Assessing the risk of birth defects associated with antiretroviral exposure during pregnancy

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.

Pharmacoepidemiologic Evaluation of Birth Defects from Health-Related Postings in Social Media During Pregnancy

Introduction

Adverse effects of medications taken during pregnancy are traditionally studied through post-marketing pregnancy registries, which have limitations. Social media data may be an alternative data source for pregnancy surveillance studies.

Objective

The objective of this study was to assess the feasibility of using social media data as an alternative source for pregnancy surveillance for regulatory decision making.

Methods

We created an automated method to identify Twitter accounts of pregnant women. We identified 196 pregnant women with a mention of a birth defect in relation to their baby and 196 without a mention of a birth defect in relation to their baby. We extracted information on pregnancy and maternal demographics, medication intake and timing, and birth defects.

Results

Although often incomplete, we extracted data for the majority of the pregnancies. Among women that reported birth defects, 35% reported taking one or more medications during pregnancy compared with 17% of controls. After accounting for age, race, and place of residence, a higher medication intake was observed in women who reported birth defects. The rate of birth defects in the pregnancy cohort was lower (0.44%) compared with the rate in the general population (3%).

Conclusions

Twitter data capture information on medication intake and birth defects; however, the information obtained cannot replace pregnancy registries at this time. Development of improved methods to automatically extract and annotate social media data may increase their value to support regulatory decision making regarding pregnancy outcomes in women using medications during their pregnancies.

A Multicenter Analysis of Elvitegravir Use During Pregnancy on HIV Viral Suppression and Perinatal Outcomes

Background

There is a knowledge gap on the clinical use of elvitegravir (EVG) during pregnancy and maternal viral suppression. Our objective was to evaluate the effects of EVG use in pregnancy on rates of HIV virologic suppression and perinatal outcomes.

Methods

We conducted a retrospective, multicenter study of pregnant women living with HIV (WLHIV) who used EVG-containing antiretroviral therapy (ART) between January 2014 and March 2017 at 9 tertiary care centers in the United States. WLHIV were included if they took EVG at any time during pregnancy. We described the characteristics of the WLHIV using EVG during the study period and evaluated the rates of HIV suppression and perinatal outcomes.

Results

Among 134 pregnant WLHIV who received EVG at any time during pregnancy, viral suppression at delivery (HIV-1 RNA < 40 copies/mL) occurred in 81.3%. In WLHIV who initiated EVG before pregnancy and continued through delivery (n = 68), the rate of viral suppression at delivery was 88.2%. The average gestational age at the time of delivery was 37 weeks 6 days, and the overall rate of preterm birth was 20%. No cases of open neural tube defects were noted in women on EVG at the time of conception (n = 82). The perinatal HIV transmission rate was 0.8%.

Conclusions

EVG use was associated with high sustained levels of HIV suppression during pregnancy and a low rate of perinatal HIV transmission.

Managing Mother-to-Child Transmission of HIV Infection in Developed-Country Settings

This article reviews current understanding of the management of mother-to-child transmission of HIV-1 infection in the context of developed-country settings. The advent of highly active antiretroviral therapy has facilitated the virtual elimination of mother-to-child transmission of HIV infection in developed countries, reducing transmission rates to approximately 1–2%. This review describes the epidemiology of HIV infection among women of child-bearing age and the risk factors, timing and mechanisms of mother-to-child transmission, followed by a discussion of the identification of pregnant HIV-infected women and their therapeutic and obstetric management.

In Utero Tenofovir Exposure Is not Associated With Fetal Long Bone Growth

BACKGROUND

Despite widespread use of tenofovir disoproxil fumarate (TDF) in pregnant and breastfeeding women, few data exist on fetal bone development after in utero TDF exposure. We evaluated fetal long bone growth in human immunodeficiency virus (HIV)-infected pregnant woman/fetus dyads in Cape Town, South Africa.

METHODS

Women were recruited from primary care antenatal services and underwent ultrasonography to determine femur (FLZ) and humerus (HLZ) length z scores. The duration of in utero TDF exposure was calculated in weeks. Linear regression models were applied to assess the associations between the duration of in utero TDF exposure and change in FLZ and HLZ.

RESULTS

A total of 646 woman/fetus dyads contributed 1376 ultrasonographic scans to this analysis: 132 dyads with ≥25 weeks, 326 with 10-24 weeks, and 188 with <10 weeks of TDF exposure. Women receiving TDF for ≥25 weeks were older than those receiving TDF for 10-24 or <10 weeks (median age, 31 vs 28 and 28 years, respectively; P < .01), and had lower HIV RNA levels (median log10 HIV RNA level, 1.59 vs 4.08 and 3.83, respectively; P < .01). Throughout gestation, overall median FLZ and HLZ were 0.30 (interquartile range, -0.03 to 0.63) and 0.22 (-0.26 to 0.59) respectively. In multivariate analysis, there was no association between duration of in utero TDF exposure per 1-week increment and change in FLZ (ß = .00; P = .51) or change in HLZ (ß = .00; P = .40). Results were similar using mixed-effects models.

CONCLUSIONS

Although longer follow-up is needed, these in utero data are reassuring and support the continued use of TDF in pregnancy.

Challenges in Studying Modifiable Risk Factors for Birth Defects

Conducting research to identify modifiable risk factors for birth defects is difficult for a variety of reasons. While some challenges are familiar to researchers across many disciplines, the confluence of issues affecting birth defects research may not be well understood by those outside of the field. This article describes several methodological challenges to the study of birth defects and ways these challenges might be addressed: (1) ascertainment, definition and classification of birth defects; (2) exposure assessment on modifiable risk factors; (3) analytical challenges related to small numbers and multiple statistical tests; (4) the role of genetics, including the collection of specimens and analysis of genetic data; and (5) challenges in translating research and demonstrating public health impact. Understanding these issues is important for researchers planning studies, reviewers evaluating the scientific merit of results from these studies, and consumers of the research, including fellow researchers, policy makers, health care providers, and families.

Metabolic complications of in utero maternal HIV and antiretroviral exposure in HIV-exposed infants

BACKGROUND

Despite a wide body of literature supporting the use of antenatal antiretrovirals (ARV) for the prevention of mother-to-child transmission, there remains a need for continued monitoring as the intrauterine interval is a critical period during which fetal programming influences the future health and development of the child.

METHODS

We conducted a systematic review of the current literature addressing potential metabolic complications of in utero HIV and ARV exposure. We describe studies evaluating metabolic outcomes such as intrauterine and early postnatal growth, bone health and mitochondrial toxicity.

