Medical Journal of The Islamic Republic of Iran (MJIRI)

Introduction: Twin pregnancy is associated with a high risk of mortality and morbidity. It is necessary to estimate the weight difference of the fetuses with a reliable method to prevent possible complications. This study was conducted to compare the association between the Estimated fetal weight (EFW) discordance and the Abdominal Circumference (AC) discordance with birth weight in twins.

    Methods: This was a descriptive-analytical and retrospective study. The statistical population was all twin pregnant mothers referred to Imam Khomeini Hospital in Ahvaz from 2017 to 2019. The sample size was determined with a census (540 people). Based on abdominal circumference (AC), the size of head circumference (HC), femur length (FL), the Biparietal Diameter (BPD), and using the Hadlock formula, estimate of fetal weight(EFW) was calculated. Then the EFW Discordance and AC Discordance were calculated and compared with the birth weight. Data were analyzed using SPSS18. Unpaired, Two-Tailed T-test and Pearson correlation test was used.

   Results: The results showed that the mean percentage difference of fetal weight in twin pregnancies in the EFW method was 9.25%, in the AC method was 9.89% and finally at birth was 10.72%. The correlation of the weight difference between the two embryos in the AC method with the time of birth (r = 0.922 and P <0.001) was higher than in the EFW method with the time of birth (r = 0.69 and P <0.001) and finally it was found that in detecting the difference more from 20% and 25%, AC diagnostic power was good, but EFW was moderate.

   Conclusion: Therefore, to evaluate the weight and weight difference in twin embryos, the AC

method has the appropriate accuracy and compatibility. Another major prospective study to evaluate the diagnostic performance of AC and EFW mismatch based on gestational age at scan, incision point, maternal and placental characteristics to determine true ultrasound diagnostic accuracy in predicting growth

mismatch in twin pregnancy and optimal post-case management option is needed.