Synopsis
Use consented pregnancy testing according to pregnancy potential and clinical consequence, interpret early or persistent hCG safely, and escalate pain, bleeding or instability without false reassurance from a single result.
- Base testing on whether pregnancy is biologically possible and clinically relevant, not on age, gender identity, relationship status, reported contraception or assumptions about sexual activity.
- Explain why the result affects diagnosis, medicines, anaesthesia or imaging, seek consent and agree confidential communication; do not perform a hidden test simply because urine is available.
- Home and clinical urine tests are most reliable from the first day of a missed period; if cycle timing is unknown, NHS advice is to test at least 21 days after the last unprotected sex.
- A negative urine test may reflect testing too early, dilute urine, incorrect technique or reduced assay sensitivity; repeat with first-morning urine or obtain serum hCG when the consequence of missing pregnancy is high.
- A positive urine or serum test does not locate the pregnancy. Pelvic pain, bleeding or risk factors require clinical assessment and usually transvaginal ultrasound through the early-pregnancy pathway.
- For a pregnancy of unknown location, NICE advises two serum hCG measurements as close as possible to 48 hours apart and no earlier; interpret change only to plan follow-up, never to declare location.
- An hCG rise greater than 63% over 48 hours suggests a developing intrauterine pregnancy but cannot exclude ectopic pregnancy; arrange the NICE-timed transvaginal scan and give symptom-led return advice.
- If hCG falls by more than 50% over 48 hours, NICE supports follow-up testing as directed; a smaller fall or rise below 63% requires early clinical review because ectopic or failing pregnancy remains possible.
- Urgent necessary imaging and treatment should be optimised for pregnancy but not withheld when delay poses greater harm; discuss radiation and medicine risk proportionately with the relevant specialist.
Key red flags
Pain, bleeding or haemodynamic change can precede a clearly positive urine result, so an early negative test does not close ectopic pregnancy when timing is uncertain.
A positive test establishes hCG exposure but not an intrauterine location, viable pregnancy or gestational age; ectopic risk remains until location is established.
Symptoms worsening during pregnancy-of-unknown-location follow-up require immediate review regardless of previous hCG trend or planned scan date.
Unexpected pregnancy testing in a child, possible exploitation, reproductive coercion or unsafe disclosure requires confidential safeguarding assessment and a protected contact plan.
Persistent hCG after pregnancy loss, termination or birth needs follow-up because retained pregnancy tissue, ectopic pregnancy or gestational trophoblastic disease may be responsible.
Amenorrhoea or an atypical period plus unilateral pain, bleeding, syncope or shoulder-tip pain warrants ectopic assessment even when reported contraception lowers probability.
Investigation priorities
Rapidly identify pregnancy in acute or routine presentations where the result changes care.
Management branches
Pregnancy could change the differential diagnosis, medicine, imaging or procedure.
- Ask privately about pregnancy potential, last normal period, cycle, contraception, sperm exposure, fertility treatment and recent pregnancy, then explain why testing matters.
- With consent, perform a correctly timed urine test; use serum hCG when urgent sensitivity or quantified follow-up is needed.
- Interpret the result against timing and symptoms, document limitations and ensure confidential result communication and follow-up ownership.