Differential impact of antiretroviral therapy initiated before or during pregnancy on placenta pathology in HIV-positive women

Challenges, risks, and opportunities of antiretroviral drugs in women of reproductive potential

INTRODUCTION

The HIV/AIDS epidemic has been one of the greatest challenges in global health, significantly affecting women of reproductive potential. Considerable advances in antiretroviral therapy for women living with HIV have contributed to improvements in quality of life, better reproductive and birth outcomes, and a reduced risk of perinatal transmission.

AREAS COVERED

Despite the progress made, persistent challenges in access and adherence to antiretroviral drugs may limit their benefits for some women. More pharmacokinetic and safety studies in pregnant and lactating women are urgently needed, as are prospective surveillance systems to evaluate associations between fetal and infant antiretroviral exposures, drug-drug interactions, and pregnancy outcomes.

EXPERT OPINION

Multipurpose technologies, such as combined HIV and other STI or unintended pregnancy prevention, and innovative delivery methods, such as the development of long-acting antiretrovirals, have the potential to reduce adherence challenges and enhance quality of life for women with HIV. Parallel advances in drug safety testing and surveillance are needed to ensure the health and safety of women with or at risk for HIV and children at risk for perinatal transmission.

Maternal and birth outcomes in pregnant people with and without HIV in the Western Cape, South Africa

INTRODUCTION

We evaluated associations of HIV and antiretroviral therapy (ART) with birth and maternal outcomes at a province-wide-level in the Western Cape, South Africa, in a recent cohort before dolutegravir-based first-line ART implementation.

METHODS

This retrospective cohort study included pregnant people delivering in 2018-2019 with data in the Western Cape Provincial Health Data Centre which integrates individual-level data on all public sector patients from multiple electronic platforms using unique identifiers. Adverse birth outcomes (stillbirth, low birth weight (LBW), very LBW (VLBW)) and maternal outcomes (early and late pregnancy-related deaths, early and late hospitalizations) were compared by HIV/ART status and adjusted prevalence ratios (aPRs) calculated using log-binomial regression.

RESULTS

Overall 171,960 pregnant people and their singleton newborns were included, 19% (N = 32 015) identified with HIV. Amongst pregnant people with HIV (PPHIV), 60% (N = 19 157) were on ART preconception, 29% (N = 9276) initiated ART during pregnancy and 11% (N = 3582) had no ART. Adjusted for maternal age, multiparity, hypertensive disorders and residential district, stillbirths were higher only for PPHIV not on ART [aPR 1.31 (95%CI 1.04-1.66)] compared to those without HIV. However, LBW and VLBW were higher among all PPHIV, with aPRs of 1.11-1.22 for LBW and 1.14-1.54 for VLBW. Pregnancy-initiated ART was associated with early pregnancy-related death (aPR 3.21; 95%CI 1.55-6.65), and HIV with or without ART was associated with late pregnancy-related death (aPRs 7.89-9.01).

CONCLUSIONS

Even in the universal ART era, PPHIV experienced higher rates of LBW and VLBW newborns, and higher late pregnancy-related death regardless of ART status than pregnant people without HIV.

The impact of HIV and ART exposure during pregnancy on fetal growth: a prospective study in a South African cohort

BACKGROUND

In utero exposure to human immunodeficiency virus (HIV) and antiretroviral (ART) is associated with adverse birth outcomes, which are often attributed to alterations in placental morphology. This study used structural equation models (SEMs) to examine the impact of HIV and ART exposure on fetal growth outcomes and whether these associations are mediated by placental morphology in urban-dwelling Black South African women.

METHODS

This prospective cohort study included pregnant women living with HIV (WLWH, n = 122) and not living with HIV (WNLWH, n = 250) that underwent repeated ultrasonography during pregnancy, and at delivery, to determine fetal growth parameters in Soweto, South Africa. The size and the velocity of fetal growth measures (i.e., head and abdominal circumference, biparietal diameter, and femur length) were calculated using the Superimposition by Translation and Rotation. Placenta digital photographs taken at delivery were used to estimate morphometric parameters and trimmed placental weight was measured. All WLWH were receiving ART for the prevention of vertical transmission of HIV.

RESULTS

A trend towards a lower placental weight and significantly shorter umbilical cord length was reported in WLWH compared to their counterparts. After sex stratification, umbilical cord length was significantly shorter in males born to WLWH than in male fetuses born to WNLWH (27.3 (21.6-32.8) vs. 31.4 (25.0-37.0) cm, p = 0.015). In contrast, female fetuses born to WLWH had lower placental weight, birth weight (2.9 (2.3-3.1) vs. 3.0 (2.7-3.2) kg), and head circumference (33 (32-34) vs. 34 (33-35) cm) than their counterparts (all p ≤ 0.05). The SEM models showed an inverse association between HIV and head circumference size and velocity in female fetuses. In contrast, HIV and ART exposure was positively associated with femur length growth (both size and velocity) and abdominal circumference velocity in male fetuses. None of these associations appeared to be mediated via placental morphology.

