Diagnosis of Pregnancy

Amenorrhea is usually the first sign of conception prenatal care. Other early pregnancy symptoms include breast fullness and tenderness, skin changes, nausea, vomiting, urinary frequency, and fatigue.

Pregnancy tests. Urine pregnancy tests may be positive within days of the first missed menstrual period. Serum beta human chorionic gonadotropin (HCG) may be accurate up to a few days.

Fetal heart tones can be detected as early as 11-12 weeks from the last menstrual period (LMP) by Doppler.

Fetal movements ("quickening") are first felt by the patient.

Ultrasound will visualize a gestational sac at 5-6 weeks and a fetal pole with movement and cardiac activity by 7-8 weeks. Ultrasound can estimate fetal age accurately if completed.

Estimated Date of Confinement. The mean duration of pregnancy is 40 weeks from the LMP. Estimated date of confinement (EDC) can be calculated by Nägele's rule: Add 7 days to the first day of the LMP.

Contraceptive History. Recent oral contraceptive usage often causes postpill amenorrhea, and may cause erroneous pregnancy dating.

Gynecologic and Obstetric History

Previous gynecologic infections or problems.

Gravidity is the total number of pregnancies. Parity is expressed as four numbers (term, preterm, abortions, live births).

The character and length of previous labors, type of delivery, complications, infant status, and birth weight are recorded.

Assess prior cesarean sections and determine type of C-section (low transverse or classical), and determine reason it was performed.

Medical and surgical history and prior hospitalizations are documented.

Medications and allergies are recorded.

Family antepartum care History of medical illnesses, hereditary illness, or multiple gestation is sought.

Social History. Cigarettes, alcohol, or illicit drug use.

Review of Systems. Abdominal pain, constipation, headaches, vaginal bleeding or discharge, dysuria or urinary frequency, or hemorrhoids.

Weight, funduscopic examination, thyroid, breast, lymph nodes, lungs, and heart are examined.

An extremity and neurologic exam are completed, and the presence of a cesarean section scar is sought.

Estimation of Gestational Age by Uterine Size

The nongravid uterus is 3 x 4 x 7 cm. The uterus begins to change in size at 5-6 weeks.

Gestational age is estimated by uterine size: 8 weeks = 2 x normal size; 10 weeks = 3 x normal.

At 12 weeks the fundus becomes palpable.