Blunted fetal growth by tenofovir in late pregnancy

Benefits and Risks of Antiviral Treatment during Pregnancy in Patients with Chronic Hepatitis B

Hepatitis B virus (HBV) is a main cause of chronic liver disease worldwide and can lead to severe liver diseases. The World Health Organization has planned to eliminate viral hepatitis, including hepatitis caused by HBV and hepatitis C virus, by 2030. As mother-to-child transmission (MTCT) of HBV is a main cause of chronic HBV infection, MTCT prevention is the main target to reduce the risk of chronic HBV infection and eliminate the disease. Recent clinical trials and meta-analyses found that antiviral therapy could prevent MTCT effectively in mothers with ≥200,000 IU/mL of HBV DNA, in combination with serial vaccination and hepatitis B immune globulin administration in infants. Despite the preventive role of antivirals for MTCT of HBV, there are several concerns regarding antiviral therapy with respect to the safety of the mother and fetus during pregnancy. This review summarizes the benefits and risks of antiviral treatment during pregnancy in women with chronic HBV infection.

Influence of maternal use of tenofovir disoproxil fumarate or zidovudine in Vietnamese pregnant women with HIV on infant growth, renal function, and bone health

Tenofovir disoproxil fumarate (TDF) is still widely prescribed for human immunodeficiency virus (HIV)-infected pregnant women, despite its renal and bone toxicity. Although TDF-exposed infants often show transient growth impairment, it is not clear whether maternal TDF causes infantile rickets via maternal/fetal renal dysfunction in Asian populations. This prospective observational study was conducted in Vietnam and involved pregnant HIV-infected women treated with TDF-based regimen (TDF group) or zidovudine-based regimen (AZT-group). At birth, 3, 12, and 18 months of age, and included body length, weight, head circumference, serum alkaline phosphatase (ALP), creatinine, calcium, phosphorus, urine-β2-microglobulin (U-BMG), percentage of tubular reabsorption of phosphate (%TRP), and radiographic wrist score for rickets. Age-adjusted multivariate linear regression analysis evaluated the association of TDF/AZT use during pregnancy with fetal renal function and bone health. The study included 63 mother-infant pairs (TDF group = 53, AZT group = 10). In the mothers, detectable U-BMG (>252 μg/L) was observed more frequently in the TDF- than AZT group (89 vs 50%, p<0.001), but other renal/bone parameters were similar. In infants, maternal TDF use was not associated with growth impairment, renal dysfunction, or abnormal bone findings, but with a slightly higher ALP levels (p = 0.019). However, shorter length was associated with maternal AZT (p = 0.021), and worse radiographic scores were associated with LPV/r (p = 0.024). In Vietnamese population, TDF usage during pregnancy was not associated with infant transient rickets, growth impairment, or renal dysfunction, despite mild maternal tubular impairment. Maternal AZT and LPV/r influenced infant growth and bone health, though further studies are needed to confirm this finding.

Maternal Tenofovir Disoproxil Fumarate Use During Pregnancy Is Not Associated With Adverse Perinatal Outcomes Among HIV-infected East African Women: A Prospective Study

Background

Tenofovir disoproxil fumarate (TDF) is commonly used in antiretroviral treatment (ART) and pre-exposure prophylaxis regimens. We evaluated the relationship between adverse perinatal outcomes and prenatal TDF use.

Methods

Longitudinal data were analyzed from human immunodeficiency virus (HIV)-infected women who became pregnant during 2 HIV prevention studies conducted among HIV-serodiscordant couples in Kenya and Uganda. Pregnancies included were singleton, not terminated by an induced abortion, and had documented 3-drug ART use. Multivariate generalized estimating equation models were used to determine the association of prenatal TDF and perinatal outcomes.

Results

The most frequent ART regimens were TDF/3TC/EFV (39%) and AZT/3TC/NVP (34%); 49% of pregnancies had prenatal TDF exposure and 6% used a protease inhibitor. Neonatal death, preterm birth, and pregnancy loss occurred in 2%, 8%, and 12% of pregnancies, respectively. No differences were observed between pregnancies with and without exposure to TDF in the frequency of pregnancy loss (adjusted prevalence rate ratio [aPRR] 1.19, P = .8) or neonatal death (aPRR 0.68, P = .6). Preterm birth occurred less frequently among pregnancies exposed to TDF (aPRR, 0.34, P = .02).

