Part 2: Ectopic Pregnancy

Definition Pregnancy occurring outside the uterus

Sites Fallopian tube 93% (ampullary 70%,

isthmic 12%, fimbrial 11.1%) Interstitial 2.4% Ovarian 3.2% Abdominal 1.3% Cervical 1%

Incidence 1.6% all pregnancies (NSW 1998) Increasing incidence until about 1992

then plateauing/?falling (1970 0.3%, 1992 1.7%)

?decreased rates associated with contraceptive failures versus no decrease with reproductive failure

Similar rates Western countries

Age 15-24 years: 0.7% 25-34 years: 1.3% 35-44 years: 1.9%

Mortality small but 15% all maternal deaths

Tubal damage

Change in tubal motility

Pelvic infection Especially chlamydial 45% of patients have evidence of prior

salpingitis on pathological specimens Laparoscopically-proven PID confers a

risk of 13% after one episode and 35% after two

Treatment of chlamydia decreases rates

Previous tubal pregnancy 10-25% recurrence after one tubal

ectopic

Current IUD Excellent contraceptive efficacy but

prevents implantation in uterus more effectively than in the tube

Copper IUD: 4% of contraceptive failures are ectopics

Progesterone IUD: 17% of contraceptive failures are ectopics

No increased risk once removed

Progesterone hormonal contraceptives(Likely association)Mechanism: changes to muscular activity of

tube progesterone IUD mini-pill (4-10% of contraceptive failures

are ectopics) morning after pill Implants (30% of contraceptive failures

are ectopics)

Infertility Without treatment – if a woman

conceives after >1 year unprotected intercourse she has 2.6 x increased risk

With treatmentSurgery such as reversal of sterilisation and tuboplastyOvulation induction (likely small increase)IVF - 2-8% all conceptions, 17% increased risk if tubal factor for infertility identified (Why- ?Fluid reflux into tube, ?embryo placed high in uterus)

Other abdominal surgery Ruptured appendix Other? – not clear

Smoking > 2 x risk (increased with increased dose) Nicotine affects tubal motility, ciliary

function and blastocyst implantation

Tubal abnormalities Eg. Salpingitis isthmica nodosa

(diverticulae) – abnormal myometrial electrical activity

In utero diethylstilboestrol (DES) exposure

4-13%

Tubal abortionspontaneous resolutionExpulsion from the fimbrial end of the tube

Involution spontaneous resolution Rupture (usually about 8 weeks) Chronic inflammatory mass (uncommon)

hCG may be low or absentFrom bleeding into tubal wallPersistent symptoms, usually requires salpingectomy

Classic triad (50%) Amenorrhoea Vaginal bleeding Pain

Abnormal menstrual pattern Pain of any sort – unilateral/bilateral,

dull/sharp, upper/lower abdomen

Vital signs Abdomen

Non-tender to mildly tenderSigns of rupture: distension, decreased bowel sounds, peritonism

Cervical motion tenderness Adnexal mass (50%) – but may be the

corpus luteum

hCG positive in virtually all ectopics presenting

Positive in unstable patient Not rising appropriately Not falling appropriately Not seeing an intra-uterine pregnancy at

hCG over the discriminatory zone(1000-2000 on transvaginal scanning)

UltrasoundTransvaginal and transabdominal importantPresence of intrauterine sac virtually excludes

ectopic pregnancy Heterotropic pregnancy 1/30,000 (Increased

with IVF/ovulation induction) Beware pseudogestational sac of ectopic

pregnancy (sac-like fluid lucency, probably from bleeding) – ideal to see cardiac activity – yolk sac – double decidual sac sign (concentric echogenic rings)

Doppler ultrasound improves diagnosis

Possible Ultrasound Findings Absence of intrauterine pregnancy over the

hCG discriminatory zone Adnexal gestation with fetal pole and

cardiac activity – 10-17% Adnexal rings (fluid sacs with thick

echogenic rings) – 38% Complex or solid adnexal rings (DDx corpus

luteum, other cysts, pedunculated fibroid) Intra-abdominal free fluid or cul-de-sac fluid

