"First uterine pass effect" is observed when estradiol is placed in the upper but not lower third of the vagina.

In postmenopausal women, the "first uterine pass effect" is seen when E(2) is placed in the upper but not lower third of the vagina.

Placement of the vaginal 17beta-estradiol tablets in the inner or outer one third of the vagina affects the preferential delivery of 17beta-estradiol toward the uterus or periurethral areas, thereby modifying efficacy and endometrial safety.

Objective: The purpose of this study was to investigate whether the effects of 17beta-estradiol tablets that are designed for the treatment of postmenopausal urovaginal atrophy are influenced by the site of placement into the vagina.

Study Design: In this controlled crossover trial, 10 postmenopausal women received a single 17beta-estradiol tablet in the outer or inner one third of the vagina. Before and 3 hours after treatment, the pulsatility index, resistance index, and blood flow were evaluated in the uterine and periurethral vessels by Doppler examination.

Twice-weekly transdermal estradiol and vaginal progesterone as continuous combined hormone replacement therapy in postmenopausal women: a 1-year prospective study.

Objective: The purpose of this study was to evaluate the acceptability and endometrial safety of a twice-weekly administration of transdermal estradiol (0.05 mg) systems and vaginal progesterone gel (Crinone [Serono, Rome, Italy] 4%, 45 mg/d) as a continuous combined nonoral hormone replacement therapy regimen.

Study Design: Thirty-five postmenopausal women took part in this 1-year prospective observational trial.