The impact of maternal celiac disease on birthweight and preterm birth: a Danish population-based cohort study

Adverse pregnancy outcomes have been associated with maternal celiac disease (CD). In this study, we investigate the effect of treated and untreated maternal CD on infant birthweight and preterm birth. A population-based cohort study consisted of all singleton live births in Denmark between 1 January 1979 and 31 December 2004 was used. A total of 1 504 342 babies were born to 836 241 mothers during the study period. Of those, 1105 babies were born to women with diagnosed CD and 346 were born to women with undiagnosed CD. Women with diagnosed CD were considered as treated with a gluten free diet while women with undiagnosed CD were considered as untreated. The outcome measures were: birthweight, small for gestational age (SGA: birthweight < 10th centile), very small for gestational age (VSGA: birthweight < 5th centile) and preterm birth. We compared these measures in treated and untreated women with those of a reference group (no history of CD). Women with untreated CD delivered smaller babies [difference = -98 g (95% CI: -130, -67)], with a higher risk of SGA infants [OR = 1.31 (95% CI: 1.06, 1.63)], VSGA infants [OR = 1.54 (95% CI: 1.17, 2.03)] and preterm birth [OR = 1.33 (95% CI: 1.02, 1.72)] compared with women without CD. Women with treated CD had no increased risk of reduced mean birthweight, risk of delivering SGA and VSGA infants or preterm birth compared with women without CD. Untreated maternal CD increases the risk of reduced birthweight, the risk of delivering SGA and VSGA infants and preterm birth. Diagnosis and presumed treatment of maternal CD with a gluten-free diet appeared to result in a birthweight and preterm birth rate similar to those in women without CD.