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 HIV and Hepatitis.com Coverage of the
49
th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2009)
September 12-15, 2009, San Francisco, CA
 The material posted on HIV and Hepatitis.com about the 49th ICAAC is not approved by the American Society for Microbiology
Antiretroviral Pregnancy Registry Indicates Use of Tenofovir (Viread) by Pregnant Women Does Not Raise Risk of Birth Defects

Data submitted to the Antiretroviral Pregnancy Registry (APR), which collects reports of adverse events associated with use of antiretroviral drugs by HIV positive women during pregnancy, show no link between use of tenofovir (Viread, also in the Truvada and Atripla coformulation) and congenital abnormalities, according to a presentation at the 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2009) this week in San Francisco.

By Liz Highleyman

While studies have shown that zidovudine (AZT; Retrovir) is safe and effective for preventing mother-to-child HIV transmission, newer antiretroviral drugs have not been as extensively studied. Rather than using single agents, treatment guidelines in wealthy countries recommend that HIV positive pregnant women should receive a fully suppressive combination antiretroviral therapy (ART) regimen.

Zidovudine has fallen out of favor for non-pregnant HIV patients due to toxicities. Tenofovir is a generally well-tolerated and widely recommended nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) component of ART that may be suitable for use during pregnancy.

Kathleen Squires and colleagues looked at data submitted to the APR, an international prospective registry established in 1989 that collects voluntary reports from healthcare providers and is designed to detect teratogenic effects (congenital anomalies or birth defects) associated with antiretroviral drug exposure during pregnancy. Because most exposures -- especially in developed countries -- involve multiple antiretroviral agents, the investigators also evaluated congenital anomalies associated with selected commonly used regimens.

Through July 31, 2008, a total of 11,950 prospective instances of pregnancy in HIV positive women taking antiretroviral drugs were reported to the registry. Among these, 1146 cases involved use of tenofovir (FDA-approved in 2001). Some cases were still under investigation and others were lost to follow-up, so the final analysis included 10,471 pregnancies, of which 1056 involved tenofovir exposure. Out of these 10,471 pregnancies, 9948 resulted in live births.

The median age of the women enrolled in the registry was about 28 years overall, and 30 years for those who used tenofovir. Among tenofovir recipients, 64% were black, 17% were Hispanic, and 12% were white. About 20% had advanced immune deficiency with a CD4 count below 200 cells/mm3.

Results

The overall prevalence of congenital anomalies in live-born infants with any antiretroviral drug exposure was 2.7% (272 out of 9948 live births).
For exposure during the first trimester -- the most sensitive period for fetal development -- the prevalence was 2.9% (126 out of 4329 live births).
For exposure during the second or third trimester, the prevalence was 2.6% (145 out of 5618 live births).
These rates are comparable to those for infants born to HIV negative mothers, according to the Centers for Disease Control and Prevention (CDC) population-based birth defects surveillance system (2.7% among live births during 1989-2003).
The prevalence of congenital anomalies among infants with first trimester exposure to any tenofovir-containing regimen was 2.3% (14 of 606 live births).
Among infants with second or third trimester exposure to tenofovir, the prevalence was 1.5% (5 of 336 live births).
None of the 5 infants born to HIV monoinfected (i.e., without viral hepatitis) women using tenofovir plus emtricitabine (Emtriva) plus efavirenz (Sustiva) -- the 3 drugs in the Atripla coformulation -- had congenital anomalies, although efavirenz is considered contraindicated due to birth defects observed in animal studies and in humans.
Among infants exposed to tenofovir plus emtricitabine (the 2 drugs in the Truvada coformulation) plus any third drug other than efavirenz, the congenital anomaly prevalence was 2.2% (7 out of 321 live births).
Among infants born to women taking any other tenofovir-containing regimen, the rate was 1.4% (8 out of 556 live births).
In addition, no anomalies were reported among women exposed to tenofovir during pregnancy who had spontaneous abortions (miscarriages), induced abortions, or stillbirths.

Based on these findings, the investigators concluded, "no increase in prevalence of congenital anomalies was seen through prospective voluntary reporting to the APR with use of [tenofovir]-containing antiretroviral regimens during pregnancy."

Prevalence of births defects among women exposed to antiretroviral drugs during the first trimester was similar to the prevalence during the second or third trimester, they added, and "no specific patterns of birth defects were observed."

Thomas Jefferson Univ., Philadelphia, PA; Gilead Sci., Inc., Foster City, CA.

9/15/09

Reference
K Squires, B Olmscheid, and S Zhang. Tenofovir-DF (TDF)-Containing Antiretroviral (ARV) Regimens for Treatment of HIV in Pregnancy: Findings from the Antiretroviral Pregnancy Registry (APR). 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2009). San Francisco. September 12-15, 2009. Abstract H-917.


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



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