Babies that require specialist hospital care have either been born prematurely, born full term with a medical condition, or born full term but have had a traumatic birth. Babies born extremely prematurely are often unable to survive on their own without medical intervention because they are not fully developed. They might require breathing support and are more susceptible to infections. They are also more prone to conditions such as cerebral palsy.
Many babies are admitted to neonatal care because they are born before 37 weeks’ gestation of pregnancy. Babies born this early often require specialist medical attention as they can suffer from a variety of problems. There are sub-categories of preterm birth, based on gestational age:
- extremely preterm (<28 weeks)
- very preterm (28 to <32 weeks)
- moderate to late preterm (32 to <37 weeks)
Why does preterm birth happen?
Most preterm births are termed ‘spontaneous premature births’, with no clear cause. Other preterm births are induced from medical necessity for mother or baby (e.g. pre-eclampsia, a condition characterised by high blood pressure and protein in the urine).
There is, however, evidence that the following may be risk factors for premature birth:
- Drinking alcohol
- Substance abuse
- Low or high maternal age
- Previous premature birth
- Multiple birth
- High blood pressure
It is also very common for twins and multiples to be born prematurely. These babies often have a lower birth weight than single babies and will require specialist care.
Incidence of prematurity in the UK
Bliss estimates that around 60,000 babies are born prematurely in the UK every year. This is based on figures from ONS, IDS Scotland and NISRA.
Not all of these babies will need to be cared for in a neonatal unit. A lot of babies born prematurely will be born late preterm, and therefore won’t need specialist hospital care. NDAU estimates that around 40 per cent of babies on a neonatal unit will have been born prematurely (NDAU, 2015, p. 4).
Incidence of prematurity in the rest of the world
Inconsistencies in data collection between different countries mean it is challenging to compare numbers globally. The most comprehensive data available is the Born Too Soon report (WHO, 2012).
According to this report, the countries which have the highest rate of premature birth include Congo and Comoros, both with a rate of 16.7 per cent, Equatorial Guinea with 16.5 per cent, Zimbabwe with 16.6 per cent and Pakistan with 15.8 per cent.
The countries with the lowest rate include Ecuador with 5.1 per cent, Latvia with 5.3 per cent and Samoa, Finland, and Croatia with 5.5 per cent.
According to the same data set, the UK has a rate of 7.8 per cent. The USA has a much higher rate of 12 per cent. A more detailed table of countries is available to see here.
Long term outcomes of premature birth
- Children born at extremely low gestational ages can face a range of health complications as they grow up. The main challenges for children born extremely preterm (<28 weeks) are:
Visual impairment: Retinopathy of Prematurity is a common condition which affects the blood vessels of the retina. It will usually improve on its own, but in severe cases it may need treatment and can potentially leave the baby with permanent damage. It occurs in around 65 per cent of premature babies with a birthweight of less than 1251g (Bliss, 2015b).
- Hearing impairment: Some research has suggested that there may be a link between very low birthweight infants and hearing loss. However, it is not fully understood. A child with hearing loss may be given a hearing aid or a cochlear implant (Sense, 2015).
- Chronic Lung disease (also known as bronchi pulmonary dysplasia): This can occur when a baby is dependent on oxygen for a long period of time. The baby’s lungs will be stiffer than normal and they will have to work harder to get air into their lungs. This usually heals on its own as the child grows, but can have long term effects (Bliss, 2014a).
- Long-term cardiovascular ill-health and respiratory conditions: Research has suggested that infants born prematurely are more likely to suffer from asthma and wheezing disorders (Been et al, 2014), as well as chronic cardiovascular diseases.
- Learning difficulties: There is extensive research to suggest that children born prematurely may suffer from learning difficulties; some studies even go as far to suggest that they will grow up to have generally poorer academic abilities than their full term peers (Basten et al, 2015).
- Cerebral Palsy and other developmental problems: many children born prematurely suffer from cerebral palsy, a neurological condition that affects movement and co-ordination. This is because there may be damage to the baby’s brain. Research has also suggested that in a preterm infant the rate of connectivity in some areas of the brain may be reduced compared to full term babies, and may help to explain why children born prematurely can be more likely to suffer from certain developmental disorders, such as autism (Toulmin et al, 2015).
- Behavioural problems: research has suggested that prematurity and low birth weight is a risk factor for various behavioural disorders, particularly Attention Deficit Hyperactivity Disorder (ADHD) (Mick et al, 2002).
Full term admissions
Around 60 per cent of babies admitted to neonatal care are born full term (NDAU, 2015, p 4). There is a variety of reasons why these babies would need to be cared for on the unit, including, but not exclusively:
- Respiratory problems: these are the commonest cause of serious neonatal illness and death and cover a variety of issues babies may have with their breathing. Common causes include respiratory distress syndrome, pneumonia, chronic lung disease, and tachypnoea (abnormally rapid breathing). Depending on the condition, the problem may be treated using a number of different treatments, including steroids, antibiotics or ventilation.
