When is a woman fertile?
Normally during each menstrual cycle an egg is released from one of the two ovaries. The release of an egg is called ovulation. The egg travels through a fallopian tube to the uterus. If the egg is not fertilized after it leaves the ovary, it is absorbed by the body or shed during menstruation. The egg can be fertilized by sperm from the moment it is released by the ovary until it has passed through the outer one third of a fallopian tube. It is during this time that a woman is fertile and can get pregnant.
The most fertile period (meaning the best time to have intercourse) consists of the few days before ovulation. There are a number of reasons why this is the most fertile time. First of all, the amount of cervical fluid increases - and the consistency of the mucus changes substantially (from being sticky and cloudy to becoming transparent, white, and slippery). The purpose of this change is to create a healthy medium for the sperm to survive and travel in. Given a fertile environment, sperm can live several days. The egg, on the other hand, can live only 24 hours - so timing is important. At the moment of ovulation, the body temperature begins to rise to create a warmer, more hospitable environment for a fertilized egg.
How do I predict when ovulation is occurring?
Basal body temperature (BBT) One method of predicting ovulation is using BBT. The BBT should be checked every morning before any physical activity, including smoking, drinking, or eating. It is best to do it while you are still in bed. You need to use a special basal body thermometer that can detect small changes in temperature. You can buy one of these thermometers at a drug store. Write down your temperature every day on a calendar. Your body temperature will rise about 0.5 to 1 degree F (0.5 degree C) just after ovulation. It will stay elevated until your next period starts. Looking at the trend over several months can give you an idea of when you typically ovulate, so that you can better time intercourse. Your obstetrician can provide you with a calendar that he/she can then review with you after you’ve tracked the BBT for a few months.
Cervical mucus You can also check the appearance and consistency of the mucus in the cervix (opening to the uterus). When the mucus appears thin, elastic, clear, and watery (like egg white), ovulation will typically occur within 4 days. During the time the wet mucus appears until 4 days after these are your most fertile time periods.
Ovulation Predictor Kits Directly prior to ovulation, a hormonal change takes place - the LH Surge. LH (or Luteinizing Hormone) is the hormone that actually facilitates ovulation: it causes the egg to separate from the ovarian surface. Ovulation predictor kits function by detecting this LH Surge, thus alerting the woman that ovulation is about to take place. These kits can be purchased at a drug store. It is important to follow the directions carefully in the package insert, for example regarding timing of day to take the test. Having an idea of your menstrual period length will also be important. |
