HIV antiretroviral exposure in pregnancy induces detrimental placenta vascular changes that are rescued by progesterone supplementation

Effects of individual drug and combination antiretroviral therapy on trophoblast proliferation

BACKGROUND

Combination antiretroviral therapy (cART) has been reported to reduce perinatal transmission of human immunodeficiency virus (HIV) and improve maternal survival outcomes. Recent studies have associated in-utero exposure to cART drugs with adverse outcomes such as pre-eclampsia, preterm delivery, low birth weight and small-for-gestational-age births. However, the exact molecular mechanisms underlying cART-induced adverse pregnancy outcomes remain poorly defined.

OBJECTIVES

To investigate the effects of cART drugs on trophoblast proliferation in the HTR-8/SVneo cell line.

STUDY DESIGN

HTR-8/SVneo cells were exposed to tenofovir (0.983-9.83 µM), emtricitabine (0.809-8.09 µM) and efavirenz (0.19-1.09 µM), the individual drugs of the first-line single tablet cART regimen termed 'Atripla', and zidovudine (1.12-1.12 µM), lamivudine (0.65-6.5 µM), lopinavir (0.32-3.2 µM) and ritonavir (0.69-6.9 µM), the individual drugs of the second-line single tablet cART regimen termed 'Aluvia'. The cells were treated for 24, 48, 72 and 96 h, and trophoblast proliferation was assessed using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltretrazolium bromide assay.

RESULTS

Two-way analysis of variance showed a significant dose-dependent decrease (p < 0.05) in trophoblast proliferation in response to individual and combined drug components of first- and second-line antiretroviral therapy.

CONCLUSIONS

First- and second-line cART drugs inhibit trophoblast proliferation, and may contribute to placenta-mediated adverse pregnancy outcomes in patients with HIV.

Placental progesterone and its receptor in HIV-infected pre-eclamptic women

Given the high prevalence of HIV infection and pre-eclampsia (PE) in South Africa, this study evaluated and compared the placental immunostaining of progesterone (P) and progesterone receptors (PR) in the synergy of HIV-infected PE compared to normotensive pregnant women using immunohistochemistry interfaced with morphometric image analysis. Progesterone immunostaining was expressed widely across exchange and conducting villi within mesenchymal, endothelial, and trophoblast cells. In contrast, PR was expressed within syncytiotrophoblasts and was absent within endothelial cells. In exchange villi, P and PR immuno-expression was significantly lower in PE compared to the normotensive group (p = < 0.0001 and p = < 0.0001, respectively) and within the early-onset pre-eclampsia (EOPE) compared to the late-onset pre-eclampsia (LOPE) group (p = < 0.0001 and p = < 0.0001, respectively). Progesterone immuno-expression was significantly lower in the HIV+ compared to the HIV- group (p = < 0.0001), whilst PR was non-significant. In conducting villi, P and PR immuno-expression was significantly lower in the EOPE compared to the LOPE group (p = < 0.0001 and p = < 0.0001, respectively) and in the HIV+ compared to the HIV- group (p = < 0.0001 and p = 0.0009, respectively). Progesterone immuno-expression was slightly higher in the PE compared to normotensive group, and PR immuno-expression was non-significant. There was a significant difference between P and PR within exchange versus conducting villi regardless of pregnancy type, with villi type accounting for 34.47% and 15.28% of total variance for P and PR, respectively. Placental P and PR immuno-expression is downregulated in the duality of PE and HIV+ infection. The use of combined antiretroviral therapy (cART) may result in defective P synthesis, which causes insufficient binding to its receptors. Consequently, PI3K/AKT, JAK-STAT, and MAPK signalling pathways are affected, impairing trophoblast invasion and leading to pre-eclampsia development. Notably, the decrease in P and PR immuno-expression in EOPE validates their effect on placentation.

Placenta analysis of Hofbauer cell profile according to the class of antiretroviral therapy used during pregnancy in people living with HIV

INTRODUCTION

The use of antiretroviral therapy drastically reduces vertical transmission of Human Immunodeficiency Virus. However, recent studies demonstrate associations between ART use during pregnancy and placental inflammation, particularly within protease inhibitor (PI)-based regimens. We sought to characterize placental macrophages, namely Hofbauer cells, according to the class of ART used during pregnancy.

METHODS

Using immunofluorescence and immunohistochemistry, placentas from 79 pregnant people living with HIV (PPLWH) and 29 HIV-uninfected people were analyzed to quantify the numbers and frequencies of leukocytes (CD45⁺) and Hofbauer cells (CD68⁺ and/or CD163⁺). PPLWH were stratified into three groups based on class of ART: non-nucleoside reverse transcriptase inhibitor (NNRTI)-based, integrase strand-transfer inhibitor (INSTI)-based, and PI-based regimens.

RESULTS

Placentas of PPLWH contained significantly more leukocytes and Hofbauer cells than controls. Multivariable analyses revealed that this increase in immune cells was associated with a predominantly CD163⁺ profile in all ART subgroups compared to the HIV-negative group. This was characterized by an increase in total CD163⁺ cells in the PI and INSTI subgroups, and a higher frequency of CD163⁺ cells and CD163⁺/CD68⁺ ratio in the NNRTI and PI subgroups.

DISCUSSION

Placentas of PPLWH treated with any ART regimen during their entire pregnancy displayed a selection for CD163⁺ cells compared to the HIV-negative group, regardless of class of ART, suggesting that class of ART does not intrinsically affect selection of CD163+ and CD68⁺ Hofbauer cells. Further investigations into the role of Hofbauer cells in ART-associated placental inflammation are warranted to identify the mechanisms behind their potential involvement in maternal-fetal tolerance maintenance.

Perinatal outcomes associated with combination antiretroviral therapy compared with monotherapy

OBJECTIVES

Increasing numbers of women living with HIV (WLHIV) worldwide receive combination antiretroviral therapy (cART) during pregnancy. We aimed to assess the risk of adverse perinatal outcomes in pregnant WLHIV receiving cART compared with pregnant WLHIV receiving zidovudine monotherapy.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched four electronic literature databases (PubMed, CINAHL, Global Health, EMBASE) for studies published between 1 January 1980 and 20 April 2020 using a comprehensive search strategy. Studies reporting data on WLHIV receiving cART compared with WLHIV receiving monotherapy for 11 adverse perinatal outcomes were sought: preterm birth (PTB), very PTB, spontaneous PTB, low birthweight (LBW), very LBW, preterm and term LBW, small for gestational age (SGA), very SGA (VSGA), stillbirth, and neonatal death. Random-effects meta-analyses were conducted to calculate relative risk (RR) and 95% confidence intervals (95% CI).