Conclusion

Maternal TDF use did not adversely affect perinatal outcomes.

Birth Outcomes for Pregnant Women with HIV Using Tenofovir-Emtricitabine

BACKGROUND

In a previous trial of antiretroviral therapy (ART) involving pregnant women with human immunodeficiency virus (HIV) infection, those randomly assigned to receive tenofovir, emtricitabine, and ritonavir-boosted lopinavir (TDF-FTC-LPV/r) had infants at greater risk for very premature birth and death within 14 days after delivery than those assigned to receive zidovudine, lamivudine, and ritonavir-boosted lopinavir (ZDV-3TC-LPV/r).

METHODS

Using data from two U.S.-based cohort studies, we compared the risk of adverse birth outcomes among infants with in utero exposure to ZDV-3TC-LPV/r, TDF-FTC-LPV/r, or TDF-FTC with ritonavir-boosted atazanavir (ATV/r). We evaluated the risk of preterm birth (<37 completed weeks of gestation), very preterm birth (<34 completed weeks), low birth weight (<2500 g), and very low birth weight (<1500 g). Risk ratios with 95% confidence intervals were estimated with the use of modified Poisson models to adjust for confounding.

RESULTS

There were 4646 birth outcomes. Few infants or fetuses were exposed to TDF-FTC-LPV/r (128 [2.8%]) as the initial ART regimen during gestation, in contrast with TDF-FTC-ATV/r (539 [11.6%]) and ZDV-3TC-LPV/r (954 [20.5%]). As compared with women receiving ZDV-3TC-LPV/r, women receiving TDF-FTC-LPV/r had a similar risk of preterm birth (risk ratio, 0.90; 95% confidence interval [CI], 0.60 to 1.33) and low birth weight (risk ratio, 1.13; 95% CI, 0.78 to 1.64). As compared to women receiving TDF-FTC-ATV/r, women receiving TDF-FTC-LPV/r had a similar or slightly higher risk of preterm birth (risk ratio, 1.14; 95% CI, 0.75 to 1.72) and low birth weight (risk ratio, 1.45; 95% CI, 0.96 to 2.17). There were no significant differences between regimens in the risk of very preterm birth or very low birth weight.

CONCLUSIONS

The risk of adverse birth outcomes was not higher with TDF-FTC-LPV/r than with ZDV-3TC-LPV/r or TDF-FTC-ATV/r among HIV-infected women and their infants in the United States, although power was limited for some comparisons. (Funded by the National Institutes of Health and others.).

Bone Age and Mineral Density Assessments Using Plain Roentgenograms in Tenofovir-exposed Infants in Malawi and Brazil Enrolled in HIV Prevention Trials Network 057

BACKGROUND

Tenofovir disoproxil fumarate (TDF) use during pregnancy has been increasing, and studies linking bone toxicity with exposure to TDF have raised concern for its use in infants.

METHODS

Hand/wrist and spine radiographs were obtained at 3 days and 12 weeks of age in infants born to HIV-infected pregnant women enrolled in the HIV Prevention Trials Network 057 pharmacokinetic study of TDF conducted in Malawi and Brazil assigned to 3 TDF dosing cohorts. In cohort 1, mothers received 600 mg of TDF during labor. In cohort 2, infants received 4 mg/kg dose on days 0, 3 and 5. In cohort 3, a 900 mg maternal dose was given during labor, followed by a 6 mg/kg infant dose on days 0, 3 and 5 of life.

RESULTS

Across all 3 cohorts, 89 infants had radiographs performed at either time point, and 85 had radiographs performed at both time points. Metaphyseal lucency was present in 1 case in Brazil and 2 in Malawi. Fifteen percent of infants from Brazil and 9% of infants from Malawi presented bone age discrepancies. No other abnormalities were identified in Brazil, whereas in Malawi, there were 7 more cases of wrist osteopenia, 2 of spine osteopenia and 3 other abnormalities.

CONCLUSION

Bone abnormalities were not uncommon in the overall cohort of HIV-exposed infants. Because of very limited study drug exposure at the time of birth, it is unlikely that TDF was associated with these findings. Untreated maternal HIV disease and/or maternal nutritional status could potentially be related to fetal bone development. This association should be explored in future cohort studies.

