Labor and membrane rupture in twin gestation - Can they affect the abilityto estimate fetal weight?

OBJECTIVE: To determine whether labor or fetal membrane rupture adversely a ffects the ability of ultrasound to accurately estimate fetal weight (EFW) in a twin gestation. STUDY DESIGN: A medical record audit suns performed of the two-yens experie nce of women delivering live born twins and undergoing a complete ultrasoun d examination within 72 hours of delivery. Those patients experiencing labo r or membrane rupture at the time of the previous ultrasound examination we re compared to those without these factors to determine if there was any de trimental impact on the accuracy of ultrasound to EFW. RESULTS: The overall ability of ultrasound to accurately EFW was in the ran ge of 64-76%. This sons not significantly different from the accuracy in wo men experiencing labor (62-80%) or in women with membrane rupture (63-81%). The ability of ultrasound to detect fetal discordance is this series range d from 78% to 100%, with specificity that ranged from 84% to 89%. CONCLUSION: The ability of sonography to accurately EFW as well as detect d iscordant twin gestation is not altered by the presence of labor or membran e rupture.