The Ovaries and the Adnexa
Arianna D'Angelo, Nazar N. Amso in Ultrasound in Assisted Reproduction and Early Pregnancy, 2020
As discussed earlier, at the beginning of the menstrual cycle, the ovaries contain a wealth of antral follicles seen on transvaginal ultrasound as simple sac-like pockets that contain anechoic fluid between 2 and 10 mm arranged at the periphery of the ovary. Quantification of these follicles is a direct assessment of a woman's ovarian reserve as the number of antral follicles that emerge will reflect the number of primordial follicles available to start the journey of maturation approximately 180 days earlier [9]. The subpopulation of antral follicles that best correlates with ovarian reserve includes those between 4 and 6 mm [10]. Counting smaller ones is likely to include atretic follicles and therefore be an overestimate. However, to avoid the time-consuming process of measuring each follicle individually, by convention, all follicles measuring 2–10 mm are included in antral follicle counts (AFCs) [11].
I am ready to build a prediction model
Thomas A. Gerds, Michael W. Kattan in Medical Risk Prediction, 2021
Similar risk plots can be obtained with any machine learning approach to risk prediction modeling (Chapter 8). For example, a random forest (Section 8.3.1) allows non-linear relationships for all continuous predictor variables and higher-order interactions. Panel B of Figure 4.9 shows the effect of the number of antral follicles on the risk of ovarian hyperstimulation syndrome for given values of the other predictor variables based on a random forest with 1000 trees. We see that the predicted risks of the forest are less extreme compared to the logistic regression. The fact that the light blue line crosses the black line illustrates that the forest can potentially pick up complex interactions. We also see that the predictions of the random forest are not monotone functions of the number of antral follicles. This behavior where small changes of a variable can let the predicted risks jump up and down would clearly hamper the application of the random forest model in clinical practice.
Ovotoxic Environmental Chemicals: Indirect Endocrine Disruptors
Rajesh K. Naz in Endocrine Disruptors, 2004
Such increases in circulating FSH levels have been observed in long-term studies in both female mice and rats treated with the occupational chemicals, 4-vinylcyclohexene (VCH) and its ovotoxic metabolite, 4-vinylcyclohexene diepoxide, respectively, for 30 days (age 28 to 58 days) and then observed for up to 1 year.[27,29] In spite of a selective loss of the majority of primordial and primary follicles measured by 30 days, FSH levels were only increased above control animals at 240 days in mice and 120 days in rats. This corresponded with a time point at which numbers of antral follicles were significantly decreased in the rat.[29] Therefore, ovarian changes preceded the rise in circulating FSH levels. In spite of such ovarian damage, vaginal cytology still displayed evidence of ovarian cyclicity in VCH-treated mice at 240 days. By 360 days (from the onset of 30 days of dosing), unlike control animals, treated animals of both species displayed complete ovarian failure, as determined by increased circulating levels of FSH, loss of estrous cyclicity, the complete absence of ovarian follicular or luteal structures, and marked ovarian atrophy. Furthermore, at 360 days there was histological evidence of pre-neoplastic changes in ovaries of treated mice. From these studies, it was concluded that the ovarian failure and pre-neoplastic changes that occur long after cessation of chemical exposure are indirect consequences resulting from the depletion of small, pre-antral follicles.
The protective effects of resveratrol pretreatment in cyclophosphamide-induced rat ovarian injury: an vivo study
Published in Gynecological Endocrinology, 2021
Zhaoyan Nie, Lei Zhang, Wei Chen, Yanan Zhang, Wei Wang, Rui Hua, Tiantian Zhang, Chunfang Zhao, Miao Gong, Haifeng Wu
For histological examination, the ovaries were fixed in 4% PFA for 48 h and then dehydrated, and 5-mm thick sections were prepared. The paraffin-embedded sections were stained with hematoxylin for 5 min and eosin for 2 min. The follicles were counted as defined previously [17]. All ovarian tissue cells in five areas were evaluated and follicle count was performed. The follicle stage is classified according to the accepted definitions. A primordial follicle was counted when the identified nucleus was surrounded by a single layer of flattened squamous follicular cells. A primary follicle was defined as an oocyte surrounded by a single layer of cuboidal granulosa cells. A preantral follicle had two or more layers of cuboidal granulosa cells. The antral follicle was identified by a fluid-filled cavity.
