Pregnancy Testing in the Emergency Department
All female patients who have reached menarche (first menstrual period) through age 50-55 years should be offered pregnancy testing in the emergency department, regardless of their stated sexual history or contraceptive use.
Recommended Age Range
The lower age threshold is menarche (typically 9-13 years), not a specific chronological age, as pregnancy becomes biologically possible once menstruation begins 1.
The upper age threshold is 50-55 years, corresponding to the typical age range for menopause and end of reproductive capacity 2.
The CDC contraceptive guidelines define "childbearing age" as the period during which pregnancy is biologically possible, which aligns with post-menarche through menopause 1.
Clinical Rationale
Pregnancy testing should be routine and universal in this age group because patient history is unreliable—many women do not suspect pregnancy, some conceal it, and self-reported sexual history has poor sensitivity for detecting pregnancy risk 3, 4.
Among women of reproductive age presenting to the ED, approximately 19.6% have positive pregnancy tests, with the highest rates among those with abdominal pain (15.8% positive) and nausea/vomiting (11.5% positive) 4.
Critically, 70.9% of women presenting to the ED cannot accurately recall their last menstrual period, making history-based screening inadequate 4.
Specific Clinical Scenarios Requiring Testing
All female patients of reproductive age with abdominal pain should receive pregnancy testing, as this is a key quality measure for detecting ectopic pregnancy, which can be life-threatening 2.
Before any procedure requiring general anesthesia, ionizing radiation, or medications contraindicated in pregnancy, all post-menarchal girls and women of reproductive age should be offered urine pregnancy testing 5.
In sexual assault cases, baseline urine pregnancy testing is mandatory before administering emergency contraception or other prophylactic treatments 1.
Implementation Approach
Use an "opt-out" approach with patient notification—inform the patient that pregnancy testing will be performed as part of routine care, but allow them to decline 1.
Urine pregnancy tests are preferred over serum testing in the ED setting due to rapid turnaround time and adequate sensitivity (20-25 mIU/mL) for clinical decision-making 1.
Testing should be available 24 hours per day, 7 days per week in all facilities with emergency departments 1.
Critical Limitations and Pitfalls
Pregnancy tests cannot detect very early pregnancy from recent sexual intercourse (within the past 5-7 days), as hCG levels may not yet be detectable 1.
Pregnancy tests may remain positive for several weeks after delivery, miscarriage, or abortion due to persistent hCG, potentially causing false interpretation 1.
An additional 11 days past the expected missed menses may be needed to detect 100% of pregnancies with qualitative urine tests 1.
Never rely solely on patient-reported sexual history, contraceptive use, or menstrual history to exclude pregnancy—these have poor predictive value in the acute care setting 3, 4.
Special Populations
Adolescent girls require particular attention—all girls who have reached menarche should be routinely offered pregnancy testing before procedures under general anesthesia, as approaching this topic can be challenging but is medically necessary 5.
In pregnant trauma patients ≥23 weeks gestation, pregnancy status must be immediately identified to enable appropriate fetal monitoring and potential perimortem cesarean section if maternal cardiac arrest occurs 6.