After age 30, a woman's chance of conceiving decreases.
With the number of reported unexpected pregnancies each year, it may be hard to believe that the odds of getting pregnant each month are fairly low, but it's true. Healthy couples who are trying to conceive should know that success might take time and a bit of effort, even under the best of circumstances. On the other hand, women trying to avoid conception should know that even with protected sex, it is essentially a game of Russian roulette.
Time Frame
Women's cycles can vary from 23 to 35 days between periods, but the average menstrual cycle is 28 days. Ovulation normally occurs 14 days before the start of a woman's period, and the egg survives for about 48 hours. Sperm can survive two to three days, so the best time to have sex to get pregnant is 13 to 16 days before the start of her next period. Signs of ovulation include a raised basal temperature, minor abdominal twinges and vaginal discharge that resembles egg whites.
Features
There is about a 25 percent chance that the sperm will fertilize the egg; thus, a healthy couple who times ovulation correctly has a 25 percent chance to conceive each month. For a couple who is not actively trying to conceive and not timing ovulations, the chance drops for the sperm and egg encountering each other at the right time and fertilization taking place. So, a woman who is regularly sexually active who is not using any form of birth control has an 11 percent chance of conceiving each month.
Considerations
A trying woman in her 20s will most likely be expecting within four months. A number of factors come into play, however, that may reduce chances. One factor is age; after age 30, a woman's chance of conceiving begins to decrease. There are also many medical conditions, both for men and for women, that can result in difficulty conceiving, or infertility. After six months, a couple might consider seeking fertility testing. After a year of trying without success, a couple might consider fertility treatments.
Misconceptions
It is unnecessary for a woman trying to conceive to lay on her back, upside down or hold her legs up after sex. Sperm reaches the cervix within moments. There is also not a need to "build up" sperm by abstaining from sex a few days before ovulation. Chances of pregnancy improve when couples have sex two to three times per week throughout the woman's cycle, and every other day during the week she expects to ovulate.
Prevention/Solution
Other than abstinence, there is no 100 percent effective form of birth control. Under the best conditions, condoms are 97 percent effective, but in typical use, they are effective only 85 percent of the time. Birth control pills are only 99 percent effective if they are taken every single day, on time. Any variance reduces chances of effectiveness, and if one pill is missed, a backup birth control method should be used. Even after a vasectomy or tubal ligation, a couple has about half of a percent chance of getting pregnant every year.
