Sometimes urine pregnancy tests are positive but when you go for an obstetric ultrasound scan it turns out to be negative for pregnancy. This is a common finding encountered by many women.
Sometimes urine pregnancy tests are positive but when you go for an obstetric ultrasound scan it turns out to be negative for pregnancy. This is a common finding encountered by many women. Various reasons or causes of this finding includes the following:
1. False positive UPT (Urine pregnancy test).
2. Very early ultrasounds: Tvs scan before 4.5 weeks of gestation or Transabdominal ultrasound scan (TAS) before 5.5 weeks of gestation can’t detect gestational sac which is the 1st reliable marker of pregnancy on ultrasound scan.
3. Ectopic pregnancy: Implantation at an abnormal site such as fallopian tube, ovaries, c-sec scar results in ectopic pregnancy. Empty uterine cavity is often found on ultrasound scan in case of ectopic pregnancy.
4. Miscarriage or pregnancy loss: After miscarriage or pregnancy loss, beta hCG hormone level remains high for up to 6 weeks and then start returning to its non-pregnant state.
5. Misinterpretation: In Urine pregnancy test kits, there is one control line and one test line. Sometimes a faint pink line appears on test line which may represent an early pregnancy or it may be a user error leading to a positive urine pregnancy test but an empty uterine cavity on ultrasonography.
6. Abnormal conditions: Some conditions may lead to false positive urine or blood pregnancy test due to an elevated hCG hormone levels in body without an intrauterine pregnancy such as:
- After medical termination of pregnancy
- Abortion
- Pregnancy failure
- Anembryonic pregnancy
- Complete molar pregnancy
- Pituitary abnormality
- Invasive mole
- Choriocarcinoma
- Placental site trophoblastic tumour (PSTT)
- Epithelioid trophoblastic tumour
- Germ cell tumours of ovary
- Infertility treatment such as synthetic hCG injection etc.
