Your Baby's Development Your baby's brain continues to develop, and tiny fingernails and toenails start to form. Vocal cords are formed this week, the last week of your first trimester. Your baby's kidneys are functioning! After swallowing amniotic fluid, your baby will now be able to pass it out of the body as urine (pee). And the intestines will make their way into the abdomen because there is room for them now. Your Body Has anyone told you that you have that "pregnancy glow"? It's not just from the joy you may feel because you're having a baby — there's a physical reason for smoother, more radiant skin during pregnancy. Increased blood volume and pregnancy hormones work together to give you that glow. The greater blood volume brings more blood to the blood vessels and the hormones increase oil gland secretion, making skin look flushed, plumper, and smoother. Sometimes, though, the increased oil gland secretion can cause temporary acne. PREGNANCY CALENDAR: A week-by-week guide Previous Next 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Trimester 1 Trimester 2 Trimester 3 Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.