RESULTS

We included 30 studies reporting on 317 101 pregnant women in 27 countries. WLHIV receiving cART were at increased risk of PTB (RR 1.32, 95% CI 1.18-1.46), LBW (1.35, 1.19-1.53), SGA (1.32, 1.13-1.53), VSGA (1.64, 1.34-2.02), and stillbirth (2.41, 1.83-3.17) compared to WLHIV receiving monotherapy. The significance of these results was maintained in subgroup analyses for studies conducted in low and middle-income countries and average quality studies. Additionally, WLHIV receiving nonnucleoside reverse transcriptase inhibitor-based cART were associated with increased risk of PTB, LBW, and stillbirth, while WLHIV receiving protease inhibitor-based cART were associated with increased risk of PTB, compared with WLHIV receiving monotherapy.

CONCLUSION

Pregnant WLHIV receiving cART are associated with increased risk of adverse perinatal outcomes, compared with WLHIV receiving monotherapy.

Adverse perinatal outcomes associated with prenatal exposure to protease-inhibitor-based versus non-nucleoside reverse transcriptase inhibitor-based antiretroviral combinations in pregnant women with HIV infection: a systematic review and meta-analysis

BACKGROUND

About 1.3 million pregnant women lived with HIV and were eligible to receive antiretroviral therapy (ART) worldwide in 2021. The World Health Organization recommends protease inhibitors (PI)-based regimen as second or third-line during pregnancy. With remaining pregnant women exposed to PIs, there is still an interest to assess whether this treatment affects perinatal outcomes. Adverse perinatal outcomes after prenatal exposure to PI-based ART remain conflicting: some studies report an increased risk of preterm birth (PTB) and low-birth-weight (LBW), while others do not find these results. We assessed adverse perinatal outcomes associated with prenatal exposure to PI-based compared with non-nucleoside reverse transcriptase (NNRTI)-based ART.

METHODS

We performed a systematic review searching PubMed, Reprotox, Clinical Trial Registry (clinicaltrials.gov) and abstracts of HIV conferences between 01/01/2002 and 29/10/2021. We used Oxford and Newcastle-Ottawa scales to assess the methodological quality. Studied perinatal outcomes were spontaneous abortion, stillbirth, congenital abnormalities, PTB (< 37 weeks of gestation), very preterm birth (VPTB, < 32 weeks of gestation), LBW (< 2500 grs), very low-birth-weight (VLBW, < 1500 g), small for gestational age (SGA) and very small for gestational age (VSGA). The association between prenatal exposure to PI-based compared to NNRTI-based ART was measured for each adverse perinatal outcome using random-effect meta-analysis to estimate pooled relative risks (RR) and their corresponding 95% confidence intervals (CI). Pre-specified analyses were stratified according to country income and study quality assessment, and summarized when homogeneous.

RESULTS

Out of the 49,171 citations identified, our systematic review included 32 published studies, assessing 45,427 pregnant women. There was no significant association between prenatal exposure to PIs compared to NNRTIs for VPTB, LBW, SGA, stillbirth, and congenital abnormalities. However, it was inconclusive for PTB, and PI-based ART is significantly associated with an increased risk of VSGA (sRR 1.41 [1.08-1.84]; I² = 0%) compared to NNRTIs.

CONCLUSIONS

We did not report any significant association between prenatal exposure to PIs vs NNRTIs-based regimens for most of the adverse perinatal outcomes, except for VSGA significantly increased (+ 41%). The evaluation of antiretroviral exposure on pregnancy outcomes remains crucial to fully assess the benefice-risk balance, when prescribing ART in women of reproductive potential with HIV.

PROSPERO NUMBER

CRD42022306896.

Progesterone and prolactin levels in pregnant women living with HIV who delivered preterm and low birthweight infants: A nested case-control study

BACKGROUND

Antiretroviral therapy (ART) is associated with high rates of adverse birth outcomes, including preterm birth and low birthweight. Studies suggest that progesterone and prolactin may play important intermediary roles.

METHODS

We analyzed data from the Antenatal Component of the PROMISE trial, a multi-center study of pregnant women taking antiretroviral regimens (lopinavir/ritonavir-containing ART or zidovudine alone) to prevent mother-to-child HIV transmission. In a nested case-control study, we compared data from women who gave birth to preterm (<37 weeks gestation) and/or low birthweight (<2500 g) infants to matched individuals who did not. We measured serum progesterone and prolactin at 24-34 weeks gestation. We used conditional logistic regression to describe relationships between hormone levels, birth outcomes, and antiretroviral regimens.

RESULTS

299 women and their newborns were included (146 cases, 153 controls). When compared to women receiving zidovudine alone, those on ART had higher odds of progesterone levels under the 10th percentile (adjusted odds ratio [AOR]:2.34, 95%CI:1.41-3.89) and 25th percentile (AOR:2.07, 95%CI:1.46-2.94). However, higher levels of progesterone-rather than lower levels-were associated with our composite case outcome at the 10th percentile (AOR:1.88, 95%CI:0.77-4.59) and 25th percentile (AOR:1.96, 95%CI:1.06-3.61). Associations were not observed between prolactin, antiretroviral regimen, and birth outcomes.

CONCLUSION

We observed lower progesterone levels among women allocated to ART regimens; however, higher progesterone levels were associated with preterm birth and/or low birthweight. While features of the study design may have contributed to these findings, they nevertheless highlight the potentially complex mechanisms underpinning adverse birth outcomes and HIV.

Effect of weekly 17-hydroxyprogesterone caproate on small for gestational age among pregnant women with HIV in Zambia

The IPOP trial demonstrated a reduced risk of severe small for gestational age among infants born to women with HIV who received weekly intramuscular 17 alpha-hydroxyprogesterone caproate. This secondary analysis examined the 17P treatment effect in subgroups of maternal BMI, parity, timing of antiretroviral therapy (ART) initiation, and ART regimen. We found that 17P was more effective among nulliparous women, women who started ART before pregnancy, and those taking protease inhibitors.

