As per a government report the main reason for the increased infant mortality rate in the U.S. is the number of premature births due to the poor care of low-income pregnant women.
 
As many as 1 out of every 8 births in the U.S. is premature. This number is much lesser in Europe which can be seen in the example of premature births in Ireland and Finland which is 1 in 18 babies.
 
Experts attributed the preterm babies to poor access to prenatal care, maternal obesity and smoking, too-early cesarean sections, induced labor and fertility treatments.
 
The lead author of the new report, Marian MacDorman of the U.S. Centers for Disease Control and Prevention said that premature babies born before 37 weeks tend to be more fragile and have under-developed lungs.
 
U.S. is ranked 30th in the world in infant mortality rate and the main cause is premature births. It has ranked poorly in this field among industrialized nations.
 
MacDorman says that no clear reason can be pin-pointed for the increased number of preterm births in the U.S. but teens, older mothers and smokers all have higher preterm rates.
 
Another possible reason could be that in some countries where the infant deaths are dropping, births after less than 22 weeks are excluded. Some other countries also have limits on birth registration requirements and very small babies who die soon after birth are excluded in some data.
 
However, the U.S. infant mortality rate was high for full-term babies as well.