D3.1.7 Use of hormones in in vitro fertilization (IVF) treatment Notes

Hormones in IVF Treatment Controls the Process of Fertilization

1. Hormones play a critical role in IVF, enabling doctors to control and optimize egg production and fertilization.

Why Are Hormones Needed in IVF?

1. In a natural menstrual cycle, a woman typically releases only one egg per month.
2. However, IVF requires multiple eggs to increase the chances of successful fertilization.
3. Hormones are used to:
   1. Suppress the natural menstrual cycle to gain control over egg production.
   2. Stimulate the ovaries to produce multiple eggs (a process called superovulation).
   3. Prepare the uterus for embryo implantation.

Steps in IVF Hormonal Treatment

1. Downregulation: Suspending the Natural Cycle

1. The first step in IVF is to suspend the woman's natural menstrual cycle.
2. This is achieved through a process called downregulation.
3. How It Works:
   1. A drug is administered (via injection or nasal spray) to suppress the pituitary gland's production of FSH and LH.
   2. This stops the secretion of oestradiol and progesterone, halting the menstrual cycle.

2. Superovulation: Stimulating Egg Production

1. Once the natural cycle is suppressed, the ovaries are stimulated to produce multiple eggs.
2. How It Works:
   1. Daily injections of FSH are given for 7 to 12 days.
   2. The goal is to achieve a higher concentration of FSH than in a normal cycle, promoting the development of multiple follicles (each containing an egg).

3. Maturation: Preparing the Eggs for Collection

1. When the follicles reach an optimal size (approximately 18 mm in diameter), they are triggered to mature.
2. How It Works:
   1. An injection of human chorionic gonadotropin (hCG) is given.
   2. hCG mimics the natural surge of LH, stimulating the final maturation of the eggs.