Table 2

Comparison of survival rates of extremely preterm infants with a gestational age between 22 and 25 completed weeks in Switzerland, the UK, Finland, the USA and Sweden (all are population-based, multicentre studies including inborns and outborns)

SwitzerlandUK TrentFinlandUSA (NICHD)Sweden
16Current study2019542
ReferenceOverallCTC rangeOverallCTC range
Time period2000 to 20042005 to 20091994 to 19992000 to 20051996 to 19971999 to 20001998 to 20032003 to 20072004 to 2007
Total population
 Live births, N51655168266915216044464160707
 Survivors, N180192174236577522672077497
 Survivors, %35%16–53%35%20–53%26%35%38%47%51%50%70%
22 weeks
 Live births, N185481692119NA42151
 Survivors, N000010NA255
 Survivors, %0%0%0%0%0%0%5%0%5%6%10%
23 weeks
 Live births, N821011481313629NA871101
 Survivors, N44151247NA22653
 Survivors, %5%0–20%4%0–27%10%9%11%24%26%26%52%
24 weeks
 Live births, N1581791982274453NA1370144
 Survivors, N475540821825NA74896
 Survivors, %30%0–53%31%0–73%20%36%41%47%56%55%67%
25 weeks
 Live births, N2582172552425159NA1498205
 Survivors, N1291331191423443NA1078167
 Survivors, %50%38–74%61%38–82%47%59%67%73%75%72%81%
  • CTC, centre-to-centre; NICHD, National Institute of Child Health and Human Development; NA, not available.