Contraceptives

In addressing the question of which statement is incorrect regarding oral contraceptives, we can examine each given option:

1. Oral contraceptives indeed contain small doses of progestogens or a combination of progestogen and estrogen. This hormonal combination is a cornerstone of their function.
2. These contraceptives work primarily by inhibiting ovulation, thereby preventing the release of eggs from the ovaries, and they also make the uterine lining less suitable for implantation. Therefore, this statement is accurate.
3. The statement that is incorrect is that oral contraceptives "suppress sperm motility and its fertilizing capacity." Oral contraceptives do not primarily work by affecting sperm; instead, they primarily prevent ovulation and alter the cervical mucus and uterine lining.
4. Some oral contraceptives may include non-steroidal preparations, which are designed to have fewer side effects while maintaining high contraceptive efficacy. Hence, this statement is also valid.

Thus, the statement "They suppress sperm motility and its fertilizing capacity" is incorrect as it does not reflect the primary mechanism of action for oral contraceptives.