LH hormone or luteinising hormone is used as a medicine in assisted reproduction treatments.
This medicine is prescribed during controlled ovarian stimulation in artificial insemination, conventional in vitro fertilisation or ICSI to reproduce at the maximum the conditions happening when the menstrual cycle develops naturally.
This hormone participates in the regulation of the sexual cycle.
In the woman it participates in the menstruation as follows:
- It is necessary in order that the synthesis of oestrogens occurs.
- It makes easier that ovarian follicles respond to the FSH hormone.
- It stimulates theca cells (granulose). These cells act as nurse cells by providing necessary growth factors in order that follicles mature.
- In the natural ovarian cycle ovulation is triggered from a LH peak.
The use of LH in assisted reproduction is mainly aimed at three types of women:
- Poor responders: women who have not obtained many oocytes in previous cycles can obtain a better result with LH.
- Women with hypogonadotropic hypogonadism: as a result of this endocrine defect they have amenorrhoea (primary or secondary) or very few menstrual periods(oligomenorrhoea).
- Women with very low basal levels of gonadotropins such as LH and/or FSH.
The advantages of administering LH during ovarian stimulation to the right patients are as follows:
- LH levels more similar to physiological levels.
- A higher number of oocytes obtained per simulation cycle.
- Serum oestradiol level improves.
- The endometrium is better prepared for receiving embryos in the transfer.
- Better pregnancy rates.
The main disadvantage of this hormone is that its effect depends on its concentration, it may cause some effect or other, so that:
- Too high LH levels: it may inhibit the synthesis of oestrogens and affect oocyte maturing.
- Too low LH levels: it may cause bad results in the stimulation, poor response.
There are two types of LH to be used as a medicine depending on the form of obtaining of this hormone:
- Of urinary origin: obtained by purification from postmenopausal women’s urine. This is the hMG (human menopausal gonadotropin) that contains 75 IU of FSH and 75 IU (international units) of LH. Medicines are called Menopur and HMG lepori.
- Of recombinant origin: obtained by genetic engineering. It is the recombinant LH and does not contain FSH. The medicine is called Luveris. There is another medicine called Pergoveris containing 75 IU of recombinant LH and 150 IU of recombinant FSH.