Maternal diabetes mellitus and congenital anomalies of the kidney and urinary tract (CAKUT) in the child.

BACKGROUND: Congenital anomalies of the kidney and urinary tract (CAKUT) are the primary cause of chronic kidney disease in children. The relevance of timing of diabetes mellitus (DM) exposure on risk of CAKUT in exposed children is unknown.

STUDY DESIGN: Population-based nested case-control study.

SETTING & PARTICIPANTS: Infants born between fiscal years 1996/1997 and 2009/2010 in Manitoba, Canada, identified using administrative data housed at the Manitoba Centre for Health Policy.

PREDICTORS: Pregestational (including first 20 weeks' gestation) and gestational (>20 weeks) DM and relevant confounders (maternal age; renin-angiotensin-aldosterone system inhibitor use; low socioeconomic status; alcohol, illicit drug, and smoking use during pregnancy; region of residence; and size for gestational age [surrogate of glycemic control]).

OUTCOME: CAKUT identified by International Classification of Diseases codes.

RESULTS: 945 case patients with CAKUT and 4,725 controls (matched for gestational age, sex, and birth year) were identified. Maternal pregestational DM occurred in 39 (4.1%) of the CAKUT group and 111 (2.3%) controls (P = 0.002), whereas gestational DM occurred in 40 (4.2%) of the CAKUT group and 157 (3.3%) controls (P = 0.2). In the conditional multivariable logistic regression model, pregestational DM was associated with CAKUT (OR, 1.67; 95% CI, 1.14-2.46), whereas gestational DM was not (OR, 1.29; 95% CI, 0.90-1.85). Both large (LGA) and small for gestational age (SGA) also were associated significantly with CAKUT (LGA: OR, 1.34 [95% CI, 1.11-1.63]; SGA: OR, 1.59 [95% CI, 1.26-2.01]).

LIMITATIONS: Lack of data for maternal glycemic control and body mass index.

CONCLUSIONS: This study suggests that DM in the first 20 weeks of pregnancy is associated with CAKUT in exposed infants. The association between CAKUT and LGA suggests that poor glycemic control increases risk. Screening and intervention studies in women of childbearing age with DM are warranted to determine whether the risk of chronic kidney disease in children can be modified.