Miscarriage Flashcards
What is the physiology of early pregnancy?
Oocyte fertilised in ampulla of fallopian tube=zygote
Divides as is swept towards uterus by ciliary action and peristalsis
Enters uterus day 4 as multicellular morulla
Morulla becomes blastocyst by developing a fluid filled cavity within
Outer layer of blastocyst forms trophoblast which will form placenta and from day 6-12 invades endometrium to achieve implantation
Trophoblast produces hormones – B-HCG (peaks at 12 weeks). (note invasion and B-HCG production GTD)
Endometrium becomes deciduous (rich in glycogen and lipids) under influence of oes/pro from corpus luteum (maintained by HCG)
Trophoblastic proliferation leads to formation of chorionic villi – this proliferates on endometrial surface of embryo – to form cotyledons of placenta for nutrient transfer
Placenta complete at 12 weeks.
Heart beat at 4-5 weeks. Visible on u/s at 6-7 weeks.
What is the definition of miscarriage?
Pregnancy loss before 24 completed weeks of gestation
What is the epidemiology of miscarriage?
- approx 15-20% of clinically recognised pregnancies spontaneously miscarry
- 14,000 per year in Ireland
What are the majority of miscarriages gestation?
<12 weeks
When does the rate of miscarriage increase?
With maternal age
What are the different classifications of miscarriage?
- threatened
- inevitable
- incomplete
- complete
- septic
- missed
- recurrent
How can you define the classification of miscarriage?
Bleeding/pain/tissue loss?
Uterine size / foetal HB
Os open/closed
Where is the site of fertilisation?
Ampulla of Fallopian tubes
What are clinically recognised pregnancies?
HCG +
What is an early miscarriage?
First 12 weeks (first trimester)
What are late miscarriages?
12-24 weeks
What are Threatened Miscarriages?
- bleeding in early pregnancy
- not usually pain
- not usually tissue loss
- uterine size appropriate
- foetal heartbeat present
- cervical os closed
What happens with threatened miscarriages?
75% will have normal pregnancy
Increased risk of congenital abnormalities and low birth weight
What is seen in an inevitable miscarriage?
- bleeding
- pain
- no tissue loss
- foetal HB may no be present
- open os (>3cm)
What is incomplete miscarriage?
- bleeding
- pain
- tissue loss
- uterine size could be appropriate
- no foetal HB
- open os
What are complete miscarriages?
- would have had bleeding
- pain
- had tissue loss
- uterine size small for gestational age
- foetal HB not present
- closed os
What are septic miscarriages? (6)
- contents of uterus has become infected - Endometritis
- Sign of sepsis
- offensive discharge
- high temperature
- tenderness or peritonism when palpating abdomen
- signs of shock
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What is a missed miscarriage?
- either no foetal development (just a gestational sac) or in utero death
- either bleeding or u/S diagnosed
- small uterine size
- closed os
- often seen at 12 week scan
What are recurrent miscarriages?
3 or more miscarriages in succession (ie in a row)
- 1% of couples
What is the etiology of miscarriages? (4)
- isolated chromosomal abnormalities (>60% of spontaneous miscarriages)
- anatomical factors (uterine, cervical)
- infection (of genital tract like BV, or others like STI, TORCH)
- antiphospholipid antibodies
When are infections as the cause of miscarriage more common?
Late miscarriages
What types of chromosal abnormalities are there seen in miscarriage?
- majority are numerical issues (eg trisomies)
- could also be parents who had balanced translocation
How common are uterine abnormalities?
<5% of all women
25% with miscarriages or preterm
What are some uterine abnormalities?
How do uterine abnormalities present in pregnancy? (4)
- abnormal lie, presentation
- miscarriage
- pre-term labour
- retained placenta
What is a common congenital uterine abnormality?
Incomplete fusion of malarian ducts in uterus
What is cervical incompetence?
Painless cervical dilatation, over 16 weeks (ie second trimester) = miscarriage
What do you need to diagnose anti-phospholipid syndrome?
One clinical and one laboratory criteria
What are the clinical criteria for antiphospholipid syndrome? (4)
- vascular thrombosis
- 1+ foetal death >10 weeks
- 3+ foetal deaths <10 weeks otherwise unexplained
- pre-eclampsia or IUGR needing delivery <34 weeks
What are the laboratory criteria (that must be present on two occasions) for antiphospholipid syndrome? (3)
- lupus anticoagulant
- anti cardiolipin abs
- antiB2 glycoprotein 1 Abs.
How can you optimise antiphospholipid syndrome to aid prevention of miscarried?
while trying to conceive = Low dose aspirin
Once + pregnancy test = LMWH (clexane)
What are the 3 most common clinical features in the history of someone presenting with miscarriage?
Bleeding
Pain
Tissue loss
What clinical features should be checked on examination of suspected miscarriage?
- general = BP, HR, temp (iMEWS)
- abdo: size of uterus, tenderness
- pelvic: VE/speculum - cervical os open, cervical exicitation, degree of bleeding/products
What is cervical excitation?
Cervical motion tenderness
Chandelier sign
What are the 2 DDx for cervical excitation?
PID
Ectopic
Why must the HCP be careful when doing a VE to check for miscarriage?
Placenta not fully developed so esp be careful in later miscarriages
What investigations would EPAC/ gynae on call do at the weekend with a suspected miscarriage?
- ultrasound
- ? Intrauterine pregnancy? Viable
- ? Retained products of conception
- blood tests
- FBC (+/- others CRP/ESR/U&E/LFTs/Coag screen)
- blood group and hold and rhesus group
- BHCG
What do you look at with the BHCG in a suspected miscarriage?
- discriminatory zone
- serial measurements: rise >63% in 48 hours in viable IUP
What is the discriminatory zone?
Level at which you would expect to see an inter uterine pregnancy if it was there - would worry about ectopic if higher than this and can’t see it