What is a miscarriage?
- Loss of pregnancy at less than 24 weeks gestational age - Early miscarriage in first trimester (12-13wk), more common than late miscarriage (13-24wk).
- Occur in 20-25% of pregnancies, classified according to clinical/US features.
Name 9 risk factors of miscarriage?
1) Maternal age >30-35 due to chromosomal abnormalities
2) Chromosomal abnormalities (maternal or paternal)
3) Previous miscarriage
4) Obesity
5) Smoking
6) Previous uterine surgery
7) Uterine abnormalities
8) Antiphospholipid syndrome
9) Coagulopathies
Clinical features of miscarriage?
1) Vaginal bleeding (passing of clots/conception products)
2) Accompanied by suprapubic/cramping pain (similar to primary dysmenorrhoea)
3) Haemodynamic instability - dizziness, shortness of breath, tachycardia, tachypnoea, pallor, hypotension
On examination:
Abdominal examination - distention with local areas of tenderness?
Speculum examination - cervical canal - any contraception products? local areas of bleeding? diameter of cervical os?
Bimanual examination - any uterine tenderness, adnexal masses or collections (ectopic)
Ddx of miscarriage?
1) Ectopic pregnancy
2) Hydatidiform mole
3) Cervical/uterine malignancy
Dx of miscarriage?
Suspected miscarriage (positive urine pregnancy + vaginal bleeding +/- pain) should e investigated in Early Pregnancy Assessment Unit.
1) TRANSVAGINAL ULTRASOUND SCAN - fetal cardiac activity (usually observed transvaginally at 5/6 weeks gestation).
- Gestation can be estimated by fetal crown rump length (CRL) - if CRL <7mm and no foetal heart identified - repeat scan in 7 days required.
- Fetal pole not identified - interuterine pregnancy confirmed with gestational sac and yolk sac - management depends on mean sac diameter (>25mm diagnosis of failed pregnancy can be made, <25mm repeat scan required in 10-14 days)
2) Bloods - b-HCG (useful in assessing possibility of ectopic), FBC, blood group and rhesus state, triple swabs and CRP (if pyrexial)
Management of miscarriage - 3 options:
If patient is rhesus negative and is greater than 12 weeks gestation - needs anti-D prophylaxis, if managed surgically need anti-D regardless of gestation.
1) Conservative
2) Medical
3) Surgical
Conservative management of miscarriage?
- Allows products of contraception to pass naturally - should have access to gynaecology services at all times.
- Advantages: Remain at home, no medication side-effects, no anaesthetic or surgical risk.
- Disadvantages: Unpredictable timing, heavy bleeding na pain during passage of POC - chance of being unsuccessful - needing further intervention and need for transfusion.
- Follow up - repeat scan in 2wk/pregnancy test in 3wk
CONTRAINDICATIONS: Infection, high risk of haemorrhage (coagulopathies and haemodynamic instability)
Medical management of miscarriage?
- Involves use vaginal misoprostol (prostaglandin analogue) to stimulate cervial ripening and myometrial contractions. (Preceeded by mifepristone) 24-48 hours before admission.
- Advantages: Can be a home if patient desires with 24/7 access to gynaecology services, avoids surgical or anaesthetic risk.
- Disadvantages - side effects of medication (vomiting and diarrhoea, heavy bleeding/pain during POC passage, risk of requiring emergency surgical intervention.
- Follow-up - pregnancy test 3 weeks later.
Surgical management of miscarriage?
- Manual vacuum aspiration with local (if under 12 weeks) or evacuation of retained products of conception (ERPC) with general.
- ERPC - General anaesthetic - speculum to visualise cervix, dilated and allows suction tube to be passed and remove POC, attend and discharged on the same day.
Definite indication: Haemodynamically unstable, infected tissue, gestational trophoblastic disease.
Advantages: Planned procedure (may help cope), unaware during process
Disadvantages: Anaesthetic risk, infection (endometritis), uterine perforation/haemorrhage, Asherman’s syndrome, bowel/bladder damage, retained POC.
Recurrent miscarriage definition?
The occurrence of three or more consecutive pregnancies that end in miscarriage of the foetus before 24 weeks of gestation.
Aetiology of recurrent miscarriage? (6 possible causes?)
1) Antiphospholipid syndrome - association between antiphospholipid antibodies and vascular thrombosis or pregnancy failure/compications.
2) Genetic factors - Parental chromosomal rearrangements (Robertsonian I chromosomal translocation), or embryonic chromosomal rearrangements.
3) Endocrine factors - Diabetes mellitus, thyroid disease, PCOS
4) Anatomical factors - uterine malformations, acquired uterine abnormalities (adhesions/fibroids), cervical weakness
5) Infective agents - Severe infection (bacteraemia/viralaemia) or bacterial vaginosis (1st trimester) - RARE
6) Inherited thrombophilias - (Factor V Leiden, prothrombin gene mutation, deficiencies of protein C/S and antithrombin III) - ass w/ 2nd trimester loss due to thrombosis of uteroplacental circulation.
Risk factors of recurrent miscarriage?
1) Advanced maternal age - decline in number and quality of oocytes.
2) Number of previous miscarriages
3) Smoking, alcohol, caffeine and obesity.
Investigations for recurrent miscarriage?
Blood tests:
1) Antiphospholipid antibodies (Dx of APS) - 2 positive tests 12 weeks apart (lupus anticoagulant, anticardiolipin, anti-B2-glycoprotein).
2) Inherited thrombophilia screen - factor V Leidin, prothrombin gene mutation and protein S deficiency.
Genetic testing (Karyotyping):
1) Cytogenic analysis - tests for chromosomal abnormalities in third and subsequent miscarriage POC.
2) Parental peripheral blood karyotyping - when testing POC reports unbalanced structural chromosomal abnormality - test both partners.
Imaging:
Pelvic ultrasound scan - assess uterine anatomy - abnormality indication require further investigation through hysteroscopy, laparoscopy or 3D pelvic ultrasound.
Management of recurrent miscarriage due to genetic abnormalities?
Refer to recurrent miscarriage clinic
Genetic abnormalities:
1) Clinical geneticist - genetic counselling - familial chromosome studies - discuss reproductive options.
2) Preimpantation genetic screening with IVF ?
Management of recurrent miscarriage due to anatomical abnormalities?
Anatomical abnormalities:
Benefit of uterine correction surgically unproven,
1) Cervical cerclage (suture closing cervis to treat cervical weakness) - for previous poor obsetetric history, cervical length shortening on USS, symptomatic women with premature cervical dilatation.
Complications of cervical cerclage: bleeding, membrane rupture, stimulating uterine contractions.
Management of recurrent miscarriage due to thromophilia and antiphosphlipid syndrome?
Thrombophilia and antiphospholipid syndrome:
Women with second-trimester miscarriage associated with inherited thrombophilias - may improve live birth rate with HEPARIN THERAPY during pregnancy.
APS - low-dose aspirin plus heparin considered in women with APS.
