A New Record (IMAGE) Brown University Caption In 2014 US moms gave birth to more twins per 1,000 live births than ever, according to the CDC. Implemented differently than in the past, IVF, a technology partly responsible for the increase, could help the rate come back down. Credit Brown University/CDC Usage Restrictions with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.