Should prevention of chronic kidney disease start before pregnancy?

The objective was to evaluate whether there is a role for the prevention of future chronic kidney disease (CKD) in children by improving maternal health at conception, this review addresses: the risk of childhood obesity in the development of CKD, trends in childhood obesity and body composition in children with renal diseases, trends in pre-pregnancy BMI and its association with neonatal outcome, and the effect of pre-pregnancy body mass index (BMI) on blood pressure and body composition in the offspring.

It is now well established that the presence of hypertension increases the risk of CKD. Increased BMI can also increase the risk of the development of CKD indirectly, through an increase in the prevalence of hypertension, and, possibly, through a direct effect independent of hypertension.

An unprecedented epidemic of childhood obesity has been witnessed since the 1970s. An estimated 35% of children in North America are reported to be overweight. Children with CKD have even higher BMIs. TRENDS IN PRE-PREGNANCY BMI AND ITS ASSOCIATION WITH NEONATAL OUTCOME: The average BMI of mothers delivering in a single hospital in London, Ontario, rose from 24.3 kg/m2 in 1995 to 25.1 kg/m2 in 2004, whereas the average age of conception of the first child remained unchanged at 28 years. High pre-pregnancy BMIs increased the proportion of large-for-gestational-age newborns, a high proportion of congenital anomalies including renal abnormalities, and the need for Cesarean sections. EFFECT OF PRE-PREGNANCY BMI ON BLOOD PRESSURE AND BODY COMPOSITION IN THE OFFSPRING: Among 1,915 children (mean age 8.3 +/- 5.2 years), studied at the Children's Hospital, London Health Science Centre, BMI z-score correlated significantly with systolic (Spearman r = 0.214, P < 0.0001), and diastolic blood pressure z-scores (Spearman r = 0.143, P < 0.0001). The pre-pregnancy BMI correlated with both BMI z-score (Spearman r = 0.144, P < 0.0001) and blood pressure z-score (Spearman r = 0.13, P = 0.0005) in the children. The birth weight also correlated significantly with a higher BMI z-score (Spearman r = 0.134, P < 0.0001).

There are increasing trends in childhood obesity and pre-pregnancy maternal BMI. Higher pre-pregnancy BMI increases the risk for increased BMI z-score and blood pressure z-score in children. Since elevated BMI and blood pressure clearly are known risk factors of future CKD, targeting healthier weights prior to conception is likely to reduce the CKD burden in children.