Prenatal Labs Deep Dive: First Trimester Through Delivery
Prenatal Labs Deep Dive: First Trimester Through Delivery NIPT sensitivity by condition, the GDM screening controversy, Rh typing pitfalls, and the labs that must happen three times now. First Prenatal Visit Labs Test Why Key Pitfall CBC Screen for anemia, thrombocytopenia, establish baseline MCV Physiologic anemia of pregnancy (hemodilution) begins in 2nd trimester; don't treat mild drops in Hgb without iron studies Blood type + Rh + antibody screen Identify Rh-negative mothers; detect alloantibodies that could cause hemolytic disease of the newborn Rh-negative mothers need RhoGAM at 28 weeks AND within 72 hours of delivery if baby is Rh-positive. Also after any sensitizing event (miscarriage, amniocentesis, trauma, ectopic). HIV (4th-gen) Universal screening. Early detection enables treatment to prevent vertical transmission. Opt-out screening is the standard. Repeat in 3rd trimester for high-risk patients. Syphilis (RPR or treponemal screen) Universal. Now recommended ×3: firs...