Effect of body weight and BMI on the efficacy of levonorgestrel emergency contraception.

Objectives: To further evaluate the effect of weight and body mass index (BMI) on the efficacy of levonorgestrel emergency contraception.

Methods: Data from two large, multicenter, randomized controlled trials designed to assess emergency contraceptive efficacy were pooled to evaluate the effect of weight and BMI on pregnancy rates among women who received levonorgestrel. Descriptive methods (comparison of means and distributions according to pregnancy status and pregnancy rates across weight and BMI categories) as well as cubic spline modeling were used to describe the relationship between pregnancy risk and weight/BMI.

Molecular determinants of the recognition of ulipristal acetate by oxo-steroid receptors.

The human progesterone receptor (PR) plays a key role in reproductive function in women. PR antagonists have numerous applications in female health care including regular and emergency contraception, and treatment of hormone-related pathological conditions such as breast cancer, endometriosis, and leiomyoma. The main factor limiting their long-term administration is the fact that they cross-bind to other oxo-steroid receptors.

Can we identify women at risk of pregnancy despite using emergency contraception? Data from randomized trials of ulipristal acetate and levonorgestrel.

Background: Emergency contraception (EC) does not always work. Clinicians should be aware of potential risk factors for EC failure.

Study Design: Data from a meta-analysis of two randomized controlled trials comparing the efficacy of ulipristal acetate (UPA) with levonorgestrel were analyzed to identify factors associated with EC failure.

Immediate pre-ovulatory administration of 30 mg ulipristal acetate significantly delays follicular rupture.

Background: Current methods of hormonal emergency contraception (EC) are ineffective in preventing follicular rupture when administered in the advanced pre-ovulatory phase. This study was designed to determine the capacity of ulipristal acetate (UPA), a selective progesterone receptor modulator developed for EC, to block follicular rupture when administered with a follicle of >or=18 mm.

Methods: This was a double-blind, crossover, randomized, placebo-controlled study.

Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis.

Background: Emergency contraception can prevent unintended pregnancies, but current methods are only effective if used as soon as possible after sexual intercourse and before ovulation. We compared the efficacy and safety of ulipristal acetate with levonorgestrel for emergency contraception.

Methods: Women with regular menstrual cycles who presented to a participating family planning clinic requesting emergency contraception within 5 days of unprotected sexual intercourse were eligible for enrolment in this randomised, multicentre, non-inferiority trial.