Allometric scaling relationships in mouse placenta

Fetal growth and maturation are highly intertwined with placental development during pregnancy. Here we used placental vascular morphology measurements (depth and span) as well as the umbilical artery (UA) diameter of previously published studies on three different mouse strains (C57BL6/J, CD-1 and BALB/c), which were exposed to different conditions (combination antiretroviral therapy, chronic maternal hypoxia and malaria infection) at different embryonic days, to test the hypothesis that placental vascularization and specifically the UA size affect conceptus weight. Interaction of each study parameter with embryonic day, strain and exposure to treatments are studied to investigate the stability of the scaling relationships across and/or within strains and conditions. In addition, the effect of UA diameter on the placental growth measurements (depth and span) is studied. These results show that the power-law scaling relationship of conceptus weight and placental depth with the UA diameter is conserved across strains and conditions with the scaling exponent of approximately 3/8 and 5/8, respectively. By contrast, the relationship between conceptus weight and either the placental span or depth is different between strains and conditions, suggesting multiple mechanisms of vascular adaptation.

Effects of HIV Infection on Pregnancy Outcomes Among Women Attending Antenatal Care in Referral Hospitals of the Amhara Regional State, Ethiopia: A Prospective Cohort Study

Background

Human immunodeficiency virus (HIV) has remained to be a significant public health problem worldwide mainly affecting women. Despite a 2 to 3 times higher risk of adverse pregnancy outcomes, around 2 million HIV positive women give birth each year globally. However, there is a dearth of evidences in Ethiopia about the effect of maternal HIV infection on pregnancy outcomes where adverse birth outcomes are still a significant health problem. This study is, therefore, aimed to examine the effect of HIV on the risk of adverse pregnancy outcomes in Amhara Regional State, Ethiopia.

Methods

A prospective cohort study was conducted among 704 pregnant women (352 women with HIV and 352 women without HIV infection). Systematic random sampling technique was employed to select the study participants. Data on socio-demographic, obstetric, clinical, as well as behavioral and psychosocial characteristics were collected using a validated tool. Data on the outcome variables were also collected following delivery. Modified Poisson regression was employed to estimate the relative risk (RR) of HIV on low birth weight (LBW), preterm birth, and still birth at 95% confidence level. Attributable fraction (AF) was used to report the impact of HIV infection on pregnancy outcomes.

Results

Of the total 704 pregnant women enrolled for the study, 96.3% (678) completed the study. The mean age of the study participants was 30.8 (SD ± 5.4) for HIV positive and 27 (SD ± 5.4) for HIV negative women. The cumulative incidence of low birth weight, preterm birth, and stillbirth were 21.4%, 9.4%, and 4.1%, respectively. The incidence of LBW was 24.7% among HIV positive and 17.8% among HIV negative women. The incidence of preterm birth was 10.7% among HIV positive and 7.9% among HIV negative women. And the incidence of stillbirth was 3.7% and 4.6% among HIV positive and those HIV negative women. New-borns from women with HIV infection had a higher risk of low birth weight and preterm birth than those HIV negative women (Adjusted Relative Risk (ARR) = 1.47; 95% CI: 1.06–2.03) and (ARR = 1.74; 95% CI: 1.08–2.79), respectively. The attributable risk of HIV on low birth weight was 32% (Attributable Fraction (AF) = 32%, 95% CI: 23–46%), and 43% (AF = 43%, 95% CI: 23–46%) for preterm birth.

Conclusion

Maternal HIV infection increased the risk of low birth weight and preterm birth. This implies due attention is required while providing maternal health services primarily antenatal care and delivery services. These services should be aimed at reducing adverse pregnancy outcomes with more attention given to women with HIV infection. Moreover, reinforcement of HIV prevention intervention strategies should be considered at all levels.

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.

Perinatal outcomes in women living with HIV-1 and receiving antiretroviral therapy-a systematic review and meta-analysis

INTRODUCTION

Antiretroviral therapy-naïve pregnant women living with HIV are at an increased risk for adverse pregnancy outcomes. It remains controversial whether this risk persists with antiretroviral therapy. We conducted a systematic review and meta-analysis to evaluate whether pregnant women living with HIV and receiving antiretroviral therapy antenatally, are at an increased risk of adverse outcomes compared with HIV-negative controls.

MATERIAL AND METHODS

We searched MEDLINE, Embase, International Pharmaceutical Abstracts, EBM Reviews, PubMed (non-MEDLINE records), EBSCO CINAHL Complete, Clarivate Web of Science, African Index Medicus, LILACS and Google Scholar for all observational studies comparing pregnant women living with HIV on antiretroviral therapy with HIV-negative controls from 1 January 1994 to 10 August 2021 with no language or geographic restrictions. Perinatal outcomes included preterm birth (PTB), low birthweight, small-for-gestational age and preeclampsia. Using a random-effects model we pooled raw data to generate odds ratio (OR) with 95% confidence intervals (CI) for each outcome. Sub-analyses for high and low resource countries and time of antiretroviral therapy initiation were performed. This systematic review and meta-analysis is registered with PROSPERO, number CRD42020182722.

RESULTS

Of the 7900 citations identified, 27 were eligible for analysis (12 636 pregnant women living with HIV on antiretroviral therapy and 7 812 115 HIV-negative controls). ORs (95% CI) of PTB (1.88 [1.63-2.17]), small-for-gestational age (1.60 [1.18-2.17]) and low birthweight (2.15 [1.58-2.92]) were significantly higher in pregnant women living with HIV than in HIV-negative women, while the risk of preeclampsia (0.86 [0.57-1.30]) was comparable. The risk of PTB and low birthweight was higher in both high resource and low resource countries, while the risk of small-for-gestational age was higher only in the former. Preconceptional antiretroviral therapy was associated with a higher risk of PTB compared with antenatal initiation.

CONCLUSIONS

Pregnant women living with HIV on antiretroviral therapy have an increased risk of PTB, low birthweight and small-for-gestational age in high resource countries, as well as PTB and low birthweight in low income countries compared with HIV-negative controls.

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.

Weekly 17 alpha-hydroxyprogesterone caproate to prevent preterm birth among women living with HIV: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Women with HIV face an increased risk of preterm birth. 17 alpha-hydroxyprogesterone caproate (17P) has been shown in some trials to reduce early delivery among women with a history of spontaneous preterm birth. We investigated whether 17P would reduce this risk among women with HIV.

