Twin birth weight discordance and risk of pre-term birth

The association between discordant growth and the complication of twin pregnancy has been recognized for more than 30 years. Recent publications have presented evidence that 30% or even 40% discordance presents the threshold for significant. Our purpose was to define twin growth discordance on the basis of perinatal outcome and other factors like maternal age pariety and systemic disease. Twins delivered at age more than 32 week’s gestation between 1998-2000 at Deziani Hospital Gorgan was identified. Birth weight, pre-term birth, maternal age pariety and systemic disease and sex of Twins recorded. Discordance was calculated as: 100×larger BW-smaller BW/larger BW. The mean discordance for 435 twins was 8.18±6.79, 96.4% of pre-term birth associated with discordance?20%. 10.6% of mothers had a systemic disease and mean discordance in twins term and pre-term of normal mothers was 5.8±4.5, 7.9±6.3 and in systemic disease was 9±9.2, 11.1±8.8 (P?0.008). There were no differences in pariety age and sex. Twin birth weight discordance had now clearly been demonstrated to be a risk factor for pre-term birth. The effect was found particularly with discordances?20% after 32 week’s gestation.