The purpose of the study is to analyse the patterns of antipsychotic use for pregnant women in an Australian Principal Referral and Specialist Women and Newborn Hospital. This retrospective, observational study involved an analysis of dispensing data of antipsychotics from 1998 to 2014 extracted from the pharmacy dispensing systems. The study included 282 antipsychotic dispensings in the years 1999 to 2006 and 3041 dispensings in the years 2007 to 2014. Second-generation antipsychotic use during pregnancy increased over time, while first-generation-antipsychotics showed declining trend. The use of quetiapine has increased from 2.9% of total antipsychotic dispensings in 2002 up to 77.9% of total antipsychotic dispensings in 2008. Olanzapine use decreased from 78.1% in 2003 to around 20% since 2006. When comparing the age distribution, there was an increased proportion of patients receiving antipsychotics in the 30-39 age range in the second period of 2007 to 2014 compared to 1999 to 2006. The proportion of women on more than one antipsychotic increased from 5% (n = 8) to 9.8% (n = 81) when comparing between 1999 and 2006 and between 2007 and 2014. Our findings indicate a significant shift in prescribing patterns over the study period, with the increased use of antipsychotics, particularly the emergence of SGAs from 2007, changing trends in the use of specific medications as published findings on their safety profiles becomes evident, and more polypharmacy prescribing.