Groutz A, , et al. - This study seeks to assess the impact of a sharp increase in estrogen levels on overactive bladder (OAB) symptoms among women undergoing ovulation induction. Researchers prospectively included 100 consecutive women (mean age 36.9±5.2 years) who underwent IVF treatments. They examined patient's OAB symptoms before ovulation induction (low estradiol level) and prior to ovum pickup (peak estradiol level) applying three validated questionnaires on urinary urgency (USIQ), urinary incontinence, and lower urinary tract symptoms. The study indicated that 49 recorded OAB symptoms prior to ovulation induction (mean USIQ severity score 33) and 51 women were asymptomatic out of the 100 women.  During ovulation induction, a higher estradiol level seems to have a protective impact against the development of OAB symptoms. Moreover, it was noted that in most (63%) women who remained asymptomatic, peak estradiol levels were higher than 1500 pg/ml. The data may imply a threshold for estradiol activity in the lower urinary tract.