Your baby now weighs nearly 875 grams (1.93 pounds) and measures just over 37 cm (14.6 inches) from head to toe. Their eyes can open and close, and they sleep and wake at regular intervals. They may suck on a finger or thumb. Their sense of sight is functioning. Some experts believe that babies begin dreaming around this week. Blood vessels are forming throughout both lungs. At their first breath of air, their lungs will absorb oxygen and circulate the oxygenated blood throughout their body. The baby is also producing surfactant, the substance that will allow them to breathe properly after birth. Your baby is gaining weight rapidly. The baby's crown-to-rump length is 25 cm (9.8 inches), and they weigh between 1000-1100 grams (2.2-2.4 pounds). They start to recognize your voice in the third trimester. If the baby is a boy, his testes are descending.