METHODS

We did a randomised, double-blind, placebo-controlled trial in pregnant women with HIV at the University Teaching Hospital and Kamwala District Health Centre in Lusaka, Zambia. Eligible patients were women aged 18 years or older with confirmed HIV-1 infection, viable intrauterine singleton pregnancy at less than 24 weeks of gestation, and were receiving or intending to commence antiretroviral therapy during pregnancy. Exclusion criteria were major uterine or fetal anomaly; planned or in situ cervical cerclage; evidence of threatened miscarriage, preterm labour, or ruptured membranes at screening; medical contraindication to 17P; previous participation in the trial; or history of spontaneous preterm birth. Eligible participants provided written informed consent and were randomly assigned (1:1) to receive 250 mg intramuscular 17P or placebo once per week, starting between 16 and 24 weeks of gestation until delivery, stillbirth, or reaching term (37 weeks). Participants and study staff were masked to assignment, except for pharmacy staff who did random assignment and prepared injections but did not interact with participants. The primary outcome was a composite of delivery before 37 weeks or stillbirth at any gestational age. Patients attended weekly visits for study drug injections and antenatal care. We estimated the absolute and relative difference in risk of the primary outcome and safety events between treatment groups by intention to treat. This trial is registered with ClinicalTrials.gov, NCT03297216, and is complete.

FINDINGS

Between Feb 7, 2018 and Jan 13, 2020, we assessed 1042 women for inclusion into the study. 242 women were excluded after additional assessments, and 800 eligible patients were enrolled and randomly assigned to receive intramuscular 17P (n=399) or placebo (n=401). Baseline characteristics were similar between groups. Adherence to study drug injections was 98% in both groups, no patients were lost to follow-up, and the final post-partum visit was on Aug 6, 2020. 36 (9%) of 399 participants assigned to 17P had preterm birth or stillbirth, compared with 36 (9%) of 401 patients assigned to placebo (risk difference 0·1, 95% CI -3·9 to 4·0; relative risk 1·0, 95% CI 0·6 to 1·6; p=0·98). Intervention-related adverse events were reported by 140 (18%) of 800 participants and occurred in similar proportions in both randomisation groups. No serious adverse events were reported.

INTERPRETATION

Although 17P seems to be safe and acceptable to participants, available data do not support the use of the drug to prevent preterm birth among women whose risk derives solely from HIV infection. The low risk of preterm birth in both randomisation groups warrants further investigation.

FUNDING

US National Institutes of Health and the Bill and Melinda Gates Foundation.

Placental pathology in women with HIV

Recognizing the importance of placental features and their unique functions can provide insight into maternal health, the uterine environment during the course of pregnancy, birth outcomes and neonatal health. In the context of HIV and antiretroviral therapy (ART), there have been great strides in the prevention of mother to child transmission of HIV. However, there is still paucity of data on the impact of HIV/ART exposure on placental pathology and studies available only examine specific patterns of placental injury, further justifying the need for a more defined and comprehensive approach to the differential diagnoses of HIV/ART-exposed placentae. The purpose of this review is to consolidate findings from individual studies that have been reported on patterns of placental injury in the context of HIV/ART exposure. In both the pre- and post-ART eras HIV and/or ART has been associated with placental injury including maternal vascular malperfusion as well as acute and chronic inflammation. These patterns of injury are further associated with adverse birth outcomes including preterm birth and current evidence suggests an association between poor placental function and compromised fetal development. With the ever increasing number of pregnant women with HIV on ART, there is a compelling need for full incorporation of placental diagnoses into obstetric disease classification. It is also important to take into account key elements of maternal clinical history. Lastly, there is a need to standardize the reporting of placental pathology in order to glean additional insight into the elucidation of HIV/ART associated placental injury.

Placental Vascular Abnormalities in Association With Prenatal and Long-Term Health Characteristics Among HIV-Exposed Uninfected Adolescents and Young Adults

BACKGROUND

HIV-exposed uninfected (HEU) individuals are predisposed to adverse health outcomes, which in part may stem from the influence of an altered intrauterine milieu on fetal programming. The placenta serves as a readout for the effects of the maternal environment on the developing fetus and may itself contribute to the pathogenesis of disease.

SETTING

US academic health system.

METHODS

We leveraged a previously established registry-based cohort of HEU adolescents and young adults to identify 26 subjects for whom placental histopathology was available. We further obtained placental tissue from 29 HIV-unexposed pregnancies for comparison. We examined differences in placental histopathology between the groups and related villous vascularity in the HEU group to prenatal maternal characteristics and long-term health outcomes.

RESULTS

Placentas from HEU pregnancies demonstrated a higher blood vessel count per villus as compared with controls (5.9 ± 1.0 vs. 5.4 ± 0.8; P = 0.05), which was independent of maternal prenatal age, race, body mass index, smoking status, hemoglobin, and gestational age. Furthermore, within the HEU group, lower CD4+ T-cell count during pregnancy was associated with greater placental vascularity (r = -0.44; P = 0.03). No significant relationships were observed between placental blood vessel count per villus and body mass index z-score or reactive airway disease among HEU individuals later in life.

CONCLUSIONS

Placentas from HEU pregnancies demonstrated increased villous vascularity compared with HIV-unexposed controls in proportion to the severity of maternal immune dysfunction. Further studies are needed to examine intrauterine exposure to hypoxia as a potential mechanism of fetal programming in HIV.

Assessment of the impact of HIV infection and anti-retroviral treatment on the cardiometabolic health of pregnant mothers and their offspring (ARTMOMSBABES)

BACKGROUND

The risk of cardiovascular diseases (CVDs) is becoming more prevalent in pregnant women though not much data is available for pregnant women with human immunodeficiency virus (HIV). Foetoplacental vascular endothelial dysfunction is thought to be at the origin of chronic diseases such as diabetes and obesity later on in life. Because HIV and anti-retroviral treatment (ARTs) are associated with endothelial dysfunction, children exposed in utero to these conditions may be at greater risk of developing CVDs. Despite the high prevalence of HIV in pregnant South African women, little is known about the effects of ART on the cardiovascular health of the mother and offspring. Hence, the proposed study intends to investigate how HIV/ARTs may affect the cardiovascular health of the mother and offspring at different time points during the pregnancy and up to 2 years after birth.