RESULTS

Overall, infants exposed to HIV/ARV do not appear to exhibit vastly compromised intrauterine or early postnatal growth. However, some studies on the effect of combination antiretroviral therapy on small for gestational age and low birth weight outcomes in low-middle income countries show a risk for small for gestational age/low birth weight while those in the United States do not. Postnatal growth to 1 year does not appear to be affected by intrauterine tenofovir exposure in African studies, but a US study found statistically significant differences in length for age z scores (LAZ) at 1 year. Little data exists on long-term bone health. Mitochondrial toxicity including abnormal mitochondrial morphology and DNA content, as well as neurologic deficits and death, have been demonstrated in HIV/ARV-exposed infants.

CONCLUSION

Although gross measures of metabolic well-being appear to be reassuring, careful vigilance of even small risks for potential serious adverse effects to infants exposed to intrauterine HIV/ARVs is warranted as intrauterine fetal metabolic programming may substantially impact the future health of the child.

HIV protease inhibitors in pregnancy : pharmacology and clinical use

The impact of antiretroviral therapy (ART) on the natural history of HIV-1 infection has resulted in dramatic reductions in disease-associated morbidity and mortality. Additionally, the epidemiology of HIV-1 infection worldwide is changing, as women now represent a substantial proportion of infected adults. As more highly effective and tolerable antiretroviral regimens become available, and as the prevention of mother-to-child transmission becomes an attainable goal in the management of HIV-infected individuals, more and more HIV-positive women are choosing to become pregnant and have children. Consequently, it is important to consider the efficacy and safety of antiretroviral agents in pregnancy. Protease inhibitors are a common class of medication used in the treatment of HIV-1 infection and are increasingly being used in pregnancy. However, several studies have raised concerns regarding pharmacokinetic alterations in pregnancy, particularly in the third trimester, which results in suboptimal drug concentrations and a theoretically higher risk of virologic failure and perinatal transmission. Drug level reductions have been observed with each individual protease inhibitor and dose adjustments in pregnancy are suggested for certain agents. Furthermore, studies have also raised concerns regarding the safety of protease inhibitors in pregnancy, particularly as they may increase the risk of pre-term birth and metabolic disturbances. Overall, protease inhibitors are safe and effective for the treatment of HIV-infected pregnant women. Specifically, ritonavir-boosted lopinavir- and atazanavir-based regimens are preferred in pregnancy, while ritonavir-boosted darunavir- and saquinavir-based therapies are reasonable alternatives. This paper reviews the use of protease inhibitors in pregnancy, focusing on pharmacokinetic and safety considerations, and outlines the recommendations for use of this class of medication in the HIV-1-infected pregnant woman.

Does pregnancy affect the early response to cART?

OBJECTIVE

A part of women starting antiretroviral therapy during pregnancy fail to attain undetectable viral load by delivery. Here we studied whether pregnancy affects the early immunovirological response to combined antiretroviral therapy (cART), taking into account treatment duration and baseline characteristics.

DESIGN

Antiretroviral-naive women initiating cART since 2004 and followed in three French ANRS multicenter HIV cohorts (French Perinatal Cohort, PRIMO and COPANA).

METHODS

The early virological response (at 1, 3 and 6 months) and immunological increase after cART initiation were compared between women starting cART during (n = 708) and outside (n = 110) pregnancy. Relative risks were estimated in multivariate models adjusted for treatment duration, baseline viral load and CD4, sociodemographic factors and chronic hepatitis B. CD4 increases were compared by using mixed models.

RESULTS

Only 63.8% of treated pregnant women attained a viral load less than 50 copies/ml by delivery. Similarly to nonpregnant women, nearly 90% of pregnant women reached a viral load less than 400 copies/ml at M3 [adjusted RR: 1.0 (95% confidence interval 0.7-1.4)], and nearly 100% at M6 following cART initiation [0.9 (0.4-1.9)]. viral load less than 50 copies/ml was attained by 61.5% of pregnant versus 67.9% of nonpregnant women at M3 (P = 0.26), and by 82.1 versus 87.0% at M6 (P = 0.48). CD4 recovery (both number and percentage) was similar in pregnant and nonpregnant women. Results were similar for the subset of women starting a boosted protease inhibitor-containing cART.

CONCLUSION

Pregnancy does not affect the virological response to cART below 400 copies/ml, or CD4 increase. The main reason for pregnant women not achieving viral load less than 50 copies/ml at delivery appears to be a short duration of treatment.

The efficacy and safety of antiviral therapy with lamivudine to stop the vertical transmission of hepatitis B virus

The purpose of this study was to investigate the efficacy and safety of lamivudine (LAM) in stopping the vertical transmission of hepatitis B virus (HBV). Pregnant women with normal alanine transaminase (ALT) (n = 100) and with abnormal ALT (n = 100) who were positive for hepatitis B e antigen (HBeAg), and with HBV DNA (deoxyribonucleic acid) levels ≥1.0 × 107 copies/ml were enrolled in this study. One hundred volunteers (50 with normal ALT, 50 with abnormal ALT) received 100 mg of LAM daily from the 24th to 32nd week of gestation and the untreated 100 volunteers served as controls. All infants received passive-active immunoprophylaxis. Compared to the control group, the study group got a marked reduction in serum levels (P < 0.001) and high negativity (P < 0.001) of HBV DNA before delivery. They also got normalization in ALT levels as much as controls received general medication (P > 0.05). The prenatal transmission rate in the study group was significantly lower than that of the control group (P < 0.05). There were no differences in incidences of congenital malformation between the two groups (P > 0.05). LAM treatment can effectively and safely stop vertical transmission of HBV and normalize the ALT levels of pregnant women.

Free and total plasma levels of lopinavir during pregnancy, at delivery and postpartum: implications for dosage adjustments in pregnant women

BACKGROUND

Physiological changes associated with pregnancy may alter antiretroviral plasma concentrations and might jeopardize prevention of mother-to-child HIV transmission. Lopinavir is one of the protease inhibitors more frequently prescribed during pregnancy in Europe. We described the free and total pharmacokinetics of lopinavir in HIV-infected pregnant and non-pregnant women, and evaluated whether significant alterations in its disposition and protein binding warrant systematic dosage adjustment.

METHODS

Plasma samples were collected at first, second and third trimester of pregnancy, at delivery, in umbilical cord and postpartum. Lopinavir free and total plasma concentrations were measured by HPLC-MS/MS. Bayesian calculations were used to extrapolate total concentrations to trough (Cmin).

