Duley L, Henderson-Smart DJ, Meher S, King JF Antiplatelet agents for preventing pre-eclampsia and its complications. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD004659. doi: 10.1002/14651858.CD004659.pub2.
Henderson JT, Whitlock EP, O'Conner E, Senger CA, Thompson JH, Rowland MG Low-Dose Aspirin for the Prevention of Morbidity and Mortality From Preeclampsia: A Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2014 Apr. Report No.: 14-05207-EF-1. Available from http://www.ncbi.nlm.nih.gov/books/NBK196392/
Lisonkova S, Joseph KS Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease. Am J Obstet Gynecol. 2013 Dec;209(6):544.e1-544.e12. doi: 10.1016/j.ajog.2013.08.019. Epub 2013 Aug 22.
Perneby C, Vahter M, Akesson A, Bremme K, Hjemdahl P Thromboxane metabolite excretion during pregnancy--influence of preeclampsia and aspirin treatment. Thromb Res. 2011 Jun;127(6):605-6. doi: 10.1016/j.thromres.2011.01.005. Epub 2011 Feb 12. No abstract available.
Roberge S, Nicolaides K, Demers S, Hyett J, Chaillet N, Bujold E The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction: systematic review and meta-analysis. Am J Obstet Gynecol. 2017 Feb;216(2):110-120.e6. doi: 10.1016/j.ajog.2016.09.076. Epub 2016 Sep 15.
Seidler AL, Askie L, Ray JG Optimal aspirin dosing for preeclampsia prevention. Am J Obstet Gynecol. 2018 Jul;219(1):117-118. doi: 10.1016/j.ajog.2018.03.018. Epub 2018 Mar 26. No abstract available.
Shanmugalingam R, Hennessy A, Makris A Aspirin in the prevention of preeclampsia: the conundrum of how, who and when. J Hum Hypertens. 2019 Jan;33(1):1-9. doi: 10.1038/s41371-018-0113-7. Epub 2018 Sep 19.
Vainio M, Riutta A, Koivisto AM, Maenpaa J Prostacyclin, thromboxane A and the effect of low-dose ASA in pregnancies at high risk for hypertensive disorders. Acta Obstet Gynecol Scand. 2004 Dec;83(12):1119-23. doi: 10.1111/j.0001-6349.2004.00396.x.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.