6 (i) Which form of contraception is a barrier method? A oral contraception B female condom C rhythm (calendar) method D contraceptive implant (ii) State why a barrier method of contraception may be used in addition to a hormonal method - Edexcel - GCSE Biology - Question 6 - 2021 - Paper 1

A barrier method of contraception may be used in addition to a hormonal method to provide extra protection against pregnancy and also to reduce the risk of sexually transmitted infections (STIs). This dual approach increases the overall effectiveness and adds a layer of safety.

The endocrine gland that releases oestrogen is the ovaries. They are responsible for the production and secretion of oestrogen hormones.

High levels of oestrogen and progesterone in the combined contraceptive pill prevent pregnancy through several mechanisms:

1. Inhibition of Ovulation: The hormones suppress the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland, which inhibits the ovary's ability to release an egg.

2. Thickening of Cervical Mucus: Progesterone causes the cervical mucus to thicken, creating a barrier that makes it difficult for sperm to travel through the cervix.

3. Endometrial Changes: These hormones also alter the endometrium (uterine lining), making it less receptive to implantation should fertilization occur.

Together, these effects significantly decrease the likelihood of pregnancy.