Changes in perinatal care and outcomes in newborns at the limit of viability in Spain: the EPI-SEN Study. 
Advances in perinatal care can influence morbidity and mortality in newborns at the limit of viability.  Knowledge of these changes over time may help improve clinical decision making, optimize resource allocation and increase quality of care.  To evaluate the influence on morbidity and mortality of changes introduced in the perinatal care of preterm infants (22-26 weeks' gestational age, GA) in Spain between two consecutive periods (2002-2006 and 2007-2011).  An analysis of prospectively collected data in a national database network (SEN1500) was performed.  All live newborn infants of 22-26 weeks' GA born in or transferred to referral centers of the SEN1500 network in the first 28 days of life were included.  Perinatal interventions, clinical management, neonatal morbidity, and survival until hospital discharge were retrieved.  A total of 5,470 newborns were included (2,533 and 2,937 in each period, respectively).  The major changes introduced during the second period were as follows: (1) lower proportion of extramural births (11.0 vs. 8.9%, p = 0.01), (2) increase in antenatal steroids (69.5 vs. 80.8%, p < 0.001), (3) delivery by C-section (41.8 vs. 48.3%, p < 0.001) and (4) use of CPAP during resuscitation (7.8 vs. 20.7%, p < 0.001).  Death in the delivery room decreased from 5.1 to 3.2% (p < 0.001).  Survival increased from 49.9 to 57.9% (p < 0.001), and survival without major morbidity increased from 18.1 to 21.2% (p = 0.006).  During the second period, a greater attachment to practices proven to have a beneficial impact on survival and reduction of morbidity in the extremely preterm infant was noted, and survival and survival without major morbidity increased.  A more conservative approach was detected for newborns of 22 weeks' GA.