RESULTS

A total of 42 HIV-positive pregnant women and 37 non-pregnant women on lopinavir/ritonavir were included in the study. Compared to postpartum and control values, total lopinavir Cmin was decreased moderately (31-39%) during pregnancy, and free Cmin minimally, showing significant alteration only at delivery (-35%). However, total and free Cmin remained in all patients above the target concentrations for wild-type virus of 1,000 ng/ml, and above the unbound IC50(WT) of 0.64-0.77 ng/ml of lopinavir, respectively. Lopinavir free fractions remained higher during pregnancy compared to postpartum and controls, and were influenced by α-1-acid-glycoprotein and albumin decrease. Free cord-to-mother ratio (0.43) was 2.7-fold higher than total cord-to-mother ratio (0.16), suggesting higher fetal exposure.

CONCLUSIONS

The moderate decrease of total lopinavir concentrations during pregnancy is not associated with proportional decrease in free concentrations. Both reach a nadir at delivery, albeit not to an extent that would put treatment-naive women at risk of insufficient exposure to the free, pharmacologically active concentrations of lopinavir. No dosage adjustment is therefore needed during pregnancy as it is unlikely to further enhance treatment efficacy but could potentially increase the risk of maternal and fetal toxicity. Nonetheless, in case of viral resistance in treatment-experienced pregnant women, loss of virological control or questionable adherence, it is justified to consider lopinavir dosage adjustment based on total plasma concentration measurement.

A prospective and open-label study for the efficacy and safety of telbivudine in pregnancy for the prevention of perinatal transmission of hepatitis B virus infection

BACKGROUND & AIMS

In the Asia-Pacific region, perinatal transmission of the hepatitis B virus (HBV) is the primary cause of chronic hepatitis B infection. Despite the use of HBIG and HBV vaccination, HBV perinatal transmission (PT) occurs in 10-30% of infants born to highly viremic mothers. We evaluated the efficacy and safety of LTD use during late pregnancy in reducing HBV transmission in highly viremic HBeAg+mothers.

METHODS

Two hundred and twenty-nine HBeAg+HBV DNA levels>1.0×10(7) copies/ml mothers received telbivudine 600 mg/day from week 20 to 32 of gestation (n=135) or served as untreated controls (n=94). All infants in both arms received 200 IU of HBIg within 12 h postpartum and recombinant HBV vaccine of 20 μg at 0, 1, and 6 months. HBsAg and HBV DNA results of infants at week 28 were used to determine perinatal transmission rate. All telbivudine treated subjects were registered in the Antiretroviral Pregnancy Registry.

RESULTS

Telbivudine treatment was associated with a marked reduction in serum HBV DNA and hepatitis B e antigen (HBeAg) levels and normalization of elevated ALT levels before delivery. A striking decline of HBV DNA levels started from treatment onset to week 4, and sustained in a low level since week 12. Forty-four (33%) of the 135 telbivudine-treated mothers and none (0%) of the untreated controls had polymerase chain reaction-undetectable viremia (DNA<500 copies/ml) at delivery. Seven months after delivery, the incidence of perinatal transmission was lower in the infants that completed follow-up born to the telbivudine-treated mothers than to the controls (0% vs. 8%; p=0.002). HBV DNA levels were only detectable in HBsAg+infants. No significant differences in anti-HBs levels were observed during postnatal follow-up. No serious adverse events were noted in the telbivudine-treated mothers or their infants.

CONCLUSIONS

Telbivudine used during pregnancy in CHB HBeAg+highly viremic mothers can safely reduce perinatal HBV transmission. Telbivudine was well-tolerated with no safety concerns in the telbivudine-treated mothers or their infants on short term follow up. These data support the use of telbivudine in this special population.

Efavirenz-based combination antiretroviral therapy after peripartum single-dose nevirapine

Single-dose nevirapine (sdNVP) reduces mother-to-child HIV transmission, but induces NVP resistance and subsequent NVP-based combination antiretroviral therapy (cART) may fail. Some resistance mutations affect NVP more than efavirenz (EFV). We evaluated virological suppression of EFV-based cART in women after sdNVP. A retrospective analysis matched 107 women who had received sdNVP within the 24 months before cART (cases) with women who had never received sdNVP (controls). By total cohort (intention-to-continue treatment) at week 96, 65% of cases and 73% of controls had a viral load (VL) <400 copies/mL and 63% of cases and 64% of controls had VL <25 copies/mL. At weeks 48 and 96, women starting cART less than six months after sdNVP (n = 20) had VL <400 copies/mL of 90% and 75%, respectively compared with 90% and 70%, respectively, for controls. Overall 172 (80%) women reached week 96. EFV-based cART, in field conditions, was effective for women after sdNVP, even within six months of sdNVP.

Nevirapine-associated hepatotoxicity was not predicted by CD4 count ≥250 cells/μL among women in Zambia, Thailand and Kenya

OBJECTIVE

The aim of the study was to determine risk factors for developing severe hepatotoxicity (grade 3 or 4 hepatotoxicity) and rash-associated hepatotoxicity (rash with ≥ grade 2 hepatotoxicity) among women initiating nevirapine-based antiretroviral therapy (ART).

METHODS

The Non-Nucleoside Reverse Transcriptase Inhibitor Response Study was a prospective cohort study carried out in Zambia, Thailand and Kenya. Between May 2005 and January 2007, we enrolled antiretroviral-naïve HIV-infected women initiating nevirapine-based ART. At enrollment and at weeks 2, 4, 8, 16 and 24, participants had serum alanine transferase (ALT) and aspartate transaminase (AST) measured and were evaluated clinically for hepatitis and rash.

RESULTS

Nevirapine-based ART was initiated in 820 women and baseline ALT or AST results were abnormal (≥ grade 1) in 113 (14%) women. After initiating nevirapine-based ART, severe hepatotoxicity occurred in 41 (5%) women and rash-associated hepatotoxicity occurred in 27 (3%) women. In a multivariate logistic regression model, severe hepatotoxicity and rash-associated hepatotoxicity were both associated with baseline abnormal (≥ grade 1) ALT or AST results, but not with a baseline CD4 cell count ≥250 cells/μL. Three participants (0.4%) died with symptoms suggestive of fatal hepatotoxicity; all three women had baseline CD4 count <100 cells/μL and were receiving anti-tuberculosis therapy.

