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For further information, see CMDT Part 19-01: Diagnosis of Pregnancy

For further information, see CMDT Part 19-02: Essentials of Prenatal Care

For further information, see CMDT Part 19-03: Nutrition in Pregnancy

Key Features

Essentials of Diagnosis

  • Amenorrhea, weight gain, nausea and vomiting, and breast changes

  • Positive pregnancy test

General Considerations

  • Prompt diagnosis of pregnancy allows early prenatal care and avoidance of harmful activities or exposures

  • In the event of an unwanted pregnancy, early diagnosis allows for counseling regarding adoption or termination

Clinical Findings

Symptoms and Signs

  • Amenorrhea, weight gain

  • Nausea and vomiting

  • Breast tenderness and tingling

  • Urinary frequency and urgency

  • "Quickening" (perception of the first fetal movement) is noted at about 18 weeks' gestation

  • Signs

    • Breast changes, abdominal enlargement, and cyanosis of the vagina and cervical portio (week 7)

    • Softening of the cervix (week 7)

    • Generalized enlargement and softening of the corpus (post-week 8)

    • Uterine fundus is palpable above the pubic symphysis by 12–15 weeks from last menstrual period

    • Fundus reaches the umbilicus by 20–22 weeks

    • Fetal heart tones heard by Doppler at 10–12 weeks

Differential Diagnosis

  • Myomas can be confused with a gravid uterus

  • A midline ovarian tumor may displace a nonpregnant uterus

  • Ectopic pregnancies may show lower levels of human chorionic gonadotropin (hCG) that level off or fall

  • Premature menopause


Laboratory Tests


  • All urine or blood pregnancy tests rely on detection of placental hCG and are accurate at the time of a missed period or shortly after it

  • Laboratory and home assays use monoclonal antibodies specific for hCG

  • hCG levels increase shortly after implantation, double every 48 hours (this rise can range from 30% to 100% in normal pregnancies), peak at 50–75 days, and fall in second and third trimesters


  • The following are recommended

    • Urinalysis; culture of a mid-stream urine sample

    • Complete blood count (CBC)

    • Random blood glucose

    • Serologic test for syphilis

    • Rubella antibody titer

    • History of varicella

    • Blood group and Rh type

    • Antibody screening

    • Hepatitis B surface antigen testing

  • HIV testing should be encouraged

  • Cervical cultures for Neisseria gonorrhoeae and Chlamydia trachomatis as well as Papanicolaou smear are indicated

  • Testing for abnormal hemoglobins should be done in patients at risk for sickle cell or thalassemia traits

  • Tuberculosis skin testing is recommended for high-risk groups

  • Screening for Tay-Sachs, Canavan disease, and familial dysautonomia should be offered to

    • Jewish women with Jewish partners (especially those of Ashkenazi descent)

    • Couples of French-Canadian or Cajun ancestry

  • Hepatitis C screening should be offered to mothers at high risk


  • In the first ...

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