Perinatal mortality rate (PMR) is defined as the number of stillbirths plus the number of neonatal deaths within the first completed week of life, per 1000 total live births. It was proposed by the World Health Organization in 1975 as an international definition of late fetal and early neonatal loss and is a measure of antepartum care and wellbeing, care during delivery and immediate care postpartum. Perinatal mortality is thus generally accepted as a good indicator of general health and healthcare provision across different countries.
In developed countries, PMR is about 6-12 per 1000 births, whereas in developing countries rates of up to 60 per 1000 births are reported, although many countries are unable to provide data. In England and Wales it has fallen from 32.8 per 1000 in 1961 to 6.6 per 1000 in 2016.
In some countries, infant mortality rate (IMR; the number of deaths in the first completed year after delivery per 1000 total live births) is used as the standard indicator, and it is generally about 3-8 in developed countries. In the UK, it was 3.8 in 2016, compared to 4.6 in 2009.
Problems and special considerations
Apart from difficulties collecting data, the figures are susceptible to variations in other definitions used; for example in the UK, an upward ‘blip’ in PMR was caused in 1991 when the definition of a live birth was changed from 28 weeks’ to 24 weeks’ gestation.
Perinatal mortality has been found to increase with lower birth weight, lower gestational age, lower social class, maternal age < 20 or > 40, parity < 1 or > 5, body mass index > 30 kg/m2, presence of medical conditions, method of delivery (e.g. forceps) and poor management of labour. It has been estimated that application of what is already known about good and poor practice would achieve a greater reduction in perinatal mortality than any other single measure.
For many years, the annual Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI) reported on causes of perinatal death and areas of suboptimal care, joining with the Confidential Enquiries into Maternal Deaths (CEMD) in 2003. From 2012, the programme has been commissioned by the Healthcare Quality Improvement Partnership (HQIP). Recommendations from the enquiries include establishing strategies and protocols for improving communication, training and peripartum clinical practice, appropriate involvement of senior medical staff and improvements in neonatal resuscitation.
Key points
• Perinatal mortality rate (PMR) equals the number of stillbirths and neonatal deaths within the first completed week of life, per 1000 total live births.
• PMR is generally accepted as a measure of the quality of provision of general health care for a particular country, as well as specific maternity and neonatal care.
• In the UK, PMR was 6.6 in 2016.
Further reading
Draper ES, Gallimore ID, Kurinczuk JJ, et al.; MBRRACE-UK Collaboration. MBRRACE-UK Perinatal Mortality Surveillance Report, UK Perinatal Deaths for Births from January to December 2016. Leicester: Infant Mortality and Morbidity Studies, Department of Health Sciences, University of Leicester, 2018.