Neonatal death rate continues to fall in England, Wales, and Northern Ireland

The number of neonatal and perinatal deaths has decreased since 2000, particularly deaths in babies from twin pregnancies, but there has been no reduction in the stillbirth rate, according to figures for England, Wales, and Northern Ireland published this week.

The neonatal mortality rate (deaths in babies in the four weeks after birth) was 3.4 per 1000 total births in the newly reported figures for 2006, decreasing slightly from 3.5 per 1000 total births in 2005. It continues the downward trend in neonatal deaths over the past few years, from 3.9 per 1000 live births in 2000 (P<0.001).

The commonest cause of neonatal death in the latest figures was immaturity (47%), followed by lethal or severe congenital anomalies (23%) and infection (10%).

Further data reported by the Confidential Enquiry into Maternal and Child Health in its report, Perinatal Mortality 2006, showed that the perinatal mortality rate (stillbirths and deaths in the first week after birth) was also continuing to decrease, falling from 8.2 to 7.9 per 1000 total births between 2005 and 2006.

In contrast, the stillbirth rate has not decreased, with a similar rate in 2006, at 5.3 per 1000 total births, as in 2000 (5.4 per 1000). The major causes of stillbirths in 2006 were severe or lethal congenital abnormalities (16%), antepartum haemorrhage (9%), and intrapartum causes (8%).

More than a third of unexplained stillbirths (40%) had a birth weight below the 10th centile for gestation, and a quarter (26%) were below the 3rd centile. The report concluded: “This suggests that being small for gestational age may be an important factor in unexplained stillbirths.”

Maternal age, social deprivation, and ethnic origin were important factors for perinatal mortality. Mothers aged under 20 or over 40 had the highest rates of stillbirth (5.6 and 8.1 per 1000 total births, respectively). Of the women who had a stillbirth and a recorded body mass index, 26% were obese (BMI >30 kg/m²); for neonatal deaths, 22% of mothers were obese. Stillbirths and neonatal death rates for mothers living in the most deprived areas were 1.7 times the rates for those living in the least deprived areas.

Professor Sabaratnam Arulkumaran, president of the Royal College of Obstetricians and Gynaecologists, said: “The death of a baby is a tragic occasion for all involved—parents, relatives, and equally for healthcare professionals. The RCOG supports good research that examines why these deaths occur and will work with others to reduce the perinatal mortality rate. We would like to see increased investment in midwifery and senior consultant staffing to help improve outcomes for mothers and their babies.”

In twin pregnancies, rates of stillbirth and perinatal and neonatal mortality decreased significantly, with the stillbirth rate declining from 17.1 per 1000 total births in 2000 to 12.5 per 1000 in 2006 (P<0.001). The perinatal death rate decreased from 35.3 to 27.2 per 1000 total births (P<0.001), and the neonatal death rate fell from 22.3 to 19.3 per 1000 total births in 2006 (P=0.02). In contrast, there has been no reduction in higher order births (multiparity greater than two).

Mortality rates varied markedly between different NHS trusts and neonatal networks, even after adjustment for babies born at less than 22 weeks’ gestation and for babies with birth weight below 500 g. However, the report noted, “These differences should not be interpreted as direct indicators of the quality of care as it is not yet possible to adjust for case mix or the sociodemographic characteristics of the population.”

The report’s authors were concerned that post-mortem examinations were carried out in fewer babies who died (38% in 2006) than in the past (48% in 2000). They recommended: “Concerted efforts should be made to try to re-establish perinatal pathology centres.”