Diagnosis of tubal ectopics
The combination of sensitive urinary pregnancy tests, transvaginal ultrasound and serum hCG estimations enables the early diagnosis of ectopic pregnancy in modern clinical practice. However, the diagnostic accuracy and sensible application of these tests relies on good basic clinical skills. There is no substitute for eliciting a clear history and taking the woman’s symptoms and signs into account.
The incidence of ectopic pregnancy is about 1-3%, depending on the population studied. 95-97% of ectopic pregnancies are tubal pregnancies.
Ectopic pregnancies are classified as follows:
Early diagnosis allows a wider choice of management options, potentially decreasing morbidity and mortality.
The classical symptoms of an ectopic pregnancy are abdominal pain and vaginal bleeding. The typical history is of an abnormal ‘period’ where the bleeding is prolonged with brown ‘prune juice’ spotting. The woman may not realise that she is pregnant if the bleeding started around the time of her expected period. The patient may also complain of shoulder tip pain if the ectopic pregnancy is causing intraperitoneal bleeding. Some women do not experience severe pain despite intraperitoneal bleeding, but may only have mild discomfort or diarrhoea.
A French collaborative study set out to develop a symptom score to predict ectopic pregnancy rupture. The study examined a number of different pain variables, the most significant being: vomiting during pain, diffuse abdominal pain, pain lasting more than 30 minutes and “flashing” pain. The presence of one or more of these pain features gave a detection rate for rupture of 93%, a 44% specificity and a negative likelihood ratio of 0.16. What this means is that most ectopic pregnancies have one or more of these pain features – but they are not very specific – in other words other conditions will also give rise to these symptoms. The absence of any of these factors usually, although not exclusively, means rupture has not happened yet.
The risk factors for ectopic pregnancy are:
- Previous ectopic pregnancy (odds ratio (OR) 13). Approximately 10% of spontaneous pregnancies after an ectopic pregnancy will be recurrent ectopic pregnancies. One recent study from Denmark suggests this figure is closer to 17%.
- History of PID (OR 7)
- History of infertility or assisted conception (OR 3)
- Conception with IUD in situ (OR 3)
- Smoking (OR 2)
- Conception whilst using POP
- Use of emergency contraception in current pregnancy
- Pelvic or tubal surgery
Trustee and Medical Advisor to the EPT, Professor Tom Bourne is Adjunct Professor at Imperial College London, and Consultant Gynaecologist at Queen Charlotte’s and Chelsea Hospital. He is also visiting Professor at KU Leuven, Belgium. He has extensive clinical and research experience in early pregnancy care as well as gynaecological ultrasound. He has published over 230 academic papers with an H-index of 51. Here, he discusses with BMJ Learning the diagnosis and management of ectopic pregnancies.
If you need any support or advice regarding the diagnosis or treatment of an ectopic pregnancy please email us at firstname.lastname@example.org or call 020 7096 1838 and we will put you in touch with clinical specialists who would be happy to offer a point of view.
Karaer A, Avsar FA, Batioglu S. Risk factors for ectopic pregnancy: a case-control study. Aust N Z J Obstet Gynaecol 2006; 46(6):521-527.
Ankum WM, Mol BW, van d, V, Bossuyt PM. Risk factors for ectopic pregnancy: a meta-analysis. Fertil Steril 1996; 65(6):1093-1099.
Crochet JR, Bastian LA, Chireau MV Does this woman have an ectopic pregnancy?: the rational clinical examination systematic review. JAMA 2013; 309: 1722-1729.
Huchon C, Panel P, Kayem G, Bassot A, Nguyen T, Falissard B, Fauconnier A. Is a standardized questionnaire useful for tubal rupture screening in patients with ectopic pregnancy? Academic Emergency medicine 2012 Jan; 19(1):24-30.