KNOW YOUR OPTIONS

Endocrinologist Dr Lisa Owens offers an evidence-based briefing on the different contraceptives a doctor will offer you

COMBINED ORAL CONTRACEPTIVE PILL

What? A mix of oestrogen and progestogen that prevents ovulation.

Wins: More effective than condoms; menstrual bleeding is usually regular, lighter and less painful. Can reduce symptoms of endometriosis and PCOS. Normal fertility returns within three months of stopping.

Watch-outs: Nausea, headache, breast tenderness and irregular bleeding are commonly reported.

PROGESTOGENONLY PILL

What? Works in the same way as the combined pill, but only releases progestogen.

Wins: It may be suitable if you react badly to the combined pill, and certain types may be beneficial for women managing painful periods.

Watch-outs: Pills must be taken at the same time each day, or within three hours. Random bleeding and breast tenderness may occur when you begin taking it.

INTRAUTERINE SYSTEM

(such as a Mirena coil)

What? A long-acting contraceptive that prevents implantation of a fertilised egg by releasing a synthetic form of progesterone.

Wins: It can be kept in for up to five years and the failure rate is low.

Watch-outs: Irregular bleeding is common in the first six months. One in eight women who have one inserted will get an ovarian cyst; most are symptomless and 94% will disappear within a few months.

CONTRACEPTIVE INJECTION

What? Injected every eight to 12 weeks, it prevents ovulation by releasing progestogen.

Wins: The pregnancy rate is very low (fewer than four in 1,000 over two years) and there’s no evidence of links with depression, acne or headaches.

Watch-outs: Irregular bleeding, weight gain (between 2-3kg in one year) and a small loss of bone density (which largely recovers after stopping). Fertility can take a year to return.

CONTRACEPTIVE IMPLANT

What? A piece of rubbery plastic that works primarily by preventing ovulation with progestogen.

Wins: Very low failure rate, with less than one pregnancy per 1,000 over three years; there’s no evidence of a delay in return to normal fertility after the implant has been taken out.

Watch-outs: Menstrual bleeding may stop, become more or less frequent or prolonged during implant use.

COPPER COIL

What? Made of copper and plastic, it stops fertilisation through copper’s effect on the egg and sperm.

Wins: Pregnancy rates for IUDS with copper are between 0.1% and 1% after the first year of use. There are no hormones involved, so no related side effects. It may reduce the risk of endometrial and cervical cancer.

Watch outs: Irregular bleeding and if pregnancy does occur, there’s an increased risk that it’ll be ectopic.