HIV Testing Among Pregnant
Women --- United States and Canada, 1998--2001
Since 1994, the availability of increasingly effective antiretroviral drugs
for both the prevention of perinatal human immunodeficiency virus (HIV)
transmission and maternal treatment has resulted in a greater emphasis on
prenatal HIV testing and substantial increases in prenatal testing rates. In
2000, preliminary data indicated that 766 (93%) of 824 HIV-infected women in
25 states knew their HIV status before delivery (CDC, unpublished data,
2002). However, an estimated 280--370 perinatal HIV transmissions continue
to occur in the United States each year (1). The primary strategy to
prevent perinatal HIV transmission is to maximize prenatal HIV testing of
pregnant women. States and Canadian provinces have implemented three
different prenatal HIV-testing approaches. To assess their effectiveness,
CDC reviewed prenatal HIV-antibody testing rates associated with these
approaches. Medical record data suggest that the "opt-in" voluntary testing
approach is associated with lower testing rates than either the "opt-out"
voluntary testing approach or the mandatory newborn HIV testing approach.
Under the opt-in approach, women typically are provided pre-HIV test
counseling and must consent specifically to an HIV-antibody test. Under the
opt-out approach, women are notified that an HIV test will be included in a
standard battery of prenatal tests and procedures and that they may refuse
testing (2). Under mandatory newborn HIV testing, newborns are tested
for HIV, with or without the mother's consent, if the mother's HIV status is
unknown at delivery.
Three methods were used to estimate prenatal testing rates among all women
who delivered, regardless of whether they received prenatal care. First,
eight U.S. areas that participated during 1998--1999 in CDC's Active
Bacterial Core Surveillance/Emerging Infections Program (ABC) Network
assessed HIV testing during prenatal care and <2 days before delivery
by reviewing a stratified random sample of labor and delivery records and
prenatal records forwarded to birthing hospitals (3); in
collaboration with CDC, network staff received a sample of records from all
birthing hospitals in the surveillance areas and weighted testing rates to
represent all live-born infants in those areas. Second, public health
investigators in each of the five Canadian provinces tallied the number of
HIV tests among pregnant women that were submitted to provincial
laboratories and divided the total by an estimate of all live and stillborn
births in each province during the same year. Third, CDC analyzed weighted
data collected in 1999 by interviewers in nine states for CDC's Pregnancy
Risk Assessment Monitoring System (PRAMS) (an ongoing, population-based
survey conducted in 32 states and New York City among women who have given
birth during the preceding 2--6 months ), who had asked women if
they had been tested for HIV during pregnancy. Data on state prenatal
HIV-testing policies were obtained from the American College of
Obstetricians and Gynecologists (5).
HIV-testing rates varied depending on which approach to testing was used.
Rates for states using the opt-in approach to prenatal HIV testing included
in the ABC Network ranged from 25% to 69% (Table 1), testing rates in Canada
ranged from 54% to 83% (Table 2), and rates derived from PRAMS data ranged
from 61% to 81% (Table 3). Two U.S. states (Arkansas and Tennessee) and two
Canadian provinces (Alberta, and Newfoundland and Labrador) reported using
an opt-out prenatal HIV-testing policy. ABC Network data indicated that
Tennessee had a testing rate of 85% (Table 1). Canada's population-based
data indicated a 98% testing rate in Alberta and a 94% testing rate in
Newfoundland and Labrador (Table 2). PRAMS interview data indicated a 71%
testing rate in Arkansas (Table 3), compared with a 57% testing rate early
in 1997 before the law was implemented (Arkansas Department of Health,
personal communication, 2002). Two states (New York and Connecticut) require
HIV testing of newborns whose mothers were not tested during pregnancy. In
New York, an ABC Network review of medical records in seven counties in the
Rochester area indicated that the proportion of pregnant women who received
a prenatal HIV test increased from 52% of 438 charts during January
1998--July 1999 to 83% of 112 charts during August--December 1999 after New
York required that newborn HIV testing results be made available within 48
hours of specimen collection (Table 1). PRAMS data for 1999 indicated that
the proportion of women statewide who reported having received an HIV test
during pregnancy increased from 69% of 758 women during January--July to 93%
of 502 during August--December (Table 3). In separate, statewide analyses of
prenatal testing reported on newborn metabolic screening forms from all
live-born infants, New York reported prenatal HIV-testing rates of 89% in
2000 and 93% in 2001 (New York State Department of Health, personal
communication, 2002). In Connecticut, an ABC Network review of 668 charts
indicated a testing rate of 31% during January 1998--September 1999,
compared with 81% of 93 charts reviewed during October--December 1999 after
enactment of the mandatory newborn testing law (Table 1).
