Ovulation, a key moment in reproduction
Technological progress allows us to know the moment of ovulation and in that way, pinpoint the most fertile time of the cycle for achieving a pregnancy
There are certain days during the woman’s monthly cycle when maximum fertility is achieved: this is when the process known as ovulation occurs. In women with regular cycles, this time is between the12th and the 16th day before their period, as a consequence of an increase in oestrogen levels in the blood. This brings about an increase in the LH hormone which is responsible for triggering ovulation. This phase is very difficult to predict, since it depends on several factors and may even vary from cycle to cycle in the same woman.
Until a little over 25 years ago, women controlled their fertility through ovulation using the methods available at that time. “Unfortunately, these methods were not very reliable”, explains Dr. Ricard Vidal, an assisted reproduction specialist at Eugin Clinic. “Systems such as the calendar and baseline temperature systems are not advisable nowadays because their chances of success are barely 30 per cent”, he adds. “Fortunately, we now have safer and more accurate methods for controlling ovulation”, he says.
Fertility monitors, a reliable method
In the case of women with regular cycles, the tests available in the market allow them to detect increases in the LH hormone levels in urine and in that way, know when ovulation will occur. There are also other more complex fertility monitors that detect simultaneous increases in the LH hormone and in the oestrogen that causes the increase in LH and gives rise to ovulation.
“These are systems that give advance warnings”, explains Dr. Vidal, from Eugin Clinic. “They prevent the main problem found in other methods, which gave the warning when it was too late and for that reason, were ineffective”. On the contrary, fertility monitors determine these hormone changes and allow us to calculate the right moment for having sexual intercourse with a higher probability of conceiving –provided there is no medical problem that makes this impossible.
Furthermore, it should be considered that an egg has a life of 12 to 24 hours, while that of a sperm is several days. For that reason a woman can become pregnant if she has had sexual intercourse three or four days before ovulating. In that respect, fertility monitors will also detect those days immediately before ovulation which could also be fertile days.
In the event of trying to conceive using this method and not being able to after six cycles, it is best to consult a specialist. This way, the reason for the difficulty in conceiving can be identified and the appropriate treatment can be administered.
Programmed ovulation for assisted reproduction treatments
In cases in which artificial insemination is recommended – either because the woman has no partner or due to a medical reason – hormone treatment will be administered to stimulate the ovaries. The quantity and size of the follicles (the structures which house the eggs) is controlled through regular ultrasound scans and once they have developed, ovulation is induced by administering another hormone that triggers ovulation, leading to the final maturing and subsequent release of the egg.
In this way, we ensure that the ovulation period coincides with insemination, to increase the chances of conceiving.
In the case of women who are recommended to undergo in vitro fertilisation with their own eggs for other reasons, ovarian stimulation is also performed – but with less intensity- to obtain a larger number of eggs. As in the above case, once the eggs have developed correctly, a hormone is administered to the woman that triggers ovulation. After 36 hours, a follicular puncture is performed to extract the eggs before they are released. The eggs will be fertilised in the laboratory with the sperm form the woman’s partner or from a donor.
After two or three days, 1 or 2 embryos are selected, depending on their shape, and are transferred to the patient’s womb using a transfer catheter. Two weeks later, a pregnancy test is performed to allow us to ascertain whether the long-awaited pregnancy has occurred.