There is an article from the CDC on this titled "Behind International Rankings of Infant Mortality: How the United States Compares with Europe". They show the different reporting requirements, and the US is indeed one of the countries with the strictest reporting requirements. But 14 out of 19 European Countries have the same reporting requirements as well.
The authors then compare only births after 22 weeks of gestation, which eliminates the differences in reporting between countries. The graph then looks like this:
This is a lower rate than the uncorrected one, but still significantly higher than most European Countries.
The authors also explicitly state that the reporting differences are unlikely to be the cause of the low international ranking of the US:
In 2005, the United States ranked 30th in the world in infant mortality, behind most European countries, Canada, Australia, New Zealand, Hong Kong, Singapore, Japan, and Israel. There are some differences among countries in the reporting of very small infants who may die soon after birth. However, it appears unlikely that differences in reporting are the primary explanation for the United States’ relatively low international ranking.
The study further notes that:
The main cause of the United States’ high infant mortality rate when compared with Europe is the very high percentage of preterm births in the United States