ABSTRACT
BACKGROUND/OBECTIVES: Oral retinoids are teratogenic, and pregnancy avoidance is an important part of retinoid prescribing. Australia does not have a standardised pregnancy prevention programme for women using oral retinoids, and the contraception strategies for women who use oral retinoids are not well understood. The objectives were to determine trends in the use of prescription retinoids among Australian reproductive-aged women and whether women dispensed oral retinoids used contraception concomitantly. METHODS: This was a population-based study using Australian Pharmaceutical Benefits (PBS) dispensing claims for a random 10% sample of 15-44-year-old Australian women, 2013 - 2021. We described rates and annual trends in dispensing claims for PBS-listed retinoids and contraceptives. We also estimated concomitant oral retinoid and contraceptive use on the day of each retinoid dispensing and determined if there was a period of contraceptive treatment that overlapped. Estimates were then extrapolated to the national level. RESULTS: There were 1,545,800 retinoid dispensings to reproductive-aged women; 57.1% were oral retinoids. The rate of retinoid dispensing to reproductive-aged women increased annually, from 28 dispensings per 1000 population in 2013 to 41 per 1000 in 2021. The rate of oral retinoid dispensing doubled over the study period, from 14 dispensings per 1000 population in 2013 to 28 per 1000 in 2021, while topical retinoid dispensing did not change. Only 25% of oral retinoid dispensings had evidence of concomitant contraceptive use in 2021. CONCLUSIONS: Rates of oral retinoid dispensing have doubled among reproductive-aged women over the past decade. A large percentage of oral retinoid use does not appear to have concomitant contraception use, posing a risk of teratogenic effects in pregnancies.
ABSTRACT
BACKGROUND: Women who have previously had a caesarean section often face the choice between planning for a vaginal birth after caesarean (VBAC) or an elective repeat caesarean section (CS) for future pregnancies. Informing a woman of her individualised chance of a successful VBAC can aid her decision making. AIMS: The aim is to create two VBAC prediction models using an Australian cohort - one for use in labour when labour variables are known, and one for use antenatally when labour characteristics are unknown. MATERIALS AND METHODS: This study was a retrospective analysis of perinatal data in Victoria, Australia, over a 10-year period. During this time, 22 062 women were recorded as attempting a VBAC with a term singleton live birth. The data were separated into three parts. A 'training set' was used to build the complete VBAC prediction model and the antenatal VBAC prediction model using multivariate logistic regression. The models were then adjusted to only include the variables that contributed to model performance. The models were validated by testing the receiver operating characteristic (ROC) area under the curve within the 'validation set'. Then the models were tested for accuracy within the 'test set'. RESULTS: Using a 'test set' of data, the models demonstrated an area under the ROC curve of 0.7887 and 0.7384 for the complete and antenatal models respectively, showing adequate performance of both models. CONCLUSIONS: With these models, Australian women can be counselled about their predicted chance of VBAC success.
