Baby boys at higher risk of death and disability due to preterm birth
15 November 2013
Baby boys are at a higher risk of death and disability due to preterm (premature) birth than baby girls, according to new research carried out by almost 50 researchers at 35 institutions and led by the London School of Hygiene & Tropical Medicine.
The forthcoming research and editorial on preterm birth and disability, published in the journal Pediatric Research, are being launched in association with World Prematurity Day. The studies show that boys are 14% more likely to be born preterm than girls. Disabilities that can result from preterm birth range from learning problems and blindness to deafness and motor problems, including cerebral palsy.
Professor Joy Lawn, Director of the School’s Centre for Maternal, Adolescent, Reproductive & Child Health and team leader of the new research, said: “Baby boys have a higher likelihood of infections, jaundice, birth complications, and congenital conditions but the biggest risk for baby boys is due to preterm birth. For two babies born at the same degree of prematurity, a boy will have a higher risk of death and disability compared to a girl. Even in the womb, girls mature more rapidly than boys, which provides an advantage, because the lungs and other organs are more developed.
“One partial explanation for more preterm births among boys is that women pregnant with a boy are more likely to have placental problems, pre-eclampsia, and high blood pressure, all associated with preterm births.”
However, after the first month of life, in some societies where girls receive less nutrition and medical care, the girls are more likely to die than boys, despite this biological survival advantage for girls.
Global health burden of preterm babies
These are just a few of the new and confirmed findings on the death and disability of premature infants, a massive global health problem. Of the 15.1 million babies born too soon every year, some one million die due to prematurity, accounting for one-third of the world’s 2.9 million newborn deaths, a huge impact for families, societies and economies in both high and low-income countries. Newborn conditions, especially premature birth, are responsible for almost 10% of the global burden of disease for all ages and all countries.
In the last three years, some £15 billion (US$25 billion) in new funds have been spent on maternal, newborn and child health, according to a 2013 report by The Partnership for Maternal, Newborn & Child Health (PMNCH). Low- and middle-income countries, as well as private foundations, non-government organisations, and the private sector have raised about 40% of this. However, as highlighted by a recent analyses led by Catherine Pitt, also from The School, less than 1% is specifically directed at premature or newborn care.
Improving prematurity prevention and care is a key part of a wider drive to reduce newborn deaths and improve quality care at the time of birth, when risks are highest for both women and their babies.
UN Secretary General Ban Ki-moon, whose Every Woman Every Child movement has provided major worldwide impetus for women and children, said: “Three quarters of the one million babies who die each year from complications associated with prematurity could have been saved with cost-effective interventions, even without intensive care facilities. World Prematurity Day is an opportunity to mobilise partners to improve the care available to all women and children.”
More than 50 partners including the London School of Hygiene & Tropical Medicine, convened by UNICEF and the World Health Organization (WHO), are developing a major new global plan to improve newborn health. The plan will focus on improving the quality of care for women and children during labor and delivery, as well as the critical few days before and after birth, when risks are highest. The Every Newborn plan will be launched during the World Health Assembly in May 2014.
Key research findings being highlighted to mark World Prematurity Day include:
- Of the 15 million preterm babies born annually, 13 million survived beyond the first month of life, 2.7% of which had moderate or severe impairment
- Of the 185,000 newborns affected by retinopathy of prematurity, 20,000 suffered moderate to severe disabilities
- Most newborn deaths can be prevented without intensive care with low-cost interventions including antenatal corticosteroids, antibiotics, continuous positive airways pressure and Kangaroo Mother Care
- More needs to be done to prevent the exclusion of children with disabilities, which begins for many in the first days of life with their birth going unregistered
- The majority of preterm births are in low-income countries in South Asia and sub-Saharan Africa, where 2.2 million newborns died, and more than 606,000 had some degree of impairment following newborn complications
The studies, funded through the Bill & Melinda Gates Foundation, present the first systematic estimates of disability in preterm babies. Worldwide, of the 15.1 million preterm babies, 13 million survived beyond the first month of life. Of the survivors, 345,000 (2.7%) had moderate or severe impairment and 567,000 (4.4 %) had mild impairment.
Risks for disabilities or impairments are affected by where a preterm baby is born:
- In upper income countries, more than 80% of babies born under 37 weeks survive and thrive. Risk of death and disability is greatest for those born at less than 28 weeks. Infants who survive preterm birth face lifelong physical and intellectual disabilities. Even babies born just a few days early are more likely to be re-hospitalised and have learning and behavioral challenges.
- In middle-income countries, great progress has been made in reducing deaths. For example, Turkey has more than halved preterm and newborn deaths in the last two decades. But, in middle-income countries, the risk of disability for babies born at 28-32 weeks is double that of high-income countries. For these countries, learning from past experiences is essential to improve quality of care.
- In low-income countries, preterm babies are 10 times more likely to die than those in high-income countries. Without basic care, few survive even with severe disabilities. Death is twice as likely as disability in these countries.
Dr Hannah Blencowe, who carried out the preterm data analyses said: “Urgent attention is required for systems to follow up newborns who have had life-threatening conditions and are born too soon and too small – this will help the children, their families and also improve the data."
Preterm babies are vulnerable to eye complications. Of the estimated 185,000 newborns affected by retinopathy of prematurity, an abnormal blood vessel development in the retina of the eye in some premature infants, about 20,000 suffered moderate to severe disabilities, including blindness, and another 12,000 had other visual problems.
