How does my baby grow at 4 weeks?

Congratulations! The bundle of cells nestled in your womb is now an embryo! It’s about the size of a poppy seed. The inner cells will start forming into layers, first two, then three. The inner layer will become your baby’s breathing and digestive systems, which include the lungs, gut, stomach, and bladder. The middle layer will develop into the heart, muscles, blood vessels, and bones. Finally, the outer layer will become the nervous system, eye lenses, skin, tooth enamel, nails, and the brain.

The amniotic sac protects the embryo because it is filled with cushioning fluid. The embryo gets all the nourishment it needs via a tiny yolk sac. The placenta develops later and provides your baby with oxygen and nutrients.

What are the pregnancy symptoms at 4 weeks?

At four weeks, you might start noticing some changes in your body. Tender breasts or tingling nipples can be an early sign of pregnancy. Light spotting or bleeding might also appear, either now or when you usually get your period. This is known as breakthrough bleeding and can be triggered by the hormones that regulate your menstrual cycle. This is usually nothing to worry about.

What else do I need to know about being 4 weeks pregnant?

If you know you are pregnant, you should start taking daily folic acid supplements. Folic acid helps protect your baby against neural tube defects such as spina bifida. A daily supplement should contain 400mg.

To help support your pregnancy, also consider taking a 10g vitamin D supplement. This helps your baby grow strong teeth and bones.

If you know you’re pregnant and have a regular menstrual cycle, you can use a due date calculator. After all, it’s important to know when your baby will be born!

What Does My Pregnancy Look Like at Four Weeks?

What does my pregnancy look like at 4 weeks?