By week five of your pregnancy, you’re already one month into your first trimester. You’ve only just started the embryonic period of development, which is a critical stage of growth, so remaining healthy is paramount during this period.
By week five, your baby is around the size of a sesame seed and resembles a tadpole. Implantation may fall into week four or week five—the timing of these events can vary slightly–but by week five, implantation should have taken place, marking the beginning of the embryonic stage.
Following implantation, the cells continue to quickly grow and divide, as they have been, but now they begin to perform specific functions; this is called differentiation. Another process, gastrulation, creates three distinct layers within the embryo:
- The endoderm: the innermost layer that will eventually develop into your baby’s pancreas, thyroid gland, gastrointestinal tract lining, and lungs.
- The mesoderm: the middle layer that will grow into sex organs, skeleton, muscles, connective tissues, heart, and circulatory system.
- The ectoderm: the outer layer, which develops into the nervous system, skin, hair, nails, eyes, and teeth.
Differentiation takes place over several weeks, as it is this process that will create all of the different body parts and organs. This is why the embryonic stage is so critical to fetal health—it is essentially building your baby. At week five, blood cells, nerve cells, kidney cells, gastrointestinal tract, brain, spinal cord, and heart all begin to develop, along with the baby’s external features.
Your baby’s nourishment and blood supply are handled by the amniotic sac, the placenta, and the umbilical cord, all of which are still developing.
Week 5 Ultrasound
Your baby is still extraordinarily small, measuring only 3 millimetres long, but this is usually the earliest week in which you can see your baby’s heartbeat. You’ll be able to see your yolk sac and gestational sac; the former is the tiny white dot in the larger surrounding black area, which is the gestational sac. You will also be able to identify fetal poles. Having an ultrasound at five weeks can give you an early warning on if you are having multiple babies, if there are any abnormalities, and ensure normal growth and development.
Changes in You
Your uterus begins to enlarge and you may start noticing the effects of the standard pregnancy symptoms. Morning sickness is to be expected, though it often does not start until week six, if you find that you are constantly throwing up and are unable to keep anything down, see a doctor to check for hyperemesis gravidarum, which is basically extreme morning sickness, but it is easily treated. In addition to frequent urination, cramping, nausea, and the other side effects that have been discussed in the articles for the previous weeks, you may also now start feeling lightheaded. This is because your blood pressure drops during pregnancy, causing you to feel dizzy or even faint. Other symptoms that may start to appear include constipation, mood swings, and an increased amount of vaginal discharge.
What You Should Be Doing
By week five, you should make your first prenatal appointment. Keeping up with your chosen health professional and taking their advice is the best way to ensure a healthy pregnancy. Be sure to maintain your nutrient levels, especially your folic acid, vitamin D, and calcium. Calcium is particularly important for you because if there is not enough extra calcium in your body for the baby, your body will start to draw it from your teeth and bones.
You should also be avoiding the following:
- Cat litter, so that you do not have to worry about catching toxoplasmosis.
- Raw eggs and any foods that include them
- Raw/undercooked shellfish, meats, and fish.
- Unpasteurized milk, juices, and cheeses (Brie, feta, Camembert, etc.)
- Potentially mercury-rich foods, such as marlin, swordfish, and shark.
The End of Week 5
As the first week of the embryonic stage comes to a close, your baby will continue to develop its various parts and organs, as well as external features, and, if you are like most women, you will begin to experience the bulk of the unpleasantness that pregnancy brings with it if you have not felt them already.