- Email: [email protected]
670: Quantitative ultrasound assessment of cervical microstructure
SMFM Abstracts
www.AJOG.org 667
IMPACT OF PLACENTAL LOCATION ON FETAL WEIGHT ESTIMATION BASED ON CONVENTIONAL VERSUS VOLUMETRIC ULTRASOUND PARAMETERS FADI KHOURY1, BRADLEY STETZER1, STEPHEN MYERS1, BRIAN MERCER1, 1Case-MetroHealth Medical Center, Cleveland, Ohio OBJECTIVE: To determine the impact of placental location (anterior vs. other) on the accuracy (absolute percent difference [A%D], absolute weight difference [AWD]) of ultrasound estimation of fetal weight (EFW) calculated by standard biometry (EW2D) and EFW based on fractional thigh volumes (EW3D). STUDY DESIGN: We prospectively evaluated 100 singleton pregnancies at 32- 42 weeks gestation within 48 hours of delivery. 2D parameters and 3D fractional thigh volumes, derived from the middle 50% of the femur, were determined for each fetus. EFW was calculated based on standard biometry [EW2D: femur length (FL), biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC)] (Hadlock 1984). EW3D was calculated using BPD, AC and fractional thigh volume (Lee 2006). Placental location (anterior vs. other) at ultrasound and infant birth weight (BW) were recorded. The A%D was calculated as the absolute value of (EFW-BW)x100/BW. AWD was calculated as the absolute value of (BWEFW). Paired analyses were performed, with p⬍0.05 considered significant. RESULTS: Mean BW was 3070 ⫾ 600 g at 38.4 ⫾ 2.2 weeks. The placenta was anterior in 43 of 100 patients. Gestational age and BW were similar between those with anterior vs. other placental location. EW3D was within 15% of BW more frequently than EW2D (89 vs. 69%, p⫽0.001). The AWD (345 ⫾ 223 g vs. 228 ⫾ 148g, p⫽0.002) and A%D (11.6 ⫾ 7.4% vs. 7.7 ⫾ 5.3%, p⫽0.003) between EW2D and BW were greater for anterior placentas. In contrast, the placental location did not impact the AWD (231 ⫾ 187g vs. 222 ⫾ 187g, p⫽0.8) or A%D (7.9 ⫾ 6.2% vs. 7.2 ⫾ 5.5%, p⫽0.5) between EW3D and BW. For anterior placentas, the AWD (p⫽0.0003) and A%D (p⫽0.002) of EW3D were less than for EW2D. For posterior placentas, there were no differences in the AWD (p⫽0.8) and A%D (p⫽0.6) between EW3D and EW2D. CONCLUSION: EW3D based on fractional thigh volume is more accurate than that based on conventional 2D parameters and, unlike EW2D, is not affected by placental location.
