A 35-year-old female presented with acute sharp pain in the lower abdomen radiating to the back. She had a history of primary sub-fertility for five years, gravida 2 para 0+1. Her first pregnancy (IVF) miscarried at seven weeks with evacuation of retained products of conception (ERPC). A second IVF procedure with two implanted embryos was performed six weeks prior to this presentation. Physical examination revealed a soft abdomen, mildly distended, with no tenderness. Beta hCG was significantly elevated.

Transvaginal and transabdominal ultrasound scanning revealed a gestational sac, yolk sac and foetal pole with cardiac pulsations in the right adnexa, affirmative of an ectopic pregnancy. Crown-rump length (CRL) was 6mm, corresponding to a gestational age of 6+4 weeks. Free fluid with a ‘ground glass’ appearance was also visualised in the right adnexa and the pouch of Douglas (POD).In the left adnexa, a large complex mass was identified, highly suggestive of an ectopic pregnancy.

The couple was counselled on the poor outcome and risks associated with delaying surgical intervention until the foetus in the right-tube died. Consent for intervention was obtained following protracted discussion. Laparoscopy was performed, revealing an intact right ectopic pregnancy, a ruptured left ectopic pregnancy, 100ml of blood in the POD, and normal ovaries. A laparoscopic bilateral salpingectomy was performed with haemostatic measures, drainage and antibiotic therapy. The histological analysis of the excised tissue confirmed the intraoperative diagnosis of bilateral tubal pregnancy. 

The patient was anxious to become pregnant once again and underwent IVF six months later followed by successful vaginal delivery of a healthy baby at term.

Discussion

The incidence of bilateral ectopic pregnancies (BEP) is exceptionally rare, accounting for one in 200,000 live births,¹ and as many as one in every 1,580 ectopic pregnancies.² To date, there have been a little over 200 cases documented in English language literature, and in recent years the rates have been on the increase due to more women undergoing assisted reproductive techniques (ART). It has been estimated that in such women, the occurrence may be as high as one in 35.³

Risk factors of BEP include use of a contraceptive intrauterine device, previous tubal surgery, pelvic inflammatory disease, family history of twins and the twinning rate of an ethnic group, and ART.⁴ However, there have been a number of reported cases where none of the established risk factors were present, indicating the need for its inclusion in the differential diagnosis.

The clinical presentation of BEP has no peculiarities to distinguish it from a unilateral ectopic pregnancy, as it shares the classic triad amenorrhoea, vaginal bleeding and abdominal pain. Serum levels of beta hCG have proven unreliable for patients with bilateral disease,^5,6 as has ultrasonography, with a scan of the literature only finding three atypical cases of early diagnosis by ultrasound.^6,7,8 Therefore, the vast majority of diagnoses are made intraoperatively, with the second ectopic most commonly detected by direct inspection of the contralateral tube.³ This highlights the importance of meticulous examination of each tube during surgery, even when substantial adhesions and scarring have been noted. 

The significance of a timely diagnosis cannot be stressed enough. The tangible complications of the delayed detection of a second ectopic may lead to devastating consequences, both in relation to the future fertility of the patient and especially in relation to the risk of fatality. There has been a report of a failure to uncover the presence of a second concomitant tubal pregnancy during surgery for a presumed unilateral left ectopic, causing the patient to return 10 days later with a ruptured right tube.³ Such cases draw attention to the need for BEP to be included in the differential diagnosis of acute abdominal pain presenting in the days or weeks following treatment for a singleton ectopic. The measurement of serum beta hCG in this scenario, particularly when compared with the previous pre-op number, will be invaluable.

There are no guidelines for the treatment of BEP, however laparoscopic salpingectomy is considered the gold standard for singleton ectopic pregnancy and is the most common method in BEP. Medical management with methotrexate in such cases is rare and generally unsuccessful. 

Women with a history of ectopic pregnancy have a 6-16% chance of recurrence, thus future fertility is affected and patients need to be counselled on the possible outcomes.⁹ There is only a handful of reported cases of successful intrauterine pregnancies following BEP, however whether this is due to decreased fertility or due to report being published very soon after the BEP remains unclear.

References

1. Basly Met al. Extra-uterine twin pregnancy. Case Report of Spontaneous bilateral tubal ectopic pregnancy. Internet J Gynecol Obs 2012; 16(2)
2. Andrews J, Farrell S. Spontaneous Bilateral Tubal Pregnancies: A Case Report. J Obs Gynaecol Canada 2008; 30(1): 51-54
3. Ryan MT, Saldana B. Bilateral tubal ectopic pregnancy: A Tale of Caution. Academic Emergency Medicine 2000; 7:1160–1163
4. Lobo RA, Patrício L, Milheiras E et al. Bilateral Tubal Ectopic Pregnancy. Acta Obstétrica e Ginecológica Portuguesa 2012; 6(3):141-144
5. Hugues J et al. 1995. Two-step diagnosis of bilateral ectopic pregnancy after in vitro fertilization. J Assisted Reprod & Genetics. 12(7):460-2
6. Sentilhes L et al. Ultrasound diagnosis of spontaneous bilateral tubal pregnancy. Austral New Zealand J Obs Gynaecol 2009; 49(6):695-6
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8. Pan J et al. Bilateral interstitial pregnancy after in vitro fertilization and embryo transfer with bilateral fallopian tube resection detected by transvaginal sonography. J Ultrasound in Med 2010 ; 29(12):1829-32
9. Jurkovic D. Ectopic Pregnancy, in Dewhurst’s Textbook of Obstetrics & Gynaecology, Seventh Edition 2008 (ed Edmonds DK), Blackwell Publishing, Oxford, UK