Causes of ectopic pregnancies

“An ectopic pregnancy is often due to a damaged fallopian tube. If the tube is damaged, it impairs the motility of the fertilised egg to reach the uterus. This causes the fertilised egg to attach itself to the tube. Unlike the womb, which can expand to accommodate a growing pregnancy, the tube cannot do so and further growth of the implanted pregnancy tissue may result in rupture of the tube causing internal bleeding,” says Dr Khoo Chong Kiat, Head and Consultant, Ambulatory Service, Department of General Obstetrics and Gynaecology, KK Women’s and Children’s Hospital (KKH), a member of the SingHealth group.

Risk factors for ectopic pregnancies

The risk factors for ectopic pregnancy are:

  • Smoking
  • Pelvic inflammatory disease (PID) – This is usually caused by sexually transmitted infections such as chlamydia or gonorrhoea.
  • Endometriosis
  • Use of birth control measures such as intrauterine device (IUD) or tubal ligation – Although pregnancy using these contraceptive methods is not common, if it does occur, it is more likely to be ectopic.
  • Previous ectopic pregnancy – If you have had one ectopic pregnancy, you are likely to have another one.
  • Previous surgery on the tubes

Diagnosis of ectopic pregnancies

Your doctor might do a pelvic exam to check for an ectopic pregnancy, but the diagnosis is usually confirmed with blood tests and an ultrasound. Sometimes, however, it may be too early for an ultrasound to detect the pregnancy. In this case, your doctor might monitor your condition with blood tests until the diagnosis can be confirmed, usually by four to five weeks after conception.

Ref: R14