Ectopic pregnancies occur in approximately 11 per 1000 pregnancies, with nearly 12,000 women diagnosed with an ectopic in the UK each year. There are many risk factors, of which tubal pathology or surgery and the use of an intrauterine device are the most important. Other risk factors are infertility, younger or older maternal age and smoking. The incidence is thought to be increasing as a result of pelvic inflammatory disease.
Ectopic pregnancy accounted for almost 5% of deaths prior to 24 weeks’ gestation in the Confidential Enquiries into Maternal Deaths and Morbidity report in 2016 (MBRRACE- UK). Most ectopic pregnancies occur in the fallopian tube, but up to 5% occur elsewhere within the genital tract or abdomen. Typically, the tube initially expands to accommodate the growing zygote, but when it is unable to do so any more, there may be bleeding from the site of implantation or even rupture of the tube.
Problems and special considerations
Diagnosis of ectopic pregnancy may be difficult. Most ectopic pregnancies present 6-8 weeks from the last menstrual period and thus many of the physiological changes of pregnancy are absent or mild - the patient may even be unaware that she is pregnant. Signs and symptoms of an ectopic pregnancy vary. The most commonly reported symptoms are abdominal pain, amenorrhoea and vaginal bleeding. Other symptoms include gastrointestinal upset and rectal pressure or shoulder-tip pain from intraperitoneal blood. Sudden decompensation may occur due to concealed haemorrhage, leading to haemodynamic collapse.
A common theme in deaths associated with ectopic pregnancy is the failure to consider the diagnosis before collapse; ectopic pregnancy was not considered as a diagnosis in five out of the nine women who died from ectopic pregnancy in the 2016 Confidential Enquiry report. Non-specific abdominal signs including diarrhoea or vomiting may be misinterpreted as other intra-abdominal conditions such as appendicitis or gastroenteritis. Haemodynamic collapse may be misinterpreted as signs of pulmonary embolism, and MBRRACE-UK reported that a third of women who died of ectopic pregnancy received thrombolysis. Ectopic pregnancy must be considered in all women of childbearing age who present with haemodynamic collapse, particularly if anaemic, and it is now recommended that a focused assessment with sonography in trauma (FAST) ultrasound scan should be performed before thrombolysis if pulmonary embolism is considered likely.
A urinary pregnancy test should be performed in all women of reproductive age in whom the diagnosis is unclear or any of the above symptoms or signs are present; the bladder should be catheterised if necessary to facilitate this. Abdominal ultrasound has low specificity, and transvaginal ultrasound is the imaging modality of choice. If ultrasound is not convincing, then diagnosis may be aided by blood tests and laparoscopy. In a less acute situation, serum levels of human chorionic gonadotrophin (hCG) and progesterone are often measured, but these measurements often resemble those levels seen in a normal pregnancy. Previously, the gold standard for diagnosis of an ectopic pregnancy was a laparoscopy; however, its diagnostic accuracy has been questioned when the procedure is performed too early.
The implications for the current and future pregnancies pose a great psychological stress on the patient and her partner. There may be a previous history of ectopic pregnancy, since its occurrence is itself a risk factor for subsequent ectopics.
Management options
Initial management is directed at treating and preventing massive haemorrhage; thus the patient requires at least one large-bore intravenous cannula and careful observation, at least until the diagnosis has been excluded. Similarly, once the decision to operate has been made, surgery needs to occur as soon as possible, since the risk of tubal rupture is always present.
Operative management usually involves laparoscopy unless there is severe haemodynamic instability, in which case laparotomy may be performed. Traditionally, laparoscopy was performed purely for diagnostic purposes, but laparoscopic removal of the zygote with or without tubal resection has become routine in many units.
Anaesthetic management is as for any emergency surgery, given the above considerations. Haematological assistance and admission to the intensive care unit should be available if required. Point-of-care haematological testing may be a useful adjunct. In severe cases, anaesthesia must proceed as for a ruptured aortic aneurysm: full preoperative resuscitation may be impossible, and the patient is prepared and draped before induction of anaesthesia, which may be followed by profound hypotension.
Medical management may be considered in selected cases; thus systemic methotrexate may be offered to suitable women in whom the diagnosis of ectopic pregnancy is absolutely clear and the absence of a viable intrauterine pregnancy has been confirmed. The drug antagonises folic acid and prevents further growth of the trophoblast, which is especially vulnerable at this early stage. Similar outcomes to those following surgical management have been claimed. Local injection of hyperosmolar glucose or potassium chloride, with aspiration of the sac, is an option for clinically stable women with a heterotopic pregnancy. Finally, expectant management has been used in selected patients, although women whose pregnancies are selflimiting cannot yet be identified reliably.
Key points
• Ectopic pregnancy must be considered as a diagnosis in all women of reproductive age presenting with non-specific abdominal symptoms or haemodynamic collapse.
• Severe haemorrhage and/or cardiovascular collapse is always a risk.
Further reading
Elson CJ, Salim R, Potdar N, et al.; Royal College of Obstetricians and Gynaecologists. Diagnosis and management of ectopic pregnancy. Green-top Guideline 21. BJOG 2016; 123: e15-55.
Jurkovic D, Wilkinson H. Diagnosis and management of ectopic pregnancy. BMJ 2011; 342: d3397.
Knight M, Nair M, Tuffnell D, et al.; MBRRACE-UK. Saving Lives, Improving Mothers’ Care: Surveillance of maternal deaths in the UK 2012-14 and lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2009-14.
Oxford: National Perinatal Epidemiology Unit, University of Oxford, 2016.