An ectopic pregnancy is when the fertilized egg implants outside the uterus instead of inside. This sad outcome represents approximately 2% of all pregnancies in North America. There is one ectopic pregnancy for 13 miscarriages and it represents 9% of all maternal deaths.
Here is a little recap of the creation of a human being: the sperm heads towards the fallopian tube. This is where the winner of the sperm race meets the egg. The egg produced by this fertilization is then propelled by cilia located inside the tube until it lodges in the uterus.
In the case of an ectopic pregnancy, the fertilized egg will not leave the fallopian tube – it is called tubal pregnancy – or will move towards the ovary or, more rarely, into the cervical canal, or in the abdominal or pelvic cavities.
Causes and risk factors of ectopic pregnancy
How can the fertilized egg not reach the destination where it will become an embryo and a foetus? There are two possibilities. The tube could be blocked for various reasons or the cilia have been destroyed.
The risks of ectopic pregnancy are higher among women who underwent unsuccessful tubal ligation or women who have a history of extra-uterine pregnancy as well as those who had an infection or a surgery of the pelvic region.
Those who become pregnant despite the use of IUD (especially if it contains oestrogen) and those who took a progesterone-only pill are also more likely to experience ectopic pregnancy.
Although most ectopic pregnancies are diagnosed before the woman even knows she is pregnant and even if some women are still having periods, this type of pregnancy usually manifests itself through irregular vaginal bleeding and abdominal cramps.
These bleedings occur when the fertilized egg ends up breaking the wall tissue of the fallopian tube, usually between six and eight weeks after her last period.
Severe bleeding can cause a drop in blood pressure and symptoms of shock like paleness, sweating, severe weakness and fainting. The rupture of tissue that occurs later in pregnancy can be fatal.
When blood samples and urine indicate that a woman is pregnant but if her uterus is not gaining volume, the doctor can suspect a uterine pregnancy. He will then order an ultrasound to verify and if it reveals that the uterus is indeed empty, he will try to find the foetus and get him out of his location. The extraction is done by administering a drug called methotrexate or through laparoscopic surgery.
In some cases, for example if the woman’s condition is unstable, the doctor will proceed to a surgery called coeloscopy, which is the exploration of the abdominal cavity with a thin tube containing a camera and surgical tools. If the development of the egg is taking place in the fallopian tube, it must be cut and it will heal naturally. A woman who only has one fallopian tube can still become pregnant.
Unfortunately, it is impossible to prevent every kind of ectopic pregnancies but we can considerably reduce the risk of tubal pregnancy (in fallopian tubes), which is the most frequent type. Indeed, it is often caused by pelvic inflammatory diseases and sexually transmitted diseases (STD), which are preventable.