A major public health triumph for the pediatric community has been a significant decrease in transmission of HIV, the virus that causes AIDS, from pregnant women to the baby. This is especially important for prospective adoptive parents. The decrease in rates is due to the treatment of pregnant women who are HIV+ with antiviral drugs and the elective use of Caesarean section delivery for infected women. However, drug abuse continues to be a leading factor in placing an individual at risk for HIV infection, and those families who are fostering or adopting an infant whose mother has used drugs during pregnancy have to continue to be concerned about this issue.
Risk varies based on a number of factors. In a recent study of 1,106,757 pregnancies in 955,251 women from across the country, it was found that 2856 women (0.28 percent) were HIV positive. Importantly, there were significant variations in positive rates based on regions in the country. Pregnant women in Washington DC had an HIV positive rate of 5.8 percent, those in Maryland and New York had rates at about 0.9 percent, and all other states had a prevalence rate below 0.5 percent.
Although HIV screening is fairly common during pregnancy, there are many instances in which it is not performed. In addition, Hepatitis C rates are burgeoning in the drug and alcohol using populations, and it is relatively rare that the pregnant woman has been tested for this. Many adoption agencies with which I have had the opportunity to work are now testing all newborns under their supervision for both HIV and Hepatitis C. However, potential foster and adoptive families need to ask a lot of questions before they make a long-term commitment to a new baby.
Testing and evaluation of newborns for infection with HIV or with Hepatitis C is very complex, complicated by the fact that there is relatively little information regarding long-term experience with children infected with Hepatitis C. When I work with foster and prospective adoptive families, I recommend that all newborn have Hepatitis C and HIV screens at birth or as soon thereafter as possible. When an infant or child, no matter what age, is first being evaluated for possible placement, I recommend testing.
The usual first screening test is for the HIV or Hepatitis C antibody, a reaction to presence of the virus. If the initial antibody test is negative, it is highly unlikely that this is a false negative (a blood test that is negative, but the child actually is infected) for either Hepatitis C or HIV. No repeat antibody screen is needed, although parents may wish to have one done if the child was less than 6 weeks of age at the time of testing. In this case, a repeat antibody screen at three to six months of age can be considered.
If the initial antibody test for HIV or Hepatitis C is positive, a follow up second level of testing needs to be done. This test is called a PCR, which stands for polymerase chain reaction. PCR is a method to analyze a short sequence of genetic material –DNA or RNA – even in samples containing only minimal quantities of the material.
a. AIDS: A PCR in the first three months has about a 40 percent chance of being a false negative (that is, the child is infected but the test is negative). PCR for HIV infection reaches almost 100 percent accuracy by 4 months. If the PCR is negative for HIV at 4 months, no further evaluation is needed. If the parents wish to follow up with a confirmatory PCR, this should be done at six months.
b. Hepatitis C: A PCR at 6 weeks to two months of age has about a 20 percent chance of being a false negative. The accuracy slowly increases, so that by 6 months, chances for a false negative are 10 percent. Many experts recommend that a PCR not even be done until 6 months of age. However, this is untenable for many families trying to make a decision around adoption. A reasonable course would be to perform a PCR at 6 weeks to two months. If it is positive, that gives the family significant information, although it still is not 100 percent accurate. If negative, it narrows the statistical chances for the family down to a 20 percent chance. Since overall likelihood of transmission of Hepatitis C is about 5 percent from mother to child, statistically the baby probably is not infected. This information regarding Hepatitis C relates to the child who is HIV negative. If the child is HIV positive, transmission of Hepatitis C is many times higher, so the protocol for testing would be different.
These recommendations are a combination of research-based information and my own experience in working with infants and children prenatally exposed to drugs and alcohol. Though this is an issue that many prospective parents – and agencies – are reluctant to even have to think about, it is in the best interest of the child and the family to have the facts and then make decisions based on accurate information.