Location of the ectopic pregnancy

Most ectopic pregnancies are located in the fallopian tube. Pregnancies implanted elsewhere than in the fallopian tube are associated with a much greater risk of complications, mainly haemorrhage, and a higher mortality rate for the pregnant woman. This applies to pregnancies where the foetal egg has implanted in the cervix, the abdominal cavity or the ovary.

Risk factors for ectopic pregnancy

In the majority of women affected by ectopic pregnancy, it is unfortunately not possible to determine the cause of the ectopic pregnancy. The risk factors are related to the disruption of the function of the fallopian tube and the impossibility of proper transport of the fetal egg from the bulb of the fallopian tube, where fertilisation occurs, to the cavity of the uterus, where the embryo should implant in the mucous membrane, i.e. the endometrium. The main cause of impaired patency of the fallopian tubes is adhesions, which are a postoperative complication, mainly of operations on the fallopian tubes. Others include post-pelvic inflammatory conditions, caused especially by the Chlamydia trachomatis bacterium, which is now the most common sexually transmitted microorganism. Ectopic pregnancy is more common after assisted reproduction techniques. However, the cause of this phenomenon is unknown. Unfortunately, the occurrence of an ectopic pregnancy is associated with a significant risk of another ectopic pregnancy in the future.

Symptoms of ectopic pregnancy

Early diagnosis of ectopic pregnancy is extremely difficult due to the lack of characteristic symptoms. It may be abdominal pain or scanty bleeding, which the patient, unaware of being pregnant, may mistake for menstruation. On the other hand, the first symptom is sometimes a massive haemorrhage that leads to hypovolemic shock* or even death. This can be haemorrhage from the genital tract, but also into the abdominal cavity, where the predominant symptoms of shock are pallor, sweats and accelerated heart rate.

Diagnostic methods

The primary diagnostic method for ectopic pregnancy is the measurement of the hormone chorionic gonadotropin (β-HCG), produced at the beginning of pregnancy by the embryo itself. Its low value (negative result) indicates the absence not only of ectopic pregnancy, but also of pregnancy itself, as the measurement of this indicator is used in pregnancy tests. In a normal early pregnancy, where embryo implantation in the endometrium has occurred, the β-HCG level doubles every 48 hours. In ectopic pregnancies, this rise is generally much slower.

Ultrasound (Medical US) is also used in the diagnosis to visualise the gestational follicle and, at a later stage, also the echo of the embryo in the uterine cavity and, in the case of ectopic pregnancy, in the fallopian tube or ovary. With a β-HCG level of about 1500 mIU/ml, the gestational follicle should be visualised in the uterine cavity by Medical US vaginal examination. Its absence should raise the suspicion of a multifetal pregnancy (with such a low concentration of the hormone, the follicles may not yet be visible) or an ectopic pregnancy. It is then necessary to look carefully outside the uterine cavity for a lesion that may correspond to an ectopic pregnancy.

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It is worth remembering that the visualisation of a gestational follicle, does not exclude ectopic pregnancy. This is because there is a heterotopic pregnancy in which one fetal egg is located in the uterine cavity and the other is located outside the uterus.

In doubtful cases, the next diagnostic test is laparoscopy, i.e. a peritoneal cavity speculum. In ectopic pregnancy, a distended fallopian tube and bruising of its walls can be visualised in this way. The extent of the swelling depends on the stage of the pregnancy.