The Midwives Notification System is managed by the WA Department of Health. It is an administrative data collection which compiles notifications of births in Western Australia to the Chief Health Officer by registered midwives. The information in MNS consists of maternal demographics, pregnancy history, pregnancy conditions and care, labour and birth, and the condition of the newborn infant.

Midwife notified births include those that occurred in public and private hospitals, family birth centres, at home, and those that occurred before arrival at planned birth site. Births notified occurred in WA and include those for women whose usual place of residence is outside WA. Notification by a registered midwife is required when a birth occurs from 20 weeks gestation, or if gestation is unknown, when birth weight is at least 400 grams. Livebirths and stillbirths are included. Infants born from abortion were included if they meet these same conditions until 26 Mar 2024. From 27 Mar 2024 births from abortions are not notified to the Chief Health Officer by midwives.

Excludes births not attended by a registered midwife or any other registered health professional. From 27 Mar 2024 excludes birth from abortion of 20 weeks gestation or more.

The purpose for a registered midwife to notify the Chief Health Officer of births is "to protect the lives of mothers and children" as stated in the Health (Miscellaneous Provisions) Act 1911. The purpose for the MNS is to provide de-identified data for approved purposes.

Western Australia state data

Health (Miscellaneous Provisions) Act 1911 Health (Notifications by Midwives) Regulations 1994, Public Health Act 2016