CONCLUSION

Among women taking nevirapine-based ART, severe hepatotoxicity and rash-associated hepatotoxicity were predicted by abnormal baseline ALT or AST results, but not by a CD4 count ≥250 cells/μL. In resource-limited settings where transaminase testing is available, testing should focus on early time-points and on women with abnormal baseline ALT or AST results.

Lamivudine in late pregnancy to interrupt in utero transmission of hepatitis B virus: a systematic review and meta-analysis

OBJECTIVES

To evaluate efficacy of lamivudine in reducing in utero transmission of hepatitis B virus (HBV).

DATA SOURCES

A database was constructed from Medline, EMBASE, Cochrane Library, National Science Digital Library, China Biological Medicine Database, and through contact with experts in the field from January 1990 to October 2009.

METHODS OF STUDY SELECTION

We used the Jadad score and Cochrane Collaboration's tool for assessing risk of bias.

TABULATION, INTEGRATION, AND RESULTS

We abstracted data regarding HBV intrauterine infection, mother-to-child transmission, maternal HBV DNA level, treatment methods, and adverse effects. All newborns followed joint immune prophylaxis schedule of hepatitis B vaccine and hepatitis B immunoglobulin after delivery. The Mantel-Haenszel random-effects model was employed for all analyses using odds ratio (OR) and 95% confidence interval. Compared with the no-treatment group or placebo group, newborns in the lamivudine group had a 10.7–23.7% lower incidence of intrauterine infection, indicated by newborn hepatitis B surface antigen (0.38,0.15–0.94, six randomized controlled trials [RCTs], P5.04) and HBV DNA (0.22, 0.12–0.40, four RCTs, P,.001) seropositivity, and a 12.7–33.2% lower mother-to child transmission rate at 9–12 months, indicated by infant hepatitis B surface antigen (0.31, 0.15–0.63, five RCTs, P,.01) and HBV DNA (0.20, 0.10–0.39, two RCTs,P,.001) seropositivity [corrected].No significant higher adverse effects or complications in pregnancy were observed.

CONCLUSION

Lamivudine in HBV carrier-mothers with high degree of infectiousness in late pregnancy effectively prevented HBV intrauterine infection and mother-to-child transmission.

Antiretroviral therapy (ART) for treating HIV infection in ART-eligible pregnant women

BACKGROUND

This systematic review focuses on antiretroviral therapy (ART) for treating human immunodeficiency virus (HIV) infection in ART-eligible pregnant women. Mother-to-child transmission (MTCT) is the primary means by which children worldwide acquire HIV infection. MTCT occurs during three major timepoints during pregnancy and the postpartum period: in utero, intrapartum, and during breastfeeding. Strategies to reduce MTCT focus on these periods of exposure and include maternal and infant use of ART, caesarean section before onset of labour or rupture of membranes, and complete avoidance of breastfeeding. Where these combined interventions are available, the risk of MTCT is as low as 1-2%. Thus, ART used among mothers who require treatment of HIV for their own health also plays a significant role in decreasing MTCT.This review is one in a series of systematic reviews performed in preparation for the revision of the 2006 World Health Organization (WHO) Guidelines regarding "Antiretroviral Drugs for Treating Pregnant Women and Preventing HIV Infection in Infants" and "Antiretroviral therapy (ART) for HIV Infections in Adults and Adolescents." The findings from these reviews were discussed with experts, key stakeholders, and country representatives at the 2009 WHO guideline review meeting. The resulting WHO 2009 "rapid advice" preliminary guidance on adult and adolescent ART now recommends lifelong treatment for all adults with HIV infection and CD4 counts <350 cells/mm(3). These recommendations also apply to pregnant women who are HIV-infected and they place a high value on early ART to benefit the mother's own health (WHO 2009). The "rapid advice" preliminary guidance also aims to minimize side effects for mothers and their infants (WHO 2009).

OBJECTIVES

Our objective was to assess the current literature regarding the treatment of HIV infection in pregnant women who are clinically or immunologically eligible for ART. This review includes an evaluation of the optimal time to start therapy in relation to the woman's laboratory parameters and/or gestational age. It also includes an analysis of which specific antiretroviral medications to start in women who are not yet on ART and which agents to continue in women who are already on ART.

SEARCH STRATEGY

In June 2009, electronic searches were undertaken in these databases: Cochrane's "CENTRAL," EMBASE, PubMed, LILACS, and Web of Science/Web of Social Science. Hand searches were performed of the reference lists of all pertinent reviews and studies identified. Abstracts from relevant conferences were searched. Experts in the field were contacted to locate additional studies. The search strategy was iterative.

SELECTION CRITERIA

We selected randomized controlled trials and observational studies that evaluated pregnant women with HIV infection who were eligible for ART according to criteria defined by the WHO guideline review committee. Studies were included in the systematic review when a comparison group was clearly defined and where the intervention comprised triple ART. For a study to be considered, each medication in the ART regimen needed to be clearly described.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the selected studies for relevance and inclusion. Relevant data was then extracted from included studies, and the risk of bias assessed. In each included study, the relative risk (RR) for the intervention versus the comparison group was calculated for each outcome, as appropriate, with 95% confidence intervals (CIs).

