How Is HIV Transmitted from Mother to Child?
HIV can be transmitted during pregnancy, during delivery and through breast milk.
What Are the Risks?
Let us first consider the risk. Nearly 60 percent of the women becoming pregnant today in some clinics already know of their HIV status and of that number nearly half are on antiretroviral therapy. Many of the women on therapy may require regimen adjustments during their pregnancy course. What are the risks? Without any antiretroviral therapy during pregnancy, during delivery or to the infant after delivery an infant may have a twenty percent chance of being infected with HIV. With the use of antiretroviral therapy, including AZT, with or without cesarean delivery, the risk can be decreased to one to seven percent. (See options for serodiscorant couples to learn more about risk to the HIV negative partner.)
Although a cesarean delivery can decrease the risk of transmission it could increase a woman's morbidity and mortality after delivery. Complications such as postpartum infections are five to seven times more likely to occur after cesarean section with labor or membrane rupture compared to vaginal delivery. Genital infections, obesity, malnutrition, smoking, low socioeconomic status and prolonged labor or membrane rupture all can increase the risk of complications after delivery.
Cesarean complication appears to be the same in women with and without HIV infection. Women with HIV should consider viral load, immune status and therapeutic care before becoming pregnant.
According to The Body website, "Risk to the infant can be further increased before and during delivery with the use of the following procedures: amniocentesis, fetal scalp monitoring, internal monitoring, PUBS (percutaneous umbilical blood sampling), urinary catheters, artificial rupturing of membranes, forceps and vacuum extractors." This does not rule out the use of these procedures, both the doctor and patients should discuss these procedures before delivery and decisions should be based on individual clinical factors.
It is not recommended for women to use monotherapy AZT. There are a few antiretrovirals that are not recommended for use during pregnancy. These medications include Kaletra and Norvir. Sustiva is not reccomended during pregnancy due to some results from preliminary studies. Viramune is not reccomended because it can cause severe, life threatening and, in some cases, fatal hepatoxicity (liver damage). This can occur suddenly and with great severity, usually accompanied by pain. Women with hepatitis or other liver damage are not recommended to take Viramune.
A woman with HIV should be given every opportunity to maximize their health, which should include the option to use highly active antiretroviral therapy (HAART). According to PACTG (Pediatric AIDS Clinical Trials Group) 076, AZT should be considered unless the woman can not tolerate AZT.
Viral load levels should be monitored during the pregnancy. Recent viral load levels should be considered when discussing the mode of delivery.
Scheduled cesarean sections can reduce transmission among women on no antiretroviral therapy or on AZT for prophylaxis of prenatal transmission with unknown viral load levels.
Women with viral load levels higher than 1,000 copies/ml should be counseled regarding the benefit of a scheduled cesarean section delivery in reducing transmission to the newborn.
If a woman chooses to have a cesarean section then it should be scheduled and performed at 38 weeks gestation according to the best available dating parameters, and intravenous AZT should be begun at least three hours before surgery.
The benefits of a cesarean section delivery is unknown with viral loads less than 1,000 copies/ml, but given the low rate of transmission in this group of women, it is unlikely that a cesarean section should be recommended.
Women should know the risk of cesarean section delivery.
A woman should be counseled that with a low viral load she may have a two percent chance or less to transmit HIV to her newborn.
Intravenous (IV) AZT should be started immediately when the woman is in labor or has ruptured membranes. If the labor is progressing rapidly, the woman should be allowed to delivery vaginally.
If cervical dilatation is minimal and a long period of labor is anticipated, some doctors have chosen to give a larger dose of AZT and proceed with a cesarean section to decrease the duration of membrane rupture and avoid vaginal delivery. Others may give pitocin augmentation to enhance contractions and potentially expedite the delivery.
Infants should receive six weeks of AZT therapy after birth.
A woman should be made aware that not all the answers are known about perinatal transmission and for this reason her choice should be respected and honored.
Options for HIV-Serodiscordant Couples
Many couples in which one is HIV positive and the other is HIV negative take the risk of having unprotected sex in the hopes of producing a HIV-negative child. The risk of perinatal transmission has gone down significantly over the last seven years. Making parenting a realistic possibility for couples today. The risk of infected the uninfected partner is still very much real. If the man is HIV positive and the woman is negative the couple takes the risk of infecting the woman and the unborn child with HIV.
To reduce this risk a couple has only a few options in the United States. One is to go to a sperm bank to get a donor sperm for the HIV negative woman. Although, this is a safe method, this is not the choice of many couples. Another option is adoption, but many couples find it very difficult to adopt a child when one partner is HIV positive. Also this option means that the child has neither parents genes. This brings us to our final option of intrauterine insemination after washing sperm free of HIV. This is a practice that is being used in Europe and to date, Enrico Semprini, a pioneer in this process, has performed 1,954 inseminations in 623 women, resulting in 272 pregnancies and 242 healthy children, giving a pregnancy rate per insemination of 14%. So far there have not been any reports of HIV transmission from HIV positive partner to HIV negative partner.
Since 1990 the Center for Disease Control and Prevention (CDC) has not recommended the insemination of women with semen from an HIV infected man. This recommendation came after a single report came out about a woman who was inseminated with her HIV-positive husband sperm and HIV was transmitted to the woman. In order to protect individuals from errors during sperm washing, most centers offer a sperm-washing service advocate PCR HIV (viral load) testing of an aliquot of washing sperm before insemination.