Reported by: A Roome, PhD, J Hadler MD, Connecticut Dept of Public
Health. G Birkhead, MD, AIDS Institute, New York State Dept of Health. S
King, MD, The Hospital for Sick Children, Toronto; C Archibald, MD, Health
Canada. S Schrag, DPhil, Active Bacterial Core Surveillance/Emerging
Infections Program Network, Div of Bacterial and Mycotic Diseases, National
Center for Infectious Diseases; A Lansky, PhD, Pregnancy Risk Assessment
Monitoring System, Div of Reproductive Health, National Center for Chronic
Disease Prevention and Health Promotion; S Sansom, PhD, M Fowler, MD, I
Onorato, MD, J Anderson, PhD, Div of HIV/AIDS Prevention, National Center
for HIV, STD, and TB Prevention, CDC.
Prenatal HIV testing affords the best opportunity for the prevention of
perinatal HIV transmission. On the basis of clinical trial data, perinatal
HIV-transmission rates among HIV-infected women who begin antiretroviral
treatment during pregnancy are as low as <2% (6), compared
with 12%--13% early transmission rates among women who do not begin
preventive treatment until labor and delivery or after birth (7) and
25% among women who receive no preventive treatment (8).
Among the three prenatal HIV testing approaches assessed in this report,
opt-out voluntary testing and the mandatory testing of newborns appear to be
associated with the highest testing rates. On the basis of the chart-review
methodology, prenatal testing rates were higher in Tennessee, which uses the
opt-out approach, than rates in states using the opt-in approach and similar
to rates achieved with mandatory newborn testing in New York during the same
time period. A similar trend was observed among Canadian provinces. In New
York and Connecticut, mandatory HIV testing of newborns was associated with
increases in prenatal testing rates. On the basis of PRAMS data, three of
seven states using the opt-in approach achieved lower prenatal HIV-testing
rates than states using the opt-out or mandatory newborn testing approaches.
Increases in prenatal HIV-testing rates were noted in states that shifted
from an opt-in approach to either an opt-out or mandatory newborn testing
approach and were probably associated with a greater likelihood that woman
were offered HIV testing during prenatal care. Data from the Perinatal
Guidelines Project indicated that the majority of women will accept HIV
testing if it is recommended by their health-care provider (9).
Perinatal HIV experts and professional organizations have advocated
streamlining prenatal HIV pre-test counseling and consent procedures to
reduce barriers to the offer of testing by health-care providers (1,2,10).
The findings in this report are subject to at least seven limitations.
First, testing results for each strategy are for all women, and the
proportion of HIV-positive women who accepted testing under each strategy is
not known. Second, among women who did not receive prenatal testing, the
proportion of women who were not tested because they did not seek prenatal
care is unknown. Third, among women who did not receive prenatal testing,
the proportion of women who were tested at labor and delivery or whose
infants were tested at birth is not known. Fourth, maternal self-reported
data from PRAMS collected 2--6 months after delivery might be subject to
recall bias. Fifth, PRAMS data do not indicate whether a prenatal-care
provider was aware of the woman's HIV status. Sixth, among the women
interviewed in PRAMS, up to 16% (in Arkansas) indicated they did not know if
they had been tested. Finally, chart abstraction can document only prenatal
HIV testing recorded in maternal medical records; without such
documentation, clinicians might not be aware of the need to offer effective
perinatal interventions to infected women and their HIV-exposed infants.
This report emphasizes the need for better data to assess perinatal HIV
testing rates in the United States. Ongoing, randomized reviews of prenatal,
labor/delivery, and pediatric charts, with a sampling framework ensuring
that the sample is representative of the population of women delivering,
might provide the most valid approach to assessing a state's progress on
perinatal HIV testing and prevention. CDC is working with states with high
HIV prevalence rates among women of childbearing age and high numbers of
pediatric AIDS cases to ensure standardized monitoring of prenatal testing
rates. The data suggest that jurisdictions that use an opt-in approach and
that have low prenatal HIV-testing rates should reevaluate their approach.
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American College of Obstetricians and Gynecologists. Survey of state
laws on HIV and pregnant women, 1999--2000. Moore KG, ed. Washington, DC:
American College of Obstetricians and Gynecologists, 2000.
Dorenbaum A, Cunningham CK, Gelber RD, et al. Two-dose intrapartum/newborn
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Fernandez MI, Wilson TE, Ethier KA, et al. Acceptance of HIV testing
during prenatal care. Public Health Rep 2000;115:460--8.
American College of Obstetricians and Gynecologists. Joint statement
of ACOG/AAP on human immunodeficiency virus screening. ACOG statement of
policy. Washington, DC: American College of Obstetricians and Gynecologists,