The dramatic shift in hormone levels, and the unpredictable ovulation pattern, that occur while a woman is going through menopause can lead to unplanned pregnancy if precautions are not taken.
Menopause is the permanent end to menstruation and fertility, defined as occurring 12 months after a woman's last menstrual period. It is a natural process that can last anywhere from two to 10 years, but on average begins for most U.S. women at age 51, according to the Mayo Clinic.
Menopause is commonly divided into three categories. The years leading up to menopause when symptoms are first noticed, also referred to as perimenopause, may last four to five years. After a woman is period-free for one year, she reaches menopause. Postmenopause refers to the years that follow.
During menopause, the body produces less estrogen and progesterone, which are the hormones responsible for regulating menstruation. Fewer viable eggs are produced and the menstrual cycle becomes irregular, making ovulation unpredictable and providing the opportunity for unexpected conception.
Unplanned pregnancies in women over the age of 40 can occur during the perimenopause stage of menopause, when the menstrual cycle occurs sporadically. According to the National Vital Statistics Report by the Centers for Disease Control and Prevention, 51 percent of pregnancies in women over the age of 40 are unintended.
In order to prevent accidental conception, women who believe they are entering menopause should contact a health care provider to determine the most appropriate form of contraception for their situation. Additionally, a doctor may conduct a blood test to check the estradiol and follicle-stimulating hormone (FSH) levels to verify the occurrence of menopause and discuss symptomatic treatment options.