Aspirin and ibuprofen such as Motrin and Advil usually aren’t recommended during pregnancy. Aspirin interferes with  the clotting action of blood. Therefore  taking aspirin at 32 weeks of pregnancy and after can contribute to maternal and fetal bleeding. These medications can also cause premature closure of a vessel in the baby’s heart. This can lead to high blood pressure in the baby’s lungs ( pulmonary hypertension ) and prolonged labor.
 

 
However sometimes low doses of aspirin is prescribed during pregnancy to treat certain medical conditions.  Women at a high risk of preeclampsia are advised to take low doses of aspirin everyday after the first trimester to reduce their risk. Taking low doses of this medication  during mid and late pregnancy can also reduce the risk of premature birth and low birth weight which may result from preeclampsia. In this case your health care provider will closely monitor you and your baby.

What are the risk of taking full doses of aspirin regularly ?

 
Taking full doses of this medication regularly during pregnancy can increase your risk of the following :

• taking the medication around conception or during early pregnancy increases your chance for a miscarriage
• taking aspirin throughout pregnancy could affect the growth of your baby or cause placental abruption
• taking this medication in late pregnancy could possibly delay labor and increase your baby’s risk of developing heart and lung problems after he’s born. It could also lead to bleeding complications for you and your baby.

 
You need to ask your health care provider if you need pain medication during pregnancy. He may recommend occasional use of acetaminophen (Tylenol and others )

Note : DO NOT start a low dose aspirin regimen during pregnancy without your doctor’s recommendation.