A placenta previa in which the placental edge just reaches the internal os is more commonly known as:

Choice A reason: Normal weight women should gain 11.5 to 16 kg during pregnancy, according to the Institute of Medicine (IOM) guidelines. This is based on the body mass index (BMI) of 18.5 to 24.9 before pregnancy.

Choice B reason: Underweight women should gain 12.5 to 18 kg during pregnancy, according to the IOM guidelines. This is based on the BMI of less than 18.5 before pregnancy. Underweight women are at risk of having low birth weight infants, so they need to gain more weight to support fetal growth and development.

Choice C reason: Adolescents are encouraged to strive for weight gains at the upper end of the recommended scale, according to the IOM guidelines. This is because adolescents are still growing themselves and need extra nutrients and calories to meet their own needs and those of the fetus.

Choice D reason: In twin gestations, the weight gain recommended for a single fetus pregnancy should not be simply doubled. The IOM guidelines suggest that women with twin gestations should gain 16.5 to 24.5 kg if they have a normal weight before pregnancy, 14 to 22.5 kg if they are overweight, and 11 to 19 kg if they are obese.

Choice E reason: Obese women should gain at least 7 to 11.5 kg during pregnancy, according to the IOM guidelines. This is based on the BMI of 30 or more before pregnancy. Obese women are at risk of having complications such as gestational diabetes, preeclampsia, and cesarean delivery, so they need to limit their weight gain to avoid further complications.

Choice A reason: Cheese is a good source of calcium, protein, and vitamin B12, but not folates. Folate is a water-soluble vitamin that is essential for the synthesis of DNA and the prevention of neural tube defects in the fetus.

Choice B reason: Potatoes are a good source of carbohydrates, potassium, and vitamin C, but not folates. Folate is found mainly in plant-based foods, especially dark green vegetables.

Choice C reason: Chicken is a good source of protein, iron, and zinc, but not folates. Folate is more abundant in legumes, nuts, and seeds than in animal products.

Choice D reason: Green leafy vegetables are a good source of folates, as well as vitamin A, vitamin K, and fiber. Folate is also known as folic acid when it is added to fortified foods or supplements. Pregnant women need at least 600 micrograms of folate per day.