Maternal weight gain and infant outcome in twin pregnancy

Objective To generate reliable weight reference curves on maternal weight gain in twin pregnancy and to compare maternal weight gain of twin pairs where both infants were lying within the 40^th and 60^th birth weight centile (outcome A) to those lying below the 5^th (outcome B).

Study Design A retrospective mixed-model analysis was performed at the Obstetric outpatient clinic, Zurich University Hospital, evaluating data from January 2004 to April 2008. Maternal weight and BMI, before gestation and at the booking visit, as well as the infant outcome were determined in 245 accurately dateable twin pregnancies of Caucasian women. Fifth, 50^th and 95^th centiles were presented and simple and multiple regression analyses were performed for various risk factors. A significance level of P<0.05 was used in all tests.

Results Mean weight gain was 19.1kg at 37 gestational weeks with values >29.2kg and <9.1kg for the 95^th and the 5^th centile, respectively. Pre-pregnancy BMI and mean children weight showed to have a significant impact on maternal weight gain (P <0.05). Furthermore, a significant difference in maternal weight gain was found between Outcome A and B (P=0.01).

Conclusions Maternal weight gain seems to be an important prognostic factor for an optimal twin birth weight outcome. The presented reference curves on maternal weight gain may be a helpful tool in counseling twin pregnancy.

Reference values - body mass index (BMI) - twin pregnancy - weight gain