Action taken to prevent CONCEPTION after sexual intercourse. The type of contraception may be hormonal, or it may be an intrauterine device (see below, and under CONTRACEPTION). Pregnancy after intercourse without contraception – or where contraception has failed as a result, for example, of a leaking condom – may be avoided with a course of ‘morning-after’ contraceptive pills. Such preparations usually contain an oestrogen (see OESTROGENS) and a PROGESTOGEN. Two doses are taken within 72 hours of ‘unprotected’ intercourse. An alternative for the woman is to take a high dose of oestrogen on its own. The aim is to postpone OVULATION and to affect the lining of the UTERUS so that the egg is unable to implant itself.
This, in effect, is a form of post-coital contraception. The IUCD is a plastic shape up to 3 cm long around which copper wire is wound, carrying plastic thread from its tail. Colloquially known as a coil, it acts by inhibiting implantation and may also impair migration of sperm. Devices need changing every 3–5 years. Coils have generally replaced the larger, non-copper-bearing ‘inert’ types of IUCD, which caused more complications but did not need changing. They tend to be chosen as a method of contraception (6 per cent) by older women in stable relationships, with a generally low problem rate.
Nevertheless, certain problems do occur with IUCDs, the following being the most common:
They tend to be expelled by the uterus in women who have never conceived, or by a uterus distorted by, say, fibroids.
ECTOPIC PREGNANCY is more likely.
They are associated with pelvic infection and INFERTILITY, following SEXUALLY TRANSMITTED DISEASES (STDS) – or possibly introduced during insertion.
They may produce heavy, painful periods (see MENSTRUATION), and women at high risk of these problems (e.g. women who are HIV positive [see AIDS/HIV], or with WILSON'S DISEASE or cardiac lesions) should generally be excluded – unless the IUCD is inserted under antibiotic cover.