Table 1.

Testing modalities for diagnosing HIV in pregnancy^∗.

HIV tests	What they test for	Window period	Available results	Sensitivity	Specificity
ELISA	HIV antibodies	3 Months	2 days–2 weeks	>99%	>98%
Antigen test (p24)	P24 viral proteins	11 days–1 month	2 days–1 week	90%	100%
4th generation tests	Antibodies and p24	11 days–1 month	2 days–2 weeks	>99.7%	>99.3%
PCR/NAAT tests	Genetic material of HIV	12 days	2 days–1 week	>99%	>99%
Rapid test	Antibodies	3 Months	Within 20 minutes	>99%	>98%

^∗AIDSinfo. Recommendations for use of antiretroviral drugs in pregnant HIV-1-infected women for maternal health and interventions to reduce perinatal HIV transmission in the United States. HHS panel on treatment of HIV-infected pregnant women and prevention of perinatal transmission, a working group of the office of AIDS research advisory council (OARAC), 2015, http://aidsinfo.nih.gov/guidelines.