April 22, 2003

Dear Colleague:

The prevention of perinatal HIV transmission requires routine HIV screening of all pregnant women and the use of appropriate antiretroviral and obstetrical interventions that begin during pregnancy. Together, these actions can reduce the rate of mother-to-child HIV transmission to 2 percent or lower. Recently, new data have emerged indicating that higher testing rates are associated with testing strategies that routinely incorporate HIV tests in the standard battery of tests for all pregnant women. In light of this information, the Centers for Disease Control and Prevention (CDC) recommends that HIV testing be a routine screening procedure. CDC also recommends implementing rapid HIV testing in postnatal settings for infants of women not tested prenatally. Considering the potential for preventing transmission, no child should be born in this country whose HIV status, or whose mother’s status, is unknown.
CDC published data on recent prenatal HIV testing rates in the United States and Canada in the Morbidity and Mortality Weekly Report (MMWR,.) of November 15, 2002. This study examined HIV prenatal testing rates associated with three different prenatal testing approaches from data gathered from 16 states and 5 Canadian provinces. A brief description of the testing approaches and data findings follows:

1. “Opt-in”: Pregnant women receive pre-HIV test counseling and must specifically consent to an HIV antibody test, usually in writing. This is the most common prenatal HIV testing approach in the United States Among eight states using the “opt-in” approach where data were collected from medical records for 1998—1999, testing rates ranged from 25 percent to 69 percent. Canadian testing rates in three “opt-in” provinces ranged from 54 percent to 83 percent.
   
2. “Opt-out”: Pregnant women are notified that an HIV test will be routinely included in the standard battery of prenatal tests for all pregnant women, but they can decline HIV testing. Currently, Arkansas, Michigan, Tennessee, and Texas have adopted some version of this approach In Tennessee, where this approach was used, a testing rate of 85 percent was reported. Two Canadian provinces using this approach showed a testing rate of 98 percent and 94 percent.
   
3. Mandatory newborn screening: If the mother’s HIV status is unknown at delivery, newborns are tested for maternal HIV-antibody, with or without the mother’s consent. Results must be available within 48 hours of testing. Connecticut and New York have implemented these approaches (in combination with an opt-in approach for pregnant
   women). In these two states, data indicate that prenatal testing rates rose from 52 percent to 83 percent in a seven-county area of New York, and from 31 percent to 81 percent in Connecticut, during the periods just before and just after implementation of mandatory newborn testing. In 2001, New York reported a statewide prenatal HIV testing rate of 93 percent based on newborn metabolic screening of all live births.

Prenatal HIV Screening

Based on information presented in the MMWR, the available data indicate that both “opt-out” prenatal maternal screening and mandatory newborn screening achieve higher maternal screening rates than “opt-in” prenatal screening. Accordingly, CDC recommends that clinicians routinely screen all pregnant women for HIV infection, using an “opt-out” approach, and that jurisdictions with statutory barriers to such routine prenatal screening consider revising them.

Newborn HIV Screening

In addition, CDC encourages clinicians to test for HIV any newborn whose mother’s HIV status is unknown. Jurisdictions should consider whether a mandatory screening policy for these infants is the best way to achieve such routine screening. Data demonstrate that detection of HIV infection during pregnancy through HIV testing of all pregnant women affords the best opportunity to deliver interventions when they are most efficacious. When intervention does not begin until the intrapartum or neonatal periods, 9 percent to 13 percent transmission rates are achievable based on clinical trial and observational data. Recent experience from the CDC funded Mother-Infant Rapid Intervention at Delivery (MIRIAD) study indicates that HIV rapid testing of women can be done during labor, and that antiretroviral interventions can be quickly delivered to HIV-infected mothers and their infants. Therefore, for those women whose HIV status is unknown at labor, CDC recommends routine, rapid testing. When the mother’s HIV status is unknown prior to the onset of labor and rapid HIV testing is not done during labor, CDC recommends rapid testing of the infant immediately post-partum, so that antiretroviral prophylaxis can be offered to HI V-exposed infants.

The federal Food and Drug Administration has approved three rapid HIV test kits (SUDS^TM Oraquick^TM and Reveal which can be used at delivery When rapid test results are positive, antiretroviral interventions can be offered to the mother intrapartum and to her infant based on the preliminary results. Confirmatory testing should occur as soon as possible after delivery.