The gestation age threshold doesn't really matter across Europe, but a birthweig...

The gestation age threshold doesn't really matter across Europe, but a birthweight threshold does somewhat. [1,2] The US doesn't look as bad for infant mortality when only comparing only births at 28 weeks or later, 2nd to last to Denmark in this [3] comparison of Canada, US and the Nordic countries rather than being almost twice as high as the rest if using 22wks as a threshold. However, my understanding is the US has higher pre-term birth rates which is certainly a confounding factor so the difference might not only be due to birth registration differences.