Currently many infants born between 22 and 25 weeks do not survive.
Preterm birth is now a leading cause of perinatal mortality (infant death), neonatal morbidity (short term preterm complications) and paediatric illness in children under 5, second only to pneumonia (1).
Preterm infant research has come a long way. Compared to 60 years ago infants born less than 32 weeks had little hope of survival. Now, given decades of research and refinement, infant survival has improved to the current level of 25 weeks, (2).
The same cannot be said for the tens of thousands of infants born at the border of viability. Internationally, agreed orthodoxy recommends that at 22 weeks gestation there is no hope of survival. With a few exceptions, most hospitals will not treat infants born less than 23 weeks. For doctors, delivery between these two gestational age limits (strictly speaking, 23 to 24 weeks 6 days), is the most challenging (3).
The pie chart shows the high mortality and morbidity data from a large population based study in 1995, of infants born in the United Kingdom between 22 to 25 weeks. The pie chart shows pooled data from infants born between 22 to 25 weeks, with survivors experiencing significant morbidity in the first six years of life.
In 2006 there was an increase in survival. In the United Kingdom this was an increase of 30% with an overall survival of 12%, up from 40% to 52%.
Improvements in survival were most evident in infants born between 24 and 25 weeks. Unfortunately the improvement in the number of babies surviving has not translated into a reduction in morbidity. For example, there has been no change in the number of babies surviving with major short term complications in 2006. For example, brain haemorrhage (15% versus 13%), chronic lung disease (75% versus 74%), (4-6)
In the United States of America data for 9,575 extremely preterm and very preterm infants was collected between 2003 and 2007. Within the first 12 hours after delivery, 1060 infants did not survive. Most deaths occurred for infants born at 22 (85%) and 23 (43%). These infants had the greatest risk of morbidity including, 93% had respiratory distress syndrome, 16% had severe brain hemorrhage and 36% had late stage sepsis (wide spread complication from infection, leading to organ failure). More than a half of the infants had damage to their eyes (7, 8).
Rates of extreme preterm birth are increasing
Studies in wealthy countries including Denmark and Australia have shown a rise in preterm birth. For example, in Australia preterm birth has increased 10-12% of all births and has resulted in two thirds of all deaths at birth. The rate of extreme preterm birth increased by 9%. The reasons for this increase are elusive and are not exclusive to mothers with traditional risk factors for preterm delivery, (9, 10).
Babies born less than 25 weeks do not do well because their lungs and hearts are too immature to receive benefit from current methods that are effective for infants born at maturity. It is noteworthy that the vast majority of these infants would be delivered healthy if they could remain in the womb.
Let Them Grow Organisation is dedicated to raising funds to find a new solution for these babies, born at the border of viability.
1. Liu L. Global, regional, and national causes of child mortality in 2000-13, with projections to inform post-2015 priorities: an updated systematic analysis. Lancet. 2014; S0140-6736 (14): 61698-6. 2. http://www.who.int/topics/preterm_birth/en/ 3. Royal College of Obstetricians and Gynaecologists. Perinatal Management of Pregnant Women at the Threshold of Infant Viability (The Obstetric Perspective). Scientific Impact Paper No. 41 2014. 4. Costeloe KL, et. al. Short term outcomes after extreme preterm birth in England: comparison of two birth cohorts in 1995 and 2006 (the EPICure studies). BMJ 2012;345:e7976. 5. http://www.nhs.uk/news/2012/12December/Pages/Premature-birth-survival-rates-on-the-rise.aspx 6. http://www.telegraph.co.uk/health/healthnews/9722109/No-change-in-survival-of-pre-24-week-babies-BMJ.html 7. Stoll, B.J. et. al. Neonatal Outcomes of Extremely Preterm Infants from the NICHD Neonatal Research Network. Pediatrics 2010;126:443–456. 8. http://www.nichd.nih.gov/about/org/der/branches/ppb/programs/epbo/pages/datashow.aspx 9. Tracy SK. Brit J Obstet Gynaecol. 2007. 10. Sarka Lisonkova. The effect of maternal age on adverse birth outcomes: Does parity matter? J Obstet Gynaecol Can 2010;32(6):541–548