Week 18 and your baby’s movements are starting to be much more noticeable now. There are also some miraculous changes taking place in your baby’s central nervous system. As for you, this is an exciting time as you feel your baby’s movements more and more each day. Your body is also experiencing some changes that will affect your day-to-day activities.
Your Baby this Week
Your sweetie is now around the size of a sweet potato, or about 14cm (5.5 inches), weighing in around 190 grammes (nearly 7oz).
Your baby’s activity level is increasing every day and he is now constantly flexing all arm and leg muscles, neck muscles, facial muscles, and even curling up the toes and fingers. If you have not yet felt your baby’s movements, you soon will. If you have already started feeling your baby’s movements, from this point forward the intensity will increase and you will feel new and different sensations each day.
At 18 weeks into your pregnancy, your baby’s skin is still transparent. Your baby’s ears, which have now moved to their final position on the side of the head, are now beginning to stick out and take on their proper shape. Week 18 also means that if you're baby is female, her uterus and fallopian tubes are formed and in place, and if your baby is a male, the genitals are now noticeable on ultrasound.
A milestone in your baby’s development at week 18 is the beginning of the process known as myelination, which is the formation of the protective cover of myelin around the nerves. This is an important development in your baby’s central nervous system. The myelin serves to insulate the nerves of the brain and spinal cord to allow transmission of impulses along nerve cells. Without this protective layer of protein and fatty substances, diseases like multiple sclerosis can take over. The formation of myelin continues throughout your pregnancy and well into the first year of life.
Your Body this Week
Week 18 of your pregnancy may find you hungrier than you have been in the past several weeks. There are several reasons for this, but the main reason is that you are starting to feel better. Your morning sickness is subsiding and may even be gone completely. You have much more energy now and are being more active, and your baby is growing and requiring more nutrients from your body. It’s critical that you make wise decisions when it comes to meal time. Choose foods that are high in nutrients and good for you. Leave the fried foods alone and try to avoid sweets. These are just empty calories and do nothing good for you or your baby. Naturally, that is easier said than done when you are craving an ice cream sundae with hot fudge and whipped cream! You don’t have to totally ignore your cravings - just make sure that you do not overindulge.
Your cardiovascular system is also experiencing some changes now. Sometime during the second trimester, your blood pressure could be lower than it normally is. This is a normal symptom and nothing to be concerned with, but you do need to recognise the feeling. You may feel dizzy if you stand up too fast or get out of bed too fast. So, just slow down and everything will be fine.
Also, when you lay down, it’s now best that you lie on your side instead of lying flat on your back. This is because your growing uterus can compress one of your major veins when lying flat on your back. The danger is that the blood flow to your heart can be decreased. So, try different positions and use pillows under your hip or to prop up your upper leg when you lay on your side.