To coincide with World Prematurity Day — commemorated on Monday, November 17 — researchers have released a new report revealing that, for the first time ever, preterm birth is now the leading cause of death worldwide among young children.
The research team, led by Dr. Robert Black of the Johns Hopkins Bloomberg School of Public Health in Baltimore, MD, published their findings in The Lancet.
According to the World Health Organization (WHO), the global mortality rate among children under the age of 5 years has dropped from 76 deaths per 1,000 live births in 2000 to 46 deaths per 1,000 live births last year, representing an annual reduction of 3.9 percent. During the same period, however, mortality rates from preterm births only reduced by 2 percent.
In this latest study, Dr. Black and his team estimated that there were around 6.3 million deaths among children under the age of 5 last year. Almost 1.1 million of these deaths were a result of complications related to preterm birth, making it the leading cause of death among young children.
Specifically, the team found that direct complications from preterm births accounted for 965,000 deaths during the first 28 days of life, with an additional 125,000 deaths between the ages of one month and five years.
Geographical variation in preterm birth complications
India was the country with the highest number of deaths from preterm birth complications — 361,600 — followed by Nigeria (361,600), Nigeria (98,300), Pakistan (75,000), Democratic Republic of the Congo (40,600), China (37,200), Bangladesh (26,100), Indonesia (25,800), Ethiopia (24,400), Angola (15,900) and Kenya (13,300).
The authors point out that some of the highest rates of preterm deaths are in West Africa — particularly in the countries currently being decimated by Ebola, where the risk will now be even higher given the challenges faced in those countries, notably Sierra Leone and Liberia.
Meanwhile, Macedonia ranked as the country with the highest percentage of deaths from preterm birth complications among under-5s, followed by: Slovenia, 47.5 percent; Denmark, 43.0 percent; Serbia, 39.8 percent; the United Kingdom, 38.7 percent; Hungary, 37.4 percent; Slovakia, 34.9 percent; Poland, 34.8 percent; Republic of Korea and Switzerland, 32.7 percent. All of these exceed the global average of 17.4 percent of under-five deaths, partly because of success in reducing infectious diseases, the authors note.
Prematurity remains a major problem in the U.S.
The preterm birth rate in the U.S. declined between 2006 and 2013. The March of Dimes estimates that 231,000 fewer babies were been born prematurely during this time, saving about $11.9 billion in health care costs.
However, the U.S. still has one of the worst preterm birth rates of any high-resource country. In 2013, 11.4 percent of babies in the U.S. were born preterm, according to the National Center for Health Statistics. Further analysis reveals some of the reasons: Nearly 10 percent of single births are premature, while 57 percent of twins and more than 90 percent of triplets are born prematurely, and 46 percent of deliveries by C-section are premature.
Race also makes a difference in the U.S., with premature delivery rates of 16.3 percent among black women, 13 percent among American Indian, 11.3 percent among Hispanic, and about 10 percent for Caucasian and Asian/Pacific Islanders.
The U.S., with 28.1 percent of its under-five deaths resulting from preterm birth complications ranks among the worst of all developed nations on this indicator, as well, followed by Germany and Canada (both at 29.1 percent), Denmark (43.0 percent), United Kingdom (38.7 percent), and Switzerland (32.7 percent),.
Findings ‘mark a turning of the tide’
In addition to preterm birth, the researchers found that pneumonia was a major cause of death among children under 5 years, killing 935,000 last year. Childbirth complications were also responsible for 720,000 deaths in under-5s, of which 662,000 occurred within the first 28 days of life – the majority on the first day – and 58,000 occurred after this point.
Commenting on the new report, co-author Dr. Joy Lawn of the London School of Hygiene and Tropical Medicine said the team’s findings “mark a turning of the tide, a transition from infections to neonatal conditions, especially those related to premature births.”
“[T]his will require entirely different medical and public health approaches,” she added. “The success we’ve seen in the ongoing fight against infectious diseases demonstrates that we can also be successful if we invest in prevention and care for preterm birth.”
