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538: Outcome of early versus late onset growth discordance in monochorionic diamniotic twin pregnancies
SMFM Abstracts 536
THE VALIDITY OF A NATIONAL REFERENCE BIRTHWEIGHT NOMOGRAM FOR ASIAN AND HISPANIC WOMEN NADAV SCHWARTZ1, LEAH PRICE2, JOONHEE PARK3, JULIAN MIERLAK4, FERESHTEH BOOZARJOMEHRI2, 1NYU School of Medicine, New York, New York, 2NYU School of Medicine, , New York, 3SUNY Buffalo-School of Medicine and Biomedical Sciences, , New York, 4NYU School of Medicine; Gouverneur Health Care Services-NYC Health and Hospitals Corporation, , New York OBJECTIVE: While it is apparent that maternal BMI varies greatly by ethnicity, we were interested to see if these ethnic variations affect the validity of using a national reference nomogram for newborn birthweight. STUDY DESIGN: The clinical database for Gouverneur Health Care Services, a clinic serving a largely immigrant population, was queried for all deliveries occurring from November 2002 through June 2006. The ethnic groups of interest were Chinese and Hispanic women who delivered ⬎⫽36 weeks gestation. Only foreignborn women were included in an attempt to minimize heterogeneity. Subjects were stratified by gestational age at delivery for the analyses. RESULTS: The query yielded 1876 Chinese and 1401 foreign-born Hispanic pregnancies. The mean maternal pre-gravid BMI was significantly lower in the Chinese group (20.8 vs 26.3, p⬍0.001). There was a poor correlation between BMI and birthweight for each ethnic group (Chinese-0.19; Hispanic-0.11). Wilcoxon rank sum test analysis showed statistically significant variations in birthweight distribution for 38, 39 and 40 weeks; however, these were clinically insignificant as the medians and 10th and 90th percentiles were all within 100gms. In addition, when comparing our ⬎⫽37 weeks deliveries to a national reference standard (Alexander et al. 1999), there was no significant difference between the proportion of Chinese vs Hispanic birthweights that were below the 10th percentile at any gestational age. In fact, at 36 weeks, a higher percentage of Hispanic births were below the 10th percentile compared to Chinese births (20% vs 4.3%, p⫽0.03). CONCLUSION: There is no clinically significant divergence in the distribution of neonatal birthweight between Chinese and Hispanic immigrants. National reference birthweight nomograms are equally applied to both groups to define a smallfor-gestational-age fetus. Assuming a constitutionally small fetus based on ethnicity and BMI should be avoided and appropriate surveillance should be implemented.
www.AJOG.org 538
0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.538
537
OUTCOME OF DISCORDANT GROWTH IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES IN THE 1ST TRIMESTER, AT 16, 20 AND 26 WEEKS LIESBETH LEWI1, JACQUES JANI1, LÉONARDO GUCCIARDO1, ELISA DONE1, TIM VAN MIEGHEM1, AGNES HUBER2, A DIEMERT2, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum Hamburg-Eppendorf, Obstetrics/Gynecology, Hamburg, Germany OBJECTIVE: To examine the outcome of discordant growth diagnosed at different time points in pregnancy in a prospective series of monochorionic diamniotic (MCDA) twins. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by the European Commission). Patients were scanned in the 1st trimester, at 16, 20 and 26 wks. Information on pregnancy outcome was provided by the referring clinicians. RESULTS: 202 MCDA twins were included. (1) In the 1st trimester, the 90th percentile of ⌬CRL was 10 mm. Survival in this group was 65% versus 91% if ⌬CRL ⬍10 mm (P⫽0.0001). Of cases with ⱖ10 mm ⌬CRL, 25% had an uneventful outcome, 35% remained growth discordant (93% survival), 20% were complicated by TTTS (38% survival) and 20% had other complications (2 double fetal deaths ⱕ16 wks, 1 anencephaly, 1 miscarriage). (2) At 16 wks, the 90th percentile of ⌬AC was 17 mm. Survival was 70% versus 92% if ⌬AC ⬍17 mm (P⫽0.001). Of those with ⱖ17 mm ⌬AC, 27% had an uneventful outcome, 36% remained growth discordant (survival 