Exposure
The exposure was conception via IVF compared with spontaneous conception. The term “IVF” is used collectively to include both conventional IVF, IVF with ICSI, and associated laboratory techniques. IVF cases were identified through the IVF database. Victorian births not identified in the IVF database were allocated to the control group. Pregnancies recorded as “IVF conception” in the VPDC but not identified within the IVF database were excluded, ensuring the control group did not contain any IVF conceptions. These cases likely represent overseas or interstate IVF conceptions, Victorian IVF conceptions not captured by our database, or failed linkages between the IVF database and state birth records.