METHODS

A longitudinal case-control study in HIV positive pregnant women on ART and HIV negative pregnant women will be conducted. All pregnant women will be assessed for cardio-metabolic risk factors and markers (lipids, anthropometric and glycaemic indies, oxidative stress), hemodynamic status (blood pressure parameters) and vascular function (arterial compliance, retinal microvasculature, uterine artery mean pulsatility index). Child health will be monitored in utero and postnatally via routine foetal health screening, placental integrity, anthropometry, blood pressure parameters, markers of oxidative stress and endothelial function in cord blood and cardiovascular epigenetic markers in urine.

DISCUSSION

There is a paucity of studies in South Africa and sub-Sahara Africa as a whole that utilised a longitudinal study model to assess the effects of ARTs on vascular endothelial changes in pregnant women living with HIV and the cardiometabolic health of their offspring. This study will therefore help to monitor changes in cardiometabolic risk during pregnancy and in children exposed in utero to HIV-infection and ART use. Findings from this study will provide useful information for developing guidelines on the use of ARTs in pregnancy and management of cardiometabolic health of the offspring of HIV positive mothers.

Pregnancy and viral infections: Mechanisms of fetal damage, diagnosis and prevention of neonatal adverse outcomes from cytomegalovirus to SARS-CoV-2 and Zika virus

Some maternal infections, contracted before or during pregnancy, can be transmitted to the fetus, during gestation (congenital infection), during labor and childbirth (perinatal infection) and through breastfeeding (postnatal infection). The agents responsible for these infections can be viruses, bacteria, protozoa, fungi. Among the viruses most frequently responsible for congenital infections are Cytomegalovirus (CMV), Herpes simplex 1–2, Herpes virus 6, Varicella zoster. Moreover Hepatitis B and C virus, HIV, Parvovirus B19 and non-polio Enteroviruses when contracted during pregnancy may involve the fetus or newborn at birth. Recently, new viruses have emerged, SARS-Cov-2 and Zika virus, of which we do not yet fully know the characteristics and pathogenic power when contracted during pregnancy.

Viral infections in pregnancy can damage the fetus (spontaneous abortion, fetal death, intrauterine growth retardation) or the newborn (congenital anomalies, organ diseases with sequelae of different severity). Some risk factors specifically influence the incidence of transmission to the fetus: the timing of the infection in pregnancy, the order of the infection, primary or reinfection or chronic, the duration of membrane rupture, type of delivery, socio-economic conditions and breastfeeding. Frequently infected neonates, symptomatic at birth, have worse outcomes than asymptomatic. Many asymptomatic babies develop long term neurosensory outcomes.

The way in which the virus interacts with the maternal immune system, the maternal-fetal interface and the placenta explain these results and also the differences that are observed from time to time in the fetal‑neonatal outcomes of maternal infections. The maternal immune system undergoes functional adaptation during pregnancy, once thought as physiological immunosuppression. This adaptation, crucial for generating a balance between maternal immunity and fetus, is necessary to promote and support the pregnancy itself and the growth of the fetus. When this adaptation is upset by the viral infection, the balance is broken, and the infection can spread and lead to the adverse outcomes previously described. In this review we will describe the main viral harmful infections in pregnancy and the potential mechanisms of the damages on the fetus and newborn.

Induction of the PPARγ (Peroxisome Proliferator-Activated Receptor γ)-GCM1 (Glial Cell Missing 1) Syncytialization Axis Reduces sFLT1 (Soluble fms-Like Tyrosine Kinase 1) in the Preeclamptic Placenta

[Figure: see text].

The Role of HIV Infection in the Pathophysiology of Gestational Diabetes Mellitus and Hypertensive Disorders of Pregnancy

Purpose of the Review: The main objective of this study is to investigate mechanisms associated with gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) in HIV infected pregnant women by looking how placental hormones such as (progesterone and prolactin) and basic haemostatic parameters are regulated in HIV infected pregnancies.

Recent Findings: HIV/AIDS are a major global obstetric health burden that lead to increased rate of morbidity and mortality. HIV/AIDS has been associated with the pathophysiology of GDM and HDP. Increased risk of GDM due to highly active antiretroviral therapy (HAART) usage has been reported in HIV infected pregnancies, which causes insulin resistance in both pregnant and non-pregnant individuals. HAART is a medication used for lowering maternal antepartum viral load and pre-exposure and post-exposure prophylaxis of the infant. In pregnant women, HAART induces diabetogenic effect by causing dysregulation of placental hormones such as (progesterone and prolactin) and predispose HIV infected women to GDM. In addition to HIV/AIDS and GDM, Studies have indicated that HIV infection causes haemostatic abnormalities such as hematological disorder, deregulated haematopoiesis process and the coagulation process which results in HDP.

Summary: This study will help on improving therapeutic management and understanding of the pathophysiology of GDM and HDP in the absence as well as in the presence of HIV infection by reviewing studies reporting on these mechanism.

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.

Antiretroviral Drugs Impact Autophagy with Toxic Outcomes

Antiretroviral drugs have dramatically improved the morbidity and mortality of people living with HIV (PLWH). While current antiretroviral therapy (ART) regimens are generally well-tolerated, risks for side effects and toxicity remain as PLWH must take life-long medications. Antiretroviral drugs impact autophagy, an intracellular proteolytic process that eliminates debris and foreign material, provides nutrients for metabolism, and performs quality control to maintain cell homeostasis. Toxicity and adverse events associated with antiretrovirals may be due, in part, to their impacts on autophagy. A more complete understanding of the effects on autophagy is essential for developing antiretroviral drugs with decreased off target effects, meaning those unrelated to viral suppression, to minimize toxicity for PLWH. This review summarizes the findings and highlights the gaps in our knowledge of the impacts of antiretroviral drugs on autophagy.

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

OBJECTIVE

To examine the association between timing of antiretroviral treatment (ART) initiation in HIV-infected women and placental histopathology.

DESIGN

A nested substudy in a larger cohort of HIV-infected women which examined the association between ART status and birth outcomes.

METHODS

Placentas (n = 130) were examined for histopathology from two ART groups: stable (n = 53), who initiated ART before conception and initiating (n = 77), who started ART during pregnancy [median (interquartile range) 15 weeks gestation (11-18)]. Using binomial regression we quantified associations between ART initiation timing with placental histopathology and pregnancy outcomes.

