According to Institute of Medicine, teenage pregnancy recommendations do not differ from adult pregnancy recommendations. Adolescents during pregnancy should gain 11-40 lbs, depending on their pre-pregnancy body mass index (BMI). BMI is an index for adults, and it will misclassify some teenagers as underweight. Still, a pregnant teenager needs to not only support the growth of the baby, but also of themselves. That's why a more prominent weight gain might be appropriate.
Read more