Obstetrics and Gynecology International 3.2.1. Epilepsy. Incomplete compliance with anticonvulsant medication was reported by 62.3% (157/252) of pregnant women with epilepsy [32]. Hair analysis was undertaken in 26 pregnant women taking carbamazepine or lamotrigine with four patients (15%) showing declines in drug concen- tration in the more proximal segments suggesting a change in drug-taking behaviour. Results were interpreted to suggest that these women had discontinued their medication during pregnancy [33]. 3.2.2. Asthma. For three categories of asthma severity before pregnancy (intermittent, mild persistent, and moderate/se- vere), mothers whose medication use fell below the recom- mended guideline experienced more severe asthma during pregnancy than women using their recommended medica- tion [34]. In an online survey, 39% of women who have been pregnant reported that they had discontinued or reduced their asthma medication during pregnancy, a third having done so without discussion with a physician. Of potential signiﬁcance in managing these patients, 40% of women indi- cated that they would be more likely to continue taking their asthma medication during pregnancy if their obstetrician alone recommended it [35]. 40% of pregnant asthmatic sub- jects reported nonadherence to inhaled corticosteroid medi- cation (ICS). However, after asthma education nonadherence to ICS decreased to 21% [36] which is important to note as lack of appropriate treatment with inhaled corticosteroids is associated with exacerbations of asthma during pregnancy [37]. 3.2.3. Inﬂammatory Bowel Disease. Although studies have suggested that exacerbations of inﬂammatory bowel disease (IBD) during pregnancy may worsen pregnancy outcomes, 84% of female patients with IBD reported concerns that their IBD medications would harm their pregnancy while only 19% reported concerns about the eﬀect of active IBD on pregnancy [38]. In Crohn’s disease 67% (37/55) of women reported adherence to medical treatment during pregnancy [39] while in ulcerative colitis 60% (37/62) of women re- ported adherence [40]. With both conditions, reasons stated for nonadherence included quiescent disease and fear of negative eﬀects on the fetus [39, 40]. 3.2.4. Nicotine Replacement Therapy. Adherence to nicotine replacement therapy (NRT) is low among pregnant smokers. Fish et al. found that overall only 29% of 104 women used NRT for the recommended 6 weeks and 41% used NRT as directed in the ﬁrst 48 hours after a quit attempt [41]. 4. Factors Affecting Medication Adherence in Pregnancy: Perception of Risk In addition to the multiple factors that may aﬀect medication adherence in the nonpregnant population, there are unique inﬂuences that may play a role in pregnant women. On the one hand, pregnant women may be motivated to take their medication for the well-being of their baby, mindful of the potential negative fetal consequences of untreated maternal 3 disease. On the other hand, it has been demonstrated that women may not take their medication due to concerns regarding potential adverse fetal eﬀects [14, 39, 40, 42]. In some cases this fear may be justiﬁed based on known ter- atogenic eﬀects; however, in many cases medications have not been demonstrated to be harmful. It has been shown that pregnant women tend to overestimate the risks asso- ciated with drug use during pregnancy. Most women who completed an internet survey were able to correctly identify that the general risk of malformation is ≤5%; however, they overestimated the teratogenic risk associated with many drugs during pregnancy [43]. 5. Improvement in Medication Adherence in Pregnancy If women with inadequately controlled disease due to inade- quate adherence with drug therapy are identiﬁed, they may be targeted for evidence-based counselling to correct their misperceptions, allay their fears, and hopefully improve medication-taking behaviour [43]. In addition, it may be possible to avoid medication nonadherence before it happens by proactively addressing the pregnant woman’s concerns about the safety of medications. Ideally, with chronic drug therapy this counselling may occur as part of prepregnancy planning. Survey studies have shown that pregnant women feel they need information about the use of drugs during pregnancy [14, 42]. Media and other sources may provide misleading information provoking anxiety amongst preg- nant women [43]. Given the overestimation of risk, the dis- cussion should include, if available, evidence-based informa- tion on the eﬀects of the medication’s use during pregnancy allowing the pregnant women to make an informed decision as to whether to continue their prescribed therapy. Education should focus on the important role of good medication adherence for the health of both the mother and fetus. Counselling by teratogen information services may play a role in inﬂuencing medication-taking behaviour [43]. After counselling by Motherisk, a Canadian teratogen information service, 61.1% (22/36) of pregnant women who had discon- tinued their antidepressant or benzodiazepine medication restarted their medication within a few days [44]. Health care workers, such as obstetricians and family physicians, are uniquely positioned to not only monitor adherence but to encourage consultation with drug information services to dispel misconceptions about the risks of medications to the fetus. A meta-analysis of studies of directly observed therapy of highly active antiretroviral therapy (DOT-HAART) found that DOT-HAART recipients were more likely to achieve un- detectable viral load and HAART adherence of greater than or equal to 95% [45]. A similar approach has been suggested for pregnant women. The third trimester of pregnancy may present an opportunity for the use of directly observed HAART to achieve virologic suppression for prevention of mother-to-child transmission of HIV [46]. Using a simula- tion model, use of DOT in women receiving HAART in 3rd trimester was associated with a relative risk of mother- to-child HIV transmission of 0.39 relative to conventional