RESULTS

One-third of all placentas were less than 10th percentile weight-for-gestation and there was no significant difference between ART groups. Placental diameter, thickness, cord insertion position and foetal-placental weight ratio were also similar by group. However, placentas from the stable group showed increased maternal vascular malperfusion (MVM) (39.6 vs. 19.4%), and decreased weight (392 vs. 422 g, P = 0.09). MVM risk was twice as high [risk ratios 2.03 (95% confidence interval: 1.16-3.57); P = 0.01] in the stable group; the increased risk remaining significant when adjusting for maternal age [risk ratios 2.04 (95% confidence interval: 1.12-3.72); P = 0.02]. Furthermore, MVM was significantly associated with preterm delivery and low birth weight (P = 0.002 and <0.0001, respectively).

CONCLUSION

Preconception initiation of ART was associated with an increased MVM risk, and may contribute to placental dysfunction. The association between MVM with preterm delivery and low birth weight suggests that a placenta-mediated mechanism likely links the putative association between long-term use of ART and adverse birth outcomes.

Exploring the impact of HIV infection and antiretroviral therapy on placenta morphology

INTRODUCTION

Women living with HIV experience more adverse birth outcomes; the mechanisms are not fully understood. We examined placenta morphology and associations with birth outcomes in a Canadian cohort of women living with HIV (HIV⁺) on antiretroviral therapy (ART) from conception and HIV-uninfected (HIV^-) women.

METHODS

Term placentas from 94 women (40 HIV^-, 54 HIV⁺) were studied. Trimmed placenta weight was collected. Placenta digital photos were used to compute morphometric parameters. Regression models investigated associations between log-transformed placenta parameters and birth outcomes.

RESULTS

We observed a trend towards lower placenta weight and smaller placenta area in the HIV⁺ group, both of which were significantly associated with small for gestational age births. HIV⁺ serostatus was associated with 6-fold (95%CI 2-20) greater odds of having placenta area in the lowest quartile (<236 cm²). Cord marginality (distance from the edge) was significantly lower in the HIV⁺ group (p = 0.004), with 35% of placenta having an abnormal (marginal or velamentous) cord insertion vs. 12.5% in the HIV^- group (p = 0.01). Velamentous cord insertion was seen in 13% of placentas in the HIV⁺ vs. 0% in HIV^- group (p = 0.02). A significant correlation between cord marginality and placenta thickness was observed in the HIV^- group, with a more marginal cord being associated with a thicker placenta. This correlation was not observed in the HIV⁺ group. HIV⁺ placentas exposed to protease inhibitors were significantly less circular compared to the HIV^- group (p = 0.03).

CONCLUSION

Our data suggest that HIV/ART exposure affects placenta morphology and is associated with higher rates of abnormal cord insertion.

Periconceptional exposure to lopinavir, but not darunavir, impairs decidualization: a potential mechanism leading to poor birth outcomes in HIV-positive pregnancies

STUDY QUESTION

Does HIV protease inhibitor (PI)-based combination antiretroviral therapy (cART) initiated at periconception affect key events in early pregnancy, i.e. decidualization and spiral artery remodeling?

SUMMARY ANSWER

Two PIs, lopinavir and darunavir, currently offered as cART options in HIV-positive pregnancies were evaluated, and we found that lopinavir-based cART, but not darunavir-based cART, impaired uterine decidualization and spiral artery remodeling in both human ex vivo and mouse in vivo experimental models.

WHAT IS KNOWN ALREADY

Early initiation of cART is recommended for pregnant women living with HIV. However, poor birth outcomes are frequently observed in HIV-positive pregnancies exposed to PI-based cART, especially when it is initiated prior to conception. The correlation between early initiation of PI-cART and adverse birth outcomes is poorly understood, due to lack of data on the specific effects of PI-cART on the early stages of pregnancy involving uterine decidualization and spiral artery remodeling.

STUDY DESIGN, SIZE, DURATION

Lopinavir and darunavir were evaluated in clinically relevant combinations using an ex vivo human first-trimester placenta-decidua explant model, an in vitro human primary decidual cell culture system, and an in vivo mouse pregnancy model. The first-trimester (gestational age, 6–8 weeks) human placenta-decidua tissue was obtained from 11 to 15 healthy women undergoing elective termination of pregnancy. C57Bl/6 female mice (four/treatment group) were administered either lopinavir-cART, darunavir-cART or water by oral gavage once daily starting on the day of plug detection until sacrifice.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Human: Spiral artery remodeling was assessed by immunohistochemical analysis of first-trimester placenta-decidua explant co-culture system. Trophoblast migration was measured using a placental explant culture. A primary decidual cell culture was used to evaluate the viability of immune cell populations by flow cytometry. Soluble factors, including biomarkers of decidualization and angiogenesis, were quantified by ELISA and Luminex assay using decidua-conditioned media.

Mouse: In the mouse pregnancy model, gestational day 6.5 or 9.5 implantation sites were used to assess decidualization, spiral artery remodeling and uterine natural killer (uNK) cell numbers by immunohistochemistry. Transcription factor STAT3 was assayed by immunohistochemistry in both human decidua and mouse implantation sites.

MAIN RESULTS AND THE ROLE OF CHANCE

Lopinavir-cART, but not darunavir-cART, impaired uterine decidualization and spiral artery remodeling in both experimental models. Lopinavir-cART treatment was also associated with selective depletion of uNK cells, reduced trophoblast migration and defective placentation. The lopinavir-associated decidualization defects were attributed to a decrease in expression of transcription factor STAT3, known to regulate decidualization. Our results suggest that periconceptional initiation of lopinavir-cART, but not darunavir-cART, causes defective maturation of the uterine endometrium, leading to impairments in spiral artery remodeling and placentation, thus contributing to the poor birth outcomes.

LARGE SCALE DATA

N/A

LIMITATIONS, REASONS FOR CAUTION

The human first-trimester placenta/decidua samples could only be obtained from healthy females undergoing elective termination of pregnancy. As biopsy is the only way to obtain first-trimester decidua from pregnant women living with HIV on PI-cART, ethics approval and participant consent are difficult to obtain. Furthermore, our animal model is limited to the study of cART and does not include HIV. HIV infection is also associated with immune dysregulation, inflammation, alterations in angiogenic factors and complement activation, all of which could influence decidual and placental vascular remodeling and modify any cART effects.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings provide mechanistic insight with direct clinical implications, rationalizing why the highest adverse birth outcomes are reported in HIV-positive pregnancies exposed to lopinavir-cART from conception. We demonstrate that dysregulation of decidualization is the mechanism through which lopinavir-cART, but not darunavir-cART, use in early pregnancy leads to poor birth outcomes. Although lopinavir is no longer a first-line regimen in pregnancy, it remains an alternate regimen and is often the only PI available in low resource settings. Our results highlight the need for reconsidering current guidelines recommending lopinavir use in pregnancy and indicate that lopinavir should be avoided especially in the first trimester, whereas darunavir is safe to use and should be the preferred PI in pregnancy.