81%), 23% were complicated by TTTS (survival 40%) and 14% had other complications (1 double fetal death at 16 wks, 1 anencephaly, 1 hydrops). (3) At 20 wks, the 90th percentile of ⌬EFW was 23%. Survival in the group was 86% versus 97% if ⌬EFW⬍23% (P⫽0.01). Of cases with ⱖ23%⌬EFW, 23% had an uneventful outcome, 59% remained growth discordant, 14% were complicated by TTTS and 4% had other complications (1 hydrops). (4) At 26 wks, the 90th percentile of was 24%. Survival was 97% versus 98% if ⌬EFW ⬍23% (P⫽NS). Of cases with ⱖ24% ⌬EFW, 32% had an uneventful outcome, 63% remained growth discordant, 5% were complicated by TTTS. Overal mortality of TTTS was 20/36 (56%), whereas that for discordant growth was 5/60 (8%) (P⬍0.000001). CONCLUSION: The earlier the discordant growth, the higher the mortality, especially if TTTS complicates it. Work supported by a grant of the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.539
OUTCOME OF EARLY VERSUS LATE ONSET GROWTH DISCORDANCE IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES LIESBETH LEWI1, JACQUES JANI1, TIM VAN MIEGHEM1, LÉONARDO GUCCIARDO1, ELISA DONE1, AGNES HUBER2, A DIEMERT2, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum Hamburg-Eppendorf, Obstetrics/Gynecology, Hamburg, Germany OBJECTIVE: To examine the outcome of early versus late onset growth discordance in a prospective series of monochorionic diamniotic (MCDA) twins included in the 1st trimester. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by the European Commission). Patients were scanned in the 1st trimester, at 16, 20 and 26 wks. Information on pregnancy outcome was provided by the referring clinician. Isolated severe discordant growth was defined as ⬎25% difference in birth weight without the occurrence of TTTS. “Early onset” growth discordance was defined as discordant growth diagnosed ⱕ20 wks and as “late onset ”growth discordance when diagnosed at 26 wks or only at birth. RESULTS: 202 MCDA twins were included in the study. Isolated severe discordant growth occurred in 25/174 (14%) of live born twins. Of these 25, 12 had early onset growth discordance, whereas 13 had late onset growth discordance. Median gestational age at birth was 32 wks in the early onset group as compared to 35 wks in the late onset group (P⬍0.05). Severe hemoglobin differences (anemia in the smaller and polycythemia in the larger twin) requiring immediate postnatal transfusion and/or exchange transfusion were present in 4/13 (31%) of the late onset cases, whereas none occurred in the early cases. Abnormal umbilical artery Dopplers were present in 7 with early onset growth discordance, whereas umbilical artery Dopplers were normal in all late onset cases. There were no neonatal deaths in either group. The occurrence of abnormal neonatal brain scan was not different in early versus late onset cases (3/24 versus 2/26, NS). CONCLUSION: MCDA twins with late onset growth discordance more commonly had severe hemoglobin differences at the time of birth than those with early onset discordance. Work supported by a grant of the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.540
539
PLACENTAL CHARACTERISTICS IN EARLY VERSUS LATE ONSET GROWTH DISCORDANCE IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES LIESBETH LEWI1, JACQUES JANI1, ELISA DONE1, TIM VAN MIEGHEM1, LÉONARDO GUCCIARDO1, AGNES HUBER2, A DIEMERT2, MIEKE CANNIE3, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum HamburgEppendorf, Obstetrics/Gynecology, Hamburg, Germany, 3University Hospitals Leuven, Radiology, Leuven, Belgium OBJECTIVE: To examine the placental characteristics of early versus late onset growth discordance in a prospective series of monochorionic diamniotic (MCDA) twins followed-up from the 1st trimester onwards. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by European Commission). Discordant growth was defined as ⬎25% difference in birth weight (BW) without the occurrence of TTTS. “Early onset” growth discordance was defined as discordant growth diagnosed ⱕ20 wks and as “late onset” growth discordance when diagnosed ⬎26 wks or at birth. X-ray barium dye angiograms and digital photographs of the chorionic surface were taken. On the angiogram, we delineated the venous territory of each twin. On the digital photograph, minimal diameters of arterio-arterial and veno-venous anastomoses and of each vein of an arterio-venous anastomosis were measured. Birthweight (BW) discordance was calculated as BW larger/BW smaller twin. Placental territory discordance was calculated by dividing the venous surface area of the larger part of the placenta by that of the smaller part. RESULTS: 202 MCDA twins were included in the study. Discordant growth occurred in 25/174 (14%) of live born twins. Overall, growth discordant pairs had a more unequally shared placenta than growth concordant pairs (1.78 [1.09-4.05] vs 1.26 [1.09-2.13]; P⬍0.0001). Placentas of pregnancies with early onset growth discordance were more unequally shared (2.41 [1.60-4.05] vs 1.57 [1.09-2.26]; P⬍0.001) for a similar degree of BW discordance (31%, 25-33 vs 28%, 25-44; NS) and had larger arterio-arterial anastomoses (3.1 mm [1.8-5.8] vs 1.2 mm [0.0-2.79]; P⬍0.01) and total diameter of all anastomoses (11.4 mm [6.4-29.0] vs 3.4 mm [1.2-16.1]; P⬍0.01) as compared to placentas from cases with late onset discordance. CONCLUSION: MCDA twins with early onset growth discordance had a more unequally shared placenta and a more elaborate intertwin circulation as compared to those with late onset discordance. Work supported by the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.541
S156
American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2007
THE VALIDITY OF A NATIONAL REFERENCE BIRTHWEIGHT NOMOGRAM FOR ASIAN AND HISPANIC WOMEN NADAV SCHWARTZ1, LEAH PRICE2, JOONHEE PARK3, JULIAN MIERLAK4, FERESHTEH BOOZARJOMEHRI2, 1NYU School of Medicine, New York, New York, 2NYU School of Medicine, , New York, 3SUNY Buffalo-School of Medicine and Biomedical Sciences, , New York, 4NYU School of Medicine; Gouverneur Health Care Services-NYC Health and Hospitals Corporation, , New York OBJECTIVE: While it is apparent that maternal BMI varies greatly by ethnicity, we were interested to see if these ethnic variations affect the validity of using a national reference nomogram for newborn birthweight. STUDY DESIGN: The clinical database for Gouverneur Health Care Services, a clinic serving a largely immigrant population, was queried for all deliveries occurring from November 2002 through June 2006. The ethnic groups of interest were Chinese and Hispanic women who delivered ⬎⫽36 weeks gestation. Only foreignborn women were included in an attempt to minimize heterogeneity. Subjects were stratified by gestational age at delivery for the analyses. RESULTS: The query yielded 1876 Chinese and 1401 foreign-born Hispanic pregnancies. The mean maternal pre-gravid BMI was significantly lower in the Chinese group (20.8 vs 26.3, p⬍0.001). There was a poor correlation between BMI and birthweight for each ethnic group (Chinese-0.19; Hispanic-0.11). Wilcoxon rank sum test analysis showed statistically significant variations in birthweight distribution for 38, 39 and 40 weeks; however, these were clinically insignificant as the medians and 10th and 90th percentiles were all within 100gms. In addition, when comparing our ⬎⫽37 weeks deliveries to a national reference standard (Alexander et al. 1999), there was no significant difference between the proportion of Chinese vs Hispanic birthweights that were below the 10th percentile at any gestational age. In fact, at 36 weeks, a higher percentage of Hispanic births were below the 10th percentile compared to Chinese births (20% vs 4.3%, p⫽0.03). CONCLUSION: There is no clinically significant divergence in the distribution of neonatal birthweight between Chinese and Hispanic immigrants. National reference birthweight nomograms are equally applied to both groups to define a smallfor-gestational-age fetus. Assuming a constitutionally small fetus based on ethnicity and BMI should be avoided and appropriate surveillance should be implemented.
