Placentas…when they work they are life-giving. When they are impaired they can cause all kinds of grief.
In this meta-anlysis, researchers looked at the evidence for aspirin to prevention placental abruption for women at risk and found there is no evidence of an effect.1 This is despite evidence that aspirin reduces risk of preeclampsia and small for gestational age – in other words, other placental related problems. Thankfully, only 1% of pregnant women will experience placental abruption, but when it occurs, it is an emergency.
If you need a refresher on the risk factors for abruption, they include: previous abruption, smoking, over age 35, preeclampsia or hypertension, abnormal uterus
There was a difference between those who took <100 mg per day and those that took more than 100 mg, suggesting higher doses have potential to be effective. But this is where a problem lies, higher doses also have risks such as congenital defects and disruption of the fetal circulatory system. These risks are part of the reason why pregnant women are advised to use acetaminophen rather than NSAIDs (the class of drugs that includes aspirin and ibuprofen) for pain relief.