Positive Signs and Symptoms of Pregnancy
What the Examiner is Testing
- Knowledge of definitive diagnostic criteria for pregnancy confirmation
- Understanding of physiological changes during pregnancy
- Ability to distinguish between presumptive, probable, and positive signs
- Clinical reasoning skills in pregnancy diagnosis
- Application of evidence-based practice in obstetric assessment
Interpretation for Student
- Question requires listing definitive diagnostic signs that confirm pregnancy
- Focus on objective findings that cannot be attributed to other conditions
- Positive signs provide absolute certainty of pregnancy
- Distinguish from presumptive (subjective) and probable (objective but not definitive) signs
Main Points in Question Stem
- Five positive signs of pregnancy required
- Definitive evidence of pregnancy needed
- Objective clinical findings that confirm pregnancy beyond doubt
Positive Signs and Symptoms of Pregnancy
1. Visualization of Fetus
- Ultrasound detection of gestational sac, yolk sac, embryo, or fetus
- Transvaginal ultrasound can detect gestational sac at 4-5 weeks
- Fetal cardiac activity visible by 6-7 weeks gestation 1
- Transabdominal ultrasound detects pregnancy by 6-7 weeks
2. Detection of Fetal Heart Activity
- Fetal heart tones detected by Doppler at 10-12 weeks
- Distinct from maternal pulse in rate and rhythm
- Rate typically 120-160 beats per minute
- Auscultation with fetoscope possible after 20 weeks 1
3. Palpation of Fetal Parts
- Distinct fetal parts felt through abdominal examination
- Fetal movement felt by examiner (not maternal perception)
- Ballottement - fetus rebounds after being displaced by examiner's fingers
- Leopold maneuvers confirm fetal position after 28 weeks
4. Positive Serum or Urine hCG
- Human Chorionic Gonadotropin detected in maternal blood or urine
- Serum tests detect pregnancy 8-11 days post-conception
- Quantitative serum hCG provides definitive diagnosis 2
- Urine tests typically positive 14 days post-conception
5. Visualization of Embryo/Fetal Products
- Direct observation of products of conception
- Placental tissue identified after delivery or miscarriage
- Chorionic villi visible on pathologic examination
- Fetal tissue identified during procedures or after pregnancy loss
6. Quickening
- Maternal perception of fetal movement
- First felt between 16-20 weeks in primigravidas
- Earlier detection (14-16 weeks) in multigravidas
- Regular pattern develops as pregnancy progresses
7. Braxton Hicks Contractions
- Intermittent uterine contractions palpable on examination
- Painless tightening of uterus
- Increase in frequency as pregnancy advances
- Distinguished from labor by irregularity and lack of cervical change
Clinical Pearls and Pitfalls
Pearls
- Serum hCG is detectable earlier than urine hCG 2
- Ultrasound is the most reliable early positive sign
- Multiple confirmatory signs increase diagnostic certainty
- Serial hCG measurements help monitor early pregnancy viability
Pitfalls
- False positive urine tests can occur with certain medications
- Pseudocyesis (false pregnancy) can mimic presumptive signs
- Ectopic pregnancy may present with positive hCG but no intrauterine findings
- Gestational trophoblastic disease produces hCG without true pregnancy 2
Additional Considerations
- Timing of detection varies for each positive sign
- Combination of signs provides greater diagnostic certainty
- Documentation of positive signs essential for pregnancy dating
- Early detection enables timely prenatal care initiation 1