Ectopic pregnancy


Risk factors for ectopic pregnancy


  • Previous ectopic pregnancy
  • Known inflammatory condition, for example, pelvic inflammatory disease (PID), endometriosis
  • IUCD
  • IVF
  • Previous surgery or instrumentation (eg, caesarean section, tubal ligation).


Clinical signs and symptoms


Clinical diagnosis may be difficult because the symptoms and signs are often non-specific, but they will include:


  • pain
  • PV bleeding (vaginal bleeding)
  • a positive pregnancy test
  • poorly rising serum βhCG
  • signs of haemodynamic instability (eg, drowsiness, fatigue, pale skin, sweating).


Atypical symptoms and signs


In up to 70 percent of cases, there will be:


  • vague discomfort
  • contralateral pain
  • no PV bleeding
  • back pain, vaginal pain, bowel symptoms
  • low or normal serum βhCG
  • asymptomatic.


Sonographic features of ectopic pregnancy


Sonographic features of ectopic pregnancy may include:



Ectopic pregnancy ultrasound examination


  • Sac location – atypical location of the gestational sac in relation to the endometrial cavity should be reported. This is particularly important for:
    • low-positioned gestational sac, adjacent to or bulging into a caesarean section scar (see Appendix 2)
    • cornual or cervical location, separate to the endometrial cavity (often best shown on three-dimensional coronal imaging); document overlying myometrial thickness
    • yolk sac
  • Embryo (fetal pole)
  • CRL
  • Embryonic cardiac activity – document with a cine clip if possible; otherwise annotate cardiac activity present or absent on the relevant image
  • Adnexa
  • Document free fluid.


Reporting guide and referral recommendations


Minimum reporting requirements


Scan technique (TA/TV). Document if the woman declined a TV scan.


Document findings as per Ectopic pregnancy ultrasound examination (see above):


  • sac location (see Appendix 3: Ectopic pregnancy location)
  • CRL (date pregnancy if embryo is present)
  • MSD if no embryo identified
  • cardiac activity
  • adnexal mass or haemorrhage
  • largest diameter of ectopic mass or gestational sac
  • free fluid – location and amount (document free fluid at or above the uterine fundus).


Note: It is strongly recommended that a βhCG result is available at the time of the ultrasound scan.

Pregnancy of unknown location


There is no defined cut-off βhCG level at which ectopic pregnancy can be excluded.


Rather, it is the change in hCG over time that is of value.


The clinical scenario in which there is a positive pregnancy test and in which there is no sonographic evidence of intra- or extra-uterine pregnancy and where there are no obvious retained products of conception on TVS, is defined as a pregnancy of unknown location (PUL).


Under these circumstances, there are three possibilities.


  • Early intrauterine pregnancy
  • Ectopic pregnancy
  • Early pregnancy loss.

Reporting alerts

  • Ruptured ectopic pregnancy
  • Ectopic without evidence of rupture
  • Early pregnancy loss
  • Implantation of the sac on the caesarean scar, see Appendix 2 (this indicates a risk of placenta accreta spectrum disorder and requires specialist referral).