After ovulation, follicles transform into the corpus luteum or ‘yellow body’. Corpus luteum development depends on the luteinising hormone (LH) surge before ovulation and on the number of receptors for this gonadotropin in the granulosa cells and in the theca cells. Both types of cells go through significant changes in structure and composition and this turns the walls of the corpus […]
Hormones are messengers that are present in all multicellular organisms – be they animal or plant organisms – that coordinate the functions of each part of that organism.
The sex hormones par excellence are oestradiol in females and testosterone in males. However, the adrenal glands in men and women produce both hormones and they are both necessary for normal development of the two sexes. […]
Residual follicle is the term given to the structure remaining in the ovary following a process of stimulation, whether this has been for insemination or during a cycle of in vitro fertilisation (IVF). Diagnosis is generally carried out using ultrasound imaging.
On the whole, before embarking on a course of ovarian stimulation, a basal ultrasound scan is carried out. The aim is to check that the ovary is resting. In other words, that it has antral follicles measuring under 10 millimetres in length. […]
In vitro fertilisation (IVF) techniques aim to generate multiple follicles (ovarian stimulation) from which to obtain eggs which will later be fertilised. The ovarian stimulation process culminates with the use of a drug which induces the final stage of egg maturation. The most commonly used one is human chorionic gonadotropin (hCG). This final step is essential in order to obtain eggs during ovarian puncture and it also indicates when the procedure should be carried out. The origin of empty follicle syndrome (EFS) is not fully understood and, when it occurs, no eggs are obtained following meticulous ovarian puncture, despite adequate follicle growth following ovarian stimulation and normal hormone results. […]
What are ovarian follicles?
To start with, let’s state what follicles are not. Follicles are not oocytes (eggs). Many patients confuse these terms, believing that follicle equals oocyte.
The female gamete is the egg, and the male gamete is the sperm. These are the cells involved in embryos obtained after fertilization. […]