The importance of asking questions
The questions asked should provide information on factors that are critical to the risk assessment for each individual pregnancy.
Identifying risk factors
All pregnancies have some risk. It is important to note that there is a 2-3% background risk of congenital malformations for a normal healthy young mother, irrespective of any medicines used during pregnancy.
The risk of having a baby with a congenital malformation may be increased by factors including increasing age, poor maternal health and poor familial and obstetric history.
Informing risk v benefit assessment
When prescribing for a pregnant woman it is important to balance the (often poorly defined) risk of a medicine to the fetus, against the risks to both mother and fetus from failing to treat the maternal condition. The answers to these questions provide useful information to assess the risk to the fetus, and the needs of and benefits to the mother.
The case for each medicine should be assessed on an individual patient basis.
Many maternal conditions are treatable, and adverse outcomes can often be avoided by appropriate therapy, informed by a good risk versus benefit assessment.
The information you need includes:
- Age – increased age (particularly over 35 years) is associated with increased risk of miscarriage and malformation
- General health – poor maternal health may increase the risk to the fetus
- Pregnant or trying to conceive?
- Has the patient taken the medicine already or are they considering taking it?
- Does the patient want to breastfeed?
- It is helpful to know the indication in order to be able to provide the best information about potential risk, benefit, and clinical need for a medicine; and to suggest alternatives if necessary or clinically possible.
Medicine and therapy
- The proposed medicine(s) and any other medicines the patient is taking or wants to take (generic or brand name, dose, frequency, route, duration).
- Stage of pregnancy when exposure occurs
- Route of administration
- Long or short-term administration
- Has the medicines been taken already or is it just being considered?
The ideal is to consider medicines before exposure. You may be in a position to simply advise against exposure if it has not already been taken.
- Is the medicine necessary?
A stepwise approach may be possible, starting with non-pharmacological options.
- Have other therapies or medicines been tried?
- Has the patient been on this or alternative medicine(s) previously (including during previous pregnancies) and were symptoms controlled?
- How many weeks was the woman pregnant when she first started taking the medicine?
- How many weeks pregnant is she now?
The stage of pregnancy in weeks is very useful; at the time of the enquiry and at the time of the exposure. Be as accurate as possible because developmental sensitivities to teratogens may be dependent on stage of pregnancy.
- Has the woman had any previous pregnancies and what was the outcome?
- Is there a family history of malformations or history of recurrent miscarriages?
Obstetric history can be useful as a factor for establishing background risk, irrespective of the medicine(s) being considered or taken.
- Have any investigations been performed (eg ultrasound scans)?
More detailed scans, dose changes, additional drug monitoring etc. may be necessary if exposure has already occurred.
Using the information gathered
Once you have collected as much information as you can in response to these questions, you should then look at the information resources for information about the use of the medicine, that is relevant to this individual patient, as described by the answers to the questions.
You are then in a good position to do a risk assessment for the use of the medicine in pregnancy.
The risk assessment and the application of the principles will enable you to formulate your answer and provide advice that informs the decision about the use of a medicine for that individual pregnancy.