One of the most common worries for pregnant women is weight gain. This can easily be controlled with a healthy diet and exercise. Nourishing your baby usually requires that you gain weight.
In most cases, the recommended weight gain is 25 to 35 pounds over the course of the pregnancy. To accommodate the baby’s weight, the placenta, the amniotic fluid, increased blood volume, and an enlarged uterus and breasts will register a few extra pounds on the weighing scale.
A woman usually gains 2 to 5 pounds during the first trimester, 13 pounds during the second trimester, and 11 pounds during the last trimester. If you were overweight or underweight before pregnancy, your health care provider may have different recommendations for weight gain.
You’re not the only one growing in size! From this week until week 20, your baby will be growing rapidly in size from about 1.7 to 2.4 inches (44 to 60 mm) and 0.3 ounces (8 grams) to about 5.5 to 6.3 inches (14 to 16 centimeters) and 9 ounces (260 grams). To accommodate all this growth, the blood vessels in the placenta are increasing both in size and in number to provide the baby with more nutrients.
Your baby now weighs about 8 grams, and the head of your baby seems to take up 1/2 of the baby’s size at the moment. Your baby’s irises will start to develop and the finger nails are appearing.
Your baby’s reproductive organs develop rapidly right now. By the end of this week, your baby’s external genitalia are recognizable.
Revision date: July 9, 2011
Last revised: by Janet A. Staessen, MD, PhD