MAIN RESULTS

To our knowledge, there are no randomized controlled trials or observational studies that address the optimal time to start antiretroviral drugs in ART-eligible pregnant women in relation to the woman's laboratory parameters and/or gestational age. The medications to continue in ART-eligible pregnant women who are already receiving ART also have not been evaluated systematically in the current literature. The long-term mortality of HIV-positive pregnant women on ART for their own health, and the long-term virologic or clinical efficacy of ART in treating them, has not been evaluated in randomized clinical trials. In this review, surrogate outcomes for long-term mortality and virologic and clinical efficacy (e.g. MTCT and infant HIV transmission or death) were evaluated to determine the efficacy of specific antiretroviral regimens to start in women who are not yet on ART.Three randomized controlled trials and six observational studies were selected. No studies addressed comparative maternal mortality, which regimens to continue in women already on ART, or the laboratory parameters and gestational age at which to start therapy. The use of zidovudine (AZT), lamivudine (3TC) and lopinavir/ritonavir (LPV-r) starting at 28-36 weeks gestation in a breastfeeding population reduced infant HIV-transmission or death at 12 months compared to a short-course regimen (RR 0.64, 95% CI: 0.44-0.92) (deVincenzi, 2009). Starting AZT, 3TC, and nevirapine (NVP) at 34 weeks in a mixed-feeding population reduced infant HIV-transmission or death at 7 months compared to a short-course regimen (RR 0.39, 95% CI: 0.12-0.85) (Bae, 2008).In the Mma Bana study (a randomized controlled trial in a breastfeeding population) there was no difference in MTCT at six months between the AZT/3TC/LPV-r and AZT, 3TC, and abacavir (ABC) arms (RR 0.17, 95% CI: 0.02-1.44) (Shapiro, 2009). Both regimens also showed 92-95% efficacy in virologic suppression at delivery and during the breastfeeding period. In the Kesho Bora study there was a significant difference in MTCT at 12 months between breastfeeding women who initiated AZT/3TC/LPV-r starting between 28 and 36 weeks and those receiving a short course regimen (RR 0.58, 95% CI: 0.34-0.97) (deVincenzi, 2009). MTCT also decreased significantly when AZT/3TC/NVP was compared with a short-course regimen at seven months in a feeding intervention study (RR 0.15, 95% CI: 0.04-0.62) (Bae, 2008) and 12 months in a population where either exclusive breastfeeding or replacement feeding was encouraged (RR 0.14, CI: 0.04-0.47) (Ekouevi, 2008).In the Mma Bana study, there was increased risk of prematurity among infants born to women receiving AZT/3TC/LPV-r (RR 1.52, CI: 1.07- 2.17) compared with AZT/3TC/ABC (Shapiro, 2009). Ekouevi 2008 showed higher rates of infant low birth weight on AZT/3TC/NVP started at 24 weeks compared to a short course regimen started between 32 and 36 weeks (RR 1.81, 95% CI: 1.09- 3.0). Tonwe-Gold 2007 showed an increase in maternal severe adverse events among the women receiving AZT/3TC/NVP compared with a short-course regimen (RR 25.33, CI 1.49- 340.51).

AUTHORS' CONCLUSIONS

In ART-eligible pregnant women with HIV infection, ART is a safe and effective means of providing maternal virologic suppression, decreasing infant mortality, and reducing MTCT. Specifically, AZT/3TC/NVP, AZT/3TC/LPV-r, and AZT/3TC/ABC have been shown to decrease MTCT. More research is needed regarding the use of specific regimens and their maternal and infant side-effect profiles.

HEPATITIS B AND PREGNANCY, THE SCIENTIFIC BASIS FOR PERINATAL PREVENTION

Hepatitis B and its complications are one of the major global health problems. Around 2 billion individuals are infected by hepatitis B virus (HBV) worldwide, more than 350 million are chronically infected, and approximately 15 to 40 percents of them will develop serious complications such as liver cirrhosis, hepatic failure, or hepatocellular carcinoma (HCC). The worldwide prevalence of chronic HBV infection ranges from 0.1 to 20 percent and varies widely in different geographic areas. According to the prevalence rate, WHO has classified countries into 3 levels: high areas (>8%) such as Africa, Asia, Western Pacific and Middle East; intermediate areas (2–8%) such as South America and Eastern Europe, and low areas (<2%) such as Western Europe, North America, and Australia.

Birth defects following exposure to efavirenz-based antiretroviral therapy during pregnancy: a study at a regional South African hospital

OBJECTIVES

To determine the prevalence and type of birth defects among infants following exposure to efavirenz-based antiretroviral therapy (EFV-based ART) during pregnancy.

METHODS

A Pregnancy Registry was established to enable prospective follow-up of women taking EFV-based ART. In women who conceived on EFV-based ART, EFV was switched with another drug if they presented during the first trimester but was continued if they presented at or after 14 weeks' gestation. Pregnant women needing lifelong ART were commenced on EFV-based ART from 14 weeks' gestation onwards. Infants were followed up for 6 weeks after birth.

RESULTS

Between January 2006 and December 2008, 623 ART-naive pregnant women initiated EFV-based ART in the second/third trimester and 195 women conceived on EFV-based ART. Birth defects were observed in 16 of 623 live births [2.6%; 95% confidence interval (CI) 1.5-4.2] and in six of 184 live births (3.3%; 95% CI 1.2-7.0) from women exposed to EFV in the second/third trimester and first trimester, respectively. The prevalence of birth defects was not significantly different between the first and second/third trimester EFV exposure (prevalence ratio 1.27; 95% CI 0.50-3.20; P = 0.301).

CONCLUSION

No significant increase in the prevalence of birth defects following exposure to EFV-based ART in the first trimester was observed in this cohort. However, the limited number of first trimester EFV-exposed infants precludes definitive conclusions on the teratogenicity or safety of EFV.

Side effects of long-term oral antiviral therapy for hepatitis B

The aim of this review is to summarize the safety profile of the five approved oral nucleoside analogs used to treat chronic hepatitis B virus (HBV) infection, focusing on both the class adverse effects and those that have been reported with individual agents, as well as their safety in pregnancy. All nucleoside analogs have a "Black Box" warning because of their potential for inhibition of human DNA polymerase gamma involved in mitochondrial DNA replication. A reduction in intracellular mitochondrial DNA levels can lead to varying clinical manifestations of mitochondrial toxicity (i.e., neuropathy, myopathy, lactic acidosis), but these side effects are rarely reported with the oral antiviral agents active against HBV. Adefovir and tenofovir are associated with a dose-dependent but usually reversible proximal renal tubular toxicity. For these reasons, patients receiving these agents should be monitored for renal toxicity and the dose modified for renal insufficiency. Prolonged use of tenofovir has also been reported to lead to reduced bone mineral density in patients with human immunodeficiency virus infection, but prospective studies in patients with HBV infection are lacking. Telbivudine treatment is associated with moderate serum creatine phosphokinase elevations in up to 12% of patients. There have been few prospective studies on the safety of nucleoside analogs during pregnancy. According to the Antiretroviral Pregnancy Registry, the incidence of birth defects associated with lamivudine and tenofovir use during pregnancy is not increased. Studies on the safety of long-term therapy with the nucleoside analogs, alone and in combination, are needed as are further studies of children, the elderly, pregnant women, and patients with renal insufficiency.

[Birth defects in a cohort of uninfected children born to HIV-infected women]

INTRODUCTION

Mother-to-Child HIV transmission is now just 1% in western countries, due to prevention measures. Antiretroviral Treatment (ART) drugs do have adverse effects, anaemia and myelosupression caused by cidovudina being the most commonly observed effects. In the present study, we have analysed the proportion and characteristics of congenital malformations (CM) or birth defects (BD) in a cohort of uninfected children born to HIV-infected women.

