Twin weight discordance and maternal weight gain in twin pregnancies.

Objective: To evaluate the association between twin weight discordance and maternal weight change during the gestational period.

Method: One hundred forty-seven twin pregnancies (Group A: <25%, Group B: > or =25% birth weight discordance) were analyzed using Student's t-test, chi(2)-test, and two-way ANOVA at three gestational intervals: before 18 weeks, 18 to 28 weeks, and 28 weeks to birth.

Result: There was no statistically significant difference between the two groups involving maternal age, parity, duration of pregnancy, height, pregravid weight, and conception method. Group A showed a pattern of constantly increasing maternal weight without a significant change in the twin weight discordance throughout gestation. However, Group B showed a fluctuation in maternal BMI with remarkably elevated twin weight discordance at 28 weeks to birth.

Conclusion: The results suggest that in twin pregnancies constant maternal weight gain throughout gestation is important for maintaining a twin weight discordance of less than 25%.