Twins—smaller at birth, on average, than singletons—start out smaller in pregnancy than was previously known, according to a ...

NIH findings could lead to more efficient monitoring of twin pregnancies.

The National Institutes of Health April 7 released a study that found twins — smaller at birth on average than singletons — ...

Previous studies of twin growth in the womb involved 2D ultrasound scans and had documented decreased twin growth relative to singletons only in the early 3 rd trimester (28 to 40 weeks).