A contraceptive that permanently prevents the union of the sperm and egg is a
A contraceptive that physically blocks the sperm from reaching the egg is a
The "typical use" contraceptive failure rate is based on studies that measure the percentage of women experiencing unintended pregnancy in the first
A)six months of use.
B)one year of use.
C)two years of use.
D)five years of use.
Oral contraceptives primarily prevent conception by
A)reducing the number of sperm that penetrate the cervix by thickening cervical mucus.
B)blocking sperm from reaching the ovum.
C)changing the acidity of the vaginal canal.
D)preventing ovulation by mimicking the hormonal activity of the corpus luteum.