Increased Rates of Premature Births Reported From Western European Women Taking HAART

In high-income countries, highly active antiretroviral therapy (HAART) has dramatically reduced rates of life-threatening complications and deaths due to HIV/AIDS. It has also reduced rates of HIV transmission from pregnant mothers to their babies during birth. However, now researchers in Western Europe have found that there appears to be an increased risk of adverse outcomes from pregnancy among some HIV-positive women who use HAART. These outcomes included premature births and babies born with less-than-normal weight. Their conclusions were not reached because of carefully controlled clinical trials, but from analysis of data collected from many clinical centres over time. Until carefully controlled trials are conducted -- together with detailed histories about substance use and co-infection with sexually transmitted diseases (STDs), along with the type of care that these women received during pregnancy -- European researchers cannot be sure about the cause of pregnancy outcomes in HIV-positive women on HAART in that continent.

A recent, similar study in the United States and France did not find any significant increase in abnormal pregnancy outcomes in HIV-positive women taking HAART. According to the results of an American-French study called PACTG 316, which had 1,409 HIV-positive women, the use of HAART has not been linked to an increased risk of premature babies in those countries.

Study Details

Since 1986, researchers across Western Europe have been collecting health-related information on HIV-positive women and their infants. An analysis of data collected between 1986 and May 2004 focused on 3,131 women who had the following profile:

• 74% were white

• 22% were black

• 4% were of other ethno-racial backgrounds

• average age at time of delivery was 28 years

Results -- Trends in Premature Births

The breakdown of premature births in different time periods chosen by the researchers was as follows:

• 1985-1989: 16%

• 1990-1994: 16%

• 1995-1999: 18%

• 2000-2004: 25%

This increase was statistically significant.

Results -- Trends for Low-Weight Infants

Over the length of the study period, babies were at increasing risk of being born underweight. This is not surprising as there was also an increase in premature babies, who are usually underweight. Moreover, premature babies are at increased risk of death. Indeed, the risk of death for premature infants in this study was twice as high as for premature infants born to HIV-negative mothers in Europe.

In analysing many factors, the research team found that women who began to use HAART before becoming pregnant were at highest risk for giving birth prematurely. The researchers note that the use of HAART is clearly beneficial in reducing the risk of mother-to-child transmission of HIV.

If the European research team is to be certain about the effects of HAART on adverse pregnancy outcomes, then detailed reports about specific anti-HIV agents taken, whether there was any substance use and the presence of STDs in the mother are needed because these factors have previously been linked to adverse outcomes in pregnancy in both HIV-positive and HIV-negative women. Also, research on HIV-negative women has found that the provision of proper care during pregnancy can greatly reduce the risk of premature birth.

References

1. Thorne C, Patel D and Newell ML. Increased risk of adverse pregnancy outcomes in HIV-infected women treated with highly active antiretroviral therapy in Europe. AIDS 2004;18(17):2337-2339.

2. Watts DH, Balasubramanian R, Maupin R, et al. Maternal Toxicity and Pregnancy Outcome According to Antiretroviral Therapy during Pregnancy: An Analysis of the PACTG 316 Study. In: Programs and Abstracts of the 10th Conference on Retroviruses and Opportunistic Infections; February 10 -14, 2003, San Francisco. Abstract 888.

3. Lambert JS, Watts DH, Mofenson L, et al. Risk factors for preterm birth, low birth weight, and intrauterine growth retardation in infants born to HIV-infected pregnant women receiving zidovudine. Pediatric AIDS Clinical Trials Group 185 Team. AIDS 2000;14(10):1389-1399.

4. Visscher WA, Feder M, Burns AM et al. The impact of smoking and other substance use by urban women on the birth weight of their infants. Substance Use and Misuse 2003;38(8):1063-1093.

5. Armstrong MA, Gonzales Osejo V, Lieberman L, et al. Perinatal substance abuse intervention in obstetric clinics decreases adverse neonatal outcomes. Journal of Perinatology 2003;23(1):3-9.