + emtricitabine + efavirenz). Last menstrual period (LMP)-based gestational age was identified to be biased, and LMP measures were thus corrected using multiple overimputation. Comparing WLHIV and HIV-negative women, adjusted risk ratio (aRR) of overall pregnancy loss was 1.26 (95% confidence interval [CI] 0.98, 1.61); aRR of preterm delivery was 1.02 (95% CI 0.88, 1.20); aRR of small for gestational age infants was 1.43 (95% CI 1.14, 1.80). Among WLHIV, outcomes were similar by ART initiation timing.

CONCLUSIONS

In this routine care cohort, risk of SGA, and possibly of pregnancy loss, was increased in WLHIV compared with HIV-negative women, with no evidence of increased risk of preterm delivery. Further research is needed to improve mechanistic understanding of the contribution of ART to adverse birth outcomes to optimize treatment for pregnant WLHIV and ensure optimal maternal and infant outcomes.

Methodological Considerations for Preterm Birth Research

Complications from preterm birth are a leading cause of infant mortality, with long-term implications for morbidity and quality of life of preterm infants. There are many important risk factors for preterm births however in this article, we focus on the maternal infection etiological pathway, given its significance in low-to-middle income countries. In high preterm birth settings such as sub-Saharan Africa, maternal HIV infection and antiretroviral therapy (ART) use have been associated with an increased risk of preterm births. Consequently, we highlight methodological considerations related to selection and measurement bias in preterm birth research. We further illustrate the potential impact of these biases in studies investigating the relationship between HIV/ART and preterm births. We also briefly discuss issues related to population-level estimations based on routinely collected clinical or civil registration data. We conclude by emphasizing the importance of strengthening of antenatal care services to improve quality of population data as well as optimizing current and future study designs, by taking into account the important methodological considerations described in this article.