Obstetric cholestasis - AKA intrahepatic cholestasis of pregnancy (ICP)
- Most common in third trimester
- Don't confuse with "normal" pregnancy itching
- Affects palms and soles too
- May be worse in evening
- Does not respond to antihistamines
- Mechanism pretty much unknown:
- Oestrogens reduce hepatocyte bile acid uptake
- Recurs in between 45% and 70% of subsequent pregnancies
- Management
- Ursodeoxycholic acid (secondary bile acid) to reduce bile acid reabsorption
- Cholestyramine
- Early delivery (by 37 weeks)
- Correct clotting
Vitamin K deficiency bleeding (VKDB) - AKA haemorrhagic disease of the newborn (HDN)
- Due to deficiency of clotting factors as a result of vitamin K deficiency
- Onset
- Early VKDB occurs within 24 hours of birth (rare)
- Mostly due to drugs during pregnancy
- Classic VKDB happens between day 1 and day 7 of life (44%)
- Late VKDB occurs between week 2 and week 12 of life (56%)
- Can result in significant morbidity and mortality due to intracranial haemorrhage
- Risk factors
- Children who are entirely breast-fed have a 20 times greater risk of developing VKDB
- Low levels of vitamin K in breast milk
- Low levels of bacteria which help to synthesize vitamin K in the guts of breast-fed babies
- Medications: Isoniazid, rifampicin, anticoagulants, anticonvulsant agents
- Warm environmental temperatures
- Unsuspected liver disease, especially alpha-one-antitrypsin deficiency
- Malabsorption of fat-soluble vitamins due to diarrhoea, coeliac disease or cystic fibrosis
- Management
- Vitamin K (1 mg IM normally given to everyone at birth)
- FFP if already bleeding
- Indications (for non-sensitised RhD-negative women )
- Miscarriage
- Threatened, spontaneous complete or incomplete miscarriage at or after 12+0 weeks of gestation
- Not required for spontaneous miscarriage before 12+0 weeks of gestation, unless there is instrumentation or medical evacuation of the uterus
- If the woman continues to bleed intermittently after 12+0 weeks of gestation, anti-D Ig should be given at 6-weekly intervals
- Ectopic pregnancy / TOP
- All women who have an ectopic pregnancy or termination of pregnancy, regardless of method of management
- Sensitising events
- Prenatal diagnosis, other intrauterine procedures, antepartum haemorrhage, ECV, any abdominal trauma, fetal death
- Recurrent vaginal bleeding after 20+0 weeks of gestation
- Anti-D Ig should be given at a minimum of 6-weekly intervals
- Routine antenatal anti-D prophylaxis (RAADP) programme
- Not uniformly offered
- Protects against "silent" sensitisation (? common in third trimester)
- Postnatal prophylaxis
- Give within 72 hours of delivering a rhesus positive infant
- No universally accepted postnatal dose
- Dose
- Take an anticoagulated blood sample is taken from the susceptible mother as soon as possible (within two hours)
- Kleihauer screening quantifies extent of fetal-maternal haemorrhage
- 500 IU anti-D immunoglobulin (anti-D Ig) intramuscularly will neutralise an FMH of up to 4 ml (99% of women).
- For each millilitre above 4 ml, 125 micrograms of extra anti-D Ig are required.
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