Combined oral contraceptives, also called “the pill” have been in use for the past half a century.
What are Combined Oral Contraceptives (COCs)?
Combination oral contraceptives are synthetic pills that mimic woman’s natural hormones, progesterone (progestin) and estrogen.
They are usually packaged in packs of 21 or 28 tablets. Only the first 21 pills in the packet of 28 are active (i.e., contain hormones). The last seven tablets often contain iron and are inert.
Types of Combined Oral Contraceptives
There are three primary types of COCs based on the concentration of estrogen and progesterone in the pills.
Monophasic: Throughout the cycle, the level of estrogen and progestin in these pills remains constant. After taking them for 21 days, there is a 7-day respite during which no medications are taken. Due to this, the woman is able to have her monthly period.
Biphasic: Throughout the 21-day cycle, these have the same amount of estrogen but the quantity of progestin varies. Progestin levels are reduced in the early half of the cycle to facilitate the thickening of the endometrium. This is the uterine lining, which thickens organically during menstruation. In order to facilitate endometrial ripening, a higher amount of progestin is used in the second part of the cycle.
Triphasic: The progestin in these tablets fluctuates over the cycle, but the estrogen is either stable or changes. This implies that in order for birth control tablets to function as effective contraceptives, the dosage needs to be taken precisely every day.
Mode of Action
COCs have a dual action:
- They prevent the release of eggs from the ovaries (suppress ovulation)
- They also thicken the cervical mucus, thus interfering with sperm motility.
Effectiveness of Combined Oral Contraceptives
Effectiveness varies with the user: when used appropriately and consistently, it has a 99.7% success rate in preventing pregnancy. The biggest risk of pregnancy occurs when a woman begins a new pill pack three days or more later than usual, or when she misses three or more tablets around the start or finish of a pill pack.
Notably, COCs DO NOT interfere with an existing pregnancy.
Advantages of Combined Oral Contraceptives
Contraceptive Benefits
- They are highly effective if used correctly and consistently
- They are easy to use, easy to obtain and can be provided by trained non-clinical service providers
- They are generally safe for the majority of women
Non-contraceptive Health Benefits
- They reduce menstrual flow to lighter, and shorter periods
- They decrease dysmenorrhea (painful periods)
- They reduce the symptoms of endometriosis and polycystic ovarian syndrome (PCOS)
- They prevention of iron – deficiency anaemia
- Protection against ovarian and endometrial cancer and symptomatic pelvic inflammatory disease
- They can be used to treat acne and hirsutism
Limitations of COCs
- If a client is receiving anti-epilepsy medication, anti-TB treatments (such as Rifampicin or Rifabutin therapy), or some ARVs, their efficacy may be reduced, necessitating the use of a backup technique.
- The effectiveness of contraceptives may also be reduced by diarrhea, acute vomiting, or gastroenteritis.
- They do not provide protection against STIs, HIV and hepatitis B.
- They decrease the amount of milk in nursing mothers.
Caution and Contraindications
They are used cautiously in:
- Women aged 40 years or more
- Non-breastfeeding women 21 days or more postpartum with no risk of venous thromboembolism
- Women who have unexplained vaginal bleeding
- Antiretroviral therapy with the following NNRTIs: Efavirenz (EFV), Nevirapine (NVP), ritonavir or ritonavir boosted Pls
- Women with a family history of DVT (first degree relatives)
They are contraindicated in:
- Breastfeeding mothers before six months postpartum or non-breastfeeding mothers before three weeks postpartum
- Women with current or history of ischaemic heart disease, complicated valvular heart disease or stroke
- Women with severe hypertension with BP equal or higher than 160/100, or hypertension complicated by vascular disease
- Women with diabetes mellitus that is complicated by vascular disease or that is longer than 20 years in duration
- Women with a history of or current breast cancer
- Women with severe (decompensated) liver cirrhosis
- Women who have had major surgery with prolonged immobilization
Side Effects of COCs
Minor Side Effects
- Nausea especially in the first three months
- Breakthrough per vaginal bleeding
- Mild headaches
- Breast tenderness
- Weight changes
- Mood changes
- Amenorrhea (some women see amenorrhea as an advantage)
Major Side Effects (Rare, But Possible)
- Myocardial infarction
- Stroke
- Venous thrombosis or embolism, or both
Management of COCs
Method Prescription and Use
- A woman can start using COCs at any time provided she is not pregnant.
- If she begins using COCs within five days after the start of her menses, she will not need a back-up contraceptive method.
- If she begins using COCs more than five days after the start of her menses, she should use a backup method for seven days.
- For postpartum women, the use of COCs is not usually recommended for women less than 6 months postpartum who are primarily breastfeeding.
- Post abortion women can start COCs immediately
Management of Side Effects
Service providers should ensure that clients are informed about known risks connected with using COCs, emphasizing that even if these risks are uncommon, they should still return if they encounter any of the following warning indicators (ACHES):
A: Abdominal pains
C: Chest pain or shortness of breath
H: Headaches
E: Eye problems
S: Severe calf muscle pain
- Nausea and dizziness: Assess for pregnancy. Reassure client that this is a common side effect in
COC users and may diminish in a few months. Advise client to take pills with meals or at bedtime. - Amenorrhoea: Assess for pregnancy. If client is not pregnant, explain that this is one of the possible side effects of COC use.
- Spotting: Assess for pregnancy. Reassure client that irregular spotting is a harmless and common side effect in COC users, especially during the first three months. Assess for other illnesses if appropriate. Encourage client to take pills at the same time each day. If spotting persists and is unacceptable for client, prescribe 800 mg ibuprofen three times a day for
five days (or other NSAID, except aspirin). If this does not offer relief, help client to choose another method.
Management of Missed Pills
- Take a missed hormonal pill as soon as possible.
- If a woman has missed pills 3 or more days in a row in the first or 2nd week or has started new pack 3 or more days late, advise her to take a hormonal pill as soon as possible and use a backup method for the next 7 days. If she had sex in the past 5 days, she should consider emergency contraceptive.
- If a woman has missed 3 or more pills in the 3rd week, she should;
- Take a hormonal pill as soon as possible.
- Finish all hormonal pills in the pack. Throw away the 7 nonhormonal pills in a 28-pill
pack.
- Start a new pack the next day.
- Use a backup method for the next 7 days.
- Also, if she had sex in the past 5 days, she can consider EC.
- If the woman has missed any nonhormonal pills (last 7 pills in a 28-pill pack), she should;
- Discard the missed non-hormonal pill(s).
- Start the new pack as usual.
- If she vomits within 2 hours after taking a pill, she should take another pill from her pack as soon as possible, then keep taking pills as usual.
- If she has vomiting or diarrhea for more than 2 days, follow instructions for 3 or more
missed pills, above.
Further reading on the medical eligibility criteria for contraceptive use
