Im 32 weeks pregnant and my baby measure small 3.1. what that's mean and what can i do for my baby to gain some weight.

Eat well: Babies gain most of their weight in the last month of pregnancy so eatting well and staying healthy is the most important thing that you can do.The ultrasound margin of error increases as the pregnancy progresses so this doesn't necessarily mean anything bad for you baby. As one of my teachers said "great danes don't have chihauhaus and chihauhaus don't have great danes".You'll be a great mom.

Ask your OB!: I assume this was confirmed by ultrasound. Many factors can contribute to a baby who's "small for gestational age." Poor maternal nutrition, some medications, a placenta that's not functioning properly, health conditions like smoking and high blood pressure are all possibilities. It's critical that you discuss this with your OB so that the cause(s) can be identified and, hopefully, treated.