Risk factors for ectopic pregnancy
- Previous ectopic pregnancy
- Known inflammatory condition, for example, pelvic inflammatory disease (PID), endometriosis
- 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:
- 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
Sonographic features of ectopic pregnancy
Sonographic features of ectopic pregnancy may include:
- no intrauterine gestational sac
- endometrial pseudogestational sac (see Appendix 4: Findings in ectopic pregnancy)
- adnexal mass
- free fluid or haemoperitoneum (see Appendix 4: Findings in ectopic pregnancy).
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)
- Embryonic cardiac activity – document with a cine clip if possible; otherwise annotate cardiac activity present or absent on the relevant image
- 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.
- 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).