Drug use during pregnancy: are risk classifications more dangerous than the drugs?

Teratogenic risk perception and confidence in use of medicines in pairs of pregnant women and general practitioners based on patient information leaflets

OBJECTIVE

The aim of this study was to examine teratogenic risk perceptions and confidence in the use of medicines in pairs of pregnant women and general practitioners (GPs) through assessments of medicines information texts from patient information leaflets (PILs).

METHODS

A questionnaire was handed out to women attending regular ultrasound examination in week 17-19 of pregnancy. The women stated name and address of their GP and questionnaires were sent to the GPs' clinic. The questionnaires contained texts regarding pregnancy from PILs for pivmecillinam, metoclopramide, paracetamol, escitalopram, Valeriana officinalis and dexchlorpheniramine. For each PIL, teratogenic risk (scale from 0: never teratogenic to 10: always teratogenic), confidence in use of medicines (yes or no) and clarity of the text (scale from 0: exceptionally clear to 3: exceptionally unclear) were assessed.

RESULTS

In total, 171 pregnant women and 74 GPs participated, of which 98 pairs were identified. Pregnant women had significantly higher perceptions of teratogenic risks and lower confidence in use of medicines compared to GPs. Differences in teratogenic risk perceptions and confidence in use were highest for escitalopram and lowest for dexchlorpheniramine, representing texts with different phrasing and length. Neither pregnant women nor GPs were confident in using Valeriana officinalis.

CONCLUSIONS

Perceptions of teratogenic risks and confidence in use of medicines during pregnancy differ within pairs of pregnant women and their GP when they assess PILs. Phrasing of medicines information texts can influence teratogenic risk perceptions and thereby prescribing of medicines and adherence.

Prescription of Hazardous Drugs During Pregnancy

BACKGROUND

Prescribing drugs to pregnant women requires the balancing of benefits and risks. Only a small proportion of drugs are known to be harmful to the fetus, but for the vast majority of drugs little evidence of fetal safety exists.

AIM

To determine the prescription pattern of potentially and clearly harmful prescription drugs during pregnancy with reference to drug safety categorisation, and to define the drug groups primarily responsible for multiple drug use during pregnancy.

STUDY DESIGN

A retrospective, register-based cohort study.

METHODS

Linkage of three nationwide registers in Finland. Data collection included prescription drugs purchased during the preconception period and each trimester in the pregnant cohort, and the corresponding time periods in the non-pregnant controls. The pregnancy safety categorisation was determined for each drug (Anatomic Therapeutic Chemical [ATC] code) by using the Swedish classification of approved medicinal products (Farmaceutiska Specialiteter i Sverige [FASS]) and if not available, the corresponding Australian (Australian Drug Evaluation Committee [ADEC]) or US categorisation (FDA). GROUPS STUDIED: Women applying for maternity support (maternal grants) during the year 1999 (n = 43 470) plus non-pregnant control women matched by age and hospital district (n = 43 470).

RESULTS

In the pregnant cohort, 20.4% of women purchased at least one drug classified as potentially harmful during pregnancy, and 3.4% purchased at least one drug classified as clearly harmful. A significant decline occurred in the number of pregnant women purchasing potentially and clearly harmful drugs during the first trimester when compared with the preconception period, and the decline continued from the first to the second trimester. In the pregnant cohort, 107 (0.2%) women purchased at least ten different drugs during pregnancy. The drugs most commonly purchased in this group were topical corticosteroids and nasal preparations.

CONCLUSION

The use of hazardous prescription drugs declines during pregnancy but prescriptions of known teratogens and the relatively frequent practice of polypharmacy in epilepsy place emphasis on the need for careful pre-pregnancy counselling. However, drug safety classifications give a very crude estimation of risk and should only be used as general guidelines when planning treatment. Risk assessment must always be made on an individual basis, and pregnant women with illnesses requiring treatment must be treated adequately.