669
0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.699
0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.697 670 668
ALTERATION OF GENE EXPRESSION RELATED TO CARBOHYDRATE METABOLISM IN PLACENTA OF FETUS WITH INTRAUTERINE GROWTH RESTRICTION YOUNG JU KIM1, MI HEE LEE2, SUNG CHUL JUNG2, SANG MI LEE3, MI-HYE PARK4, SUN HEE CHUN4, 1Ewha Womans University, Obstetrics and Gynecology, Seoul, South Korea, 2Ewha Womans University, Biochemistry,, South Korea, 3Ewha Womans University, Molecular medicine, Seoul, South Korea, 4Ewha Womans University, Obstetrics and Gynecology,, South Korea OBJECTIVE: Intrauterine growth restriction (IUGR) is caused by malnutrition of placenta that carries nutrient and oxygen to the fetus. IUGR is suggested to have important consequences fro adult health by increasing the risks of metabolic disorder such as hypertension, diabetes, and obesity.The aim of study was to investigate the alteration of gene expression related to carbohydrate metabolism in placentas of fetus with IUGR and to analyze the change of glucose metabolism related enzyme in the blood and cord blood of normal pregnant women and pregnant women with IUGR fetus. STUDY DESIGN: We collected the blood and cord blood from normal pregnant women (n⫽30) and pregnant women with IUGR (n⫽30) and measured the levels of glucose, insulin, and insulin-like growth factor II (IGF-II) in blood and cord blood by radioimmunoassay. After delivery, we collected the placentas from normal pregnant women (n⫽4) and pregnant women with IUGR fetus (n⫽4) and used cDNA microarray analysis, RT-PCR, and western blot analysis. RESULTS: The expression of genes related to carbohydrate metabolism was up-regulated in placentas of fetus with IUGR including dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex, DLAT), 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 2, lactate dehydrogenase C, IGFII, and Insulin. In contrast to the result, IGFI was down-regulated in placentas of fetus with IUGR. In the IUGR group, the glucose concentration was significantly decreased in maternal serum and in cord blood. However insulin concentration was increased in maternal serum and in cord blood. Moreover IGFII concentration was higher in maternal serum and lower in cord blood. CONCLUSION: These results suggest that alteration of carbohydrate metabolism in fetus with IUGR might be important for metabolic disorder cause after birth. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.698
MATERNAL-FETAL CHARACTERISTICS AND FETAL FEMUR DIAPHYSIS LENGTH IN A PREDOMINANTLY HISPANIC POPULATION. IYABODE AGBOOLA1, HALEH SANGIHAGHPEYKAR1, NIKOLAOS ZACHARIAS1, 1Baylor College of Medicine, Obstetrics & Gynecology, Houston, Texas OBJECTIVE: Fetal femur diaphysis length (FDL) is an important component of biometry and a marker of intrauterine growth. The nomograms used for reference have been derived from predominantly Caucasian populations. Existing literature includes conflicting reports regarding the effect of maternal race on FDL, ranging from none to significant; customized birthweight standards vary by maternal race. We sought to compare fetal FDL distribution across gestational age among gravidae from different racial groups presenting for prenatal sonogram at an inner-city screening center serving an indigent, predominantly Hispanic population – controlling for other maternal-fetal characteristics. The resulting nomogram is compared to the latest European standard by Chitty and Altman (2002). STUDY DESIGN: Following IRB approval, we retrospectively collected and analyzed data from singleton, non-anomalous pregnancies with fetal surveys between 15-40 weeks of sonographically estimated gestational age. Information on maternal (race, age, height, weight, gravidity, parity), fetal (gender) characteristics and ultrasound biometric measurements was extracted. The relationship between maternal-fetal characteristics and FDL was explored with multivariate analysis controlling for potential confounders (SPSS) [p⬍0.05 statistically significant]. RESULTS: 1141 unselected examinations were included between 2005 and 2008 (out of ⬎15500), including 896 Hispanics, 129 African-Americans, 91 Caucasians and 25 Asians. Univariate analysis revealed that Hispanic fetuses have shorter FDLs than African-American fetuses (p⫽0.048), however this difference was attributable to maternal anthropometric characteristics and disappeared in multivariate analysis. The resulting FDL nomogram did not differ at any gestational age from the Chitty-Altman standard (3rd, 50th, 97th %tiles compared). CONCLUSION: Fetal FDL in our population is independent of maternal race and consistent with established nomograms. Maternal height and weight, not race, account for shorter FDLs in Hispanic compared to African-American fetuses.
