Fertility Definitions

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Menstrual Cycle
Dynamics of Becoming Pregnant

Ovulation
Ovulation is the process in the menstrual cycle when a mature ovarian follicle discharges an ovum – or egg. This is a woman’s most fertile time of the month to conceive a baby.

Ovulatory Phase
Facilitated by an increase in the hormone LH, enzymes are secreted by the ovarian follicle that soften the follicular tissue and create a hole in the surface called a stigma. Ovulation takes place when the follicle ruptures and the egg exits the follicle into the fallopian tube. Here, the ovum is carried along by cilia on its way to the womb or uterus. Fertilization of the egg will typically take place in the fallopian tube. If fertilization does not take place, the egg will disintegrate about twenty-four hours after ovulation.

Hormones
Estrogen is a rerpoductive hormone that promotes the thickening of the endometrium and helps regulate different aspects of the menstrual cycle. Estrogen appears in elevated levels during the peri-ovulatory phase. Saliva ovulation tests detect this “estrogen surgre”.

Follicle stimulating hormone (FSH) is a hormone that stimulates the growth of the ovarian follicle – which houses the developing ovum. When the ovarian follicle is mature, there is a sudden increase in LH or luteinizing hormone. This is called the “LH surge” and it takes place around the 12th day of your cycle. An increase in LH facilitates ovulation. Urine ovulation tests detect your LH surge and predict your time of peak fertility.

Progesterone is produced by the “corpus luteum” (the name of the ovarian follicle following ovulation). Progesterone levels increase during the second half of your menstrual cycle (luteal phase) in order to support the endometrium and warm the body to create a fertile environment for the embryo.

LH Surge
Your LH (luteinizing hormone) surge takes place 12-36 hours before ovulation, making urine LH tests excellent tools for predicting fertility. An LH surge is very sudden and just as brief, and a “positive” test result will likely only last a day or two.

Fertilization and Implantation
An ovum is another word for egg. An embryo is a fertilized ovum. Fertilization takes place when a sperm penetrates the egg. For pregnancy to occur, the embryo must lodge in the wall of the womb (or uterus). This is called implantation.

Back to:
Menstrual Cycle
Dynamics of Becoming Pregnant