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.