Pregnancy (main)

Background

Timeline of pregnancy, including (from top to bottom): Trimesters, embryo/fetus development, gestational age in weeks and months, viability and maturity stages.
Preembryonic development showing fertilization and implantation.

Clinical Features

Normal pregnancy at 26 weeks.
Estimated gestational age based on physical exam.
Melasma: pigment changes to the face due to pregnancy.
Linea nigra in a woman at 22 weeks pregnant.

Normal Vitals in Pregnancy[1]

Vital Nonpregnant 1st Trimester 2nd Trimester 3rd Trimester
HR 70 78 82 85
SBP 115 112 112 114
DBP 70 60 63 70
Hcrt 40 36 33 34
WBC 7.2k 9.1k 9.7k 9.8k

Estimated Gestational Age by Fundal Height[2]

Weeks Fundal Height / Finding
12 Pubic symphysis
20 Umbilicus
20-32 Height (cm) above symphysis = gestational age (weeks)
36 Xiphoid process
>37 Regression
Post delivery Umbilicus

Physiologic Changes in Pregnancy[3]

  • Heart rate (HR) increases 15-20 bpm (75-95 bpm)
  • Mean arterial pressure (MAP) increases 10 mmHg (80 mmHg)
  • Tidal volume (TV) increases 40% (700 cc)
  • Minute volume (MV) increases 40% (10.5 L/min)
  • Functional residual capacity (FRC) decreases 25% (1300ml)

Differential Diagnosis

Abdominal distention

Vaginal Bleeding in Pregnancy (<20wks)

Vaginal Bleeding in Pregnancy (>20wks)

Abdominal Pain in Pregnancy

The same abdominal pain differential as non-pregnant patients, plus:

<20 Weeks

>20 Weeks

Any time

3rd Trimester/Postpartum Emergencies

Evaluation

Estrogen, progesterone, beta-hcg levels throughout pregnancy.

Repeat B-hCG Levels

Pregnancy Type B-hCG Change
Normal
  • Increase >53% in 48hrs (until 10,000 mIU/ml)
  • Depends on the initial value:
    • <1500 --> 50% increase
    • 1500-3000 --> 40% increase
    • > 3000 --> 30% increase
Ectopic
  • Increases or decreases slowly ("plateau")^
Miscarriage
  • Decreases >20% in 48 hrs

^Initial level CANNOT be used to rule-out ectopic

Maternal Laboratory Changes in Pregnancy[4]

  • CBC
    • Increased WBC count (5k-15k)
    • Decreased hematocrit (32-34%) due to increased plasma volume
    • Decreased platelets
  • Chemistry
    • Decreased BUN and creatinine (<0.8mg/dL)
    • GFR increases up to 60% (140ml/min)
    • Decreased Bicarb
  • Other
    • Increased D-dimer and Fibrinogen
    • Increased ESR ~78
    • Decreased PaCO2 ~30
  • ECG with Qs in III & aVF, left axis
  • Beta-HCG Levels

Management

Disposition

  • Uncomplicated pregnancy is managed as an outpatient
  • For particular problems in pregnancy, see individual pages

See Also

External Links

References

  1. ↑ Kuklina EV, Ayala C, Callaghan WM. Hypertensive disorders and severe obstetric morbidity in the United States. Obstet Gynecol 2009; 113:1299-1306.
  2. ↑ Vasquez V, Desai S. Labor and delivery and their complications. In: Walls RM, Hockberger RS, Gausche-Hill M, et al., eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier Saunders; 2018:2296–2312.
  3. ↑ Kuklina EV, Ayala C, Callaghan WM. Hypertensive disorders and severe obstetric morbidity in the United States. Obstet Gynecol 2009; 113:1299-1306.
  4. ↑ Kuklina EV, Ayala C, Callaghan WM. Hypertensive disorders and severe obstetric morbidity in the United States. Obstet Gynecol 2009; 113:1299-1306.
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