History, Diagnosis and Management of Ectopic Pregnancy
Ectopic derived from Greek ektopos simply means ‘away from a place’. An ectopic pregnancy is a pregnancy that develops outside the uterus. This happens when the fertilised egg from the ovary does not implant itself normally in the uterus. Instead, the egg develops somewhere else in the abdomen. Ectopic pregnancy is usually found in the first five to ten weeks of pregnancy. The most common place that ectopic pregnancy occurs is in one of the fallopian tubes (a so-called tubal pregnancy). Ectopic pregnancies can also be found on the outside of the uterus, on the ovaries, or attached to the bowel. The most serious complication of an ectopic pregnancy is intra-abdominal haemorrhage (severe bleeding). In the case of a tubal pregnancy, for example, as the products of conception continue to grow in the fallopian tube, the tube expands and eventually ruptures. This can be very dangerous because a large artery runs on the outside of each fallopian tube.
Prior to 1883, no woman ever underwent a deliberate and successful operation for a ruptured ectopic pregnancy. Robert Lawson Tait, sometimes known as ‘the father of gynaecological surgery’, was born in Edinburgh on May 1, 1845. In 1881, it was suggested to him to remove the ruptured tube in case of an ectopic pregnancy. “… the suggestion staggered me, and I am ashamed to say that I did not receive it favorably.” The postmortem examination convinced him, however, that it could be done. Two years later, Tait ligated the broad ligament and tube in another patient, and this patient survived. In 1888, Tait reported only two deaths out of 42 operated cases, a marked improvement for a condition that had been almost always fatal. Following Tait’s accomplishment, little occurred in the management of ectopic pregnancy until the 1940s, when blood banking came into use. While this was a major development, the serious difficulty of diagnosis remained in the treatment of ectopic pregnancy. Many women with a little abnormal bleeding and abdominal pain were considered to possibly have an ectopic pregnancy, but only a few did. One of the major tools for diagnosis was culdocentesis. This was of no benefit if the findings were negative, and the findings were only positive if the ectopic pregnancy was already ruptured.
Until approximately 30 years ago, then, ectopic pregnancy was a difficult diagnosis and a very common cause of maternal mortality. Because of the development of a rapid test for the beta subunit of human chorionic gonadotropin (hCG) and the development of high-quality ultrasound images, ectopic pregnancy is now frequently diagnosed early and treated before it can cause morbidity or mortality.
The advent of these two tests is the major reason that maternal morbidity is now measured as cases per 100,000 live births instead of cases per 10,000 live births, as it was 35 years ago. The advent of laparoscopic surgery has further reduced morbidity.
Pregnancy tests in the 1960s did not return positive results until approximately six menstrual weeks. Around 50% of all women with proven ectopic pregnancies had a negative result from the pregnancy test. Starting in the late 1960s, ultrasound was developed, along with a sensitive and accurate test for the beta subunit of hCG. This technology revolutionised the diagnosis of ectopic pregnancy. At approximately the same time, laparoscopy was developed. This led to the minimally invasive treatment of ectopic pregnancies. Then, in the 1980s, medical treatment of ectopic pregnancy with methotrexate was developed.
Laparoscopy was first performed in animals in the early 1900s by Dr. Georg Kelling in Berlin. The Swedish surgeon Dr. Hans Christian Jacobaeus published a description of a technique he called ‘laparothoroscopy’ (used to evaluate peritoneal tuberculosis) in 1910. However, it has been only since the 1960s that better techniques and instruments have lead to the acceptance of laparoscopy as a safe and valuable procedure.
Initially, gynecologic laparoscopy was performed almost exclusively for diagnosis and to perform tubal ligations. By the late 1970s, the role of laparoscopy expanded to include lysis of adhesions, treatment of endometriosis, and removal of ovarian cysts. Laparoscopy has become a treatment of choice for removal of ectopic pregnancy. Compared with laparotomy, multiple studies have shown laparoscopy to be safer, to be less expensive, and to have a shorter recovery time
The most common clinical presentation is pelvic pain, vaginal spotting, or both. This usually occurs four to eight weeks after the last menstrual period. Abdominal tenderness may be noted upon examination. Upon pelvic examination, tenderness is usually observed. If a mass is palpable, it is most likely a corpus luteum on the ovary. The ectopic pregnancy is usually too small, tender, and soft to be palpable. Pain is usually the result of stretching of the peritoneum over the tube. Once the tube ruptures, pain usually decreases or disappears. If the tube has ruptured, the patient may present in shock with tachycardia and hypotension. Shoulder pain from diaphragmatic irritation is a late sign and is seldom seen in current practice.
The quantitative level of beta-hCG found in ectopic pregnancy varies. Serum beta-hCG levels correlate with the size and gestational age in normal embryonic growth. In a normal pregnancy, the beta-hCG level doubles every 48 hours until it reaches 10,000-20,000 mIU/mL. With ectopic pregnancies, beta-hCG levels usually increase less. The discriminatory zone of beta-hCG is the level above which a normal intrauterine pregnancy (IUP) is reliably visualised. Once beta-hCG has reached a level of 2000 mIU/mL, a gestational sac should be seen within the uterus on transvaginal ultrasound scan images. Once it has reached 6000 mIU/mL, a gestational sac should be visualised within the uterus on abdominal scan images. Endovaginal ultrasonography to exclude an IUP can be performed in the outpatient clinic or emergency department.