Early pregnancy Flashcards
Ectopic incidence and locations
~1%
Most common site: ampulla (where fertilisation occurs)
- Tubal = 98%
Other locations - cervix, ovary, abdominal cavity
Risk factors of ectopic pregnancy
25-50% will have risk factors Previous PID Tubal surgery (prev sterilisation) Previous ectopic pregnancy Infertility ART IUCD Smoking Maternal age >40y
HCG for assessment of ectopic
HCG increase <66% in 48h is a/w either ectopic or failing IUP in >85% of cases
Discriminatory zone (ADHB)
- > 6000 IU/L - IUP will be seen on TA USS
- > 2000 IU/L - IUP will be seen on TV USS
- Unreliable for multiple pregnancy
Long-term fertility
Ectopic
In the absence of a history of subfertility or tubal pathology, no difference in the rate of fertility, the risk of future tubal ectopic pregnancy or tubal patency rates between the different management methods
If Hx of subfertility
- Expectant or medical management a/w improved reproductive outcomes compared with radical surgery
MTX has no effect on ovarian reserve
Tubal patency rates (examined by HSG) no different in:
- Ipsilateral tube if managed by MTX or expectant
- Contralateral tube if managed by surgery, MTX or expectant
Recurrence of ectopic
First ectopic with remaining tube normal: 6-12%
First ectopic with remaining tube abnormal: 28-50%
>1 ectopic: 26-40%
USS features of tubal ectopic
Three ultrasound features required to diagnose an ectopic pregnancy
- ‘Empty’ uterus
- Corpus luteum present
- Ectopic mass - usually an adnexal ring or ‘donut’
Visualise adnexal mass that moves separate to the ovary
- Apply doppler as vascular (colour flow more prominent around corpus luteum)
- Ectopic has a thick echogenic rim >6mm (c.f. <2mm with CL)
- Internal structures (yolk sac or fetal pole) are a more definitive sign of ectopic pregnancy
Pseudosac in up to 20%
- Lacks intradecidual and double decidual sign
Free fluid
- Echogenic fluid in 28-56%
USS features of cervical ectopic
- Empty uterus
- Barrel-shaped cervix
- Gestational sac present below the level of the internal cervical os
- Absence of the ‘sliding sign’ - distinguishes from miscarriage in progress
- Blood flow around the gestational sac using colour Doppler
Management of cervical ectopic
Methotrexate
- HCG >10,000, >9+0, CRL >10mm, FH activity a/w decreased chance of successful MTX
- <12+0, absence of FH activity and lower HCG a/w more successful conservative management
Surgical methods are a/w high failure rate
- Reserve for those suffering life-threatening bleeding
Adjunctive methods to control haemorrhage have been described - uterine artery ligation, UAE
Diagnosis of Caesarean scar ectopic
Incidence 1 in 2000
TVS supplemented by TA
1. Empty uterine cavity
2. Gestational sac or solid mass of trophoblast located anteriorly at the level of the internal os embedded at the site of the previous LSCS scar
3. Thin or absent layer of myometrium between the gestational sac and bladder
4. Evidence of prominent trophoblastic / placental circulation of Doppler
5. Empty endocervical canal
Management of CS scar ectopic
Insufficient evidence to recommend one over the other, but current literature supports surgical rather than medical approach as the most effective
Cochrane 2020 - Uncertain if differences in success rates, complications or adverse events between UAE and administration of systemic MTX before suction curettage
Blood loss lower if ERPOC after UAE than after MTX
Interstitial ectopic diagnosis
Ectopic implants in the interstitial part of the fallopian tube (which is 1-2cm in length)
Incidence 1-6.4% of ectopic pregnancies
USS:
- Empty uterine cavity
- sac located laterally in the interstitial (intramural) part of the tube
- bulging cornua with thin myometrial rim
- transverse fundal view, at top of uterus can appear outside of expected cavity
Criteria and outcomes for expectant management of ectopic
Minimal symptoms
No significant FF in the POD
HCG <1500 IU/L
Ectopic pregnancy <30mm on USS with no cardiac activity
Patient able to consent, and understand the need for and be able to f/u
Reported success rates from 57-100% - dependent on initial HCG and rate of decline
- intervention required in up to 30%
Monitoring for expectant management of ectopic pregnancy
Repeat HCG on days 0, 2, 4, and 7
- If HCG drops by >15% from the previous value then repeat weekly until a negative result
- If HCG drops by <15%, stays the same or rises, review
Methotrexate dose and mode of action