- Infection: the National Neonatal Research Database has identified that 9.1 per cent of admissions to a neonatal unit were primarily because of infection (NHS England, Infection). These may be contracted in the womb or during birth. There are a number of different types of infection which a full term baby can contract; many of them can be caused by a bacteria known as group B streptococcus, including septicaemia, meningitis and pneumonia.
- Hypoglycaemia: this is where a newborn has low levels of blood glucose in the first 24 hours of life. It can usually be addressed by feeding, or giving the baby a sugar solution. If left untreated, hypoglycaemia can cause brain damage.
- Jaundice: this is a common condition which causes yellowing of the skin and whites of the eyes. It is caused by a build-up of a chemical called bilirubin and is easily treated with phototherapy. This involves placing the baby under a light source or on top of a light blanket.
- Asphyxia/Hypoxic-Ischemic Encephalopathy (HIE): this is where there is a lack of oxygen and/or blood flow getting to the baby during birth. It affects all of the baby’s organs and can lead to severe brain injury. It isn’t always known what causes HIE, but it can be treated by cooling the baby. This limits the extent of brain injury.
How long will a baby spend in neonatal care?
The duration of a baby’s stay in neonatal care varies greatly, and entirely depends on the severity of the condition and the gestation at which they were born. A report by NDAU found that the average length of a stay in England and Wales is eight days (NDAU, 2015, p. 19). However, some of the smallest, sickest babies can spend months in hospital and we know that most of the babies admitted to neonatal care were born sick, but not prematurely, needing only a few days, or even hours, of care.
The table below shows the average length of stay for babies born at different gestations in 2014 in England, Scotland and Wales (NDAU, 2015, p. 19).
It is not uncommon for a baby in neonatal care to be transferred to another hospital. This may be because they need specialist care which the current hospital cannot provide, because they are getting better and can be moved to a hospital closer to home, or because the hospital has more babies than it can safely care for. According to the 2014 annual report from the Royal College of Paediatrics and Child Health, of the 86,264 babies included in their data, there were a total of 12,335 transfers involving 8,245 babies. This means 10 per cent of babies experienced at least one transfer. Of those transfers, 17 per cent were to a unit outside of the first recorded network of care (RCPCH and NDAU, 2015, p. 14).
The following survival rates have been calculated from the number of live births and deaths (under one year old) at each gestation in 2013, as detailed in the ONS gestation-specific infant mortality report (ONS, 2015). The figures below do not include stillbirth.
Basten, et al. (2015). Preterm Birth and Adult Wealth: Mathematics Skills Count. Psychological science, vol. 26, 10: pp. 1608-1619. Retrieved from: http://pss.sagepub.com/content/26/10/1608.full.pdf+html
Been at al. (2014). Preterm Birth and Childhood Wheezing Disorders: A Systematic Review and Meta-Analysis. PLOS Medicine, 11 (1). Retrieved from: http://www.plosmedicine.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pmed.1001596&representation=PDF
Bliss. (2014a). Bliss family handbook. Retrieved from: http://www.bliss.org.uk/information-for-parents
Bliss. (2015b). Screening for retinopathy of prematurity (ROP). Retrieved from: http://www.bliss.org.uk/factsheets
Mick et al. (2002). Impact of Low Birth Weight on Attention-Deficit Hyperactivity Disorder. Developmental and Behavioral Pediatrics, 23 (1). Retrieved from: http://journals.lww.com/jrnldbp/Abstract/2002/02000/Impact_of_Low_Birth_Weight_on_Attention_Deficit.4.aspx.
NDAU. (2015). NDAU 2014 report. Retrieved from: https://www1.imperial.ac.uk/resources/98E6A2BD-03B3-4D5D-89B8-A7DEC031537D/ndau2014reportv1.2.pdf
NHS England. Infection. Retrieved from: https://www.england.nhs.uk/patientsafety/re-act/red-term-ad/infection/
ONS. (2015). Gestation-specific infant mortality in England and Wales, 2013. Retrieved from: http://www.ons.gov.uk/ons/rel/child-health/gestation-specific-infant-mortality-in-england-and-wales/2013/index.html
RCPCH and NDAU. (2014). Annual Report 2013: National Neonatal Audit Programme. Retrieved from: http://www.rcpch.ac.uk/system/files/protected/page/RCPCH_NNAP_Report%202013%20final%20PRINT%20VERSION%20without%20Printer%20Marks.pdf
Sense. (2015). Hearing impairment and prematurity. Retrieved from: https://www.sense.org.uk/content/hearing-impairment-and-prematurity
Toulmin et al. (2015). Specialization and integration of functional thalamocortical connectivity in the human infant. PNAS, 112 (20). Retrieved from: http://www.pnas.org/content/112/20/6485.full.pdf
World Health Organisation. (2012). Born Too Soon: The global action report on preterm birth. Retrieved from: http://www.who.int/pmnch/media/news/2012/201204_borntoosoon-report.pdf