Weight gain above guidelines during pregnancy is common, according to researchers, and infants born to women with high weight gain tend to have worse outcomes.

Dr. Naomi E. Stotland, of the University of California, San Francisco, and colleagues examined the association between weight gain during pregnancy and adverse outcomes among 20,465 full-term infants for 20,465 single births. None of the infants were from multiple births.

Mothers’ weight gain during pregnancy was categorized using the Institute of Medicine guidelines, as well as by extremes of weight gain, either less than 15.4 lbs. or greater than 39.6 lbs. The authors’ findings appear in the September issue of Obstetrics and Gynecology.

Overall, 43.3 percent of the women had weight gain above the Institute of Medicine guidelines and 20.1 percent had weight gain below the guidelines. Twenty-nine percent of women gained more than 39.6 lbs. during pregnancy, and 4.8 percent gained less than 15.4 lbs.

Excessive weight gain was associated with poor Apgar scores, a gauge of how well the baby looks and responds immediately after birth. In addition, excessive weight gain was linked to infant seizures, low blood sugar levels, and a potentially serious breathing condition called meconium aspiration.

Excessive weight gain was also associated with a decreased risk of having a small baby, whereas low weight gain was tied to an increased risk.

Based on the study findings, the researchers recommend that public health efforts emphasize the prevention of excessive weight gain during pregnancy.

SOURCE: Obstetrics and Gynecology, September 2006.