From the Guidelines
Low-dose aspirin (75-81 mg daily) is recommended for pregnant women at high risk for preeclampsia, including those with a history of preeclampsia, diabetes, chronic hypertension, renal or autoimmune disease, or multifetal pregnancies, starting as early as 12 weeks of gestation. The World Health Organization and other reputable health organizations, such as the National Institute for Health and Care Excellence and the American Heart Association, support the use of low-dose aspirin in high-risk women to prevent morbidity and mortality from preeclampsia 1. Specific indications for low-dose aspirin include:
- Women with a history of previous preeclampsia
- Women with chronic hypertension
- Women with pre-gestational diabetes (type 1 or 2)
- Women with renal disease
- Women with autoimmune disorders
- Women with multifetal pregnancies Additionally, women with more than one moderate risk factor, such as nulliparity, obesity, maternal age >35 years, family history of preeclampsia, or conception through assisted reproductive technology, may also benefit from low-dose aspirin therapy 1. Treatment should begin between 12-20 weeks of gestation and continue until delivery, with the medication taken daily, preferably at bedtime. The use of low-dose aspirin has been shown to improve placental blood flow and reduce placental inflammation, thereby preventing the placental ischemia and endothelial dysfunction that contribute to preeclampsia and other adverse pregnancy outcomes 1.
From the FDA Drug Label
If pregnant or breast-feeding ask a health professional before use. it is especially important to use aspirin during the last 3 months of pregnancy unless definitely directed to do so by a doctor because it my cause problems in the unborn child or complications during delivery. The FDA drug label does not answer the question.
From the Research
Indications for Low-Dose Aspirin in High-Risk Pregnancies
- Low-dose aspirin has been used during pregnancy to prevent or delay the onset of preeclampsia, with the American College of Obstetricians and Gynecologists recommending daily low-dose aspirin beginning in the late first trimester for women with a history of early-onset preeclampsia and preterm delivery at less than 34 0/7 weeks of gestation, or for women with more than one prior pregnancy complicated by preeclampsia 2, 3.
- The U.S. Preventive Services Task Force recommends the use of low-dose aspirin (81 mg/d) as preventive medication for preeclampsia after 12 weeks of gestation in persons who are at high risk for preeclampsia, with a substantial net benefit of daily low-dose aspirin use to reduce the risk for preeclampsia, preterm birth, small for gestational age/intrauterine growth restriction, and perinatal mortality in pregnant persons at high risk for preeclampsia 4.
- Women at risk of preeclampsia are defined based on the presence of one or more high-risk factors (history of preeclampsia, multifetal gestation, renal disease, autoimmune disease, type 1 or type 2 diabetes, and chronic hypertension) or more than one of several moderate-risk factors (first pregnancy, maternal age of 35 years or older, a body mass index greater than 30, family history of preeclampsia, sociodemographic characteristics, and personal history factors) 2, 3.
- Low-dose aspirin prophylaxis should be considered for women with more than one of several moderate risk factors for preeclampsia, and should be initiated between 12 weeks and 28 weeks of gestation (optimally before 16 weeks) and continued daily until delivery 2, 3.
- The optimal dosage of aspirin for preventing preeclampsia is still a topic of debate, with some studies suggesting that doses of >100 mg of aspirin daily initiated before 16 weeks' gestation may be more effective at reducing the risk of preeclampsia 5.
- A study found that about 1/3 of women at high risk for preeclampsia did not respond adequately to 150 mg of aspirin daily, suggesting a need for further research to allow a personalized approach for individualized aspirin therapy 6.