www.AJOG.org 538
0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.538
537
OUTCOME OF DISCORDANT GROWTH IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES IN THE 1ST TRIMESTER, AT 16, 20 AND 26 WEEKS LIESBETH LEWI1, JACQUES JANI1, LÉONARDO GUCCIARDO1, ELISA DONE1, TIM VAN MIEGHEM1, AGNES HUBER2, A DIEMERT2, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum Hamburg-Eppendorf, Obstetrics/Gynecology, Hamburg, Germany OBJECTIVE: To examine the outcome of discordant growth diagnosed at different time points in pregnancy in a prospective series of monochorionic diamniotic (MCDA) twins. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by the European Commission). Patients were scanned in the 1st trimester, at 16, 20 and 26 wks. Information on pregnancy outcome was provided by the referring clinicians. RESULTS: 202 MCDA twins were included. (1) In the 1st trimester, the 90th percentile of ⌬CRL was 10 mm. Survival in this group was 65% versus 91% if ⌬CRL ⬍10 mm (P⫽0.0001). Of cases with ⱖ10 mm ⌬CRL, 25% had an uneventful outcome, 35% remained growth discordant (93% survival), 20% were complicated by TTTS (38% survival) and 20% had other complications (2 double fetal deaths ⱕ16 wks, 1 anencephaly, 1 miscarriage). (2) At 16 wks, the 90th percentile of ⌬AC was 17 mm. Survival was 70% versus 92% if ⌬AC ⬍17 mm (P⫽0.001). Of those with ⱖ17 mm ⌬AC, 27% had an uneventful outcome, 36% remained growth discordant (survival 81%), 23% were complicated by TTTS (survival 40%) and 14% had other complications (1 double fetal death at 16 wks, 1 anencephaly, 1 hydrops). (3) At 20 wks, the 90th percentile of ⌬EFW was 23%. Survival in the group was 86% versus 97% if ⌬EFW⬍23% (P⫽0.01). Of cases with ⱖ23%⌬EFW, 23% had an uneventful outcome, 59% remained growth discordant, 14% were complicated by TTTS and 4% had other complications (1 hydrops). (4) At 26 wks, the 90th percentile of was 24%. Survival was 97% versus 98% if ⌬EFW ⬍23% (P⫽NS). Of cases with ⱖ24% ⌬EFW, 32% had an uneventful outcome, 63% remained growth discordant, 5% were complicated by TTTS. Overal mortality of TTTS was 20/36 (56%), whereas that for discordant growth was 5/60 (8%) (P⬍0.000001). CONCLUSION: The earlier the discordant growth, the higher the mortality, especially if TTTS complicates it. Work supported by a grant of the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.539
OUTCOME OF EARLY VERSUS LATE ONSET GROWTH DISCORDANCE IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES LIESBETH LEWI1, JACQUES JANI1, TIM VAN MIEGHEM1, LÉONARDO GUCCIARDO1, ELISA DONE1, AGNES HUBER2, A DIEMERT2, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum Hamburg-Eppendorf, Obstetrics/Gynecology, Hamburg, Germany OBJECTIVE: To examine the outcome of early versus late onset growth discordance in a prospective series of monochorionic diamniotic (MCDA) twins included in the 1st trimester. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by the European Commission). Patients were scanned in the 1st trimester, at 16, 20 and 26 wks. Information on pregnancy outcome was provided by the referring clinician. Isolated severe discordant growth was defined as ⬎25% difference in birth weight without the occurrence of TTTS. “Early onset” growth discordance was defined as discordant growth diagnosed ⱕ20 wks and as “late onset ”growth discordance when diagnosed at 26 wks or only at birth. RESULTS: 202 MCDA twins were included in the study. Isolated severe discordant growth occurred in 25/174 (14%) of live born twins. Of these 25, 12 had early onset growth discordance, whereas 13 had late onset growth discordance. Median gestational age at