CONCLUSION

Our findings suggest that HIV and ART exposure directly affects head circumference growth in females and abdominal circumference velocity in male fetuses; but may improve femur length growth in male fetuses only.

Adverse pregnancy outcomes associated with antiretroviral therapy initiated before pregnancy and during pregnancy: a retrospective study in Hubei province, China

Background

Antiretroviral therapy (ART) initiation before pregnancy was reported to have an increased risk of adverse pregnancy outcomes (APOs) than ART initiation during pregnancy. However, the risks of APOs associated with different ART regimens initiated before or during pregnancy remain unknown.

Methods

Pregnant women living with HIV (PWLHIV) from Hubei Province, China, were retrospectively enrolled between January 1, 2004, and December 31, 2021. The trends of ART initiation time and application of different ART regimens were evaluated over time, separately. Using no ART exposure before and during pregnancy as control, the risks of APOs associated with protease inhibitor (PI) based regimens and non-nucleoside reverse transcriptase inhibitors (NNRTIs) based regimens initiated before pregnancy were analyzed; and the risks of APOs associated with PI-based regimens, NNRTIs based regimens and zidovudine (AZT) monotherapy initiated during pregnancy were analyzed. APOs, including low birthweight (LBW), stillbirth, preterm birth (PTB) and early miscarriage, were reviewed.

Results

Among 781 PWLHIV including 1,010 pregnancies, 522 pregnancies (51.7%) were exposed to ART before or during pregnancy. Of them, the proportion of ART initiation before pregnancy per year increased from around 20% in the early period to more than 60% after 2019. Efavirenz (EFV)-nucleoside reverse transcriptase inhibitors (NRTIs) (32.2%), LPV/r-NRTIs (31.2%), and nevirapine (NVP)-NRTIs (27.4%) were the most commonly used regimens, and the proportion of LPV/r-NRTIs used per year has increased to around 50.0% in recent years. LPV/r-NRTIs was associated with higher risks of LBW whether initiated before pregnancy [adjusted OR (aOR) = 2.59, 95%CI 1.04-6.45, p = 0.041] or during pregnancy (aOR = 2.19, 95%CI 1.03-4.67, p = 0.041), compared with no exposure to ART before and during pregnancy. However, no matter initiated before or during pregnancy, LPV/r-NRTIs had no significantly increased risks of stillbirth, PTB and early miscarriage, and EFV /NVP-NRTIs and AZT monotherapy had no significantly increased risks of LBW, stillbirth, PTB and early miscarriage when compared with no exposure to ART before and during pregnancy.

Conclusion

Our data suggests that LPV/r-NRTIs has been widely used among PWLHIV in recent years. However, the potential risk of LBW should be continuously monitored among PWLHIV whether LPV/r-NRTIs is initiated before or during pregnancy.

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.

Preterm Birth in Women With HIV: The Role of the Placenta

Maternal HIV infection is associated with an increased risk of preterm birth (PTB). However, the mechanisms underlying this increased risk in women with HIV remain poorly understood. In this regard, it is well-established that labor is an inflammatory process and premature activation of the pro-inflammatory signals (associated with labor) can result in preterm labor which can subsequently lead to PTB. HIV infection is known to cause severe immune dysregulation within its host characterized by altered immune profiles, chronic inflammation and eventually, the progressive failure of the immune system. The human placenta comprises different immune cell subsets, some of which play an important role during pregnancy including participating in the inflammatory processes that accompany labor. It is therefore plausible that HIV/antiretroviral therapy (ART)-associated immune dysregulation within the placental microenvironment may underlie the increased risk of PTB reported in women with HIV. Here, we review evidence from studies that point toward the placental origin of spontaneous PTB and discuss possible ways maternal HIV infection and/or ART could increase this risk. We focus on key cellular players in the maternal decidua including natural killer cells, CD4+ T cells including CD4+ regulatory T cells, CD8+ T cells as well as macrophages.

