The combined oral contraceptive (COC) pill is an effective contraception. It has a very low-risk profile documented over several decades and its protective effect on endometrial and ovarian carcinoma has been well established.1 It is also an effective treatment for menstrual problems and polycystic ovarian syndrome,2 3 which are common in adolescents.4 5 6 7 The prevalences of menorrhagia, dysmenorrhoea, and menstrual symptoms in adolescent girls have been reported to be 17.9%, 68.7%, and 37.7%, respectively.4 The prevalence of polycystic ovarian syndrome in adolescent girls has been reported to be 16% in those who attended a local paediatric and adolescent gynaecology clinic.5 Nonetheless, the use of COC pills in Chinese women has remained low; only 1% of women of reproductive age (20-49 years) in China used the pills in 2010.8 There are some obstacles to access although family planning is a relatively well-funded area of health care in China and has been implemented for decades. In Hong Kong, the situation is slightly less unusual. From an online survey conducted in Hong Kong, 12.6% of women had used an oral contraceptive in the year prior to the survey, but many of them had stopped using it.9 According to the annual report of the Family Planning Association of Hong Kong in 2014-2015, 22% of the 48 363 clients who practised birth control, including women who were both married and unmarried, used an oral contraceptive.10 Only 6% of teenage girls who attended the youth health care centres used COC pills for contraception.11

Although sex education has been integrated into the primary and secondary educational curriculum for many years, efforts to provide quality sex education have been limited.12 According to a survey conducted by the Hong Kong SAR Government, sex education at the junior secondary school level is limited to an average of 3 to 4 school hours only.13 Sometimes concepts emphasised included protection of self and avoidance of sex, especially prior to marriage.14 The median age of marriage in Hong Kong is now close to 30 years. It is notable that Hong Kong has a high rate of therapeutic abortion that is underestimated by official statistics because an indeterminate proportion is performed in mainland China due to cost considerations. In women attending for their antenatal visit, a high proportion of 36.5% reported a previous therapeutic abortion (unpublished data from our institute). This suggests that women of reproductive age may not have been educated about contraception. There is little published information on the use of COC pills for the management of menstrual problems in Hong Kong but it is likely to be low. Misconceptions and myths about COC pills are likely to be the main obstacles to use. Although extensive high-quality information about use of COC is currently available from various sources, many women remain unaware of the non-contraceptive benefits of COC. They also have little awareness of the risks of COC.15 For female adolescents, their decision about whether to use COC is likely to be influenced by their parents, especially their mothers, who may be giving advice to their daughters based on little or erroneous knowledge. This may lead mothers to make decisions that are not in their daughter’s best interests.

Focused education about COC may lead to a more balanced view, both in adolescents and their mothers. In a study of Korean and Japanese university students, significant correlation between knowledge of and positive attitude towards COC pills was reported.16 Mothers in Asia are also often involved in their teenage daughters’ decision to begin sexual relationships, the use of contraceptives, and even vaccination.17 18 Since the mothers’ attitude may affect use of COC by their daughters, we explored Chinese mothers’ knowledge of and attitudes towards such use. Mothers’ knowledge about the COC pills and factors affecting their attitude were also evaluated.

The study was conducted from October 2012 to March 2013 in the gynaecology clinic of a tertiary teaching hospital in Hong Kong. Women who attended the clinic or accompanied a daughter to the clinic, and who had one or more daughters aged 10 to 18 years were recruited. Women who did not speak or read Chinese were excluded. The participants completed a 41-item questionnaire to assess their knowledge of and attitude towards use of COC pills by their daughters. Firstly, they were asked to self-assess their own knowledge of the COC pill. The knowledge domain consisted of 19 items testing their knowledge of the non-contraceptive health benefits and side-effects of COC pills, and three items on contra-indications to use of COC pills. For each item, participants were asked to respond “yes”, “no”, or “don’t know”. They were then asked about their attitudes to the use of COC pills by their daughters aged 10 to 18 years for the management of dysmenorrhoea, menorrhagia, acne, or as a contraceptive. They were asked to respond from “strongly agree”, “agree”, “disagree”, to “strongly disagree”. Reasons for agreeing or disagreeing with the use of COC pills and the appropriate age or life-events for using COC pills by their daughters were also asked. Finally, demographic data and their personal experience in using COC pills were collected. Knowledge score and uncertainty score were calculated for the participants based on their response15 16—knowledge score was defined as the score of correct answers with 1 score given for each correct answer (ie range from 0-22); a “don’t know” reply would create the uncertainty score. The participants provided written informed consent, and approval was obtained from the local ethics committee (CRE-2012.186).

Descriptive statistics were used to summarise participants’ demographic information. Association between participant characteristics and overall attitude was explored using Chi squared and independent-samples t test. A P value of <0.05 was considered statistically significant. All statistical analyses were conducted using the SPSS (Windows version 18.0; SPSS Inc, Chicago [IL], United States). Assuming that 50% of the women accepted the use of COC pills by their daughters with an accepted error of 0.05%, 278 women were required. An additional 10% was recruited to prepare for an incomplete questionnaire.

