Can we offer completely non-surgical management for ectopic pregnancy?

EDITOR—In his editorial Ankum discussed using measurements of serum concentrations of human chorionic gonadotrophin and transvaginal scanning to diagnose ectopic pregnancy.1 These two diagnostic modalities have opened up the possibility of a new era of non-laparoscopic diagnosis. Owing to the inconsistencies in the calibration of assays for human chorionic gonadotrophin and variations in the ability of ultrasonographers, each department should define its own “discriminatory zone” for human chorionic gonadotrophin.2 Clinicians using non-laparoscopic diagnostic algorithms should be prepared to perform a laparoscopy when the concentration of human chorionic gonadotrophin is <2000 mIU/ml and there is less than a 50% increase in human chorionic gonadotrophin in 48 hours with no intrauterine gestation sac on transvaginal scanning.3

Laparoscopy should be used for treatment more often than for the diagnosis of ectopic pregnancy. Are we in a position to offer that? A postal survey showed that only 13% of hospitals in the United Kingdom perform laparoscopic surgery routinely.4 So most women in Britain who have an ectopic pregnancy have a laparotomy. Currently there is enough evidence in favour of the efficacy of methotrexate in the treatment of ectopic pregnancy, and about 45% of all ectopic pregnancies can be managed with methotrexate.5 So when the diagnosis is accomplished without laparoscopy, treatment with methotrexate will have the advantage of avoiding the morbidity of surgery. To date there is no randomised trial between laparoscopic salpingectomy and treatment with methotrexate. Until the result of such a trial is available, it would probably be sensible to treat a selected group of women with methotrexate, especially where facilities for laparoscopic surgery are not available.

Patients with falling concentrations of human chorionic gonadotrophin should be seen regularly

EDITOR—Although I agree with much of what Ankum said in his editorial on diagnosing ectopic pregnancy,1 I have concerns on the wisdom of measuring serial serum concentrations of β human chorionic gonadotrophin in cases of possible ectopic pregnancy and have previously published a case report on falling serial serum concentrations and ectopic pregnancy.2

A woman presented with six weeks' amenorrhoea and light vaginal bleeding but no abdominal pain or discomfort. Examination of the abdomen and pelvis yielded normal results, as did transvaginal scanning. Serum concentration of β human chorionic gonadotrophin was initially 2367 IU/ml. The presumptive diagnosis was complete miscarriage, but she was followed up for 19 days, with β human chorionic gonadotrophin concentration being measured six times. The concentration fell smoothly and steadily to 97 IU/ml on the 19th day (figure). She remained well. That night, less than 12 hours after having blood taken, she became unwell with severe abdominal pain. Laparoscopy showed haematoperitoneum of 1000 ml of fresh blood with a ruptured ectopic pregnancy.

Serial β human chorionic gonadotrophin concentrations in woman with ectopic pregnancy in whom pregnancy could not be identified on transvaginal scanning

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If patients are followed up by measuring concentrations of β human chorionic gonadotrophin, there are four possibilities. At least doubling is suggestive of an early viable intrauterine pregnancy. Patients can be followed up with repeat measurements and transvaginal scanning until a viable intrauterine pregnancy is seen. A suboptimal rise or plateau, with unequivocal results on vaginal scanning, has been taken as an indication for laparoscopy. Falling concentrations of β human chorionic gonadotrophin have been taken to reflect a non-viable pregnancy, for which intervention is not necessary for so called trophoblastic regression.3

Although in most cases falling concentrations of β human chorionic gonadotrophin are reassuring, this is not so in all cases. Tubal rupture can still result, even at low concentrations. This contradicts Ankum, who says that monitoring falling concentrations of β human chorionic gonadotrophin selects a self limiting form of ectopic pregnancy for which no intervention is necessary. If patients are monitored in this manner doctors and nurses should be vigilant and wary of a continuing ectopic pregnancy that can rupture. The patients should be informed of the small risks entailed in such management and the importance of mentioning any abdominal discomfort or pain. Patients with falling concentrations of β human chorionic gonadotrophin should be seen and their status reviewed regularly and concentrations monitored until they reach the values for a non-pregnant woman. Diagnostic laparoscopy should be considered, even with minimal symptoms and low concentrations of β human chorionic gonadotrophin.