The researchers estimate that if global death rates among children under the age of 5 continue to follow their current trends, then around 4.4 million will be dying in the year 2030. What’s more, the team estimates that 60 percent of deaths among children under 5 will occur in sub-Saharan Africa by 2030. Last year, the region accounted for 50 percent of these deaths.
“Our projection results provide concrete examples of how the distribution of child causes of deaths could look in 15-20 years to inform priority setting in the post-2015 era,” the authors write.
“More evidence is needed about shifts in timing, causes and places of under-5 deaths to inform child survival agendas by and beyond 2015, to end preventable child deaths in a generation and to count and account for every newborn and every child.”
$250 million funding received to tackle preterm birth
Precisely what events trigger the start of labor at full-term, let alone preterm labor, remain a mystery. More than half of preterm births occur spontaneously. Since preterm birth is now the global leading cause of death in children under 5, four new research projects – receiving a total of $250 million in funding – are now underway to better understand the underlying causes of preterm births and find ways to prevent or delay them.
1. The Global Coalition to Advance Preterm Birth Research (GCAPR) is a new partnership initiated by the National Institute of Child Health and Human Development (NICHD), the March of Dimes, the Bill & Melinda Gates Foundation, and the Global Alliance to Prevent Prematurity and Stillbirth (GAPPS). Some 16 institutions are now members of the coalition. GCAPR will advance needed research into the field of preterm birth, a blueprint of which was detailed in The Lancet Global Health in December 2013.
2. The March of Dimes has launched a $75 million Campaign to End Premature Birth, a “medical Manhattan Project” to create a specialized network of five research centers conducting team-based research to discover the unknown causes of prematurity. Two of these research programs are well underway. The remaining three will be named by the end of 2014.
“The March of Dimes initiative is looking at the whole spectrum of prematurity,” says Joe Leigh Simpson, M.D., senior vice president for research and global programs at the March of Dimes. “Some 200 scientists from 20 disciplines already are involved in this research effort and those numbers are expected to double by next year.”
3. The University of California at San Francisco’s (UCSF) Preterm Birth Initiative (PTBi) has launched a 10-year global initiative to slow the epidemic of preterm births and improve the health of preterm babies. PTBi is currently in a planning phase to determine where UCSF and its partners can have the greatest impact. The Bill & Melinda Gates Foundation and Marc and Lynne Benioff are co-funding this $100 million initiative.
4. The last research effort led by the Global Alliance to Prevent Prematurity and Stillbirth (GAPPS), a program started by Seattle Children’s Hospital, is focusing its research on discovering the causes and mechanisms of prematurity, work that may lead to interventions to prevent it. Seven research projects are underway with more in planning stages. The work has $20 million in funding from the Bill & Melinda Gates Foundation and a $1.3 million USAID grant.
“To be successful, this has to be a team effort,” says Dr. Larry Rand, director of perinatal services as the University of California-San Francisco and co-director of the university’s Preterm Birth Initiative. “Effective collaboration will accelerate discovery, increase access to interventions that work and optimize the project’s impact on rates of early preterm birth and mortality.”
Multi-disciplinary research endeavors
Prematurity is complex. Thus, research groups are from 20 diverse fields. Besides obstetrics/gynecology, neonatology, genetics, immunology and infectious diseases, the trans-disciplinary initiatives include experts in engineering, statistics, physics, biochemistry and mathematics.
One group is working to identify a pacemaker in the uterus that initiates labor while another seeks to discover the source of the electric signals that initiate labor and discover whether the process is triggered by mother or fetus. Another group is focused on identifying biomarkers, proteins and molecules in the circulations of both mother and fetus, gene-environment interaction and the maternal microbiome (the total collective of genomes of microorganisms in the mother).
Meanwhile, other researchers are investigating why Somali women living in the U.S. have very low rates of premature births, while most black women in the U.S. have very high rates of premature birth. Researchers are also studying how poverty, nutrition, pollution, stress and other compounding factors affect preterm birth.
“This unprecedented collaborative effort will yield results in three to five years,” adds Dr. Simpson. “I expect the net effect to be greater than the sum of the parts, to be the product of collaboration among the centers.”