Are Pregnant Women More Likely to Develop Kidney Stones?

Pregnant women occasionally develop symptomatic kidney stones, but whether pregnancy is a risk factor for symptomatic stones is unclear. In this population-based case-control study, Mayo Clinic researchers compared 945 women (age range, 15–45) who presented with a first symptomatic kidney stone and 1890 age-matched female controls with no history of kidney stones.

In 19% of the kidney stone group, symptomatic stones were diagnosed between the second trimester and 1 year postpartum. The composition of most of the pregnancy-associated stones was calcium phosphate (hydroxyapatite). Pregnancy and symptomatic kidney stone formation were associated significantly: Risk for symptomatic stones began to increase during the second trimester, peaked dur…