Around 30 weeks, the growth of the brain markedly increases. Most systems are well developed, and the fetus can see and hear. A baby may survive if born this early, although the lungs may still be immature.
Review Date 7/3/2020
Updated by: Jason Levy, MD, Northside Radiology Associates, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.