Ootid – Knowledge and References

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Gametogenesis

Published in Frank J. Dye, Human Life Before Birth, 2019

Let us follow the fate of a single diploid oogonium as it undergoes oogenesis (Figure 6.6). The oogonium begins to grow and then is called a primary oocyte. As such, it will be arrested in prophase I until at least menarche. Just before ovulation from the adult ovary, the primary oocyte completes meiosis I, producing two haploid cells: one large secondary oocyte and one small first polar body. The secondary oocyte proceeds through meiosis II until it reaches metaphase II, in which it remains until it is fertilized or dies. If fertilization occurs, the secondary oocyte completes meiosis II. As in meiosis I, cytokinesis is very unequal: it produces one large, haploid ootid (also known as the ovum or egg) and one small, haploid second polar body.

A clinical observational study on the efficacy of subcutaneous etonogestrel implants for adenomyosis in 20 patients

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Journal Information

Published in Gynecological Endocrinology, 2021

Lekai Nie, Hongli Zou, Xiaotian Ma, Lei Cheng, Jun Jiao, Fenghua Wang, Weifeng Liang, Peihai Zhang

Implanon, a subcutaneous etonogestrel implant, was approved for use in China in 2012. The etonogestrel in Implanon prevents pregnancy primarily by suppressing ovulation [16]. At three years of use, the release rate of etonogestrel is 25–30 µg/day, producing serum etonogestrel levels of >90 pg/mL, which is the approximate ovulation inhibition level [17]. In addition, etonogestrel can also lead to cervical mucus thickening, affecting the growth of the endometrium and the movement of the ootid in the fallopian tube. The contraception rate was 100% in all patients in this study.