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Survival and Major Morbidity of Extremely Preterm Infants: A Population-Based Study
James G Anderson1, Rebecca J Baer2, J Colin Partridge3
1Departments of Pediatrics, james.anderson3@ucsf.edu.
Insights
Extremely preterm infants born at 22-24 weeks gestation face the highest risks of death and major morbidity. These survival rates highlight critical decision-making needs for extremely preterm births.
Area of Science:
- Neonatology
- Perinatal Epidemiology
- Public Health
Background:
- Extremely preterm infants (born 22-28 weeks gestation) have significant mortality and morbidity risks.
- Understanding survival rates and interventions is crucial for improving outcomes in this vulnerable population.
Purpose of the Study:
- To assess mortality and major morbidity rates in extremely preterm infants in California.
- To examine neonatal intervention rates and timing of death across different gestational ages (22-28 weeks).
Main Methods:
- Retrospective cohort study of California live births (2007-2011).
- Included infants with gestational age 22-28 weeks, linked to vital statistics and hospital records.
- Assessed major morbidities using ICD-9-CM codes and survival using procedure codes for resuscitation.
Main Results:
- 6009 infants were included; 1-year survival ranged from 6% (22 weeks) to 94% (28 weeks).
- 73% of deaths occurred within the first week; 80% of infants had major morbidity.
- Resuscitation rates at 22, 23, 24 weeks were 21%, 64%, 93% respectively, with survival rates of 31%, 42%, 64%.
Conclusions:
- Infants born at or before 24 weeks gestation are at the highest risk of death and major morbidity.
- These findings are vital for informing clinical recommendations and decision-making processes for extremely preterm births.
Objectives:
To assess the rates of mortality and major morbidity among extremely preterm infants born in California and to examine the rates of neonatal interventions and timing of death at each gestational age.
Methods:
A retrospective cohort study of all California live births from 2007 through 2011 linked to vital statistics and hospital discharge records, whose best-estimated gestational age at birth was 22 through 28 weeks. Major morbidities were based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Survival beyond the first calendar day of life and procedure codes were used to assess attempted resuscitation after birth.
Results:
A total of 6009 infants born at 22 through 28 weeks' gestation were included. Survival to 1 year for all live births ranged from 6% at 22 weeks to 94% at 28 weeks. Seventy-three percent of deaths occurred within the first week of life. Major morbidity was present in 80% of all infants, and multiple major morbidities were present in 66% of 22- and 23-week infants. Rates of resuscitation at 22, 23, and 24 weeks were 21%, 64%, and 93%, respectively. Survival after resuscitation was 31%, 42%, and 64% among 22-, 23-, and 24-week infants, respectively. Improved survival was associated with increased birth weight, female sex, and cesarean delivery (P < .01) for resuscitated 22-, 23-, and 24-week infants.
Conclusions:
In a population-based study of extreme prematurity, infants ≤24 weeks' gestation are at highest risk of death or major morbidity. These data can help inform recommendations and decision-making for extremely preterm births.
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