Unintended pregnancy affects women of all reproductive ages. However, young women and unmarried women are at higher risk of unintended pregnancy compared to older, married women.2
A South African study showed that in 2019, 51.6% of pregnancies in women between 15- to 49-years, and 75% among adolescent girls and single women were unintended.2
Furthermore, Woldesenbet et al found that the risk of unintended pregnancy in South Africa was higher among women who knew their HIV-positive status before pregnancy but had not initiated antiretroviral therapy (ART) until after the first anti-natal care visit, women who initiated ART before pregnancy, and women with a new HIV diagnosis during pregnancy, compared to HIV-negative women.2
Adverse maternal and infant outcomes associated with unintended pregnancy
Between 2015 and 2019, about 121 million pregnancies annually, were unintended. During this time frame, unintended pregnancies in sub-Sahara Africa were higher compared to the global average (91 vs 64 unintended pregnancies per 1000 women aged 15–49 years per annum,respectively).2
Nelson et al found that compared with an intended pregnancy, unintended pregnancy was significantly associated with higher odds of depression during pregnancy (23.3% vs 13.9%) and post-partum (15.7% vs 9.6%). Women who got pregnant unintentionally were also subjected to more interpersonal violence (14.6% vs 5.5%).1
Furthermore, the rates of pre-term birth were higher in unintended pregnancies (9.4% vs 7.7%) and associated with infant low birth weight (7.3% vs 5.2%).1
Apart from the above-mentioned, unintended pregnancy has other health, social, and economic consequences. For example, the late initiation of anti-natal care may result in delays in the diagnosis of other underlying maternal health conditions such as hypertension and diabetes, according to Woldesenbet et al.2
Unintended pregnancies also add household financial stress, which may lead to interpersonal violence, poor nutrition during pregnancy, unsafe abortion, and poor quality of life for older siblings/children. Unintended pregnancy among school-aged girls can result in school dropouts, depression, and low educational achievement.2
What contributes to unintended pregnancy?
Woldesenbet et al state that high–risk behaviours (eg unsafe sex), and inconsistent availability of contraceptive options contribute to unintended pregnancy. Low uptake of contraception has been reported as the cause of up to 75% of unintended pregnancies in South Africa.2
The low uptake of contraception is due to fear of infertility and fear of side effects leading to discontinuation of contraception, indicating inadequate knowledge about the various safe and reversible contraception options available.2
Other factors that play a role in the high rate of unintended pregnancy in South Africa include a lack of education, lack of employment opportunities, cultural and religious beliefs, social norms (eg autonomy of men in decision-making), and the quality of healthcare provision.2
Can contraceptives cause infertility?
No, contraceptive use - regardless of its duration and type - does not hurt the ability of women to conceive following termination of use but may delay contraception.3,5,6
According to Sedlander et al, a common myth among African women is that contraceptives ‘spoil the reproductive system’. The team conducted focus group discussions and key informant interviews in communities in Kenya and found that 60% of respondents believed that contraceptives result in infertility.4
Respondents indicated that they believed using contraceptives from a young age, before having at least one child, or before marriage can make ‘your womb weak’, or ‘block your uterus’, and that being ‘barren’ is proof that a woman used contraceptives and had sex before marriage.4
Asked whether the type of contraceptive used plays a role in infertility, some respondents indicated that they believe using oral contraceptives may lead to problems conceiving, while others commented that intra-uterine devices (IUD) are the only method that does not cause infertility.4
Numerous studies have investigated the link between contraceptive use and fecundability. A 2013 study by Mikkelsen et al, found that there is no evidence that long-term (>4-years) oral contraceptive use deleteriously affects fecundability. They did find that compared to barrier methods, women using oral contraceptives over the short- and long-term are likely to experience a transient delay in conception after discontinuation.4
About 51% and 68% of the participants in their study conceived within six and 12 cycles following discontinuing contraceptive use, while 4.6% indicated that they no longer wanted to conceive.4
According to the authors there is a link between the use of oral contraceptives started at a young age (±16-years), and reduced fertility – particularly among women with cycle irregularities.4
Girum et al (2018) conducted a systematic review, which included 22 studies and 14 884 participants. They found that the pooled rate of pregnancy was 83.1% within the first 12 months of contraceptive discontinuation. It was not significantly different for hormonal methods and IUD users.3
Similarly, the type of progesterone in specific contraception options and duration of oral contraceptive use does not significantly influence the return of fertility following cessation of contraception.3
More recently, Yland et al (2020) evaluate the association between a variety of contraceptive methods and subsequent fecundability. In their study, about 38% (n=6735) of participants recently used oral contraceptives, 13% (n=2398) used long-acting reversible contraceptive methods, and 31% (n=5497) used barrier methods.5
Women who recently stopped using oral contraceptives, the contraceptive ring, and some long-acting reversible contraceptive methods experienced short-term delays in return for fertility compared to users of barrier methods.5
