Long Acting Reversible Contraceptives

By Caitriona Henchion, IFPA Medical Director, November 2010

This year the contraceptive pill is celebrating its 50th anniversary and there has been much focus on the transformative effect of the pill on women’s lives. The pill offered women the chance to enjoy sexual relationships free from the fear of unwanted pregnancies and the opportunity control the number and spacing of their children.

In the last 10 years significant developments in long-acting reversible contraceptives (LARCs) means that women have even greater choice when it comes to regulating their fertility.

There are four distinct groups of LARCs:

• Injectable Contraception: Medroxy Progesterone Acetate (Depoprovera) given by intra muscular injection every 12 weeks.
• Contraceptive Implant: Etonogestrel Sub Dermal Implant (Implanon NXT). Effective for 3 years
• Levonorgestrel Intra Uterine System (Mirena Coil). Effective for 5 years.
• Copper-based Intra Uterine Contraceptive Device (IUCD). Effective for 5-15 years, depending on device.

Why use LARCs?

LARCs are highly effective. The Pearl Index for normal use of LARCs is the same as for perfect use. So they are not user dependant. In comparison failure rates of the contraceptive pill and condoms are highly dependant on user as indicated by the PEARL Index, a medical standard for comparing failure rates. See table below.

* Risk of expulsion is higher with Copper IUCD than Mirena and undiagnosed expulsion accounts for the variation in failure rate.

In addition, LARCs are associated with high continuation rates, which make them successful for longer. Furthermore, apart from Implanon NXT there are no drug interactions which affect efficacy such as antibiotic use interfering with the combined pill.

LARCs are cost effective when compared to oral contraceptives or condoms. For example the contraceptive pill costs between €160 to €244 a year depending on brand, while the Mirena coil costs €66 a year.

Finally, as all LARCs are oestrogen free, they are not associated with the oestrogen-related side effects sometimes associated with the oral contraceptive pill such as severe migraine and blood clots.

What’s the Downside?

A high initial cost and menstrual disruption are the biggest drawbacks of LARCs. In addition, there is the small possibility of procedure-related risks, such as insertion of implant too deep or uterine perforation during insertion of IUS/IUCD. Training of medical personnel is required to minimise these risks.

What’s the Verdict?

LARCs are highly effective, cost effective, easily reversible, non-user dependant contraceptives with very low levels of serious risk. A winner for women!