METHODS

A total of 623 uninfected children belonging to the FIPSE cohort were followed up according to standardised protocols. This cohort includes 8 public hospitals from Madrid and follows up HIV-infected pregnant women and their children. Children were classified according to prematurity, ethnic origin, birth weight, withdrawal syndrome, in-utero treatment. Birth defects were described and defined according to the EUROCAT, the European registry for BD. Mild errors of morphogenesis were excluded from the analysis. Categorical variables were compared with the X(2) or the Fisher test.

RESULTS

A total of 78% (486) of the mothers were of Caucasian origin; 18.8% (117) used some illicit drug (heroine, cocaine or methadone) during gestation; 51 mothers (8.1%) received no ART, 10 (1.6%) received monotherapy and 469 (75.3%) received HAART. BD were seen in 52 children, with the most frequent being genitourinary and cardiological. Anaemia in the first trimester was an associated risk for BD (17.9% vs. 8.1%, P = 0,04). Similarly, mothers who used any illicit drug (plus methadone), had a slightly higher risk for BD in their offspring (13.8% vs. 7.6%, P = 0,04) There was no increased risk for BD significantly associated with any of the in-utero used antiretrovirals, although Nevirapine use in-utero showed a protective effect. Children born to mothers who received ART in the first trimester had the same rate of BD (7.4%) as those whose mothers started ART in the second trimester (8.8%), P = 0,67.

CONCLUSIONS

The proportion of BD that we have observed seems higher than those shown in other European teratogenicity studies and also higher than those shown in cohorts with HIV and antiretroviral exposed infants. This may be due to the fact that our series show the results of an active surveillance system (that includes ultrasound), where BD classically appear in a higher proportion. Immunovirological characteristics of the mother did not influence the proportion of BD, but anaemia in the fist trimester and the use of illicit drugs (or methadone) did. No specific antiretroviral drug was associated with an increase in BD, although Nevirapine showed a possible protective effect in the statistical analysis. Mothers who started antiretrovirals in the first trimester do not have more BD in their offspring than mothers who started on antiretrovirals later on.

Antiretroviral therapy and congenital abnormalities in infants born to HIV-infected women in the UK and Ireland, 1990-2007

OBJECTIVE

To explore the rate of reported congenital abnormalities in infants exposed to antiretroviral therapy in utero.

DESIGN

Comprehensive national surveillance study in the UK and Ireland.

METHODS

Births to diagnosed HIV-infected women are reported to the National Study of HIV in Pregnancy and Childhood. Infants born between 1990 and 2007 were included.

RESULTS

The rate of reported major and minor congenital abnormality was 2.8% (232/8242) overall, and there was no significant difference by timing of ART exposure: 2.8% (14/498) in unexposed infants, 2.7% (147/5427) following second or third trimester exposure, and 3.1% (53/1708) following first trimester exposure (P = 0.690). There was no difference in abnormality rates by class of ART exposure in the first trimester (P = 0.363), and no category of abnormality was significantly associated with timing of ART, although numbers in these groups were small. There was no increased risk of abnormalities in infants exposed to efavirenz (P = 0.672) or didanosine (P = 0.816) in the first trimester.

CONCLUSION

These findings, based on a large, national, unselected population provide further reassurance that ART in utero does not pose a major risk of fetal anomaly.

Antiretroviral treatment during pregnancy

OBJECTIVE

Virologic failure of HIV-positive patients is of special concern during pregnancy. We compared virologic failure and the frequency of treatment changes in pregnant and non-pregnant women of the Swiss HIV Cohort Study.

METHODS

Using data on 372 pregnancies in 324 women we describe antiretroviral therapy during pregnancy. Pregnant women on HAART at conception (n = 131) were matched to 228 non-pregnant women (interindividual comparison) and to a time period of equal length before and after pregnancy (intraindividual comparison). Women starting HAART during pregnancy (n = 145) were compared with 578 non-pregnant women starting HAART.

FINDINGS

The median age at conception was 31 years, 16% (n = 50) were infected through injecting drug use and the median CD4 cell count was 489 cells/microl. In the majority of pregnancies (n = 220, 59%), women had started ART before conception. When ART was started during pregnancy (n = 145, 39%), it was mainly during the second trimester (n = 100, 69%). Two thirds (n = 26) of 35 women starting in the third trimester were diagnosed with HIV during pregnancy. The risk of virologic failure tended to be lower in pregnant than in non-pregnant women [adjusted odds ratio 0.52 (95% confidence interval 0.25-1.09, P = 0.08)], but was similar in the intraindividual comparison (adjusted odds ratio 1.04, 95% confidence interval 0.48-2.28). Women starting HAART during pregnancy changed the treatment less often than non-pregnant women.

CONCLUSION

Despite the physiological changes occurring during pregnancy, HIV infected pregnant women are not at higher risk of virologic failure.

Pregnancy rates and birth outcomes among women on efavirenz-containing highly active antiretroviral therapy in Botswana

BACKGROUND

Millions of HIV-infected women in developing countries are in need of safe and highly effective antiretroviral therapy. Pregnancy rates are usually high in developing countries, and efavirenz (EFV) use in women of childbearing age is of concern because of its potential teratogenicity.

METHODS

As part of a prospective study comparing 6 initial highly active antiretroviral therapy (HAART) regimens, 3 of which contained EFV, pregnancy and birth outcomes were evaluated among female participants enrolled in a randomized clinical trial in Botswana. Before enrollment, all female participants indicated a willingness to avoid pregnancy for the 3-year duration of the study. Monthly urine pregnancy testing and regular contraceptive education and counseling were given to all women on study.

RESULTS

Four hundred fifty-one (69.4%) of 650 enrolled study participants were female and experienced 71 pregnancies, for a rate of 7.9 per 100 person-years during the study. The mean time from HAART initiation to time of first pregnancy was 385 days. The median birth weight of babies was 2950 g (interquartile range: 2700-3250 g); the gender of babies (24 female and 15 male) and occurrence of early pregnancy loss (42%) and stillbirths (3%) did not differ between EFV- and non-EFV-exposed pregnancies (P=0.7). First-trimester EFV exposure occurred in 38 (53.5%) of the 71 pregnancies; 22 (57.9%) of these 38 pregnancies resulted in live births. One infant (4.5%) of the 22 EFV-exposed live births had a congenital abnormality with right limb shortening that was assessed to be unrelated to EFV exposure.

