ASPIRIN IN OBSTETRIC PRACTISE, a critical analysis

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ASPIRIN IN OBSTETRIC PRACTISE,
a critical analysis

• DR .RIHAB ALSALIH,ABOG
• OB-GYN CONSULTANT,MCH,JEDDAH

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OUTLINE

• STRUCTUREMechanism of action
• Role in common obstetric problems
• 1- recurrent abortion
• 2- thrombophilic disorders in pregnancy
• 3- preeclampsia
• 4-IUGR
• 5- other conditions
• Side effects safety
• Statements from recognized bodies
• conclusion

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Structure and mech of action

• Acetylsalicylic acid
• NSAID

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ASA
PG
TxA2
cyclooxygenase
ProstacyclinTX ratio
? Plt aggregation, ?Vasoconstrictor activity
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ROLE OF ASA IN Common obstetric problemsASPIRIN
RECURRENT MISCARRIAGE

• EARLY vs LATE
• INCIDENCE2-5
• Etiology long list,60-70 unexplained

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Rai etal,human reproduction,115(10),2000

• Observational study
• 1055 preg women with3early MC or at least 1 late
  MC
• 805 VS 250
• ASA 75 MG VS placebo

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Rai etal,human reproduction,115(10),2000
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RESULTS LIVE BIRTH RATE
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Rai etal,human reproduction,115(10),2000

• ? Amongst women with recurrent early
  miscarriages, there was no significant difference
  in the live birth rate between those who took
  aspirin compared with those who did not take
  aspirin
• ? In contrast, women with a previous late
  miscarriage who took aspirin had a significantly
  higher live birth rate compared with those who
  did not take aspirin . ? The empirical use of low
  dose aspirin amongst women with unexplained
  recurrent early miscarriage is not justified.

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Salim Daya,mineva gynecol,2003,oct,55(5), p441-9

• To date,there is no evidence of improved outcome
  with ASA compared to placebo or no treatment
• Limited human data suggest prenatal use of ASA
  may be assoc with higher bleeding tendency plus
  behavioral cognitive defects in the offspring
• Practice of prescribing ASA 4 ALL CASES OF RM
  should be discontinued

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Explained rec.Miscarriage

• Cases of antiphospholipid syndrome,ASA PLUS
  heparin improved live birth rate
• 40 Vs 80
  
• Drawbacksmall series ,no meta-analysis

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Outcome of pregnancy in women with recurrent
miscarriages and phospholipid antibodies who were
given aspirin or aspirin and heparin. All
pregnancies of longer than 32 weeks' gestation
resulted in live birth
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• Cases with thrombophilic disorders,eg prot c,
  prot s def ,factor ? mutation
• Improved live birth rate after ASA heparin
  compared to ASA alone.
• Limited data,no controlled studies

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Role in common obstetric problems

• PREECLAMPSIA
• W H O affected pregnancies 2-8
• In KSA hypertensive disorders in preg is the
  fourth leading cause of maternal mortality

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ASPIRIN as chemoprophylaxis

• Duley etalantiplt drugs for prevention of PE
• BMJ,2001,322329-33
• Cochrane systematic review
• Dipyridamole or ASA to preg women at risk of dev
  PE
• 51 trials,36500 women

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RESULTS
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• OTHER VARIABLES
• Eclampsia,Maternal death, C\S,IOL,Admission to
  SCBU, IVH
• NS
  
  

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CONCLUSION

• Although benefits are not as high as was hoped in
  early 1990s,ASA ?risk of PE its consequences.
• Benefit is considered small-mod
• ExplanationPub bias,wide range of mat
  characters,timing of intervension
• Adverse effects is low ?? under reporting
• ASA before 12wks or dosesgt75mg cant be
  recommended until more info is available about
  safety
• Current evidence should be made available to pts
  at risk of PE

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• Coomaarasamy etal ASA for prevention of PE in
  women with historical risk factorsA systematic
  Review
• ob-gyn,101(6),2003,1319-32
• 14 studies,hist risk for PE like hx of
  HTN,DM,renal dis,extreme of age,hx of PE
• 12416 pts

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RESULTS

• Reduction in PNM0.75(0.64,0.96)
• Reduction in PE 0.86(0.76,0.96)
• Reduction in spont PTL0.86(0.79,0.94)
• Fetal WT ?150 gms
• Abruptio placentaNS
• NNT is much less if multiple risk factor

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CONCLUSION

• It is reasonable to recommend ASA to women who
  are historically at high risk for PE particularly
  if they are with multiple risk factors

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US preventive service task force2005

• There is insufficient evidence to recommend for
  or against ASA proph in preg for prevention of PE
  or IUGR (recommendation C).
• Physicians may wish to inform pts at high risk of
  PE that ASA ?risk of PE but no improvement in
  fetal or maternal outcome

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Aspirin IUGR

• IUGR vs constitutionally small
• Uzand,Lancet,1991
• 323 cases ,15-18 wks preg,hx of IUGR
• 2 GRPS150MG\D ASA vs placebo
• RESULTSfetal wt ? significant in Rx gp(p0.029)

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• These results could not be reproduced in other
  studies
• EXPLANATIONvariable def,subjective entry
  criteria,..

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Other conditions

• ASA is used in cases with hx of arterial
  thrombosis (REC C)
• ASA is used for pts with high risk for venous
  thrombosis at time of long airway trip (economy
  class syndrome).RCOG guide lines,1999.(REC C)

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SIDE EFFECTS

• ?CHD
• ?Premature closure PDA
• Mat clotting disorders?gt1500mg\d
• Neonatal clotting disorders ?gt325mg\d

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CONCLUSION

• ASA is a drug with its own benefits risk.It is
  advisable to use it where benefit outweighs risk
• ASA has a beneficial role in explained RM
• ASAPE is controversy
• Inform your pt about current evidence
• Large RCT are needed

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THANK YOU