Concern about weight gain during pregnancy has historically focused on low birth weight and premature birth.  The Institute of Medicine (1990) recommended an upper range for weight gain, (35 pounds for women at normal weight before pregnancy) for young  pregnant adolescents (16 years or under) because they have a high risk for low birth weight babies. 

Rising rates of overweight among teens prompted this nursing faculty member to review studies on adolescent weight gain during pregnancy and associated risk for adult obesity. 

Most studies on adolescent maternal outcomes were conducted in the 1990s. Small studies found that adolescents with a high body mass index (BMI) before pregnancy or rapid weight gain during pregnancy were more likely to be even more overweight six to 36 months after delivery.

There was insufficient published research to indicate if weight gain during teenage pregnancy was associated with obesity later in life or to guide on the magnitude of an appropriate weight gain for overweight pregnant adolescents.   Nevertheless, nurses can stress the importance of good nutrition before pregnancy and counsel clients on “sensible” weight gain during pregnancy.  Those who have a high BMI before pregnancy or who gain weight rapidly should be monitored closely and counseled on reasonable weight gain.  Young teens need closer supervision because they are still growing and are at greater risk for excessive weight gain.
Underweight adolescents need support to achieve adequate weight gain to reduce the risk for perinatal death.  Nurses can also develop or support weight reduction interventions for postpartum teens to help them achieve a healthy weight. 

The author advised expanding the definition of a good neonatal outcome beyond a minimum birth weight of 2500 g.  The effects of weight gain during pregnancy need further attention to limit negative outcomes for adolescent mothers.

(Groth S. Matern Child Nurs J 2006; 31(2):101-105)

Comment:  While there was no definitive answer, school nurses and local healthcare providers can seek the best available evidence and develop consistent messages on nutrition and weight gain for pregnant adolescents (and their mothers and grandmothers!).         --J.O.