Your baby is 12-16cm long and weighs 80 to 100 grams. He or she is active for some time and then sleeps again. Hand and foot movements are now becoming more robust and coordinated. The baby sucks the thumb from time to time, and it can be seen during the ultrasound study. Miniature nails are forming. Baby can turn the head. From 16th week of gestation, the fundal height of the uterus is measured (McDonald’s rule), which allows to estimate the fetal growth. A Pinard horn or a “fetoscope” is used to monitor the heart rate of a fetus during pregnancy.
You could feel the baby’s first movements!. These seem like bubbles in the stomach. You may also feel stabbing pain in Your abdominal — it is related with the stretching of uterus muscles. Emotional stress and stress-related headaches may occur more frequently.
Increased hormone progesterone levels can slow down the number of bowel movements (causing gastrointestinal relaxation). Pressure of the growing uterus also affects the normal functioning of the intestine.
Progesterone is a female hormone that is produced in the ovaries (by the corpus luteum), the adrenal glands (near the kidney), and, during pregnancy, in the placenta. A woman’s body produces progesterone 3-60 times more than men. This hormone is the basis for femininity, regulates the menstrual cycle and contributes to the fertilized egg implantation and fetal development in the womb. During pregnancy, progesterone promotes breast growth, causes increased body temperature, and blood vessels and gastrointestinal relaxation. The latter may cause low blood pressure and fainting during pregnancy, and also heartburn and constipation. Progesterone keeps the uterus from contracting during pregnancy prior the childbirth and stimulates childbirth at the end of the pregnancy.