Female Reproduction

Understanding how the female reproductive system works can help to achieve a successful pregnancy. This is because it is important to have intercourse at the right time in a woman’s cycle. It will also help you comprehend why you may be having trouble conceiving and the ways in which IVF treatment can address these issues.

Overview of the Female Reproductive System

The female reproductive system consists of the vagina, cervix, uterus, fallopian tubes and ovaries:

IVF Female Illustration

Menstrual Cycle

The average length of a woman’s menstrual cycle is 28 days, calculated from the first day of her period to the day before the next period starts. There are four main phases of the menstrual cycle:

Menstruation

This is the elimination of the thickened lining of the uterus (endometrium) from the body through the vagina. The average length of a period is between 3 days and one week.

Follicular phase

This starts on the first day of menstruation and ends with ovulation. The pituitary gland (prompted by the hypothalamus in the brain) releases follicle stimulating hormone (FSH), which stimulates the ovary to produce around 5-20 follicles, each housing an immature egg. Usually only one follicle will mature into an egg.

Hormones are produced in the ovarian follicles.  These hormones prepare the lining of the uterus for pregnancy.  The cervical mucus also becomes thin and slippery at this stage to assist the sperm in swimming towards the egg so fertilisation can occur.

Ovulation

This occurs when a mature egg is released from the surface of the ovary. The egg is funnelled into the fallopian tube and moves towards the uterus.

The life cycle of the typical egg is only 24 hours so if it doesn’t meet a sperm during this time it will die.

Luteal phase

If a fertilised egg implants in the lining of the uterus, it produces hormones that ensure the thickness of the lining is maintained. If pregnancy does not occur, progesterone levels drop, causing the uterus lining to fall away (menstruation). The cycle then repeats.

The nature of the female menstrual cycle means that in order to fall pregnant you need to have intercourse in the days leading up to ovulation or within 24 hours of ovulation. Sperm is able to survive for 2 – 3 days in the female reproductive tract but an egg can only survive for 24 hours. Ovulation generally occurs 14 days before the last day of your cycle.

For information on causes of female infertility click here.