Key Concepts
Introduction
Positive signs provide conclusive proof that a fetus is present. They cannot be attributed to other conditions. Ultrasound visualization of embryo/fetus: - Gestational sac on TVUS: as early as 4.5–5 weeks - Fetal heartbeat on TVUS: as early as 6 weeks - Fetal anatomy: well defined by 10–14 weeks Auscultation of fetal heart tones (FHTs): - Doppler FHTs: detectable at 10–12 weeks - Fetoscope (Pinard stethoscope): detectable at 17–19 weeks - Normal FHT: 110–160 bpm Fetal movement perceived by examiner (ballottement confirms fetus): - Not to be confused with ballottement under probable signs - Palpable fetal parts (Leopold maneuvers at 28+ weeks) - Examiner-felt fetal movement: distinctly different from maternal perception KEY POINT: Positive pregnancy TEST (urine or serum β-hCG) = PROBABLE sign, NOT positive. This is a common exam question. For NCLEX-RN (United States), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the role named in the stem before distractors compete. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit.