Implants & Injectable Contraception
Implants (Implanon) and injectable contraception (Depo-Provera) both contain progestogen. A slow release of this type of hormone over time provides very good contraception.
What is in Depo-Provera?
We have one injection available in Ireland, Depo-Provera. This contains a progestogen called medroxyprogesterone acetate.
How is it given?
Depo-Provera is given for contraception every 12 weeks as a single injection to the buttock. To ensure that you are not pregnant, the first injection is given sometime during the first 5 days after the beginning of a normal menstrual period. After this, injections are given every 12 weeks. The doctor or nurse will give you the date for your next injection.
When is it safe to have sex?
If you get the injection on the first day of your period you are protected immediately. However, if you get the injection later in your period you should wait for 7 days to be absolutely sure that you are covered for contraception.
What if I cannot get my next injection on the right date?
You can have the injection anytime from 2 weeks early up to 7 days late. If you cannot come in on the day your injection is due, it is better for contraception that you come in before the injection is due rather than several days late. If you are more than 7 days late, you are not covered for contraception and are at risk of pregnancy.
What can reduce the effectiveness of the injection?
Because the injection causes a slow release of progestogen into your system, there is very little that can interfere with it. Unlike with oral contraceptives an upset stomach will not reduce the effectiveness of the depo injection.
Once the injection has been given, there is no way to reverse its contraceptive effect.
Do I need check-ups?
Yes. Your first injection will be given by a doctor, and then every 12 weeks you will be seen either by a nurse or a doctor for repeat injections. At each visit you will have your blood pressure checked and you will have an opportunity to discuss any concerns you may have such as any spotting or bleeding that you may have had since your last visit.
Implanon is a rod shaped device that is inserted under the skin just above the elbow. The rod contains a progestogen called etonorgestrel.
How is it inserted?
A small amount of local anaesthetic is given to numb the skin on the inner area of the arm just above the elbow. The implant is then inserted under the skin and paper stitches and/ or a small dressing is applied over the puncture wound. To ensure that you are not pregnant, the implant is fitted sometime during the first 5 days after the beginning of a normal menstrual period.
Will the implant be visible to other people?
Implanon is not likely to be visible but you should be able to feel the rod with your fingertips.
When is it safe to have sex?
If you get the implant on the first day of your period you are protected immediately. However, if the implant is fitted later in your period you should wait for 7 days to be absolutely sure that you are covered for contraception
How long does it work for?
The implant is effective for contraception for 3 years. If you are very overweight it may not be effective for the full 3 years. Your doctor may suggest that the implant is changed after 2 years, or that you consider an alternative form of contraception.
What can reduce the effectiveness of the implant?
Because the implant causes a slow release of progestogen into your system, there is very little that can interfere with it. Unlike oral contraceptives an upset stomach will not affect the action of the implant. However, women who are on some types of antiepileptic medication may not have good contraceptive cover and should consider other forms of contraception.
Do I need check-ups?
A check up is not necessary but if you are concerned about changes in bleeding pattern or any side effects such as prolonged headaches or breast tenderness please come back for review.
What about removal?
Removing the implant should be a fairly straightforward procedure provided the implant can be felt under the skin. A local anaesthetic is used to numb the area and a small incision is made at one end of the rod so that the rod can be removed. After removal either paper stitches or a dissolvable suture is used to close the wound. Some bruising is normal. In a small minority of patients where the device is not easily felt the implant may need to be removed using ultrasound imaging.
Will it leave a scar?
You will have a very small scar that fades with time.
How effective are implants and injections?
They are more than 99% effective.
How do they work?
They both contain progestogens, which are similar to the natural hormone progesterone that is produced by your ovaries during the second half of the menstrual cycle. They act as contraceptives by slowly releasing progestogen into your system and this prevents your egg cells from ripening. If an egg is not released from the ovaries during your menstrual cycle, it cannot become fertilised by sperm and result in pregnancy. Progestogen also causes changes in the lining of your womb that makes it less likely for pregnancy to happen. It also thickens the mucus at the entrance of the womb and makes it more difficult for sperm to enter the womb.
Who are they suitable for?
They can be used by most women. Unlike the contraceptive pills that contain oestrogen, progestogens can be used in women who have severe migraines and in women over 35 who smoke. If a woman has irregular cycles, it is recommended that the cause is investigated before starting a progestogen. Depression may be made worse by progestogens so they should be used with caution in women who are prone to depression
Like other hormonal contraceptives, you may get side effects such as headaches, breast tenderness, mood swings, bloating or nausea. These usually settle down within a few weeks. The bleeding pattern of your periods usually changes. To start with you may experience quite a lot of spotting and bleeding in the first few weeks. Some women will find that their periods stop completely after a number of months. There may be occasional irregular bleeding. This is nothing to worry about. However, it is worthwhile mentioning to the doctor during routine visits.
Periods return to normal within a few months of stopping treatment.
Long term use of the depo injection
Research suggests that the injection may lower bone density in some women. This does not happen in all women but we recommend that you only use this method for two to three years at a time. Weight gain is known to happen with the injection with the average gain in weight being 2-3 kgs in the first year.
Bleeding with Implanon
A considerable number of women have their implant removed due to erratic period bleeding. Unfortunately there is no way of predicting which women are likely to have bleeding problems.