Further, in current times of the COVID-19 pandemic, lopinavir is among the top drug candidates which are being repurposed for inclusion in clinical trials world-over, to assess their therapeutic potential against the dangerous respiratory disease. Current trials are also testing the efficacy of lopinavir given prophylactically to protect health care workers and people with potential exposures. Given the current extraordinary numbers, these might include women with early pregnancies, who may or may not be cognizant of their gestational status. This is a matter of concern as it could mean that women with early pregnancies might be exposed to this drug, which can cause decidualization defects. Our findings provide evidence of safety concerns surrounding lopinavir use in pregnancy, that women of reproductive age considering participation in such trials should be made aware of, so they can make a fully informed decision.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by funding from the Canadian Institutes of Health Research (CIHR) (PJT-148684 and MOP-130398 to L.S.). C.D. received support from CIHR Foundation (FDN143262 to Stephen Lye). S.K. received a TGHRI postdoctoral fellowship. The authors declare that there are no conflicts of interest. L.S. reports personal fees from ViiV Healthcare for participation in a Women and Transgender Think Tank.

Advances in imaging feto-placental vasculature: new tools to elucidate the early life origins of health and disease

Optimal placental function is critical for fetal development, and therefore a crucial consideration for understanding the developmental origins of health and disease (DOHaD). The structure of the fetal side of the placental vasculature is an important determinant of fetal growth and cardiovascular development. There are several imaging modalities for assessing feto-placental structure including stereology, electron microscopy, confocal microscopy, micro-computed tomography, light-sheet microscopy, ultrasonography and magnetic resonance imaging. In this review, we present current methodologies for imaging feto-placental vasculature morphology ex vivo and in vivo in human and experimental models, their advantages and limitations and how these provide insight into placental function and fetal outcomes. These imaging approaches add important perspective to our understanding of placental biology and have potential to be new tools to elucidate a deeper understanding of DOHaD.

Placental growth disorders and perinatal adverse outcomes in Brazilian HIV-infected pregnant women

Fetal and placental growth disorders are common in maternal human immunodeficiency virus (HIV) infection and can be attributed to both the infection and comorbidities not associated with HIV. We describe placental growth disorders and adverse reproductive outcomes in HIV-infected pregnant women whose delivery occurred between 2001-2014 in Vitoria, Brazil. Cases with gestational age (GA) ≥ than 22 weeks validated by ultrasonography, with placental and fetal weight dimensions at birth, were studied. Outcomes were summarized as proportions of small (SGA), appropriate (AGA), and large (LGA) for GA when the z-score values were below -1.28, between -1.28 and +1.28, or above +1.28, respectively. Of 187 fetal attachment requisitions, 122(65.2%) women and their newborns participated in the study. The median maternal age was 28 years and 81(66.4%) underwent ≥ 6 prenatal visits. A total of 81(66.4%) were diagnosed before current pregnancy; 68(55.7%) exhibited criteria for acquired immunodeficiency syndrome (AIDS); 64(52.4%) had detectable viral load; 25(20.5%) cases presented SGA placental weight and 6(4.9%) SGA placental thickness. SGA placental area was observed in 41(33.6%) cases, and among the SGA placental weight cases 12(48%) were also SGA fetal weight. Preterm birth (PTB) occurred in 15.6%(19/122) of cases; perinatal death in 4.1%(5/122) and HIV vertical transmission in 6 of 122 (4.9%). Women, ≥36 years old, were 5.7 times more likely to have PTB than those under 36. Also, patients with AIDS-defining criteria were 3.7 times more likely to have PTB. Prenatal care was inversely associated with PTB. Statistically significant associations were observed between AGA placental area and Protease Inhibitor usage and between SGA placental weight and SGA area. We found a prevalence of placental growth disorders in HIV-infected pregnant women and values higher than international reference values. The restriction of placental growth was a common disorder, possibly attributed to virus effects or a combination of antiretroviral regimens.

No association between early antiretroviral therapy during pregnancy and plasma levels of angiogenic factors: a cohort study

Background

Early antiretroviral therapy (ART) during pregnancy has dramatically reduced the risk of perinatal HIV transmission. However, studies have shown an association between premature delivery and the use of ART during pregnancy (particularly protease inhibitor (PI)-based therapies), which could be explained by placental dysfunction. The objective of this study was to evaluate the association of ART (class, duration of exposure and time of initiation) with placental function by using angiogenic factors placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) as biomarkers.

Methods

Clinical and biological data from 159 pregnant women living with HIV were analyzed. Levels of each biomarker were measured in the first and second trimester of pregnancy. After logarithmic transformation, we compared these using generalized estimating equations according to (a) the type of ART; (b) the duration of exposure to ART; and (c) the time of initiation of ART.

Results

After adjusting for variables such as ethnicity, maternal age, gestational age, body mass index, parity, smoking status, and sex of the fetus, we found no significant association between the class of ART (PI-based or not) and serum concentrations of PlGF or sFlt-1. Furthermore, no significant association was found between biomarker levels and the duration of ART exposure or the timing of ART initiation (pre- or post-conception).

Conclusions

This study suggests that first and second trimester angiogenic factor levels are not significantly associated with ART, regardless of the duration or type (with or without PI). These observations seem reassuring when considering the use of ART during early pregnancy.

Placental Structure in Preterm Birth Among HIV-Positive Versus HIV-Negative Women in Kenya

Background:

Preterm birth (PTB) is a major cause of infant morbidity and mortality in developing countries. Recent data suggest that in addition to Human Immunodeficiency Virus (HIV) infection, use of antiretroviral therapy (ART) increases the risk of PTB. As the mechanisms remain unexplored, we conducted this study to determine whether HIV and ART were associated with placental changes that could contribute to PTB.

Setting:

We collected and evaluated placentas from 38 HIV-positive women on ART and 43 HIV-negative women who had preterm deliveries in Nairobi, Kenya.

