Reproductive asynchrony in natural butterfly populations and its consequences for female matelessness.

1. Reproductive asynchrony, where individuals in a population are short-lived relative to the population-level reproductive period, has been identified recently as a theoretical mechanism of the Allee effect that could operate in diverse plant and insect species. The degree to which this effect impinges on the growth potential of natural populations is not yet well understood.

Future in vitro fertilization pregnancy potential of women with variably elevated day 3 follicle-stimulating hormone levels.

Objective: To determine the IVF-ET pregnancy potential of women with variably elevated day 3 FSH.

Design: Cohort evaluation of 1,868 consecutive IVF-ET cycles January 1991 to December 1994.

Setting: University hospital infertility unit.

Nafarelin acetate for pituitary down-regulation in in vitro fertilization. Comparison of two dosages.

The objective of this study was to evaluate the efficacy of intranasal (IN) nafarelin acetate (NA), 400 micrograms/d and 600 micrograms/d, in a luteal-phase-start, long protocol in women undergoing their first in vitro fertilization (IVF) cycle. A sequential comparison of 200 consecutive first IVF cycles, the study was performed in the Department of Gynaecology and Reproductive Medicine, University Hospital, London, Ontario, Canada. The participants were 200 first-cycle IVF patients who were regularly cycling--100 NA 400 micrograms IN followed by 100 NA 600 micrograms IN.