Miscarriage Flashcards
What is a miscarriage?
Spontaneous loss of pregnancy before 24 weeks of gestation
When do most miscarriages tend to occur?
In the first trimester
What percentage of all women who become pregnant will have 1 or more miscarriages?
25%
What is the major cause of first trimester miscarriages?
Chromosomal abnormalities
What percentage of the population has recurrent miscarriages?
About 1%
What classifies as recurrent miscarriage?
3 or more consecutive miscarriages
What is an early miscarriage?
<13 weeks
What is a late miscarriage?
13-24 weeks
What types of miscarriages are there?
Threatened Inevitable Incomplete Complete Septic Missed
Describe a threatened miscarriage
Bleeding and or pain up to 24/40m but TVUSS shows a foetal heart (viable pregnancy)
Closed cervical os
75% will settle
Carry high risk of preterm delivery and preterm rupture of membranes
Describe an inevitable miscarriage
Non viable pregnancy Vaginal bleeding (heavy, clots, pain) Open internal cervical os Products of conception have not been passed, but they inevitably will
Describe an incomplete miscarriage
Some products of conception passed
Some tissues and blood remain within uterus
Cervix stays open until all tissue passed
Describe a complete miscarriage
All products of conception passed
History of bleeding, passing clots and POC and pain that have now stopped
Cervix closed
No POC seen in uterus with endometrium than is <15mm diameter and previous proof of intrauterine pregnancy ie scan
What is a missed (delayed) miscarriage?
A gestational sac which contains a dead fetus before 20 weeks without symptoms of expulsion
Mother may have light bleeding/discharge
Cervical os closed
When the gestational sac >25mm and no fetal part can be seen - described as a blighted ovum or anembryonic pregnancy
What causes are there?
In most cases no identifiable cause
Abnormal fetal development - chromosomal and structural abnormalities (trisomy = most common abnormality, trisomy 16 especially)
Maternal conditions:
- infections e.g BV, CMV, rubella, HSV, toxoplasmosis, parvovirus B19
- antiphospholipid syndrome
- SLE
- thrombophilia
- endocrine problems e.g PCOS, thyroid disease, DM, hyperprolactinaemia
- genetic abnormalities in the parents
Uterine conditions
Incompetent cervix - previous cervical surgery
Iatrogenic - amniocentesis, CVS
Social factors - smoking, alcohol, cocaine
What uterine factors can cause miscarriages?
Septate, bicornuate or acute uterus can affect development of growing foetus
Cervical incompetence- not allowing normal development
Fibroids - can distort the uterus
What risk factors are there?
Advanced maternal age
Previous miscarriage (especially 2)
Lifestyle - smoking, obesity, alcohol, drug use (NSAIDS and street drugs)
Folate deficiency e.g methotrexate
Consanguinity
Paternal factors - tight (bottom) clothing, sperm abnormalities, old paternal age
Environmental- high dose radiation, heavy metal exposure
Describe the pathophysiology
Haemorrhage occurs in the decidua basalis leading to necrosis and inflammation
Ovum unable to continue development- initiates uterine contractions, cervix dilates causing loss of fetus and pregnancy tissue
Why is a complete miscarriage more likely before 12 weeks?
The placenta is unlikely to have been independently developed - thus being expelled with fetus
Why is an incomplete miscarriage more likely to occur if the miscarriage occurs between 12-24 weeks?
The gestation sac is more likely to rupture and the fetus then expelled while parts of the placenta remain in the uterus
What are the clinical features?
Vaginal bleeding - vary from brownish light spotting to heavy bright red blood with clots
Lower abdominal cramping pain
Vaginal fluid/discharge/tissue discharge
Loss of pregnancy symptoms - no more nausea, breast tenderness
Lower back pain
A missed miscarriage often does not present with any symptoms
What investigations should be done?
Urine pregnancy test
Transvaginal USS - if unable to determine status of fetus a repeat scan will be done after minimum 7 days
If the crown rump length is <7mm and no fetal heart, a conclusive diagnosis of miscarriage cannot be made - so repeat scan in at least 7 days
Serum beta-human chorionic gonadotropin (bhCG) levels
FBC, blood group and rhesus status
Triple swabs and CRP if pyrexial
If serum bhCG is > 1500 and nothing seen in uterus, what does this suggest?
Chances of ectopic high
If bhCG level is low what should be done?
Further bhCG 48 hours later - establish if pregnancy developing properly
A rise by 63% - most likely intrauterine pregnancy, but 10% of ectopics have a normally rising bhCG so should not be falsely reassured - bring patient back 1 week later for USS
If second bhCG does not rise by 63%, what is likely?
Ectopic
Could be intrauterine not developing properly
What produced bhCG?
The placenta, so bhCG levels will decrease after miscarriage
What differentials are there?
Ectopic pregnancy - but pain usually unilateral, more severe and before bleeding presents, bleeding darker and less heavy Molar pregnancy Ruptured ovarian corpus luteum cyst Ovarian torsion Fibroid degeneration
Non pregnancy related: Cervicitis Cervical ectropian Cervical polyps Cancers Haemorrhoids
What 3 types of management options are there?
Expectant
Medical
Surgical
Describe the expectant approach
Waiting for spontaneous miscarriage
Waiting for 7-14 days
Need 24 hour access to gynae services
Advantages: at home, avoid risk of surgery/medication
Disadvantages: pain and bleeding unpredictable, takes longer, may be unsuccessful
Follow up: repeat scan in 2 weeks or pregnancy test 3 weeks later
Describe medical management
Drugs used to encourage pregnancy to come away
Vaginal misoprostol - prostaglandin analogue
Stimulates cervical ripening and myometrial contractions
Give with antiemetics and pain relief
Advantages: avoid surgery, done as outpatient
Disadvantages: pain and bleeding, side effects of drug, 5% emergency SERPC
Follow up: pregnancy test 3 weeks later
How does misoprostol work?
Binds to myometrial cells for cause strong contractions leading to expulsion of tissue
What is the surgical option?
Suction curette to empty uterus
5 minutes under GA
Can do via local - NVA
What are the disadvantages of surgical option?
Perforation of bowel/bladder
Cervix damage
Asherman’s
Anaesthesia risk
What complications can occur with miscarriage?
Incomplete
Haemorrhagic shock due to excessive bleeding
Infection - retained tissue
Psychological complications
HDN - give anti-D to Rhesus neg women who have had surgical intervention
Increased risk of another miscarriage
What should be done 3 weeks after medical management?
Pregnancy test
If positive return for a review to ensure there is no molar or ectopic pregnancy
How should a threatened miscarriage be managed?
If heavy bleeding, admit/observe, if not reassure and back to GP/midwife
If more than 12w and rhesus negative: anti D
When can fetal cardiac activity be observed via TVUSS?
5 and 1/2 to 6 weeks gestation
Who required anti d prophylaxis?
Rhesus neg women, fetus greater than 12w gestation or managed surgically
When may you be advised to have surgery immediately?
Heavy bleeding
Signs of infection
Coagulopathy or unable to have blood transfusion
