Urinary calculi and pattern of fertility among women. A retrospective study.

Researchers compared retrospective data on 250 women who had urinary stones at University Hospital in Alexandria Egypt with data on 250 matched women who did not have urinary stones to examine the relationship between urolithiasis and fertility patterns among women. They defined fertility patterns by age at 1st pregnancy number of pregnancies and oral contraceptive (OC) use. Cases had experienced significantly more pregnancies than the controls (4.6 vs. 3.7; t=3.5797). The cases were significantly more likely to have suffered from a urinary tract infection than were controls (92.8% vs. 21.6%; x squared=258.8392). 95.6% of cases had stones in areas other than the urinary bladder. 56.47% of women who had ever been pregnant had a stone on their right side compared with only 42.86% of those who were never pregnant (Z=2.232). This was probably due to more dilation of the right ureter than the left and subsequent blockage from the pressure of the expanding uterus. Age at 1st pregnancy pregnancy history and duration of OC use were not associated with urolithiasis. These results did not consistently match those of other studies looking at the relationship between urolithiasis and fertility.