The use of injectable contraceptives was associated with decreased fecundability compared with the use of barrier methods (fecundability ratio 0.65). Users of injectable contraceptives had the longest delay in the return of normal fertility (five to eight menstrual cycles), followed by users of patch contraceptives (four cycles), users of oral and ring contraceptives (three cycles), and users of hormonal and copper IUDs and implant contraceptives (two cycles).5
About 56% and 77% of women conceived within six and 12 cycles of follow-up, respectively. The authors concluded that the lifetime length of use of contraceptive methods was not associated with fecundability.5
Fear of side effects
Fear of side effects or health complications due to contraceptive use accounts for about 28% of non-use in Africa.4
Side effects associated with contraceptives include:6,7
Progestin-only long-acting methods, such as the levonorgestrel (LNG) subdermal implant, have typical effectiveness rates of less than one pregnancy per 100 women per year similar to permanent methods, such as tubal ligation or vasectomy. The etonogestrelsubdermal implant is effective for up to five years.6
The bleeding profile of implants is less predictable and up to 11% of users remove it in the first year due to irregular bleeding. An analysis of 11 studies found that the bleeding pattern in the first three months (such as prolonged, frequent, or irregular episodes) is consistent with future bleeding patterns. However, those with frequent or prolonged bleeding in the first three months have a 50% chance of improvement in the subsequent three months.6
Depot medroxyprogesterone acetate (DMPA) is an injectable progestin available in intramuscular (150mg) and subcutaneous (104mg) formulations, which are administered at 12- to 14-week intervals. While DMPA is associated with irregular uterine bleeding, this pattern improves with a longer duration of use.6
A systematic review of DMPA-related bleeding patterns found that 46% of those using DMPA were amenorrhoeic in the 90 days following the fourth dose.6
DMPA is the only contraceptive method that can delay the return to fertility. The contraceptive effect and cycle irregularity can persist for up to 12 months after the last dose, likely due to persistence in adipose tissue and its effectiveness in suppressing the hypothalamic-pituitary-ovarian (HPO) axis.6
DMPA may be best suited for those who benefit from amenorrhea (eg patients with developmental disabilities, bleeding diatheses) but not for those who want to conceive quickly after discontinuation.6
The copper-bearing IUD is a highly effective non-hormonal reversible method. Typical use pregnancy rates are 1% per year. There is no effect on a user’s HPO axis and thus ovulation and menstrual cyclicity continue.6
The primary mechanism of action is spermicidal, through direct effects of copper salts and endometrial inflammatory changes. The major challenge with the copper IUD is that it can increase the amount, duration, and discomfort of menses mostly during the first three to six months of use. IUD use does not increase the later risk of tubal infertility.6
Most side effects of oral contraceptives are mild and disappear with continued use or switching to another pill formulation. The most common adverse effect of combined oral contraceptive pills is breakthrough bleeding.7
Women will also complain of nausea, headaches, abdominal cramping, breast tenderness, and increased vaginal discharge or decreased libido. Nausea can be avoided by taking the medication at night before sleep. The majority of the other consequences will resolve with time or switching OCP to a different preparation.7
Women who have a pre-existing cardiovascular condition or smoke should not use OCs. For the first six months, OC progestogens can impair glucose metabolism in healthy adult women. Women with diabetes mellitus might need to increase insulin intake to regulate blood glucose levels within the desired range.7
Oral contraceptive pills can cause hypertension in 4%-5% of healthy women and exacerbate hypertension in about 9%-16% of women with pre-existing hypertension.7
Four studies on teenage women found a small negative effect of combined oral contraceptive pills on the acquisition of bone mineral density. In addition, COC use increases the risk of venous thrombotic events (VTE), especially during the first year of initiation. VTE risk increases with high ethinyl estradiol dose and third and fourth-generation progestin.7
A meta-analysis reported that combined oral contraceptive users were at higher risk of ischaemic stroke (relative risk 1.7) and myocardial infarction (relative risk 1.6) when compared with non-users. The risks did not depend on the type or generation of progestagen.
Data analysis showed the risk of ischaemic stroke or myocardial infarction increases with higher doses of oestrogen. This risk was highest when pills had more than 50 micrograms of oestrogen.
Most preparation now contains less than 50 micrograms of oestrogen, making combined oral contraceptives substantially safer to use. Oral contraceptives containing 30μg of oestrogen and LNG are the safest oral form of combined oral contraceptive pills.7
- Nelson HD, Darney BG, Ahrens K, et al. Associations of Unintended Pregnancy With Maternal and Infant Health OutcomesA Systematic Review and Meta-analysis. JAMA, 2022.
- Woldesenbet S, Kufa T, Lombard C, et al. The prevalence of unintended pregnancy and its association with HIV status among pregnant women in South Africa, a national antenatal survey, 2019. Nature Scientific Reports, 2021.
- Girum T, Wasie A. Return of fertility after discontinuation of contraception: a systematic review and meta-analysis. Contracept Reprod Med, 2018.
- Sedlander E, Bingenheimer JB, Thiongo M, et al. They Destroy the Reproductive System”: Exploring the Belief that Modern Contraceptive Use Causes Infertility. Studies in Family Planning, 2018.
- Mikkelsen EM, Riis AH, Wise LA, et al. Pre-gravid oral contraceptive use and time to pregnancy: a Danish prospective cohort study. Human Reproduction, 2013.
- Teal S, Edelman A. Contraception Selection, Effectiveness, and Adverse Effects. A Review. JAMA, 2021.
- Cooper DB, Patel P, Mahdy H. Oral Contraceptive Pills. [Updated 2022 Sep 6]. In: StatPearls[Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.