Exposure of BPA and its alternatives like BPB, BPF, and BPS impair subsequent reproductive potentials in adult female Sprague Dawley rats
Published in Toxicology Mechanisms and Methods, 2020
Saman Ijaz, Asad Ullah, Ghazala Shaheen, Sarwat Jahan
Details on the ovarian follicles count and number of preovulatory follicles (POFs), corpus luteum (CL), antral, and atretic follicles (Atr F) after 28 days of exposure are presented in Table 6 and Figures 1–4. Number of CL was significantly decreased (p < 0.05) in BPA-2, BPA-3, BPB-2, BPS-2, BPS-3, (p < 0.001) in BPA-4, BPB-3 and (p < 0.001) in BPB-4 BPF-3, BPF-4, BPS-4 respectively when compared to control group. Follicles having a well-defined cavity in the middle of its structure are termed as antral follicles. A decent significant rise (p < 0.05 and p < 0.001) in AF count was found in BPA-3 and BPA-4, BPB-4, BPF-4, BPS-4 when compared to control. Follicles that undergo breakdown due to alterations in hormones are called Atr F. Significant increase (p < 0.05) was noted in group BPA-3 and BPS-3 (p < 0.01) when compared to control. While, BPA-4, BPB-3, BPB-4, BPF-3, BPF-4, and B PS-4 showed high significance increase (p < 0.001) in Atr F when compared to control. Graffian follicle is a fluid filled structure where the development of ovum takes place. It is also known as POFs. Non-significant results were observed in POF of all treated groups of BPA and its alternatives when compared to the control (Table 6).
The role of neopterin and anti-Mullerian hormone in unexplained recurrent pregnancy loss – a case-control study
Published in Journal of Obstetrics and Gynaecology, 2019
Halime Sencan, Nadi Keskin, Ghanim Khatib
Women with poor ovarian reserve have exceedingly high rates of pregnancy loss, regardless of age. AMH produced by the granulosa cells of the ovary is an excellent indicator of the ovarian reserve (Hofmann et al. 2000; Trout and Seifer 2000; Woo et al. 2012). Hofmann et al. (2000) demonstrated that conventional ovarian reserve tests were significantly lower in the URPL patients than those in the normal population. Trout and co-authors found that day 3 FSH and E2 values were elevated in the URPL patients (Trout and Seifer 2000). This condition was considered to be associated with the increased risk of chromosomal anomalies in RPL cases. Similar to these results, AMH levels were significantly lower in the study group compared with the control group in this study. While there was no difference in the RPL and control patients’ ages in our study. Hence, we think that only the relation between age progression and the oocyte quality and chromosomal anomalies cannot explain this result. Durlinger and co-workers illustrated that the follicles became more sensitive towards the FSH in the absence of AMH (Durlinger et al. 2002). Usually, the best one of the developing antral follicles is selected for ovulation. We think that this selection mechanism is disturbed in the patients with low AMH levels, due to the follicles becoming more sensitive to FSH, which prevents the formation of higher quality embryos and increases the risk of pregnancy loss. Nevertheless, firm conclusion cannot be made in absence of chromosomal analysis of the foetuses in the previous miscarriages, which was not performed in this study because of the design.
Related Knowledge Centers
- Androstenedione
- Corona Radiata
- Cumulus Oophorus
- Folliculogenesis
- Luteinizing Hormone
- Ovarian Follicle
- Zona Pellucida
- Androgen
- Follicular Antrum
- Follicle-Stimulating Hormone