On average, women today are having two children with approximately four years time between the first and second births. Between 1985 and 1994 the proportion of births to women in their 20s decreased from 62 percent to 53 percent, while the proportion of births to women 30 - 44 years of age increased from 25 percent to 34 percent. Since the mid 1970s there has been a four-fold increase in the percent of first births to women 30 years and older. Because fertility declines with age, having children later in life means that many couples will experience infertility in their quest to build a family. Advances in the treatment of infertility have improved a woman's chances of conception as she ages, and more couples than ever before are taking advantage of these new treatments.
Conception occurs when a sperm fertilizes the egg.
While sperm can survive for several days inside a woman's reproductive tract, an egg can only survive for up to 24 hours after ovulation. This puts a limitation on the time when conception is most likely to occur. To increase chances of becoming pregnant, women should monitor their body's fertile time period - the time that sperm can survive within a woman's reproductive tract until ovulation and fertilization can occur. Because menstrual cycles vary from one woman to another and even from one cycle to the next in the same woman, identifying a woman's fertile time period can be challenging. The BBT is a woman's temperature first thing in the morning, before getting up or doing any activity.