CONCLUSIONS

The restoration of health and longevity in many HAART-treated women is often accompanied by childbearing, as evidenced by the large fraction of women in our cohort who became pregnant despite their initial statements of intent to avoid pregnancy. Of 22 first-trimester EFV-exposed live births, 1 neonate was found to have a major congenital abnormality; however, this defect was unrelated to EFV exposure. The small sample size is insufficient to estimate accurately the underlying risk of congenital malformation after exposure to EFV in early pregnancy, underscoring the importance of reporting to the existing international Antiretroviral Pregnancy Registry. In addition to accessing safe and effective HAART regimens, HIV-infected women require access to comprehensive family planning services, including contraception and procreation counseling.

Antiretroviral therapy and premature delivery in diagnosed HIV-infected women in the United Kingdom and Ireland

OBJECTIVE

To explore the association between antiretroviral therapy in pregnancy and premature delivery, birthweight, stillbirth and neonatal mortality, in pregnancies in HIV-infected women delivering between 1990 and 2005.

DESIGN

Pregnancies in women with diagnosed HIV infection in the UK and Ireland are notified to the National Study of HIV in Pregnancy and Childhood (NSHPC) through a well-established surveillance scheme.

RESULTS

The prematurity rate (< 37 weeks gestation) was higher in women on highly active antiretroviral therapy (HAART) (14.1%, 476/3384) than in women on mono/dual therapy (10.1%, 107/1061), even after adjusting for ethnicity, maternal age, clinical status and injecting drug use as the source of HIV acquisition [adjusted odds ratio (AOR) = 1.51, 95% confidence interval (CI), 1.19-1.93; P = 0.001]. Delivery at < 35 weeks was even more strongly associated with HAART (AOR = 2.34; 95% CI, 1.64-3.37; P < 0.001). The effect was the same whether or not HAART included a protease inhibitor. In comparison with exposure to mono/dual therapy, exposure to HAART was associated with lower birthweight standardized for gestational age (P < 0.001), and an increased risk of stillbirth (AOR = 2.27; 95% CI, 0.96-5.41; P = 0.063).

CONCLUSIONS

These findings, based on comprehensive population surveillance, demonstrate an increased risk of prematurity associated with HAART, and a possible association with other perinatal outcomes, including stillbirth and birthweight. Although the beneficial effects of antiretroviral therapy on mother-to-child transmission are indisputable, monitoring antiretroviral therapy in pregnancy remains a priority.

The antiretrovirals in pregnancy registry: a fifteenth anniversary celebration

The year 2007 marks the fifteenth anniversary year of the founding of a landmark effort in drug safety risk management, the formation of the first monitoring effort of an antiretroviral (ARV) drug in pregnancy which has become the Antiretrovirals in Pregnancy Registry, the APR. This multicompany, multi-national voluntary collaborative registry monitors pregnancy exposure to a class of highly important drugs for any indication of an increase in the postexposure incidence of birth defects in the offspring of these pregnancies. To recognize the anniversary, the Steering Committee of the APR has commissioned this review of the contributions and lessons learned over the past decade and a half and, in the spirit of continuous process improvement, has committed to apply these lessons for the next fifteen years. This retrospective examines the antecedents to this registry and the context in which the APR was formed; the early efforts to establish technical and organizational procedures and policies; the evolving experiences with enrollment and follow-up, patient and participant protections, information management and oversight; public and regulatory dissemination; and of course, the accomplishments and lessons learned.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to explain the value of a drug registry in determining safety risk management; summarize that the Antiretroviral (ARV) drugs in Pregnancy Registry (APR) is a very successful multinational, multicompany collaborative effort that has been in place for 15 years; and state that it has been an ideal public interest effort dealing with the devastating pandemic of human immunodeficiency viral disease.

Update: preventing mother-to-child transmission of HIV

The success of antiretroviral therapies for prevention of mother-to-child transmission of HIV in the developed world has prompted a wide array of research efforts, from improved implementation of voluntary counseling and testing programs to innovative approaches for short-course peripartum prophylaxis to understanding the dynamics of HIV transmission via breastfeeding. Clinical trials of modified short-course peripartum regimens which are applicable to resource-limited areas are demonstrating much lower transmission rates and preliminary data are emerging on limiting transmission via breastfeeding. Some of the most recent data on these topics are reviewed. Primary prevention of HIV in women of childbearing age combined with efforts to prevent mother-to-child transmission of HIV offer the best hope for addressing the burden of HIV in women and children.

Assessment of Birth Defects According to Maternal Therapy Among Infants in the Women and Infants Transmission Study

BACKGROUND

To evaluate rate and types of birth defects according to timing of antiretroviral exposure among babies born to HIV-infected women.

METHODS

Anomalies identified during the prenatal, neonatal, or follow-up period were classified using criteria of the Antiretroviral Pregnancy Registry. Antiretroviral use was classified as none, second or third trimester only, or first trimester.

RESULTS

From January 1, 1990 through June 30, 2004, 2527 live births (LBs) occurred to 2353 women. Defects were identified in 90 babies for a rate of 3.56 defects per 100 LBs. The rate of defects was 3.19 per 100 LBs (24 of 752 LBs) with first-trimester antiretroviral exposure, 3.54 per 100 LBs (41 of 1158 LBs) with exposure later in pregnancy, and 4.05 of 100 LBs (25 of 617 LBs) with no antiretroviral use. Only genital abnormalities, specifically hypospadias, were significantly increased among babies born to women with first-trimester exposure to antiretrovirals (7 of 382 male LBs) compared with the 2 other groups (2 of 892 male LBs; P = 0.007). On logistic regression, use of zidovudine in the first trimester was associated with hypospadias (adjusted odds ratio = 10.68, 95% confidence interval: 2.11 to 54.13; P = 0.004).

CONCLUSIONS

In general, data were reassuring, although the frequency of exposure to newer agents was limited. The increased risk of hypospadias after first-trimester exposure must be explored, because this association has not been detected previously.

