BACKGROUND AND AIMS Untreated coeliac disease in the mother is associated with lower birth weight. We examined the risk of adverse neonatal outcome when the infant's mother, father, or other relative suffered from known coeliac disease.

RESULTS Infants whose father suffered from coeliac disease had a lower birth weight (95% adjusted confidence interval (CI) −459, −72 g), more often belonged to the low birth weight (LBW) category (LBW ⩽2499 g) (95% CI adjusted odds ratio (AOR) 1.48–17.18), and had a shorter pregnancy duration (95% adjusted CI −1.53, −0.08 weeks) than non-coeliac controls. They also weighed less than infants whose father suffered from other autoimmune diseases (95% CI −549, −93 g). Infants whose mother suffered from coeliac disease had a lower birth weight (95% adjusted CI −370, −74 g) and more often belonged to the LBW category (95% CI AOR 2.60–15.08) than non-coeliac controls. These infants were more often in the LBW category than infants whose mother suffered from non-diabetic autoimmune diseases (95% CI AOR 1.24–9.65). Coeliac disease in other relatives was not associated with any adverse effect on neonatal outcome.

CONCLUSIONS This study suggests that even treated coeliac disease, in either of the parents, has a negative effect on pregnancy, resulting in lower birth weight and perhaps shorter duration of pregnancy.