Introduction
A teratogen is a substance that can adversely affect the development of
an embryo or a foetus on exposure during pregnancy. A wide range of
substances have been recognised as teratogens, including some
medications [1, 2]. There is a need to ensure that potential
teratogens are used as safely as possible by women of child bearing age,
because the use of teratogenic medications is likely to be inevitable in
many cases due to the unavailability of equally effective alternative
treatment options [3, 4].
To support healthcare professionals’ and patients’ understanding
regarding the relative of safety of using different medications during
pregnancy, evidence-based classification systems have been developed
[5]. Within such systems, medications are assigned into different
risk categories based on available data on their harm to the foetus,
including type, subjects, and results of the available teratogenicity
studies [5, 6]. One example of a classification system is the Food
and Drug Administration (FDA) pregnancy categories, which classifies any
medication within one of five categories (A, B, C, D, or X) based on its
degree of safety, with class A being the safest and class X being the
most harmful to the foetus [7].
To minimise foetal harm when prescribing potential teratogens, risk
management programmes have also been developed for certain medications,
with the manufacturer of isotretinoin launching the first pregnancy
prevention programme aimed at preventing foetal exposure in 1988 [4,
8]. Subsequently, the use of teratogenic medications has been
increasingly controlled through the development of risk minimisation
activities and programmes [8]. Elements to ensure safe use of
teratogenic medications include certification of prescribers and
dispensers, patient counselling regarding contraception use and
monitoring patient contraception behaviours through regular pregnancy
testing and use of contraception [8, 9].
The development and implementation of teratogenic risk management
programmes should also take into consideration patient’s experience of
using a medication [10]. The value of recognising patient’s
experience of medication-taking as part of ensuring medications are used
effectively and deliver intended outcomes is one of the principles of
medicines optimisation, a model for informing pharmacy practice based on
the aim of improving outcomes of medication use. The four guiding
principles of medicines optimisation are: aim to understand the patient
experience; evidence-based choice of medicines; ensure medicines use is
as safe as possible and make medicines optimisation part of routine
practice [11]. Medicines optimisation is a patient-centred approach
for achieving optimal use of medications by providing personalised care
for each patient [12]. Conceptualised in terms of medicines
optimisation, with the patient at the centre of healthcare, patients’
views, opinions, and perceptions of taking a teratogenic medicine, and
understanding of teratogenic risk, are therefore important factors when
investigating the effectiveness of any risk management programme [13,
14]. Moreover, because a key actor in ensuring evidence-based choice
of medications are healthcare providers, these stakeholders’ perceptions
of teratogenic risk will play a part in understanding patients’
experience of using the medication [10]. In fact, evidence from the
literature suggests that the patient-physician relationship and
teratogenic risk communication have a significant impact on patients’
medication utilisation [13]. In this context, over-estimation of
teratogenic risk may result in poor adherence to treatment during
pregnancy, anxiety or pregnancy termination, while under-estimation of
teratogenic risk can result in foetal exposure to the harmful effects of
a teratogenic medication [15-17].
A growing body of literature has investigated the implementation of
pregnancy prevention measures while prescribing teratogenic medications
to women of child bearing age [18-22]. Additionally, research has
focused on the perceived risk of teratogenic medications of various
populations [15, 23, 24]. Yet to date, what is lacking is a
systematic synthesis of data from a medicines optimisation perspective
that explores teratogenic medication safety by systematically reviewing
publications on the implementation of risk management (pregnancy
prevention) measures when prescribing teratogens to women of child
bearing age in combination with a review of patients’ experience of
using teratogenic medications in terms of reported perceptions of
teratogenic risk.