When can HIV be transmitted from mother to child?

  • During pregnancy
  • During labor and delivery
  • Through breast feeding

Does HIV affect pregnancy?

For asymptomatic women (without any symptoms), HIV does not seem to affect pregnancy. These women don't seem to have any more complications in pregnancy than women without HIV.

Does pregnancy affect HIV?

Pregnancy has not been shown to speed up the progression of HIV.

What are the chances that HIV will be transmitted from mother to child?

Without the use of antiviral therapy, HIV is transmitted about 25% of the time. In 1994 a study (ACTG 076) showed that AZT can reduce the rate of transmission to 8%. In this study, AZT was given to women after 14 weeks of pregnancy, during labor, and then to the newborn infant for 6 weeks after birth. There's no way to know for sure which infants will be infected and which won't.

How is HIV diagnosed in infants -- PCR (polymerase chain reaction)

This test looks for the DNA (genetic material) of the virus. (This test is different from the viral load PCR tests, that are used in people that already know they are HIV+).

At 4 weeks of age, if an infant's PCR test result is positive, the test is 90% accurate. At six months of age, the test is 99% accurate. If the PCR is positive it means the infant is probably HIV+. There are very few cases of false positives.

Antibody testing

If an infant tests positive for HIV antibodies it doesn't mean that the infant is definitely HIV+. It means the infant carries the mother's HIV antibodies. These antibodies may be present in the infant's blood for up to 18 months of age. A PCR test should be done to determine whether or not the infant has HIV.

What else can affect the risk of transmission to newborns?


Since T-cells are an indicator of disease progression, your count should be monitored. A low T-cell count may increase the risk of transmission.

Viral load:

There have been some studies that indicate that a low viral load count reduces the risk of transmission. Especially during labor and delivery, the lower your viral load count, the less virus the infant will be exposed to.

Cesarean sections

Elective C-sections prior to the rupture of membranes can prevent the infant from being exposed to maternal blood and secretions while passing through the birth canal. Studies have shown that delivery more than 4 hours after the water breaks (ruptured membranes) doubles the risk of transmission. Plan ahead and discuss the possibility of a C-section with your OB/GYN.

Vaginal cleansing

Washing out the birth canal with a mild disinfectant reduces the chance of transmission.

Procedures that may increase the risk of transmission

Amniocentesis, fetal scalp monitoring, internal fetal monitoring. PUBS (percutaneous umbilical blood sampling), urinary catheters, artificial rupturing of membranes, forceps, and vacuum extractors all increase the risk of transmission. This does not rule out the use of these procedures given individual clinical factors. Since we now know that AZT monotherapy is NOT useful in fighting HIV, it is no longer recommended for any HIV positive individual.


Most of the antivirals, including protease inhibitors, have not been studied enough, if at all, to know the immediate or long-term side effects to the infant. Therefore, no matter what your child's HIV status turns out to be, it is important to inform the pediatrician that the child has been exposed to these drugs.

PWA Health Group
150 W. 26th Street
New York, NY 10001

Anemia in Women & Babies

Pregnant HIV-positive women and their neonates may be adversely affected by a triple combination of antiretroviral therapy that is administered to prevent vertical HIV transmission. As reported at the 12th World AIDS Conference in Geneva, 21 of 37 women and 17 of 30 babies studied developed one or more adverse events when treated with two reverse transcriptase inhibitors and a protease inhibitor. Complications among the women studied included grade 1 and 2 anemia, leukopenia, hypertension, and insulin-dependent diabetes. Prematurity was cited as the most common adverse effect in neonates as well as anemia, transient hepatitis, and cryptorchidia.