PCOS

what is PCOS

a common endocrine disorder affecting women of reproductive age

what is PCOS characterised by

ovulatory disfunction, hyperandrogenism and polycystic ovarian morphology

what is PCOS associated with

its a major cause of infertility and is also associated with metabolic abnormalities such as insulin resistance.

what is used to diagnose PCOS

Rotterdam criteria

what is the rotterdam criteria

oligo- or anovulation, hyperandrogenism and polycystic ovarian morphology on ultrasound

what do women with PCOS commonly present with

irregular menstrual cycles, infertility, hirsutism, acne, and weight gain

what are the ovaries like in women with PCOS

enlarged and contain multiple small follicles arranged around the periphery

key feature of PCOS

present of small follicles that fail to mature

what happens to follicles in a normal cycle

one follicle becomes dominant and proceeds to ovulation

what happens to follicles in PCOS

 this process is disrupted, and follicles become arrested at an early stage of development. As a result, ovulation does not occur regularly, leading to infertility

what defines the morphology

his accumulation of immature follicles gives the ovary its characteristic polycystic appearance.

one of the central mechanisms for PCOS is…

disruption of the hypothalamic-pituitary-ovarian axis

how does the hypothalamic-pituitary-ovarian axis get disrupted

there is an increase in the frequency of GnRH pulses from the hypothalamus whihc leads to preferential secretion of LH over FSH

what does elevated LH do

stimulates theca cells in the ovary to produce andorgens

what does low levels of FSH do

impairs the ability of granulosa cells to convert these andorgens into oestrogen

what is the result of high LH and low FSH

prevents normal follicular maturation and contributes to anovulation

hyperandrogenism

Increased androgen production by the theca cells leads to elevated levels of testosterone and other androgens. These hormones interfere with normal follicular development and contribute to follicular arrest.

what is hyperandrogenism responsible for

hirsutism and acne. It also negatively affects oocyte quality and contributes to infertility.

insulin resistance

Reduced sensitivity to insulin leads to increased insulin levels in the blood and enhances androgen production, obesity, impaired glucose tolerance, and an increased risk of type 2 diabetes

what does chronic anovulation result in

prolonged exposure to oestrogen without the opposing effects of progesterone which leads to abnormal endometrial development and can reduce receptivity to implantation

what else can prolonged unopposed oestrogen cause

endometrial hyperplasia and in some cases endometrial cancer

impact on fertility

Infertility in PCOS is primarily due to anovulation. The failure of follicles to mature and ovulate means that no oocyte is released for fertilisation

other impacts on fertility

hyperandrogenism, insulin resistance, and endometrial dysfunction all contribute to a reduced likelihood of successful conception as even when ovulation occurs, oocyte quality and endometrial receptivity may be impaired, further reducing fertility.

treatment of PCOS

lifestyle modifications, ovulation incudction (letrozole), hormonal contraceptives