Study finds twins develop slower in early pregnancy than previously believed 

The National Institutes of Health April 7 released a study that found twins — smaller at birth on average than singletons — develop slower in early pregnancy than what was previously known. The ultrasound study found that twins have less fat tissue and muscle mass than singletons beginning at 15 weeks. Scientists believe the smaller size could be a way of adapting to accommodate more resources for two fetuses later in pregnancy. The NIH said confirmation of the findings in additional research could help guide physicians in monitoring and managing twin pregnancies.