QUANTITATIVE ULTRASOUND ASSESSMENT OF CERVICAL MICROSTRUCTURE HELEN FELTOVICH1, KIBO NAM2, JOSEPHINE HARTER3, MARK KLIEWER4, TIMOTHY HALL2, 1Minnesota Perinatal Physicians/University of Wisconsin, Obstetrics & Gynecology/ Medical Physics, Minneapolis, Minnesota, 2University of Wisconsin-Madison, Medical Physics, Madison, Wisconsin, 3University of Wisconsin, Pathology, Madision, Wisconsin, 4University of Wisconsin, Radiology, Madison, Wisconsin OBJECTIVE: Understanding cervical microstructure is critical to understanding its dysfunction (cervical insufficiency). Biochemistry, molecular biology, and mechanical studies suggest that collagen is responsible for cervical strength. Human investigation has been limited by lack of noninvasive technology sophisticated enough to detect changes in collagen. Quantitative ultrasound is a promising approach. STUDY DESIGN: Hysterectomy specimens (n⫽8) were scanned with 2 linear array transducers (Siemens VFX9-4, VFX13-5). Radiofrequency (RF) echo data were acquired with the endocervical canal parallel to the transducer face. The angle between the acoustic beam and tissue was used to assess anisotropic acoustic propagation by electronic control of transmit/receive angles from ⫺20° to ⫹20°. A region of interest (ROI) was selected (with locations varied to assure result consistency) and the power spectrum of the RF signals was computed for each angle. RESULTS: Power spectra of backscattered RF signals from the cervix were 6dB higher for normal incidence than beams steered ⫹/⫺20° regardless of ROI position. Shapes of spectra for normal v steered beams were nearly identical, indicating the absence of a frequency-dependent absorption or scattering effect. The spectral power for normal v steered beams decreased monotonically (0.4dB at ⫹5° to 3.6dB at ⫹20°) when compared to a phantom with spherical scatterers. These differences in scattered power were statistically significant for all angles beyond 5°, meaning that the excess differences in incident v steered beams (compared to spherical scatterers) is consistent with scattering from an aligned structure (such as collagen). CONCLUSION: This novel approach identifies a component of cervical microstructure that is likely to be collagen. Most importantly, it is reliably and noninvasively assessable. Ongoing studies will definitively identify, quantify and track this component’s changes in pregnancy. Detecting early changes in microstructure may provide opportunity to develop earlier, more specific interventions for cervical insufficiency. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.700
Supplement to DECEMBER 2008 American Journal of Obstetrics & Gynecology
S191
www.AJOG.org 667
IMPACT OF PLACENTAL LOCATION ON FETAL WEIGHT ESTIMATION BASED ON CONVENTIONAL VERSUS VOLUMETRIC ULTRASOUND PARAMETERS FADI KHOURY1, BRADLEY STETZER1, STEPHEN MYERS1, BRIAN MERCER1, 1Case-MetroHealth Medical Center, Cleveland, Ohio OBJECTIVE: To determine the impact of placental location (anterior vs. other) on the accuracy (absolute percent difference [A%D], absolute weight difference [AWD]) of ultrasound estimation of fetal weight (EFW) calculated by standard biometry (EW2D) and EFW based on fractional thigh volumes (EW3D). STUDY DESIGN: We prospectively evaluated 100 singleton pregnancies at 32- 42 weeks gestation within 48 hours of delivery. 2D parameters and 3D fractional thigh volumes, derived from the middle 50% of the femur, were determined for each fetus. EFW was calculated based on standard biometry [EW2D: femur length (FL), biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC)] (Hadlock 1984). EW3D was calculated using BPD, AC and fractional thigh volume (Lee 2006). Placental location (anterior vs. other) at ultrasound and infant birth weight (BW) were recorded. The A%D was calculated as the absolute value of (EFW-BW)x100/BW. AWD was calculated as the absolute value of (BWEFW). Paired analyses were performed, with p⬍0.05 considered significant. RESULTS: Mean BW was 3070 ⫾ 600 g at 38.4 ⫾ 2.2 weeks. The placenta was anterior in 43 of 100 patients. Gestational age and BW were similar between those with anterior vs. other placental location. EW3D was within 15% of BW more frequently than EW2D (89 vs. 69%, p⫽0.001). The AWD (345 ⫾ 223 g vs. 228 ⫾ 148g, p⫽0.002) and A%D (11.6 ⫾ 7.4% vs. 7.7 ⫾ 5.3%, p⫽0.003) between EW2D and BW were greater for anterior placentas. In contrast, the placental location did not impact the AWD (231 ⫾ 187g vs. 222 ⫾ 187g, p⫽0.8) or A%D (7.9 ⫾ 6.2% vs. 7.2 ⫾ 5.5%, p⫽0.5) between EW3D and BW. For anterior placentas, the AWD (p⫽0.0003) and A%D (p⫽0.002) of EW3D were less than for EW2D. For posterior placentas, there were no differences in the AWD (p⫽0.8) and A%D (p⫽0.6) between EW3D and EW2D. CONCLUSION: EW3D based on fractional thigh volume is more accurate than that based on conventional 2D parameters and, unlike EW2D, is not affected by placental location.