birth was 32 wks in the early onset group as compared to 35 wks in the late onset group (P⬍0.05). Severe hemoglobin differences (anemia in the smaller and polycythemia in the larger twin) requiring immediate postnatal transfusion and/or exchange transfusion were present in 4/13 (31%) of the late onset cases, whereas none occurred in the early cases. Abnormal umbilical artery Dopplers were present in 7 with early onset growth discordance, whereas umbilical artery Dopplers were normal in all late onset cases. There were no neonatal deaths in either group. The occurrence of abnormal neonatal brain scan was not different in early versus late onset cases (3/24 versus 2/26, NS). CONCLUSION: MCDA twins with late onset growth discordance more commonly had severe hemoglobin differences at the time of birth than those with early onset discordance. Work supported by a grant of the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.540
539
PLACENTAL CHARACTERISTICS IN EARLY VERSUS LATE ONSET GROWTH DISCORDANCE IN MONOCHORIONIC DIAMNIOTIC TWIN PREGNANCIES LIESBETH LEWI1, JACQUES JANI1, ELISA DONE1, TIM VAN MIEGHEM1, LÉONARDO GUCCIARDO1, AGNES HUBER2, A DIEMERT2, MIEKE CANNIE3, KURT HECHER2, JAN DEPREST1, 1University Hospitals Leuven, OB/GYN, Leuven, Belgium, 2Universitätsklinikum HamburgEppendorf, Obstetrics/Gynecology, Hamburg, Germany, 3University Hospitals Leuven, Radiology, Leuven, Belgium OBJECTIVE: To examine the placental characteristics of early versus late onset growth discordance in a prospective series of monochorionic diamniotic (MCDA) twins followed-up from the 1st trimester onwards. STUDY DESIGN: Prospective study in 2 centers (EuroTwin2Twin project funded by European Commission). Discordant growth was defined as ⬎25% difference in birth weight (BW) without the occurrence of TTTS. “Early onset” growth discordance was defined as discordant growth diagnosed ⱕ20 wks and as “late onset” growth discordance when diagnosed ⬎26 wks or at birth. X-ray barium dye angiograms and digital photographs of the chorionic surface were taken. On the angiogram, we delineated the venous territory of each twin. On the digital photograph, minimal diameters of arterio-arterial and veno-venous anastomoses and of each vein of an arterio-venous anastomosis were measured. Birthweight (BW) discordance was calculated as BW larger/BW smaller twin. Placental territory discordance was calculated by dividing the venous surface area of the larger part of the placenta by that of the smaller part. RESULTS: 202 MCDA twins were included in the study. Discordant growth occurred in 25/174 (14%) of live born twins. Overall, growth discordant pairs had a more unequally shared placenta than growth concordant pairs (1.78 [1.09-4.05] vs 1.26 [1.09-2.13]; P⬍0.0001). Placentas of pregnancies with early onset growth discordance were more unequally shared (2.41 [1.60-4.05] vs 1.57 [1.09-2.26]; P⬍0.001) for a similar degree of BW discordance (31%, 25-33 vs 28%, 25-44; NS) and had larger arterio-arterial anastomoses (3.1 mm [1.8-5.8] vs 1.2 mm [0.0-2.79]; P⬍0.01) and total diameter of all anastomoses (11.4 mm [6.4-29.0] vs 3.4 mm [1.2-16.1]; P⬍0.01) as compared to placentas from cases with late onset discordance. CONCLUSION: MCDA twins with early onset growth discordance had a more unequally shared placenta and a more elaborate intertwin circulation as compared to those with late onset discordance. Work supported by the European Commission (5th Framework Programme #QLG1-CT-2002-01632 EuroTwin2Twin) 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.541
S156
American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2007