A: At two months of age, healthy babies should be growing and gaining weight fairly predictably. From birth to six months, most babies gain about 5 to 7 ounces each week. Like many babies, your newborn might have lost a little weight in the first week of her life, but in the second week, she should have begun gaining weight. Most pediatricians like to see newborns return to their birth weight by the time they're ten to 14 days old.
If your daughter isn't following this pattern, and if she's throwing up at 15 minute intervals, it's very important to take her in for a checkup and evaluation by her pediatrician—today. It sounds as if she's having trouble tolerating several types of formula, and the doctor can help you determine which formula is best for her. The doctor can also make sure that your daughter doesn't have a condition that might be interfering with her ability to eat and digest her food properly. Once all these issues have been addressed, your baby will be healthier, and you'll be happier.