The functioning synergy of several hormones is important in order for regular ovulation to occur and to prepare the endometrium for future nidation of the embryo. Hence, an undetected absent ovulation can be the reason for a failure in achieving pregnancy.
The hypothalamus secretes the gonadotropin releasing hormone (GnRH). This hormone, in turn, causes the pituitary gland (hypophysis) to release the follicle stimulating hormone (FSH) and the luteinising hormone (LH) into the bloodstream. Both hormones reach the ovaries and once there, trigger the growth of a follicle during the first 14 days of a 28-day monthly cycle. When the follicle is mature, it is released into the tubes marking the ovulation.
The follicle produces estradiol (E2), which ensures that the endometrium develops again after the menstruation. Moreover the follicle produces progesterone (corpus luteum). The high amounts of progesterone prepare the endometrium for the possible arrival of an embryo. If a pregnancy occurs, the progesterone is retained and menstruation ceases. In this complicated sequence many things can go wrong.
Clarification through blood tests
- Blood test during menstruation (1st-4th day of cycle):
Basic hormonal dysfunctions can be detected easily.
- Blood test prior or on the day of ovulation:
If and when ovulation takes place can be assessed.
- Blood test within the second half of the monthly cycle (luteal phase):
We check whether the hormones provide the basis for a successful nidation of the embryo.
Clarification through ultrasound examinations
- Ultrasound during menstruation:
We can detect possible ovarian cysts, uterine malfunctions and assess the status of the ovaries: depending on the size and amount of follicles we can predict to what extent a hormonal stimulation will be effective.
- Ultrasound prior or on the day of ovulation:
We can see if a follicle has developed as well as its rate of growth. This means we can predict the timing of ovulation. Furthermore, it is possible to determine the thickness of the endometrium.