The Institute of Medicine has established some general guidelines for total weight gain in twin pregnancies based on pre-pregnancy body mass index (BMI). To determine your pre-pregnancy BMI, enter your weight and height PRIOR TO PREGNANCY at this link (https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/english_bmi_calculator/bmi_calculator.html).
Once you have a value, use the table below to determine how much total weight you should gain.
Of note, it is not entirely clear how much a woman carrying twins with a BMI <18.5 should gain during pregnancy. For all women carrying twins, it is important to engage in frequent conversations about weight gain with your health care provider to ensure your babies are growing properly, and that you are staying healthy as well!
Citation:
Institute of Medicine and National Research Council. 2009. Weight Gain During Pregnancy: Reexamining the Guidelines. Washington, DC: The National Academies Press. https://doi.org/10.17226/12584.