669
0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.699
0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.697 670 668
ALTERATION OF GENE EXPRESSION RELATED TO CARBOHYDRATE METABOLISM IN PLACENTA OF FETUS WITH INTRAUTERINE GROWTH RESTRICTION YOUNG JU KIM1, MI HEE LEE2, SUNG CHUL JUNG2, SANG MI LEE3, MI-HYE PARK4, SUN HEE CHUN4, 1Ewha Womans University, Obstetrics and Gynecology, Seoul, South Korea, 2Ewha Womans University, Biochemistry,, South Korea, 3Ewha Womans University, Molecular medicine, Seoul, South Korea, 4Ewha Womans University, Obstetrics and Gynecology,, South Korea OBJECTIVE: Intrauterine growth restriction (IUGR) is caused by malnutrition of placenta that carries nutrient and oxygen to the fetus. IUGR is suggested to have important consequences fro adult health by increasing the risks of metabolic disorder such as hypertension, diabetes, and obesity.The aim of study was to investigate the alteration of gene expression related to carbohydrate metabolism in placentas of fetus with IUGR and to analyze the change of glucose metabolism related enzyme in the blood and cord blood of normal pregnant women and pregnant women with IUGR fetus. STUDY DESIGN: We collected the blood and cord blood from normal pregnant women (n⫽30) and pregnant women with IUGR (n⫽30) and measured the levels of glucose, insulin, and insulin-like growth factor II (IGF-II) in blood and cord blood by radioimmunoassay. After delivery, we collected the placentas from normal pregnant women (n⫽4) and pregnant women with IUGR fetus (n⫽4) and used cDNA microarray analysis, RT-PCR, and western blot analysis. RESULTS: The expression of genes related to carbohydrate metabolism was up-regulated in placentas of fetus with IUGR including dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex, DLAT), 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 2, lactate dehydrogenase C, IGFII, and Insulin. In contrast to the result, IGFI was down-regulated in placentas of fetus with IUGR. In the IUGR group, the glucose concentration was significantly decreased in maternal serum and in cord blood. However insulin concentration was increased in maternal serum and in cord blood. Moreover IGFII concentration was higher in maternal serum and lower in cord blood. CONCLUSION: These results suggest that alteration of carbohydrate metabolism in fetus with IUGR might be important for metabolic disorder cause after birth. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.698
MATERNAL-FETAL CHARACTERISTICS AND FETAL FEMUR DIAPHYSIS LENGTH IN A PREDOMINANTLY HISPANIC POPULATION. IYABODE AGBOOLA1, HALEH SANGIHAGHPEYKAR1, NIKOLAOS ZACHARIAS1, 1Baylor College of Medicine, Obstetrics & Gynecology, Houston, Texas OBJECTIVE: Fetal femur diaphysis length (FDL) is an important component of biometry and a marker of intrauterine growth. The nomograms used for reference have been derived from predominantly Caucasian populations. Existing literature includes conflicting reports regarding the effect of maternal race on FDL, ranging from none to significant; customized birthweight standards vary by maternal race. We sought to compare fetal FDL distribution across gestational age among gravidae from different racial groups presenting for prenatal sonogram at an inner-city screening center serving an indigent, predominantly Hispanic population – controlling for other maternal-fetal characteristics. The resulting nomogram is compared to the latest European standard by Chitty and Altman (2002). STUDY DESIGN: Following IRB approval, we retrospectively collected and analyzed data from singleton, non-anomalous pregnancies with fetal surveys between 15-40 weeks of sonographically estimated gestational age. Information on maternal (race, age, height, weight, gravidity, parity), fetal (gender) characteristics and ultrasound biometric measurements was extracted. The relationship between maternal-fetal characteristics and FDL was explored with multivariate analysis controlling for potential confounders (SPSS) [p⬍0.05 statistically significant]. RESULTS: 1141 unselected examinations were included between 2005 and 2008 (out of ⬎15500), including 896 Hispanics, 129 African-Americans, 91 Caucasians and 25 Asians. Univariate analysis revealed that Hispanic fetuses have shorter FDLs than African-American fetuses (p⫽0.048), however this difference was attributable to maternal anthropometric characteristics and disappeared in multivariate analysis. The resulting FDL nomogram did not differ at any gestational age from the Chitty-Altman standard (3rd, 50th, 97th %tiles compared). CONCLUSION: Fetal FDL in our population is independent of maternal race and consistent with established nomograms. Maternal height and weight, not race, account for shorter FDLs in Hispanic compared to African-American fetuses.
QUANTITATIVE ULTRASOUND ASSESSMENT OF CERVICAL MICROSTRUCTURE HELEN FELTOVICH1, KIBO NAM2, JOSEPHINE HARTER3, MARK KLIEWER4, TIMOTHY HALL2, 1Minnesota Perinatal Physicians/University of Wisconsin, Obstetrics & Gynecology/ Medical Physics, Minneapolis, Minnesota, 2University of Wisconsin-Madison, Medical Physics, Madison, Wisconsin, 3University of Wisconsin, Pathology, Madision, Wisconsin, 4University of Wisconsin, Radiology, Madison, Wisconsin OBJECTIVE: Understanding cervical microstructure is critical to understanding its dysfunction (cervical insufficiency). Biochemistry, molecular biology, and mechanical studies suggest that collagen is responsible for cervical strength. Human investigation has been limited by lack of noninvasive technology sophisticated enough to detect changes in collagen. Quantitative ultrasound is a promising approach. STUDY DESIGN: Hysterectomy specimens (n⫽8) were scanned with 2 linear array transducers (Siemens VFX9-4, VFX13-5). Radiofrequency (RF) echo data were acquired with the endocervical canal parallel to the transducer face. The angle between the acoustic beam and tissue was used to assess anisotropic acoustic propagation by electronic control of transmit/receive angles from ⫺20° to ⫹20°. A region of interest (ROI) was selected (with locations varied to assure result consistency) and the power spectrum of the RF signals was computed for each angle. RESULTS: Power spectra of backscattered RF signals from the cervix were 6dB higher for normal incidence than beams steered ⫹/⫺20° regardless of ROI position. Shapes of spectra for normal v steered beams were nearly identical, indicating the absence of a frequency-dependent absorption or scattering effect. The spectral power for normal v steered beams decreased monotonically (0.4dB at ⫹5° to 3.6dB at ⫹20°) when compared to a phantom with spherical scatterers. These differences in scattered power were statistically significant for all angles beyond 5°, meaning that the excess differences in incident v steered beams (compared to spherical scatterers) is consistent with scattering from an aligned structure (such as collagen). CONCLUSION: This novel approach identifies a component of cervical microstructure that is likely to be collagen. Most importantly, it is reliably and noninvasively assessable. Ongoing studies will definitively identify, quantify and track this component’s changes in pregnancy. Detecting early changes in microstructure may provide opportunity to develop earlier, more specific interventions for cervical insufficiency. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2008.09.700
Supplement to DECEMBER 2008 American Journal of Obstetrics & Gynecology
S191