key: cord-0833069-lxtdcsbj authors: Moaven, Len; Brown, James title: COVID‐19 “baby boom” date: 2021-04-15 journal: Med J Aust DOI: 10.5694/mja2.51010 sha: 7ca7a42622e431697065b2ef57a2cfcc416f04b2 doc_id: 833069 cord_uid: lxtdcsbj nan To the Editor: Modelling commissioned by the federal government estimates that the fertility rate in Australia will drop to an all-time low of 1.59 babies per woman in 2020-21. 1 However, anecdotal observation suggests this projection does not reflect the apparent increase in current bookings for antenatal appointments in our (public) practice. Therefore, we reviewed the use of the five Medicare Benefits Schedule (MBS) item numbers for "microbiological serology during a pregnancy" (ie, 69405, 69408, 69411, 69413 and 69415), as one of these numbers is usually billed at the first antenatal visit. In June 2020, the use of these item numbers increased by 25.4% and later declined to a 9.6% increase in September 2020 compared with September 2019 (Box). 2 In the period from 2018 up to the start of the coronavirus disease 2019 (COVID-19) pandemic, the mean fluctuation in billing volume in the same months over different years was about 3% less or more. 2 Therefore, the larger than expected surge in antenatal serology orders since the start of the COVID-19 pandemic likely represents a significant change in behaviour. Furthermore, this increase in serology testing is on the background of an approximate 3% decline in services for pathology tests not related to COVID-19 from June to September 2020 compared with the same period in 2019. 2 Using MBS item numbers as a surrogate for pregnancy-related appointment bookings has limitations. In general, women accessing public hospital care may have serology tests done as part of state government funding schemes whereby no MBS item is generated. We cannot exclude the possibility that, in the context of changes related to the COVID-19 pandemic and a move to telehealth, a higher proportion of women may have had pathology tests done via Medicare. However, it would be expected that if fertility were declining, there would have been a reduction in testing. Furthermore, we were unable to exclude repeat testing, although our experience indicates this would account for an insignificant number of tests. This historical trend, and its context in the timing of an apparent "baby boom" (ie, antenatal serology testing is usually done at around 6-10 weeks' pregnancy), correlates with an increase in conception starting in late March to early April 2020, during the so-called first wave of COVID-19 in Australia. Requests for antenatal serology testing increased by 12 869 from June to September 2020 compared with the same period in 2019 (Box). Factoring in miscarriages, this may mean there will be an additional 11 000 Australian babies born in the third quarter of the financial year 2020-21 compared with the same period in the previous financial year. We believe it is unlikely that fertility rates will drop in 2020-21. A projection of Australia's future fertility rates. Canberra: Commonwealth of Australia Medicare item reports