The recommended amount of weight gain during pregnancy varies based on a woman's pre-pregnancy body mass index (BMI). According to the American College of Obstetricians and Gynecologists (ACOG), women with a normal BMI (18.5–24.9) should gain between 25 to 35 pounds during a singleton pregnancy. acog.org

For overweight women (BMI 25.0–29.9), ACOG recommends a total weight gain of 15 to 25 pounds. Obese women (BMI ≥30) are advised to gain between 11 to 20 pounds. These guidelines aim to optimize outcomes for both the mother and the infant.
acog.org

In the first trimester, most women don't need to gain much weight. If you start out at a healthy weight, gaining about 1 to 4 pounds is typical. In the second and third trimesters, the recommended rate of weight gain is approximately half a pound to 1 pound per week.
mayoclinic.org

It's important to note that these recommendations are for singleton pregnancies. Women carrying twins or multiples have different guidelines. For example, the Institute of Medicine suggests that normal-weight women pregnant with twins should gain between 37 to 54 pounds.
cdc.gov

Excessive gestational weight gain has been associated with increased birth weight and postpartum weight retention. Conversely, inadequate weight gain can lead to decreased birth weight. Therefore, it's essential to aim for weight gain within the recommended ranges to support the health of both mother and baby.
acog.org

It's advisable to consult with a healthcare provider to determine the appropriate weight gain target based on individual health status and circumstances. For more detailed information, refer to ACOG's guidelines on weight gain during pregnancy. acog.org