While the need for progesterone-based luteal phase support is well documented, the required treatment duration is not well established, and a practitioners' survey showed a wide range of empiric stopping points. It is suggested that an early stop can be based on assessing endogenous luteal activity on the day of pregnancy test. To examine this approach, data were retrospectively collected on 99...

Progesterone supplementation is universally used and has been shown to be beneficial in supplementation of the luteal phase in IVF. There are multiple options and the most commonly used include intramuscular and vaginal progesterone. A progesterone vaginal ring is a novel system for luteal support with advantages of controlled release with less frequent dosing. This review examines options for ...

This study reports 21 IVF cases with excessive ovarian response, who received gonadotrophin-releasing hormone agonist (GnRHa) triggering for final oocyte maturation, followed by a human chorionic gonadotrophin (HCG)-based, progesterone-free, luteal support, individually timed ('luteal coasting') according to endogenous luteal progesterone concentrations. One patient developed a brief early-onse...

The objective of this study was to evaluate the influence of bull excretory products on the resumption of postpartum luteal function in primiparous, restricted-suckled cows. Hypotheses tested were that resumption of luteal function or proportions of cows that initiate luteal cycling did not differ among cows exposed to a bull (BE), exposed to excretory products of bulls (EPB), not exposed to a ...

The synthesis and secretion of progesterone in the corpus luteum are regulated by both endocrine and paracrine/ autocrine factors which affect the steroidogenic cells. Evidence suggests that these cells communicate via cell-cell junctional proteins, the connexins. Previously we have shown that connexin-43 is expressed in both human and baboon (Papio hamadryus anubis) corpora lutea, with differe...

It has been well demonstrated that luteal phase physiology is disrupted in in vitro fertilization (IVF) cycles conducted with either gonadotropin-releasing hormone (GnRH) agonists or antagonists, and that supplementation of the luteal phase with either exogenous progesterone or human chorionic gonadotropin (hCG) is necessary to optimize IVF cycle outcomes. Though both progesterone and hCG suppl...

Luteinizing hormone (LH) regulates several ovarian functions. However, the luteoprotective mechanisms of LH involved in the maintenance of bovine corpus luteum (CL) function are not well understood. Since prostaglandin F2α (PGF), PGE2 and progesterone (P4) are well documented as antiapoptotic factors in the bovine CL, we hypothesized that LH protects the CL by stimulating the local production a...

The ability of sheep luteal cells from the first corpus luteum formed after parturition (Group F) to secrete progesterone in the presence or absence of LH was compared with that of luteal cells obtained from normal cyclic ewes (Group C). Luteal concentrations of receptors for LH and prostaglandins (PG) F-2 alpha (PGF-2 alpha) and the cellular composition of corpora lutea from Groups F and C wer...

Single serum progesterone determinations were made in 79 apparently normal women with a regular menstrual cycle. A normal range (40 subjects) was derived from the concentrations in the follicular phase and used to define an "anovular" range for luteal phase values (nine out of 39 subjects). The remaining luteal phase values were used to construct an "ovular" range for the luteal phase and, with...

The synthesis of progesterone by the corpus luteum is essential for the establishment and maintenance of early pregnancy. Regulation of luteal steroidogenesis can be broken down into three major events; luteinization (i.e., conversion of an ovulatory follicle), luteal regression, and pregnancy induced luteal maintenance/rescue. While the factors that control these events and dictate the final s...