Week 4 of your pregnancy means that you are now entering the embryonic period. This is a time when your baby will officially become an embryo and begin to develop. This is a critical time for your baby and a good time for you to start eating and living as healthily as you possibly can.
Your Baby This Week
Your baby is now around the size of a poppy seed!
During week 4 of your pregnancy, your baby is about 1 millimetre long. That’s about the size of a poppy seed! The fertilised egg that was created at conception has now made its way to your uterus and is attaching to the inner lining where it is becoming an embryo. Once a single cell, your baby is now comprised of hundreds of cells that are dividing and multiplying at a rapid pace. In this fourth week, your baby’s organs are beginning to form and by week ten will be mostly developed.
The amniotic sac, which will house and protect your baby, is now present, as well as the yolk sac which will provide your baby with red blood cells and nutrients until the placenta takes over. The placenta, considered to be an organ, is a vascular structure that attaches to the uterine wall. Your baby is then attached to the placenta by the umbilical cord. Throughout your pregnancy, the placenta will serve as the baby’s source of blood, oxygen, and nutrients. The placenta also receives waste from the baby and processes it through your body for disposal.
At this early stage of your pregnancy, your baby consists of three distinct types of cells; ectoderm, mesoderm, and endoderm. Ectoderm cells will form your baby’s skin, mesoderm cells will become your baby’s skeleton, and the endoderm cells will form the internal organs. Your baby’s spinal cord and brain are also beginning to develop. Blood vessels and arteries have already started taking shape and your baby will soon have its own vascular system.
Your Body This Week
By now, you have probably missed your first menstrual cycle, taken a pregnancy test, and found out the good news. If you have not already started, now is the time to begin taking daily prenatal vitamins to ensure the health of you and your baby. Even if you are a healthy eater, you still need the extra folic acid and iron that prenatal vitamins provide. Folic acid has been shown to reduce the risk of certain birth defects that can develop early in a pregnancy. It’s recommended that pregnant women take prenatal vitamins that contain at least 1mg of folic acid. The extra iron is needed because your body is now producing more blood to accommodate the development of your baby. The more blood, the more iron is needed to keep you from becoming anaemic. Iron also helps with the fatigue that accompanies pregnancy. It’s recommended that during pregnancy, you should be getting at least 27mg of iron each day. That is twice the amount that your body needs when you are not pregnant.
Your symptoms during week 4 will be minimal and may even mimic the usual symptoms of your menstrual cycle; cramping, fatigue, and nausea. The cramping may feel like you are getting your period but is actually caused from the fertilised egg implanting itself in your uterus. Fatigue is the result of the increased blood that your body is now producing and nausea is believed to be caused by the extra hormones that are now produced. You may also notice that your breasts are feeling tender and are extremely sensitive, which is also a very normal symptom that occurs during a woman’s normal menstrual cycle.