(the latter doesn’t necessarily represent rupture)

Chorionic villi in saline test Useful to distinguish products of intrauterine

gestation (chorionic villi) from decidual cast of ectopic pregnancy

Chorionic villi have a lacy frond appearance and float in saline

Tissue should also be sent for histopathology to confirm

Suction curettage may be used to diagnose (hCG <2000, indeterminant ultrasound & <50% rise in hCG over 48 hours)

hCG should fall by >15% within 24 hours of evacuation of normal intrauterine pregnancy

Culdocentesis Aspiration of fluid from cul-de-sac Positive test if non-clotting blood

obtained 70-90% of patients with ectopic

pregnancy have a haemoperitoneum Rarely used now hCG and transvaginal

ultrasound available

Laparoscopy Gold standard for diagnosis Missed in 3-4% (if very small)

Surgical Laparoscopy vs Laparotomy Salpingostomy vs Salpingectomy (Salpingo-oophorectomy)

Medical Methotrexate Other (RU-486, KCl, hyperosmolar glucose,

prostaglandins). Salpingocentesis

Remember Anti-D in Rh-ve women

Laparoscopy Shorter hospital stay Less post-operative pain Less cost Shorter convalescence Less blood loss Less adhesions (but similar tubal patency

rates)

Similar: pregnancy rate, persistent trophoblast rate, operating time

Laparotomy for Haemodynamic instability Lack of laparoscopic expertise/equipment Cornual/interstitial pregnancy Ovarian/abdominal pregnancy Patient factors eg. Obesity, adhesions

Salpingectomy vs Salpingostomy Controversial No difference in future intrauterine pregnancy

rates?Some studies suggest differenceNot enough evidence yet

Increase in persistent trophoblast rates (failure to remove all tissue) with salpingostomy

No difference in recurrence of ectopic in future

Milking tubeFimbrial – may be effectiveAmpullary – double recurrence risk

Salpingo-oophorectomy No evidence of decreased recurrence

rates Improved intrauterine pregnancy rates

with conservation of ovary therefore no longer performed

Methotrexate Chemotherapeutic agent which prevents

synthesis of DNA (inhibits dehydrofolate reductase)

Much lower doses used for ectopic than malignancy

Use as primary treatment or if plateauing/ inadequately falling hCG after surgical treatment

Methotrexate Patient Selection Mild/no pain Haemodynamically stable Ectopic pregnancy <3cm? No fetal heart seen hCG < 2000 ?10000 Compliant/understanding patient

Methotrexate Baseline LFTs/FBE/UEC/hCG Dose 50mg/m2 (calculated from height and

weight) given IM Repeat hCG day 4 Repeat LFTs/FBE/UEC/hCG day 7 hCG should fall at least 15% from day 4 to

7 (normal to rise from days 1-4) Give second dose if inadequate fall Single dose successful in 91-93% of

appropriately chosen patients

Methotrexate Side Effects <1% Stomatitis, gastritis, photosensitive rash Impaired liver or renal function Pancytopaenia No evidence of increased malignancy in

future (Contraindications: liver disease, blood

dyscrasias, ulcerative colitis, peptic ulcer disease, concomitant infection)

Warn patient re: moderate increase in pain and bleeding first week

Methotrexate Follow hCG until <2 Surgery if becomes unstable/failed

treatment

Intrauterine pregnancy rates post-methotrexate comparable to surgical treatment

hCG should be followed weekly to <2 in all patients treated with methotrexate or tube-conserving surgery (salpingostomy). Some would follow patients after salpingectomy also

Patient told no pregnancy 2 months (use barrier method or OC pill). No IUD

Ultrasound at 6 weeks in subsequent pregnancy to ensure intrauterine

Overall pregnancy rates after one ectopic:

Intrauterine 50-80% Ectopic 10-25% Others infertile

Pregnancy after hysterectomy is possible (tube, cervix)

ALWAYS DO A hCG ALWAYS THINK OF POSSIBILITY OF

ECTOPIC PREGNANCY