Prevention of mother-to-child transmission of HIV: treatment options

Mother-to-child transmission of HIV-1 is responsible for 1800 new infections in children daily. The use of antiretroviral therapy can significantly reduce the risk of transmission. In settings where highly active antiretroviral therapy is available, mother-to-child transmission rates have been reduced to less than 2%, in the absence of breastfeeding. Women who require ongoing highly active antiretroviral therapy for their own health should receive this in pregnancy, which is also very effective in preventing transmission. Where resources allow, combination highly active antiretroviral therapy can also be used for preventing mother-to-child transmission in those women who do not yet need to receive ongoing treatment. The potential side effects of highly active antiretroviral therapy must be considered in pregnant women and their infants. Where highly active antiretroviral therapy is not possible, a dual combination regimen of antepartum zidovudine with single-dose nevirapine to mother and baby can reduce transmission to below 5%. In many places, the only available option is single-dose nevirapine to mother and baby, which is effective in halving transmission risk, although the effectiveness in practice will be influenced by continued infection through breastfeeding, and by program factors such as the uptake of HIV testing. Exposure to nevirapine for mother-to-child transmission prevention can select for resistant virus in the majority of women. While the long-term implications of this are not completely clear, this selection can be reduced by the addition of short courses of postpartum zidovudine and lamivudine.

Antiretroviral Therapy and Congenital Abnormalities in Infants Born to HIV-1-Infected Women in the United Kingdom and Ireland, 1990 to 2003

Antiretroviral therapy (ART) in pregnancy substantially reduces the risk of mother-to-child transmission of HIV, but concerns exist about the potential for teratogenic effects. This analysis was undertaken to explore the relation between ART in pregnancy and birth defects in infants born to HIV-infected women in the United Kingdom and Ireland between 1990 and 2003. Comprehensive obstetric and pediatric HIV surveillance is carried out through the National Study of HIV in Pregnancy and Childhood. Congenital abnormalities were reported in 101 of 3172 infants (100 of 3120 pregnancies). There was no statistically significant association between the prevalence of congenital abnormalities and exposure to ART overall: 3.4% (90 of 2657 pregnancies) in exposed pregnancies and 2.2% (10 of 463 pregnancies) in nonexposed pregnancies (P = 0.166); prevalence was similar whether or not exposure occurred in the first trimester: 3.7% (20 of 541 pregnancies) after early exposure and 3.1% (80 of 2579 pregnancies) without early exposure (P = 0.476). There was also no significant association with type of ART in early pregnancy (ie, highly active antiretroviral therapy [HAART] vs. mono- or dual therapy, HAART with protease inhibitor and/or nonnucleoside reverse transcriptase inhibitor). The lack of association was maintained after adjustment for potential confounding factors. These findings are reassuring, but continued monitoring is essential in view of the increasing number of women on therapy at conception and the likely continuing diversity of drug regimens.

Efavirenz use during pregnancy and for women of child-bearing potential

BACKGROUND

Efavirenz is the preferred non-nucleoside reverse transcriptase inhibitor for first-line antiretroviral treatment in many countries. For women of childbearing potential, advantages of efavirenz are balanced by concerns that it is teratogenic. This paper reviews evidence of efavirenz teratogenicity and considers implications in common clinical scenarios.

FINDINGS

Concerns of efavirenz-induced fetal effects stem from animal studies, although the predictive value of animal data for humans is unknown. Four retrospective cases of central nervous system birth defects in infants with first trimester exposure to efavirenz have been interpreted as being consistent with animal data. In a prospective pregnancy registry, which is subject to fewer potential biases, no increase was detected in overall risk of birth defects following exposure to efavirenz in the first-trimester.

DISCUSSION

For women planning a pregnancy or not using contraception, efavirenz should be avoided if alternatives are available. According to WHO guidelines for resource-constrained settings, benefits of efavirenz are likely to outweigh risks for women using contraception. Women who become pregnant while receiving efavirenz often consider drug substitution or temporarily suspending treatment. Both options have substantial risks for maternal and fetal health which, we argue, appear unjustified after the critical period of organogenesis (3-8 weeks post-conception). Efavirenz-based triple regimens, initiated after the first trimester of pregnancy and discontinued after childbirth, are potentially an important alternative for reducing mother-to-child transmission in pregnant women who do not yet require antiretroviral treatment.

CONCLUSION

Current recommendations for care for women who become pregnant while receiving efavirenz may need to be re-considered, particularly in settings with limited alternative drugs and laboratory monitoring. With current data limitations, additional adequately powered prospective studies are needed.

Strategies to prevent mother-to-child transmission of HIV

PURPOSE OF REVIEW

This review describes recent advances in the prevention of mother-to-child transmission, focusing on the use of antiretroviral treatment strategies in pregnancy, and discusses the emergence of viral resistance following the use of nevirapine to prevent mother-to-child transmission.

RECENT FINDINGS

Mother-to-child transmission has been dramatically reduced in developed countries by the use of antiretroviral treatment and avoidance of breastfeeding. Highly active antiretroviral therapy use in pregnancy is recommended for women who require ongoing treatment, and, where available, is also very effective in reducing mother-to-child transmission in women with higher CD4 counts. The addition of a maternal and infant nevirapine dose to antenatal zidovudine can reduce transmission to below 5%, approximately half the transmission rate that can be achieved by single-dose nevirapine alone. The emergence of resistant virus following nevirapine use is a concern, occurring in up to 60% of mothers and 50% of infants following a single dose. Addition of zidovudine and lamivudine for 4-7 days postpartum can reduce the risk of resistance to 10%.

SUMMARY

There is broad consensus on an approach to preventing mother-to-child transmission, which provides antiretroviral treatment in pregnancy and beyond to those women who need it, and an effective prophylactic regimen for those who do not yet need treatment, These regimens include highly active antiretroviral therapy, where available, a zidovudine-plus-nevirapine regimen in other settings, or nevirapine alone where this is all that is possible. More work is needed on the impact of nevirapine resistance and on reducing breast-milk transmission.

The safety of antiretroviral drugs in pregnancy

Advances in HIV therapy and mother-to-child transmission (MTCT) prophylaxis have led to increasing use of antiretroviral drugs in pregnancy. Highly active antiretroviral therapy in pregnancy has been associated with prematurity, pre-eclampsia and gestational diabetes. Women may be at increased risk of nevirapine-associated hepatotoxicity but whether or not pregnancy is an additional risk is uncertain. Although animal studies suggest a possibility of congenital abnormalities with specific antiretrovirals, such as efavirenz, results from registries and cohort studies do not support an excess of congenital malformations associated with in utero antiretroviral exposure. Concerns regarding the health of uninfected, antiretroviral-exposed children include the potential for cancers, mitochondrial disease and haematological abnormalities. However, the absence of any excess mortality in large observational cohort studies of uninfected, antiretroviral therapy-exposed children born to HIV-infected women is reassuring. Based on current knowledge, the immense benefits of antiretroviral prophylaxis in reducing the risk of MTCT, far outweigh the potential for adverse effects.