13.10.16 GP notes

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)

    • Or 1 mg PO weekly

  • FFP if already bleeding

Anti-D (Rho) immunoglobulin

• • 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.