What is a gonadotropin and what are gonadotrophins?

Generally speaking, Gonadotropins are hormones produced by the pituitary gland found at the base of the skull which stimulate the ovary to produce oestrogen and progesterone after ovulation. Gonadotropins are made up of follicle stimulating hormones, abbreviated to ‘FSH’, and luteinizing hormones, also referred to as ‘LH’, which individually act on ovarian follicles to encourage growth and development. In assisted human reproduction treatments, recombinants are used as an alternative to gonadotropins owing to characteristics similar to endogenous gonadotropins secreted in the pituitary gland.


Why are gonadotropins so important?

Gonadotropins are fundamental to assisted human reproduction treatments as such hormones establish follicular development in the ovaries (follicles are ovarian formations inside eggs). FSH gonadotropins are principally used in treatments because they enhance follicular engagement, while an example would be: small follicles in a natural cycle which are predetermined for atresia (to disappear). Treatment with FSH causes the aforementioned to grow and produce several follicles in development and later maturity. The use of FSH both increases the quantity and quality of eggs produced, while in certain cases, LH treatment or drugs which stimulate LH activity – such as HMG – are administered.


When are gonadotropins administered?

In almost all assisted human reproduction treatments, gonadotropins are used to achieve a higher pregnancy rate as they increase the number of mature follicles which then yield a greater total and quality of eggs.


Hormonal treatments with gonadotropin

In the case of artificial insemination, gonadotropins are often used at lower doses. However, in respect to in vitro fertilisation, dosage is administered at a higher dose. Between the wide-range of treatments offered, we adhear to the proceeding guidelines:

  • Step down: Consists of starting treatment with higher doses of gonadotropin and then gradually decreasing.
  • Step up: Consists of starting treatment with lower doses of gonadotropin and then gradually increasing.
  • Constant: Dosage is maintained throughout.


Types of gonadotropin

We can classify gonadotropins in assisted human reproduction treatments between:

  • Recombinant Gonadotropins: Created via laboratorial engineering
  • Urinary Gonadotropins: Extracted from the urine of menopausal women
  • Highly-purified gonadotropins

Chorionic hormone gonadotropin (hCG) is a particular variety of recombinant gonadotropin which has the LH effect. This particular hormone is introduced at the induction of ovulation in which after such administration, ovulation occurs in 36 hours.


We hope our latest blog post has helped you resolve any questions in regards to gonadotropin, while should you require further information from our team of fertility specialists, please don’t hesitate to request a free medical consultation.


A hug from the whole team,

Mallorca Fertility Institute


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