Prenatal hydroxychloroquine exposure not linked to major structural birth defects
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The use of hydroxychloroquine during pregnancy is not associated with structural birth defects or any other outcomes, save for birth head circumference, according to data published in Arthritis & Rheumatology.
“Hydroxychlorquine is an older medication that is a mainstay in treatment of some rheumatic conditions,” Christina D. Chambers PhD, MPH, of the University of California, San Diego, told Healio Rheumatology. “As is common with medications used in pregnancy, we often have insufficient information about pregnancy safety even when the medication has been in use for many years. Some recent data suggested there may be an increased risk for malformations in the infant following hydroxychloroquine treatment in the first trimester of pregnancy, especially at higher doses.”
To analyze pregnancy outcomes following the use of hydroxychloroquine, Chambers and colleagues examined data from the ongoing MotherToBaby Autoimmune Diseases in Pregnancy Study. Conducted by the Organization of Teratology Information Specialists, the MotherToBaby prospective pregnancy studies enroll participants from throughout the United States and Canada. For their study, Chambers and colleagues included a total of 837 participants who had been pregnant between 2004 and 2018.
Among these patients, 279 received hydroxychloroquine, 279 were disease-matched individuals who were unexposed to hydroxychloroquine, and 279 were healthy comparators. A total of 60 pregnancies were lost to follow-up. Data in the original study were collected through interviews, medical records and dysmorphology examinations. Assessed outcomes included major and minor birth defects, spontaneous abortion, preterm delivery and infant growth.
According to the researchers, among the examined live births, 8.6% of those preceded by first-trimester hydroxychloroquine use had demonstrated a major birth defect, compared with 7.4% in the disease-matched group (OR = 1.18; 95% CI, 0.61-2.26) and 5.4% among healthy comparators (adjusted OR = 0.76; 95% CI, 0.28-2.05). In addition, risks did not differ at doses at or exceeding 400 mg per day. The researchers observed no pattern of birth defects, and there were no differences in the rates of spontaneous abortion or preterm delivery.
Growth deficiency measures similarly did not differ between the hydroxychloroquine disease-matched groups, save of birth head circumference (aOR = 1.85, 95% CI, 1.07-3.2). However, missing values for head circumference were common across all groups, with 15% to 17% of measurements unavailable. The researchers noted that bias in reporting head circumference may account for this finding.
“Although the sample size was small, overall there was no indication of increased risks for malformations, and specifically not at higher doses,” Chambers said. “Of course, a small absolute risk for specific malformations cannot be ruled out in a study this size. Although more data are always needed, these findings are generally reassuring.”