Adverse pregnancy outcomes among pregnant women living with HIV in Hubei province, China: prevalence and risk factors

Mother-to-child transmission of Human Immunodeficiency Virus (HIV) has been greatly reduced with the advance of intervention technology. However, adverse pregnancy outcomes (APOs) are still common, and little is known about the driving forces of APOs among pregnant women living with HIV in China. Between January 2004 and December 2020, a total of 638 pregnancies among pregnant women living with HIV were enrolled in this study, 84 (13.2%) pregnancies with 87 APOs were reported. Preterm birth (3.8%), ectopic pregnancy (3.4%), spontaneous abortion (2.0%), and embryo arrest (1.7%) were the most common APOs in pregnant women living with HIV. Exposure to antiretroviral drugs (ARVs) during the first trimester (RR =  4.077, 95% CI: 0.521, 1.484, P<0.001) and the first CD4+ T lymphocyte count (CD4 count)≤ 350/μl (RR =  2.227, 95% CI: 0.063, 0.991, P = 0.026) were risk factors of APOs. The age≤ 30 years (RR =  -2.513, 95% CI: -1.067, -0.132, P = 0.012) was associated with the decreasing of APOs. Encouraging people to initiate combination antiretroviral therapy and reach a high CD4 count level before pregnancy would be helpful to prevent APOs. Pregnant women exposed to ARVs in the first trimester needed more attention for APOs.

Protease inhibitor-based antiretroviral therapy in pregnancy: effects on hormones, placenta, and decidua

The use of antiretroviral therapy (ART) in pregnancy is important for maternal health, and has been successful in reducing vertical transmission rates to almost zero in those taking effective ART regimens with good adherence. However, there are reports of higher rates of low birthweight and preterm births in women with HIV, which can be further exacerbated by ART usage in pregnancy. Protease inhibitors, and ritonavir-boosted lopinavir in particular, might directly contribute to placental and uteroplacental pathology in part by altering plasma concentrations of the essential steroid hormones of pregnancy, progesterone and oestradiol. In this Review, we collate the increasing evidence of dysregulated maternal endocrinology, reproductive physiology, and placental compromise associated with protease inhibitors. Based on findings of placental and decidual effects, we recommend that ritonavir-boosted lopinavir should be avoided in pregnancy, in line with US and European guidelines. Long-term follow-up of children exposed to protease inhibitors in utero is also recommended.

Pharmacokinetics and placental transfer of dolutegravir in pregnancy

Dolutegravir is currently recommended by the WHO as the preferred first-line treatment for all people with HIV, including pregnant women. Estimates indicate that, by 2024, nearly 22 million adults in low- and middle-income countries will have transitioned to dolutegravir-based ART. It is therefore critical that there is a clear appreciation and understanding of the risks that may be associated with in utero exposure to dolutegravir. In this review we consolidate data from studies on dolutegravir and the placenta. The studies have largely focused on the pharmacokinetics and placental transfer of dolutegravir in pregnancy. These include studies on transplacental transfer of dolutegravir, ex vivo placenta perfusion models, physiologically based pharmacokinetic (PBPK) models and animal studies. The data available clearly demonstrate that placental transfer of dolutegravir occurs in moderate to high concentrations. Intracellular placental dolutegravir has been demonstrated in the placental villous tissue. There are limited data suggesting that pregnancy is associated with decreased maternal dolutegravir levels. In addition, PBPK models have great potential in predicting the passage of drugs through the placenta and further contributing towards the elucidation of fetal exposure. The animal studies available demonstrate that in utero dolutegravir exposure can be associated with neural tube defects. Taking into consideration that antiretroviral exposure may be associated with poor placental development or function and increased risk of adverse effects to the fetus, it is crucially important that these risks are evaluated, especially with the rapid scale up of dolutegravir-based ART into national treatment programmes.

T cell Homeostatic Imbalance in Placentae from Women with HIV in the absence of Vertical Transmission

BACKGROUND

Implementation of universal antiretroviral therapy (ART) has significantly lowered vertical transmission rates but has also increased numbers of HIV-exposed uninfected children (HEU), who remain vulnerable to morbidities. Here, we investigated whether T cell alterations in the placenta contribute to altered immune status in HEU.

METHODS

We analyzed T cells from term placentae decidua and villous tissue and paired cord blood from pregnant women with HIV (PWH) who initiated ART late in pregnancy (n=21) with pregnant women not living with HIV (PWNH) (n=9).

RESULTS

Placentae from PWH showed inverted CD4:CD8 ratios and higher proportions of tissue resident CD8+ T cells in villous tissue relative to control placentae. CD8+ T cells in the fetal capillaries, which were of fetal origin, positively correlated with maternal plasma viraemia prior to ART initiation, implying that imbalanced T cells persisted throughout pregnancy. Additionally, the expanded memory differentiation of CD8+ T cells was confined to the fetal placental compartment and cord blood but was not observed in the maternal decidua.

CONCLUSIONS

T cell homeostatic imbalance in the blood circulation of PWH is reflected in the placenta. The placenta may be a causal link between HIV-induced maternal immune changes during gestation and altered immunity in newborn infants in the absence of vertical transmission.