Professor Clare Gilbert, Co-Director of the International Centre for Eye Health at London School of Hygiene & Tropical Medicine, and world expert on retinopathy of prematurity, said: “There is a risk of repeating the epidemic of blindness in preterm survivors seen in the US and Europe in the 1940s and 1950s. Much can be done to reduce blindness from retinopathy of prematurity by improving quality of neonatal care, including safer use of oxygen, and by detecting retinopathy early. Preterm infants must be followed up and their eyes must be checked.”
Elizabeth Mason, Director of WHO’s Department of Maternal, Newborn, Child and Adolescent Health, said: “Essential newborn care is especially important for all babies born preterm. This means keeping them warm, clean, initiating breastfeeding, and ensuring that babies who have difficulty breathing get immediate attention. There is a golden minute after birth that counts for every newborn.”
Most newborn deaths can be prevented without intensive care. Low-cost interventions that are very effective, but are not commonly used in the highest burden countries include:
- Antenatal corticosteroids given to mothers in preterm labor. These are injections of dexamethosone, a steroid used to treat asthma, which helps speed up the development of the baby’s lungs. At a cost of about US$1, two shots can help stop premature babies from going into respiratory distress when they are born. More widely used, corticosteroid injections could prevent 400,000 deaths annually.
- Kangaroo Mother Care, a technique where the infant is held skin-to-skin on the mother's chest, keeps the baby warm and facilitates breastfeeding. Keeping preterm babies warm is especially important because tiny bodies lose heat rapidly, making these babies highly vulnerable to illness, infection and death. Kangaroo Mother Care could prevent 450,000 deaths annually.
- Antibiotics, such as amoxicillin, to treat pneumonia, and gentamicin and penicillin to fight serious infections, could save over half a million lives each year.
- Continuous positive airways pressure ventilation system helps preterm babies with breathing difficulties.
Experts believe using an essential package of pregnancy, childbirth, and postnatal care that includes these interventions could save more than three-quarters of preterm babies from death without expensive, high-tech intensive care. Training and support needs to be increased for those delivering babies, from obstetricians and pediatricians to midwives and nurses, especially in low-income countries.
Better access to family planning, particularly for adolescent girls, could save an estimated 230,000 babies, if family planning were scaled up to 60% coverage.
For many children with disabilities, exclusion begins in the first days of life with their birth going unregistered. Lacking official recognition, they are cut off from the social services and legal protections that are crucial to their survival and prospects. Their marginalisation only increases with discrimination.
In The State of the World’s Children 2013: Children with Disabilities, UNICEF urges governments to ratify and implement the Convention on the Rights of Persons with Disabilities and the Convention on the Rights of the Child, to save more newborn lives and to support families to meet the costs of caring for children with disabilities.
Broken down by region, most of the problems were reported in low-income countries in South Asia and sub-Saharan Africa, where 2.2 million newborns died, and more than 606,000 had some degree of impairment following newborn complications.
Of the 11.7 million births in high-income countries, including the United States, Canada, Australia and most of Europe, 40,035 preterm babies died due to birth complications and infections, and another 147,000 were impaired. Major disability is most common for babies born at less than 28 weeks, and especially in those born under 25 weeks.
A country-by country analysis shows that India (3,277,200) and China (1,315,000), because of their size, had the greatest numbers of preterm births, followed by Nigeria (831,100), Pakistan (757,900), Indonesia (748,500), United States (497,600), Bangladesh (435,500), Philippines (343,400), Democratic Republic of the Congo (323,100), Ethiopia (305,900), Brazil (266,500) and Tanzania (210,300).
Rates of preterm births differed from absolute numbers, with Malawi topping the list with a rate of 18.1 per thousand live births, followed by Comoros (16.7), Zimbabwe (16.6), Equatorial Guinea (16.5), Mozambique (16.4), Gabon (16.3), Pakistan (15.8), Indonesia (15.5), and Mauritania (15.4).
These studies, based on more than 1,000 data sources, reveal significant data gaps, especially in most low-income and many middle-income countries. For instance, basic information on the number of preterm births and deaths is missing in areas where many babies are delivered at home. Follow-up information does not exist for much of the world, a crucial deficiency because many disabilities - cerebral palsy and learning difficulties among them -may not be apparent for several years.
The research is being released in association with the third annual World Prematurity Day on Sunday, November 17. In addition to the forthcoming Pediatric Research papers, the journal BMC Reproductive Health is publishing six papers based on Born Too Soon: The Global Action Report on Premature Birth, developed by March of Dimes, Save the Children, PMNCH and WHO, and co-edited by Professor Joy Lawn with more than 50 organisations involved. There is also a comment in The Lancet from national leaders in Brazil, Uganda and the UK discussing how “caring for our preterm babies is a test of how we respond to our most vulnerable citizens.”
On World Prematurity Day, many countries are planning activities, including marches, workshops, posters and other activities designed to raise public awareness. Government organizations, NGOs, foundations, medical and public health institutions, charities and families are organizing these events. Join Celine Dion, Anne Geddes and people from around the world to show your support on Twitter #worldprematurityday and Facebook.
Last year, activities in 64 countries honored preterm babies and their families. They ranged from purple lightings of major buildings like the Empire State Building to stringing tiny baby socks in public places in Europe.