OBJECTIVE: The purpose of this study was to examine whether fetal outcome in twin pregnancies is dependent on zygosity or chorionicity. STUDY DESIGN: This was a prospective observational study comprised of women with twin pregnancies who attended the fetal medicine unit at St Michael's Hospital, Bristol, Ireland, during the years 1998 to 2000 and who were delivered in hospitals in south west England. After delivery, zygosity was determined with umbilical cord blood with the use of microsatellite markers that were amplified by polymerase chain reaction. Placentae were examined histologically for chorionic type. The perinatal outcomes of 3 groups of monozygotic monochorionic, monozygotic dichorionic, and dizygotic pregnancies were compared with the use of the Mann-Whitney U test and the Fisher's exact test. RESULTS: All 92 dizygotic and 15 monozygotic dichorionic pregnancies resulted in live births. In 7 of the 39 cases in the monozygotic monochorionic group, either both twins were not live born or delivery occurred <24 weeks of gestation. The gestational age at delivery and birth weight were significantly lower, and there were a greater number of cases with birth weight discordancy of >25% in the monochorionic pregnancies compared with the other 2 groups (P < .05). There were no significant differences in any of the study parameters between the monozygotic dichorionic and dizygotic groups. CONCLUSION: Fetal outcome in twin pregnancies is related to chorionicity rather than zygosity.
OBJECTIVE: The purpose of this study was to examine whether fetal outcome in twin pregnancies is dependent on zygosity or chorionicity. STUDY DESIGN: This was a prospective observational study comprised of women with twin pregnancies who attended the fetal medicine unit at St Michael's Hospital, Bristol, Ireland, during the years 1998 to 2000 and who were delivered in hospitals in south west England. After delivery, zygosity was determined with umbilical cord blood with the use of microsatellite markers that were amplified by polymerase chain reaction. Placentae were examined histologically for chorionic type. The perinatal outcomes of 3 groups of monozygotic monochorionic, monozygotic dichorionic, and dizygotic pregnancies were compared with the use of the Mann-Whitney U test and the Fisher's exact test. RESULTS: All 92 dizygotic and 15 monozygotic dichorionic pregnancies resulted in live births. In 7 of the 39 cases in the monozygotic monochorionic group, either both twins were not live born or delivery occurred <24 weeks of gestation. The gestational age at delivery and birth weight were significantly lower, and there were a greater number of cases with birth weight discordancy of >25% in the monochorionic pregnancies compared with the other 2 groups (P < .05). There were no significant differences in any of the study parameters between the monozygotic dichorionic and dizygotic groups. CONCLUSION: Fetal outcome in twin pregnancies is related to chorionicity rather than zygosity.
Authors: Rajan Wadhawan; William Oh; Rebecca L Perritt; Scott A McDonald; Abhik Das; W Kenneth Poole; Betty R Vohr; Rosemary D Higgins Journal: Pediatrics Date: 2009-01-12 Impact factor: 7.124
Authors: Elizabeth H Ruder; Joanne F Dorgan; Sibylle Kranz; Penny M Kris-Etherton; Terryl J Hartman Journal: Clin Breast Cancer Date: 2008-08 Impact factor: 3.225
Authors: M Frost; I Petersen; K Brixen; H Beck-Nielsen; J J Holst; L Christiansen; K Højlund; K Christensen Journal: Diabetologia Date: 2012-09-07 Impact factor: 10.122