Ectopic pregnancy (EP) is the implantation of a fertilized egg outside the main cavity of the uterus. EP is one of the most common gynecologic surgical emergencies , and one of leading causes of maternal mortality in the first trimester of pregnancy. Embryo implantation exerts different pressure on uterine and tubal epithelial and smooth muscle cells, calponin 2 (CNN2) expression at the implantation site would differ between intrauterine pregnancy and tubal pregnancy. The investigators conduct this study to find out the diagnostic value of CNN2 in identifying tubal pregnancies.

This is a case-control prospective study. Women age 18-35 years old, come to My Duc, My Duc phu Nhuan Hospital and Ngoc Lan Clinic and have the indication of testing beta human chorionic gonadotropin (hCG) for determining pregnancy status because of 1-14 days period delay with or without abdominal pain, vaginal bleeding or after assisted reproductive technology. Those women will be introduced about the study. If they agree to take part in and write the consent form, they will be taken 5ml of blood more at the same time of testing beta hCG. Blood sample will then be centrifuged and collected serum will then be stored at -80 celsius degree.

Women with negative beta hCG will be excluded. Women with positive beta hCG will be followed-up pregnancy as routine until 12 6/7 weeks of gestational age (GA). At this time, those women will be screened using including and excluding criteria for each group. They then be put group into (1) tubal pregnancy, (2) viable pregnancy and (3) early pregnancy loss.

Stored serum sample will be defrosted and measured CNN2 concentration.

Case: tubal pregnancy

• Inclusion criteria

  • Patients aged 18 years to < 35 years old
  • Positive beta-hCG result
  • Diagnosed with tubal pregnancy based on pathological result.

• Exclusion criteria

  • BMI > 30 kg/m2
  • A co-existing additional pregnancy
  • Refuse to participate in the study

Control group: Women with the age corresponding to the case group (matched with the same age or +/- 2 years difference compared with the case group), diagnosed with early pregnancy loss or viable intrauterine pregnancy.

Early pregnancy loss

• Inclusion criteria

  • Patients aged 18 years old to < 35 years old
  • Positive beta-hCG result
  • Pregnancy outcome recorded as early pregnancy loss: ultrasound shows an empty gestational sac in the uterus or a gestational sac with embryos but no fetal cardiac activity within the first 12 weeks 6/7 days of pregnancy. Or there is pathological pathology of the specimen taken from the uterine lumen as placenta or fetal tissue.

• Exclusion criteria

  • BMI > 30 kg/m2
  • A co-existing ectopic pregnancy
  • Refuse to participate in the study

Viable intrauterine pregnancy

• Inclusion criteria

  • Patients aged 18 years old to < 35 years old
  • Transvaginal ultrasound records images of a living fetus in the uterine with embryos and fetal heart activity until 12 6/7 weeks of gestation (ultrasound or last menstrual period)

• Exclusion criteria

  • BMI > 30 kg/m2
  • A co-existing ectopic pregnancy
  • Multiple pregnancies
  • Refuse to participate in the study

Women aged 18 to <35 years old, coming to the clinic because their period is 1-14 days delay with or without abdominal pain, vaginal bleeding, or women at this age come to the clinic for follow-up after assisted reproductive technology at Ngoc Lan clinic, My Duc hospital, My Duc Phu Nhuan; and had a positive beta-hCG result.