Apart from 150 women who were excluded because they did not have a daughter aged 10 to 18 years, a total of 317 women were invited to participate; 302 agreed and 300 (94.6%) completed the questionnaire. Demographic characteristics of the participants are shown in Table 1. Their mean age was 45.2 years (range, 28-58 years). The median number of daughters was one and most participants (88.3%) were married. Most (>70%) had high school education. In all, 125 (41.7%) were ever-users of COC pills, including both current and ex-users. Overall, 175 (58.3%) reported that they had knowledge about the COC pills, while 125 (41.7%) reported no knowledge.

The rates of giving correct answers about the COC pill and the comparison between ever- and never-users of COC pills are shown in Table 2. Of a total possible score of 22, the mean (± standard deviation) knowledge score of all the participants was 5.0 ± 4.7. Of all the participants, only approximately 20% of the mothers correctly answered that COC pills would not cause carcinoma of ovary and corpus; 26.0%, 29.7%, and 30.3% respectively correctly answered that COC pills did not have proven teratogenicity, cause pelvic inflammatory disease and infertility; 10.3% knew that COC pills would not cause weight gain and 25.7% answered that COC pills would not lead to a depressive mood. In all, 43.3%, 33.0%, and 25.3% knew that COC pills had the benefits of regulating the menstrual cycle, decreasing menstrual flow, and helping to relieve dysmenorrhoea, respectively. Moreover only 20% knew that the COC pills are not contra-indicated in people with a family history of breast cancer but is contra-indicated in thromboembolism. The knowledge score of the 175 women who responded to have knowledge of the COC pills was significantly higher than those who reported lack of knowledge (8.0 ± 4.4 vs 3.0 ± 3.7; P<0.001). Among those who declared they had knowledge about the use of COC pills, their sources of knowledge were from medical professional (63.3%), media (30.3%), friends (24.6%), family members (6.9%), school (2.9%), and others (1%).

The rate of responding “uncertain” to the health benefit, side-effects, or contra-indications of COC use ranged from 43.7% to 71.0% for each item. The mean uncertainty score among all participants was 13.0 ± 7.6. The uncertainty score was significantly higher in participants who reported to have lack of knowledge when compared with those reported to have knowledge about COC pills (15.6 ± 7.1 vs 9.1 ± 6.7; P<0.001).

Among the ever-users, 43 (34%), five (4%), and 96 (77%) women reported that COC pills had been used to manage their own menstrual problems, acne problems, and as contraception, respectively. Table 3 lists the participants’ acceptance rate of COC use by their daughters in different gynaecological conditions and the comparison between ever- and never-users of COC pills. More ever-users than never-users accepted the use of COC for their daughter’s gynaecological indications. Participants who accepted their daughter’s use of COC also had a higher knowledge score and lower uncertainty score (Table 4). Table 5 shows the participants’ reasons for accepting use of COC pills by their daughters. Recommendation by medical professionals was the major reason, followed by the knowledge that COC pills provided effective contraception.

Age, education level, and whether they had previous experience of side-effects of COC pills were not associated with participants’ acceptance of COC use by their daughters. Among the 125 ever-users of COC pills, 65 (52.0%) reported they had experienced side-effects, including weight gain (n=45), fluid retention (n=25), headache (n=12), increase in appetite (n=8), mode disturbance (n=8), and acne (n=4). Table 6 lists the reasons for disagreement with the use of COC pills by their daughters for menstrual problems. Finally, only 71 (23.6%) participants thought that the use of COC pills was appropriate in girls aged 12 to 18 years.

Our study highlights a notable lack of knowledge about the use of COC pills in many Hong Kong Chinese mothers. Many were uncertain or had erroneous beliefs about the use of COC pills. They believed that such usage would lead to cancers, fetal deformity, and cause infertility and pelvic inflammatory disease. These misconceptions and uncertainties may further reinforce their non-acceptance of the COC pills as an appropriate medication for their daughters. This inevitably often leads to suboptimal treatment for their daughters.

Fear of increased risk of cancer is an important reason for low acceptance of COC pills and only 22% of our participants thought it did not increase the risk for carcinoma of ovary or uterus. More than 60% of the participants were uncertain about the risk of cancer with the use of COC pills (results not shown). Research has shown that contraceptives have a significantly protective effect on carcinoma of ovary and corpus uteri.19 20 In fact, a collaborative re-analysis of individual data from 53 297 women with breast cancer and 100 239 women without breast cancer from 54 epidemiological studies revealed that while women were taking COC pills and in the 10 years after stopping, there was a small increase in the relative risk of breast cancer.21 There was, however, no significant excess risk of having breast cancer diagnosed ≥10 years after stopping use of COC pills. The breast cancer incidence rises steeply with age. The estimated excess number of cancers diagnosed in the period between starting use and 10 years after stopping increases with age at last use. The estimated excess number of breast cancers diagnosed up to 10 years after stopping use from the age of 16 to 19 years among 10 000 women has been reported to be 0.5 (95% confidence interval, 0.3-0.7) only.21 The Nurses’ Health Study with 121 701 participants followed up for 36 years revealed that longer duration of COC use was strongly associated with premature mortality due to breast cancer.22 Another highlight was that only 20.7% of our participants knew that a family history of breast cancer was not a contra-indication to use of COC pills.

