Most previous studies have failed to demonstrate any effect of maternal use of 5-aminosalicylates (5-ASA) on malformation risk, but the number of infants studied have, in most cases, been low.
Professor Bengt Källén and colleagues from Sweden obtained data from a large study with prospectively ascertained exposure information.
The study was based on data in the Swedish Medical Birth Register (1996–2011) where identification of maternal drug use is made from midwife interviews in early pregnancy.
The presence of congenital malformations was ascertained from 3 national registers.
The team calculated adjusted odds ratios by the Mantel-Haenszel methodology.
|3651 women reported the use of 5-ASAs in early pregnancy|
|Scandanavian Journal of Gastroenterology|
Among 1,552,109 women, 3651 with 3721 infants had reported the use of 5-ASAs in early pregnancy.
The team found that the risk of a major malformation was increased, and still more for a cardiovascular defect.
The team noted that this effect seemed to be influenced by concomitant use of systemic glucocorticosteroids or immunosuppressants but some confounding by indication may also exist.
The researchers found no marked difference between the 4 5-ASA drugs studied.
Professor Källén and team concludes, "Infants born of women who use 5-ASA drugs in early pregnancy have an increased risk of a congenital malformation, notably a cardiovascular defect."
"This could be a drug effect or an effect of an active inflammatory bowel disease."