Natural and stimulated ovulation: what should you know?

Key differences and importance for IVF

Ovulation is a key stage of a woman's menstrual cycle, occurring every month. At this time, a mature egg is released from the ovary due to a surge of reproductive hormones. In other words, ovulation is the sign that the body is ready to conceive.

Natural ovulation is the process of the egg being released without medical intervention. A mature, healthy, and good-quality egg develops and can then be fertilized naturally or through in vitro fertilization (IVF). In the case of IVF, relying on natural ovulation is considered safer, as the egg develops in natural conditions, without excessive hormonal influence on the woman's body. In contrast, stimulated ovulation comes with a certain hormonal load.

It is important to remember that the absence of ovulation can be due to various causes: polycystic ovary syndrome, weight disorders (overweight or underweight), hyperandrogenism, thyroid gland dysfunction, as well as a high level of prolactin.

What is stimulated ovulation?

Stimulated ovulation is one of the assisted reproductive medicine methods used in cases of absent spontaneous ovulation. If the ovaries are unable to produce a mature egg, the doctor prescribes hormonal stimulation.

The stimulation process lasts on average from 9 to 12 days. During this period, the woman receives medications that promote the simultaneous growth of several follicles in the ovaries. A mature egg develops in each follicle, which is then retrieved by aspiration.

After fertilization, the obtained mature eggs transform into embryos. The more high-quality embryos there are, the higher the chances of successful implantation and pregnancy after their transfer into the uterine cavity.

Stimulated ovulation is widely used in modern reproductive practice and effectively helps many women overcome infertility and experience the joy of motherhood.

Difference between natural ovulation and stimulated ovulation

In the case of natural ovulation, multiple pregnancies are extremely rare. In contrast, when stimulating ovulation, the risk of multiple pregnancies increases significantly, as several eggs can mature at the same time.

Hormonal stimulation sometimes leads to the development of ovarian hyperstimulation syndrome, a condition characterized by the formation of fluid-filled cysts that may rupture, requiring immediate medical intervention.

Moreover, during natural ovulation, the uterine endometrium is generally better prepared for embryo implantation than during stimulated ovulation, where hormonal changes can affect the structure of the endometrium.

From an economic standpoint, IVF with natural ovulation is less expensive, as it requires fewer medications and monitoring. In the absence of contraindications, the method using natural ovulation should be considered first.