Progesterone is a hormone produced by the ovary that mainly acts during the second phase of the menstrual cycle, maturing the endometrium and enabling its embryonic receptivity. In assisted reproduction treatments, progesterone support is regularly given to facilitate embryonic implantation and maintain the pregnancy

We recommend its use as support in treatments like artificial insemination and in vitro fertilisation during the luteal phase. Above all, despite the ovaries functioning correctly, exogenous progesterone is administered during in vitro fertilisation due to the possible negative effect of the follicular puncture, to ensure adequate levels until the placenta takes over production.

By contrast, progesterone administration is essential during egg donation, embryo donation or frozen embryo transfer treatments to achieve a pregnancy and so that they develop correctly. In these treatments, we are looking for ovaries that do not work so that they do not interfere with endometrial preparation, so we have to administer ourselves the progesterone needed to achieve a pregnancy and maintain its development.

In Spain, progesterone preparations are recommended for vaginal, oral or subcutaneous administration. Initially, we recommend vaginal administration since its effect is mainly inside the uterus, thus avoiding its systemic side effects, such as dizziness. Progesterone by subcutaneous administration is an alternative for patients that have allergies or those with suspected malabsorption by vaginal administration.

Pregnancy needs progesterone for its development. In addition to the endometrial changes, progesterone also acts on the uterine muscle, relaxing it to improve pregnancy growth inside it.

On the other hand, uterine immune function suppression must also occur during pregnancy to prevent the body from reacting against the pregnancy. If not, the mother’s antibodies will attack the pregnancy, stopping its development. We have seen that progesterone also participates in uterine immunoregulation to facilitate the embryo’s proper development.

During the initial stages of pregnancy, progesterone secretion directly depends on the corpus luteum, which stays in the ovary after ovulation. As the pregnancy develops, the placenta gradually takes on the production functions of hormones like progesterone in order to completely rely upon it from the third month of gestation.

Taking into account all of the above, progesterone’s importance on pregnancy is obvious and its administration during assisted reproduction treatments is necessary.

The FSH levels vary throughout a woman’s ovarian cycle. To correctly measure FSH, we have to do so between the days 2 and 5 of the cycle. FSH levels must always be examined alongside those of estradiol since there is a correlation between the two. In normal conditions, FSH levels do not exceed 10 mUI/ml.

FSH levels indicate whether the pituitary gland needs to make a considerable effort to initiate a natural cycle or not. The higher the levels, the higher the risk of no stimulation response. A low ovarian reserve is believed to exist if we have levels greater than 10 mUI/ml.

The Anti-müllerian hormone acts by controlling the number of follicles that can be recruited during a cycle and causing reduced follicle responsiveness to FSH. AMH levels of 2.0 to 7.0 ng/ml are considered to be good. A very low level indicates a poorer prognosis. AMH has a huge advantage: it is independent of a woman’s menstrual cycle and can be produced any day.

High levels of anti-müllerian hormone means a high ovarian reserve. This must be kept in mind at the time of choosing the ovarian stimulation protocol, since we will have to avoid the risk of ovarian hyperstimulation syndrome.

Low levels of anti-müllerian hormone are the result of a low ovarian reserve and therefore cannot be changed. When the anti-müllerian hormone is low, it is telling us that there are few follicles left in the ovaries, so they will only be able to produce a few eggs when we stimulate them.

There are different tests to evaluate a woman’s ovarian reserve, but those with the highest predictive value are the antral follicle count and hormone profile.

The antral follicle count consists of an ultrasound at the start of the cycle in which the number of follicles in the ovaries are counted, sized between 2 and 9 mm. If a number equal to or higher than 8 is observed, this is usually indicative of a good ovarian reserve. The more antral follicles we see, the better the ovarian reserve to be expected.

The ovarian reserve is the ovarian response’s capacity to be subjected to stimulation. It is a parameter that exclusively evaluates the number of eggs we can expect after ovarian stimulation. Age is the most crucial factor in relation with the ovarian reserve and fertility.

There are patients with low ovarian reserve that will respond less to ovarian stimulation but will produce good-quality eggs (this is even more accurate the younger the patient is). The parameter best related to oocyte quality is age; the older you are, the poorer the quality.

The size of the ovaries is related to their activity. Small or atrophic ovaries result in these ovaries no longer being active due to a lack of follicles. These types of ovaries are generally found in women with menopause.

Women are born with a certain number of eggs in their ovaries. These eggs will be released during each cycle until menopause, at which point none remain. For an ovary to produce an egg, many will have been released during this same cycle that will not get to ovulate. In each cycle, a single ovulation will normally be produced by one of the two ovaries. There is no connection wherein each ovary ovulates in each cycle; it is completely random.

The shooting pain that some women feel in the area of their ovaries is usually related to ovulation occurring. This usually takes place halfway through the cycle.

The endometrium has a very important role in achieving a pregnancy, since it is the uterine lining which the embryo implants in. The endometrium is a tissue that changes throughout the ovarian cycle to achieve receptivity at the time of embryo implantation. Two hormones operate during endometrial preparation: oestrogen and progesterone.

Endometrial thickness is usually around 6 to 10 mm. This generally coincides with days 19-21 of the menstrual cycle, which is when the endometrium is receptive. This period of time is known as the implantation window.

Endometrial thickness and appearance are the factors that must be considered when predicting the success of a fertility treatment. An trilaminar endometrium between 6-10 mm at the time of follow-up is a sign of good endometrial response to the treatment. It is hard to set an exact cut-off point in order to know whether implantation will occur or not, given that it is a complex process and there are other factors that affect it. Having a trilaminar 8 mm endometrium does not mean that we know with certainty that the embryos will implant. On the other hand, there may be patients that can achieve a pregnancy with a 6 mm lining. Each case must be evaluated and treated individually. Therefore, do not wait any longer and get in touch with us.

An extremely thickened endometrium can be a sign of uterine disease. Given this, examination of the endometrial cavity must always be performed.

Blocked Fallopian tubes is usually asymptomatic. Therefore, we are not aware of this problem until we perform hysterosalpingography, during which we notice that the contrast does not pass through the tubes correctly.

There are several causes that can lead to blocked Fallopian tubes, among them:

• Sexually transmitted infections.
• Acute inflammation of the Fallopian tubes.
• Endometriosis.
• Side effects of using an IUD as a contraceptive method.
• Scars left by abdominal surgeries.
• Ectopic pregnancies, difficult miscarriages.
• Problems during previous pregnancies.