Maternal Tenofovir Disoproxil Fumarate Use in Pregnancy and Growth Outcomes among HIV-Exposed Uninfected Infants in Kenya

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is commonly used in antiretroviral treatment (ART) and preexposure prophylaxis regimens. We evaluated the relationship of prenatal TDF use and growth outcomes among Kenyan HIV-exposed uninfected (HEU) infants.

MATERIALS AND METHODS

We included PCR-confirmed HEU infants enrolled in a cross-sectional survey of mother-infant pairs conducted between July and December 2013 in Kenya. Maternal ART regimen during pregnancy was determined by self-report and clinic records. Six-week and 9-month z-scores for weight-for-age (WAZ), weight-for-length (WLZ), length-for-age (LAZ), and head circumference-for-age (HCAZ) were compared among HEU infants with and without TDF exposure using t-tests and multivariate linear regression models.

RESULTS

Among 277 mothers who received ART during pregnancy, 63% initiated ART before pregnancy, of which 89 (32%) used TDF. No differences in birth weight (3.0 kg versus 3.1 kg, p = 0.21) or gestational age (38 weeks versus 38 weeks, p = 0.16) were detected between TDF-exposed and TDF-unexposed infants. At 6 weeks, unadjusted mean WAZ was lower among TDF-exposed infants (-0.8 versus -0.4, p = 0.03), with a trend towards association in adjusted analyses (p = 0.06). There were no associations between prenatal TDF use and WLZ, LAZ, and HCAZ in 6-week or 9-month infant cohorts.

CONCLUSION

Maternal TDF use did not adversely affect infant growth compared to other regimens.

Infant growth outcomes after maternal tenofovir disoproxil fumarate use during pregnancy

OBJECTIVE

To determine whether maternal use of tenofovir disoproxil fumarate for treatment of HIV in pregnancy predicts fetal and infant growth.

METHODS

The study population included HIV-uninfected live-born singleton infants of mothers enrolled in the International Maternal Pediatric Adolescent AIDS Clinical Trials Group protocol P1025 (born 2002-2011) in the United States and exposed in utero to a combined (triple or more) antiretroviral regimen. Infant weight at birth and 6 months was compared between infants exposed and unexposed to tenofovir in utero using 2-sample t test, χ test, and multivariable linear and logistic regression models, including demographic and maternal characteristics.

RESULTS

Among 2025 infants with measured birth weight, there was no difference between those exposed (N = 630, 31%) versus unexposed to tenofovir in mean birth weight (2.75 vs. 2.77 kg, P = 0.64) or mean gestational age- and sex-adjusted birth weight z-score (WASZ) (0.14 vs. 0.14, P = 0.90). Among 1496 infants followed for 6 months, there was no difference in mean weight at 6 months between tenofovir-exposed (N = 457, 31%) and tenofovir-unexposed infants (7.64 vs. 7.59 kg, P = 0.52) or in mean WASZ (0.29 vs. 0.26, P = 0.61). Tenofovir exposure during the second/third trimester, relative to no exposure, significantly predicted underweight (WASZ < 5%) at age 6 months [odds ratio (95% confidence interval): 2.06 (1.01 to 3.95), P = 0.04]. Duration of tenofovir exposure did not predict neonatal or infant growth.

CONCLUSIONS

By most measures, in utero exposure to tenofovir did not significantly predict infant birth weight or growth through 6 months of age.

Safety of tenofovir during pregnancy for the mother and fetus: a systematic review

Tenofovir disoproxil fumarate (TDF) safety during pregnancy has important public health implications. This review summarizes TDF safety during pregnancy, focusing on pregnancy outcomes, congenital anomaly risk, and other potential toxicities on neonates. Although information is limited, TDF appears to be safe during pregnancy. In 6 studies of human immunodeficiency virus type 1 (and/or hepatitis B virus)-infected women receiving TDF during pregnancy, adverse events were mild to moderate; none were considered to be TDF-related. Five studies that followed in utero TDF-exposed infants showed no increased risk of growth or bone abnormalities. One study showed slightly lower infant height at age 1 year, but the significance is unclear. The Antiretroviral Pregnancy Registry database, with 1800 pregnancies exposed to TDF in the first trimester, does not indicate increased congenital anomaly risk with TDF exposure. More evidence collected prospectively, ideally with bone density measurements and randomized trial design, will be optimal to determine the effects of antenatal TDF exposure on children's health.