Methods:

Anatomical features of the placentas were examined at gross and microscopic levels. Cases were matched for gestational age and compared by the investigators who were blinded to maternal HIV serostatus.

Results:

Among preterm placentas, HIV infection was significantly associated with thrombosis (P = 0.001), infarction (P = 0.032), anomalies in cord insertion (P = 0.02), gross evidence of membrane infection (P = 0.043), and reduced placental thickness (P = 0.010). Overall, preterm placentas in both groups were associated with immature villi, syncytial knotting, villitis, and deciduitis. Features of HIV-positive versus HIV-negative placentas included significant fibrinoid deposition with villus degeneration, syncytiotrophoblast delamination, red blood cell adhesion, hypervascularity, and reduction in both surface area and perimeter of the terminal villi.

Conclusions:

These results imply that HIV infection and/or ART are associated with morphological changes in preterm placentas that contribute to delivery before 37 weeks. Hypervascularity suggests that the observed pathologies may be attributable, in part, to hypoxia. Further research to explore potential mechanisms will help elucidate the pathways that are involved perhaps pointing to interventions for decreasing the risk of prematurity among HIV-positive women.

Brief Report: Markers of Spontaneous Preterm Delivery in Women Living With HIV: Relationship With Protease Inhibitors and Vitamin D

BACKGROUND

Women living with HIV (WLHIV) have increased risk of spontaneous preterm delivery (SPTD). We sought to identify plasma predictors of SPTD and their correlations with factors that increase the risk of SPTD, such as vitamin D deficiency and use of protease inhibitors.

DESIGN

Plasma was obtained from 103 WLHIV with SPTD (≤35 weeks gestation) and 205 controls with term deliveries (TDs; ≥37 weeds) matched to cases 2:1 by race and gestational age at blood draw. TNFα, IFNγ, IL6, IL8, IL1β, IL18, IL17, granulocyte colony stimulating factor (GCSF), MCP1, IP10, sIL2Rα, sCD14, vascular endothelial factor a, monocyte colony stimulation factor, GROα, MMP9, IL10, TGFβ, sCTLA4, and eicosanoids were compared between cases adjusting for known SPTD risk factors.

RESULTS

Participants had similar demographic characteristics, but cases had higher plasma HIV RNA, lower CD4 cells, and more advanced HIV disease compared with controls. High sIL2Rα was associated with increased risk of SPTD. High sCD14, GCSF, PGF2α, and 5-HEPE were marginally associated with increased risk of SPTD. Women who initiated protease inhibitors-containing antiretroviral treatment before or during the first trimester had higher levels of GCSF and 5-HEPE compared with women without such exposure before plasma collection. Vitamin D insufficiency was associated with higher inflammatory sCD14 and PGF2α, and lower anti-inflammatory 5-HEPE.

CONCLUSIONS

The best plasma predictor of SPTD in WLHIV was sIL2Rα, a marker of T-cell activation. Markers of monocyte activation and eicosanoids were marginally increased in WLHIV and SPTD, suggesting that they may also play a role in the pathogenesis of this disorder.

The Impact of Infection in Pregnancy on Placental Vascular Development and Adverse Birth Outcomes

Healthy fetal development is dependent on nutrient and oxygen transfer via the placenta. Optimal growth and function of placental vasculature is therefore essential to support in utero development. Vasculogenesis, the de novo formation of blood vessels, and angiogenesis, the branching and remodeling of existing vasculature, mediate the development and maturation of placental villi, which form the materno-fetal interface. Several lines of evidence indicate that systemic maternal infection and consequent inflammation can disrupt placental vasculogenesis and angiogenesis. The resulting alterations in placental hemodynamics impact fetal growth and contribute to poor birth outcomes including preterm delivery, small-for-gestational age (SGA), stillbirth, and low birth weight (LBW). Furthermore, pathways involved in maternal immune activation and placental vascularization parallel those involved in normal fetal development, notably neurovascular development. Therefore, immune-mediated disruption of angiogenic pathways at the materno-fetal interface may also have long-term neurological consequences for offspring. Here, we review current literature evaluating the influence of maternal infection and immune activation at the materno-fetal interface and the subsequent impact on placental vascular function and birth outcome. Immunomodulatory pathways, including chemokines and cytokines released in response to maternal infection, interact closely with the principal pathways regulating placental vascular development, including the angiopoietin-Tie-2, vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) pathways. A detailed mechanistic understanding of how maternal infections impact placental and fetal development is critical to the design of effective interventions to promote placental growth and function and thereby reduce adverse birth outcomes.

Placental vascular abnormalities in the mouse alter umbilical artery wave reflections

Current methods to detect placental vascular pathologies that monitor Doppler ultrasound changes in umbilical artery (UA) pulsatility have only moderate diagnostic utility, particularly in late gestation. In fetal mice, we recently demonstrated that reflected pressure waves propagate counter to the direction of flow in the UA and proposed the measurement of these reflections as a means to detect abnormalities in the placental circulation. In the present study, we used this approach in combination with microcomputed tomography to investigate the relationship between altered placental vascular architecture and changes in UA wave reflection metrics. Fetuses were assessed at embryonic day (E) 15.5 and E17.5 in control C57BL6/J mice and dams treated with combination antiretroviral therapy (cART), a known model of fetal growth restriction. Whereas the reflection coefficient was not different between groups at E15.5, it was 27% higher at E17.5 in cART-treated mice compared with control mice. This increase in reflection coefficient corresponded to a 36% increase in the total number of vessel segments, a measure of overall architectural complexity. Interestingly, there was no difference in UA pulsatility index between groups, suggesting that the wave reflections convey information about vascular architecture that is not captured by conventional ultrasound metrics. The wave reflection parameters were found to be associated with the morphology of the fetoplacental arterial tree, with the area ratio between the UA and first branch points correlating with the reflection coefficient. This study highlights the potential for wave reflection to aid in the noninvasive clinical assessment of placental vascular pathology. NEW & NOTEWORTHY We used a novel ultrasound methodology based on detecting pulse pressure waves that propagate along the umbilical artery to investigate the relationship between changes in wave reflection metrics and altered placental vascular architecture visualized by microcomputed tomography. Using pregnant mice treated with combination antiretroviral therapy, a model of fetal growth restriction, we demonstrated that reflections in the umbilical artery are sensitive to placental vascular abnormalities and associated with the geometry of the fetoplacental tree.