Based on the information provided, it seems that your wife probably suffers from a disorder called Pre-eclampsia. It is a rapidly progressive condition characterized by high blood pressure and the presence of protein in the urine. Swelling especially of face, sudden weight gain, headaches and changes in vision are important symptoms; however, some women with rapidly advancing disease report few symptoms. It is a disorder that occurs only during the second half of pregnancy and the postpartum period, affects both the mother and the unborn baby and is more common in a womans first pregnancy and in women whose mothers or sisters had pre eclampsia. The exact cause of pre eclampsia is unknown though poor blood flow to the vital organs of the body is responsible for most of the signs including the leakage of albumin/protein in the urine and kidney disease. Pre eclampsia can prevent the placenta (which gives air and food to your baby) from getting enough blood. If the placenta doesn't get enough blood, your baby gets less air and food, restricting the growth of the baby as in your wife’s case which would result in low birth weight along with other complications to the baby. Intervention by the doctor is based upon the severity of pre eclampsia, mother and baby’s condition, and the duration/stage of pregnancy. Delivery of the baby is the best way to protect both mother and the baby. But this is not always possible, because it may be too early for the baby to live outside of the uterus resulting in pre-maturity and associated complications. At the current stage of pregnancy, your Obstetrician would advise your wife the steps to manage pre eclampsia until the baby can be delivered. These steps include management of severely elevated blood pressure, restricted physical activity, maintenance of normal salt intake, intravenous magnesium sulfate during labour stage and close monitoring of baby’s well being and growth. There is no role of protein infusion in the current condition.