50mg/m2 of patient body-surface area IM as a single dose
Typically 75-90mg
Cytotoxic
Folic acid antagonist
Inhibits DNA and RNA synthesis required for normal cell division
Targets cells in the body with a high metabolic rate
Monitoring for MTX for ectopic
Day 0, give MTX, bloods for HCG, FBC, AST, Cr, G&H, Rhesus status
HCG on days 4 and 7. Day 7 repeat AST and FBC
- If decreases by >15% between days 4 and 7, then monitor weekly until HCG <5 iu/l
- If decreases by <15%, consider second dose 1 week after the first (50mg/m2)
Pain can be due to tubal abortion, not rupture. Doesn’t necessarily require OT. Monitor in hospital for 24h if stable
Agrees to avoid pregnancy for 3/12
Criteria for MTX ectopic
Haemodynamically and clinically stable No significant FF in POD Gestational sac <35mm in adnexa (NICE) Normal FBC, LFTs, Cr HCG <5000, but ideally <1500 No FH seen on USS Desire for future fertility (but still an option if don't) Patient able to understand and attend f/u, consented
Contraindications to MTX
Hepatic dysfunction - AST >2x normal Abnormal renal function (elevated Cr) Bone marrow dysfunction, immunodeficiency Active peptic ulcer disease Presence of fetal cardiac activity Any active liver or renal disease
Side effects to MTX
Side effects: GI upset - excessive flatulence, bloating, abdominal pain, gastritis, nausea Conjunctivitis Stomatitis Mouth ulceration Transient mild elevation in LFTs (rare) Rash Photosensitivity
Rare:
- Marrow suppression - leucopenia, thrombocytopenia (rare)
- Pulmonary fibrosis
- Alopecia
Outcomes of MTX
Success rates of single dose: 65-95%
3-27% of women require a second dose
Criteria for salpingotomy over salpingectomy for ectopic
If healthy contralateral tube no significant difference in fertility prospects
Current ectopic pregnancy higher after salpingotomy (15% vs. 10%)
Risk of persistent trophoblast with salpingotomy - 8%
Salpingotomy if contralateral tube abnormal or Hx of subfertility
- Higher rates of subsequent IUP if Hx of fertility-reducing factors (75% vs. 40%)
- If single tube and salpingotomy performed - IUP rate 55%, repeat ectopic 20%
Define Gestational trophoblastic disease (GTD)
Group of disorders including hydatidiform mole, invasive mole, gestational choriocarcinoma, PSTT
Incidence of GTD is 1:200-1000 pregnancies
Incidence of GTD after a live birth 1 / 50,000
More common at extremes of maternal ages
Asian women
Define hydatidiform mole
Originate in villous trophoblast and are characterised by abnormal chorionic villi with trophoblast hyperplasia as a consequence of overexpression of paternal genes
Separated into complete and partial moles based on genetic and histopathological features
Complete mole
Definition
Appearance
Histology
USS features
Derived from paternal duplication (46XX, 75%) or dispermic fertilisation (46XX or 46XY, 25%) of an ‘empty’ ovum (lacking maternal genes)
Mitochondrial DNA is still maternal in origin
characteristic ‘bunch of grapes’ appearance only seen in the second trimester
Histology
- no fetal tissue
- extensive hydropic change to the villi
- excess trophoblast proliferation
- Diploid
- p57 absent
USS features:
- Polypoid mass between 5-7/40
- Thickened cystic appearance of villous tissue and no identifiable sac after 8/40
Partial mole
Definition
Appearance
Histology
USS features
Triploid (90%)
- 2 sets of paternal and 1 maternal haploid set
- Most often occur following dispermic fertilisation
Occasional may also be tetraploid or mosaic
looks like normal POC so Dx can be missed
Histology
- Contains embryonic or fetal material such a fetus or fetal red blood cells
- focal hydropic change to the villi
- Some excess trophoblast proliferation
- p57 immunohistochemistry stain is present
p57 - paternally imprinted, maternally expressed gene. Only present in partial moles as have both maternal and paternal genetic material
USS
- Enlarged placenta
- Cystic changes within the decidual reaction in a/w empty sac or delayed miscarriage
Management of suspected molar pregnancy
Suction evacuation / curettage
- Preferred initial management
- May use US guidance to minimise chance of perforation
- Medical methods a/w higher rates of chemotherapy
- Preparation of the cervix immediately prior to evac is safe
- Oxytocin infusion can be used after if brisk bleeding occurs
- Senior / experienced surgeon present
- Anti D if Rh negative
Hysterectomy not recommend for treatment of molar pregnancy alone