Ectopic Gestation: Myth or Reality

Friday, 03 April 2009 23:55

Ectopic (extra-uterine) pregnancy refers to the implantation of a fertilized ovum in any site other than the endometrial lining of the womb. It is one of the most common life-threatening surgical emergencies in gynaecological practice in the tropics. A majority of ectopics implant in the ampullary region of the fallopian tubes. Other sites include the ovaries, cervix and the abdominal cavity.

The incidence varies from country to country depending on the risk factors in the population studied. Incidence rates may vary from 2.3% - 8.6% of deliveries in the tropics. It may but rarely co-exist with a normal intra-uterine pregnancy in about 1 in 30,000 pregnancies when it is then referred to as heterotropic pregnancy.

Risk factors for ectopic gestation are numerous. A history of pelvic inflammatory disease is a strong risk factor owing to the attendant tubal damage that may follow. Tubal surgery has also been implicated as a possible risk factor especially following macrosurgery. A recent upsurge has been attributed to the use of assisted reproduction techniques aimed at treating infertility. Other risk factors include use of intrauterine contraceptive device and progesterone-only pills (mini pills).

Women with ectopic gestation can present in three distinct ways. They may present with an early unruptured ectopic pregnancy often complaining of absent menses with associated intermittent lower abdominal pain. They may also present with a chronic slow leaking variety with symptoms of irregular vaginal bleeding with or without dizzy spells in addition to complaints earlier discussed with the early unruptured ectopic.

Late presentation is the norm in the tropics and these women typically present with ruptured ectopic gestation with bleeding into the abdominal cavity (haemoperitoneum). They often complain of sudden onset sharp lower abdominal pain, menstrual irregularity, and dizzy spells.

Diagnosis is often made by an evaluation of the patient’s complaints coupled with relevant investigations as most cases are dire emergencies. A history of irregular menstrual flow coupled with lower abdominal pain in a sexually active lady is instructive and highly suspicious of ectopic gestation but not totally exclusive to the condition.

Tests to ascertain the blood level (haematocrit) is essential in supporting the diagnosis. Evaluation of the urine or blood for BHcG, Beta subunit of Human Chorionic Gonadotrophin, is imperative and is a confirmation of an ongoing pregnancy. Other biochemical markers such as progesterone and pregnancy-associated plasma protein A (PAPP-A) are not readily available in the tropics and may not contribute significantly to the diagnosis and management of ectopic gestation.

Another useful test is the use of the ultrasound in cases of suspected (early) ectopic gestation. Ultrasonography is used to localize the pregnancy and may provide information about the gestational age of the foetus. It may also provide information about other disease conditions which may mimic ectopic gestation such as gestational trophoblastic disease.

Treatment options may be medical or surgical and the choice of management would be influenced by factors which include the time of presentation (early or late), patient’s desires for future pregnancies, and the state of the fallopian tubes. Generally, medical treatment is offered for early presentation (unruptured ectopic) especially when future pregnancies are desired.

Medical treatment involves the use of cytotoxic drugs such as methotrexate, actinomycin D and etoposide. Other agents include potassium chloride, prostaglandins and hyperosmotic glucose which can be directly administered into the fallopian tube or gestational sac.

Surgery remains the treatment of choice in the tropics due to late presentation. This may be done via open surgery or pin-hole surgery (laparoscopy). Total or partial removal of the tube (salpingectomy) is often employed in the face of gross tubal destruction. Less radical surgical procedures may be employed such as salpingostomy and segmental excision with the view to preserve fertility in very young patients.

Prevention of extra-uterine gestation (ectopic) remains paramount in reducing the incidence of the condition. The need to reduce the spread of sexually transmitted disease which often leads to tubal damage is imperative. Therefore, the use and promotion of barrier contraception such as condoms amongst those who cannot abstain cannot be over-emphasized. The need for microsurgical techniques for tubal surgery would also minimize the risks of developing ectopic gestation. Also, early pregnancy detection and localization with ultrasound scan is invaluable.

Providing the necessary awareness via the use of informative, educative, and communication (IEC) materials will no doubt provide the requisite knowledge about the much dreaded ectopic pregnancy; ‘A reality in the face of ignorance’!