Another common misconception is that the use of COC pills can lead to future subfertility. The COC pill preserves fertility by diminishing the risk of ectopic pregnancy.23 According to a review, 1-year pregnancy rates after discontinuation of COC ranged from 79% to 96%, similar to those reported following discontinuation of barrier methods or no contraception.24 Moreover, the progestogen effect of COC pills results in production of thick, tenacious cervical mucus that resists penetration by bacteria and spermatozoa and reduces the risk of upper genital tract infection. Use of COC pills was also quoted to be protective against symptomatic pelvic inflammatory disease, with a 50% reduction in rate of hospitalisation for the disease, with itself being a risk factor for subfertility.25 The COC pill does not protect against sexually transmitted infections. On the other hand, there is no evidence to support the notion that the use of COC pills is associated with high-risk sexual behaviour in adolescents, which is a very common fear among Hong Kong mothers.

Primary dysmenorrhoea is prevalent during adolescence. Approximately 6.4% of adolescents or 29% of those reporting severe dysmenorrhoea seek help from a physician.4 A review and meta-analysis of five trials of the use of COC pills concluded that it was more effective than placebo in managing dysmenorrhoea.2 One of the most common problems reported by adolescents is irregular and/or profuse menstruation. The COC pill is also effective in treating and preventing heavy menstrual bleeding. In our study, only 25% to 43% of the participants knew that it is an appropriate treatment for menstrual problems and 50% were uncertain.

The fear of side-effects often leads to reluctance to using new treatments.18 In many cases, such fears are often unfounded. In our study, participants believed that weight gain and depressive mood were side-effects of COC pills, although pooled analysis of a placebo-controlled trial showed no difference in weight gain.26 Furthermore, depressive symptoms are common in adolescence.27 In a randomised controlled study, there was no difference in mood changes throughout the menstrual cycle between COC users and non-users.28 In a prospective study of 43 adolescents, subjects anticipated more side-effects than they actually experienced after 6 months of taking COC pills.29

It is important to provide correct information to women and their teenage daughters if they are contemplating the use of COC pills. In our study, 40% of participants indicated that recommendation from a medical professional was a critical factor in their acceptance of the use of COC pills by their daughters.

Only 19% of participants were aware that thromboembolism is a contra-indication to COC use. Venous thromboembolism in Asians has been reported to be low.30 A recent case-control study confirmed that current exposure to any COC poses a 3-times higher risk of venous thromboembolism compared with no exposure in the previous year.31 The risk is higher with COC pills containing desogestrel (odds ratio, 4.3), gestodene (3.6), drospirenone (4.1), and cyproterone (4.3) than the second-generation COC pills with levonorgestrel (2.4) and norgestimate (2.5).31 The risk of venous thromboembolism is also increased for COC users with a family history of venous thromboembolism.32 Clinicians should assess the woman’s personal and family history of thromboembolism, and provide information about the warning symptoms of venous thromboembolism before prescribing a new generation pill. As recommended by the World Health Organization, the COC pill is not contra-indicated in smokers <35 years old33; approximately 30% of our participants answered this correctly.

This study has several limitations. First, there may be selection bias as subjects were women who presented to the gynaecology clinic or accompanied their daughter to a gynaecology clinic for a gynaecological problem. The results may not be generalised to the whole population of Hong Kong. Second, the questionnaire was not validated and the questions did not include all aspects of the use of COC pills. Third, we relied on women’s self-reported use of COC pills and could not verify the information. Despite these, the questionnaire included the most widely studied aspects of non-contraceptive benefits and risks of the COC pill and knowledge score or uncertainty score have been used in previous literature.15 16 Although this study was conducted in only one centre and in Chinese women only, it helps clinicians to understand the low levels of acceptance of and compliance with prescribed COC pills.

The degree of misconception among Hong Kong mothers about COC use is of concern. Hong Kong has a well-developed education system with many highly regarded universities. The reported limited sex education in schools may be responsible for this knowledge gap of Hong Kong mothers.13 This may in turn have an impact on the advice they give their daughters, who are usually compliant with their mother’s wishes. Specific training in communication and counselling skills should be provided to health care professionals when promoting sexual health to women and adolescents.34

Our study found that the Hong Kong Chinese women who attended a gynaecology clinic of a tertiary centre had a low acceptance rate of the use of COC pills by their daughters. This low acceptance was associated with a lack of knowledge and misconception of the risks and benefits of the COC pills. Such ignorance will exert an adverse influence on the choice of treatment for many gynaecological problems in teenage daughters.

All authors have disclosed no conflicts of interest.

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