•  卵泡募集可能在月經週期中持續發生，68% 的健康女性在一個排卵間隔期間表現出兩波卵泡發育，32% 表現出三波[ 11] 。

• 卵泡募集卵泡波理論，卵巢刺激可以在卵巢週期的任何時間開始
• 黃體的診斷是在存在單房囊腫、直徑小於 3 cm、壁瀰漫且多普勒外周血流明顯（火環）
• 卵母細胞周圍的內分泌微環境不受卵巢刺激開始時月經週期階段的顯著影響。

• This recruitment presumably occurs continuously during the menstrual cycle even if, in most cases, it tends to assume a wave pattern: 68% of healthy women exhibit two waves of follicle development during the one interovulatory interval, and 32% exhibit three waves
• Based on this theory of continuous recruitment or “follicular waves,” ovarian stimulation could start at any time during the ovarian cycle 
• A diagnosis of corpus luteum was made in the presence of a unilocular cyst, less than 3 cm in diameter, and with diffusely thick-walled and prominent peripheral blood flow (“ring of fire” on Doppler) 
• The endocrine microenvironment surrounding oocytes is not markedly influenced by the phase of the menstrual cycle at the initiation of ovarian stimulation. 

J Assist Reprod Genet. 2023 Sep; 40(9): 2149–2156.

Follicular steroidogenesis in random start protocols for oocyte cryopreservation

Purpose

Random start protocols are commonly used for oocyte cryopreservation in women with cancer. However, albeit generally reassuring, available evidence is still insufficient to rule out a sub-optimal cycle outcome. This study aimed to compare follicular steroidogenesis between women initiating the random start protocol in the luteal phase and those initiating in the follicular phase.

Methods

Consecutive women with cancer scheduled for oocyte cryostorage were prospectively recruited. We excluded those requiring a concomitant letrozole assumption. All women received a standardized protocol with recombinant FSH and GnRH antagonists. At the time of oocyte retrieval, follicular fluids were pooled, and a sample was collected and frozen at −80 °C. All samples were assayed concomitantly after thawing by liquid chromatography-tandem mass spectrometry. The concentration of 15 different steroid hormones was determined.

Results

Seventy-one women were recruited. Thirty-three initiated the ovarian stimulation in the luteal phase, while the remaining 38 initiated in the follicular phase. Baseline characteristics were generally similar. Cycle outcome did also not differ; the median (interquartile range) number of frozen mature oocytes was 9 (5–14) and 10 (5–21), respectively (p = 0.42). None of the 15 tested steroid hormones differed.

Conclusions

The endocrine microenvironment surrounding oocytes is not markedly influenced by the phase of the menstrual cycle at the initiation of ovarian stimulation. This result further supports the validity of random start protocols.