The pattern of luteal phase plasma progesterone and estradiol in fertile cycles

Luteal phase estradiol level: a potential predictive marker for successful pregnancy in in vitro fertilization/intracytoplasmic sperm injection

“…Conversely, no significant differences were observed in early and mid-luteal E 2 levels in spontaneous and ovulation induction cycles, though significant differences in E 2 concentration in the late luteal phase were seen (7). This is in agreement with other studies in which the mean serum E 2 levels between conception and non-conception cycles did not reveal any significant difference until 10 days after oocyte retrieval (8,9).…”

Assessment of endometrial receptivity

“…Such studies were complemented by the later work of Hodgen and coworkers in the primate endometrium (12) and Novot and colleagues using donor embryos in humans (13)(14)(15)(16), leading to the conclusion that the WOI occupies a 4-to 5-day interval in the human endometrial cycle, at the time when P reaches peak serum concentrations. Understanding when implantation occurs has led to the appreciation of the importance of synchrony between embryo and endometrium, as a critical component of successful pregnancy, first in rodents (17) and later in humans (18).…”

Progestogens and Recurrent Miscarriage

“…However, there is no consensus as to the duration of such a window [17]. Work by Navot in human embryos suggested that the implantation window lasts 4-5 days synchronous with peak progesterone concentrations [18][19][20][21]. Luteal phase deficiency or luteal phase defect (LPD) is a term that was introduced in 1949 by Georgianna-Segar Jones [22].…”