The ductus arteriosus (DA) is a vital structure in fetal circulation, carrying about two thirds of the right ventricular (RV) output to the aorta. During fetal life, ductal patency is actively preserved by several different factors, and pathologic ductal constriction causes right-sided pressure overload of the heart, leading to RV failure. There have been many reports of ductal constriction so far, most of which are linked to maternal use of non-steroidal anti-inflammatory drugs, but they are mainly reported in the third trimester. In the present study, we report the case of a 25-year-old gravid 2 woman with premature constriction of the DA following maternal treatment with dexamethasone and ibuprofen at the very early age of 18 weeks of gestation. She was referred to the radiology department for fetal echocardiography after a recent ingestion of ibuprofen for back pain. She was found to have had a constricted ductus arteriosus 3 days after being medicated at the gestational age of 18 weeks.