For unsensitized Rh(D)-negative pregnant women, when does USPSTF recommend repeating Rh(D) antibody testing?

• A. At 24 to 28 weeks gestation, unless the biological father is known Rh(D)-negative.
• B. Not recommended to repeat testing.
• C. Every visit during pregnancy.
• D. Only at delivery.

Answer: (B)

The question tests how USPSTF views screening for Rh(D) incompatibility over the course of pregnancy. For unsensitized Rh(D)-negative women, the guideline is to perform an initial Rh(D) antibody screen at the first prenatal visit. If that initial screen is negative and there are no sensitizing events, USPSTF does not recommend routinely repeating Rh(D) antibody testing later in pregnancy. Repeating testing does not meaningfully change management for most pregnancies and could lead to unnecessary anxiety or interventions from false positives. If a sensitizing event occurs (or if a new antibody is suspected for other reasons), testing would be guided by clinical factors, but routine repetition is not part of the standard USPSTF recommendation.