Aspirin for Pre-eclampsia?

Max Brinsmead MB BS PhDJuly 2015

Resource for this Presentation:

Cochrane Database

“Anti platelet agents for preventing pre –eclampsia and its complications”

A Review published February 2007

And its conclusions confirmed in 2010

Hypothesis Pre-eclampsia is associated

with:

↓Intravascular Prostacyclin– A vasodilator– And...

↑Production of Thromboxane– That increases platelet stickiness

So low dose aspirin may prevent or reduce the severity of this disease

A Meta analysis of 59 trials involving 37,560 women found that

Aspirin will Reduce the risk of pre-eclampsia by

17% (RR 0.83 and CI 0.77 – 0.89) Number needed to treat is 72 But for high risk patients the number

needed to treat is 19 When high risk is defined as:– Previous severe pre-eclampsia– Chronic hypertension– Diabetes– Renal disease– Auto immune disease

Other Outcomes Reduce the risk of preterm

delivery by 8% (RR 0.92 CI 0.88 – 0.97) Reduce the risk of perinatal death

by 14% (RR 0.86 CI 0.76 – 0.98) Reduce the rate of SGA infants by

10% (RR 0.90 CI 0.83 – 0.98) No significant effect on:

– Risk of maternal death– Rate of Caesarean– Induction of Labour– Antenatal admission or Nursery Use

Is it Safe? The rate of abruptio placenta is

increased by 10% but this difference is not significant

(RR 1.10 CI 0.89-1.37) No increased rate of Neonatal

Intracerebral Haemorrhage Or any measure of neonatal bleeding One study (CLASP,1994) followed

children to 18 months of age and found no observable differences

Another study (Italy, 1993) found higher rates of gross and fine motor problems in children of treated mothers at 18 months but this study was unblinded and had other follow problems

Unanswered Questions What is the best dose?

– 75 mg daily is safe– Some evidence that higher doses may be

more effective When should the Aspirin be started?

– This study showed no difference in outcomes when analysed according to commencement before or after 20 weeks gestation

– But many argue that most benefit is likely to occur with commencement at <12 weeks and before trophoblast invasion of spiral arterioles occurs

Are adjuvants likley to be useful? e.g.– Other anti-platelet agents or even Heparin– Ca or Mg– Fish oil – (antioxidants have been ruled out)

Any Questions or Comments?

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