If you are pregnant and at 17 weeks, your baby is about 4 inches in length (crown-to-rump) and weighs close to 3 ounces. Your baby is forming “brown fat” deposits under his or her skin now. This fat will help your baby to maintain his or her body temperature after birth.
Your little one is drinking an average of 16 ounces of amniotic fluid a day now and also inhaling and exhaling it, in preparation for breathing after birth. Your baby may get hiccups at this point, although you probably won’t be able to feel them quite yet.
The taste buds are developed enough now for your baby to distinguish sweet and bitter and more reflexes are developing, including blinking. Your baby’s movements have become more coordinated and soon you will start to feel him or her exercising muscles.
You, as well as others notice your expanding belly easily now. Your uterus has grown significantly since the early weeks of pregnancy and this needs to be supported by your muscles and ligaments. Round ligaments are attached to each side of the upper uterus and also to the pelvic side wall. These ligaments are stretching to accommodate your enlarging uterus, which may explain the general achiness and pain you may notice in your belly. If you experience this type of discomfort, lying down may help.
Many women begin to experience the first detectable movements of their baby (called quickening) around this time, which can easily be described as one of the most exciting moments of your pregnancy and will undoubtedly be very reassuring. You may be more likely to feel your baby earlier if you are thin or if this is your second pregnancy.