What do we mean by newborn deaths and stillbirths?

In this step we’ll outline and describe some of the terminology used throughout this week and this is important as there are myths and misunderstandings

Defining newborns and stillbirths

A baby in its first 28 days of life is referred to as a neonate. When a baby dies during the first 27 completed days after birth, it is referred to as a neonatal death. We also use the simpler term newborn but this does not have a specific epidemiological definition.

WHO uses the term stillbirth for a baby born with no signs of life at or after 28 weeks’ gestation. This definition is used to compare stillbirth rates across countries. The definition is taken from the International Classification of Diseases (ICD-10)¹ which states that all early and late fetal deaths should be recorded and provides thresholds to classify a stillbirth as a late fetal death (more than 1000g or after 28 weeks), a early fetal death (more than 500g or between 22 to 28 weeks), or a miscarriage (before 22 weeks). Some high income countries have set their own thresholds such as 20 weeks or 23 weeks, but 22 weeks and 28 weeks should be used for multi-country comparisons. The major challenge is not the definition, but barriers to collecting data such as stigma and lack of accountability to improve and use and data.

Figure 1 shows the timeline for pregnancies, including definitions of the type of death by the stage at which they occur.

Figure 1. Defining stillbirths, neonatal deaths and associated pregnancy outcomes. Lawn et al (2011).²

Misclassification

If a baby is born alive and they show any sign of life (eg heart rate), they should be classed as a neonatal death, given a death certificate and included in national data systems. However this can be more challenging in practice, especially in settings without basic newborn resuscitation. It’s possible for a baby’s breathing or heart beat to be undetected, and the baby misclassified as stillborn.

Preterm birth, small gestational age and low birthweight

The highest risks of death in utero, in the neonatal period, and throughout infancy and early childhood, are for small babies. Being born small is either due to being born preterm (‘Born Too Soon’), being born small for gestational age (SGA; ‘Born Too Small’) or a combination of the two.

Preterm birth is defined as before 37 completed weeks (see Figure 1). This is simplistic, and there are steep increases in risk of death at lower gestational ages and some up to 39 weeks so this cut-off may be debated.

Small for gestational age (SGA), defined as below the 10th centile for sex-specific, gestation-specific standards, depends on the standard used. Estimates were previously based on a US growth standard, but an international standard has now been provided by the InterGrowth study.³

Traditionally, low birthweight (<2500g) (LBW) has been used as a marker of small babies at highest risk of mortality and morbidity during the neonatal period and infancy, as well as of long-term developmental and physical health consequences, including effects on growth, insulin resistance and cardiovascular health. With around 20 million (15%) of all newborns worldwide born with a low birthweight each year, this group represents a substantial burden. The <2500g LBW cut-off is also simplistic due to risk being aligned to birth size and gestational age especially. More detailed studies are critical for understanding and reducing the burden. Unfortunately, in the highest burden settings, babies may not be weighed at birth, and fewer have accurate gestational age dating to delineate preterm and SGA. Whilst considerable progress has recently been made for estimating the burden of preterm and SGA, much remains to be done to improve the input data.

Stillbirths in your country

What definition for stillbirth is used in your country? Are the data publicly available or hard to find? How would you describe attention for stillbirths in your country?