- Email: [email protected]
The use of CDNA microarray to identify and characterize the time course and patterns of gene expression over the final third of gestation and during spontaneous labor
SMFM Abstracts S205
Volume 189, Number 6 Am J Obstet Gynecol 535
PROTEOMICS AND MECHANISTIC CANDIDATES OF TERM AND PRETERM LABOR CRAIG D. THULIN1, MICHAEL S. ESPLIN2, STEVEN W. GRAVES1, ANTONIO FRIAS2, ROBERT M. SILVER2, MICHAEL W. VARNER2, KATIE SOUTHWICK1, 1Brigham Young University, Chemistry and Biochemistry, Provo, UT 2University of Utah, Obstetrics and Gynecology, Salt Lake City, UT OBJECTIVE: Preterm birth (PTB) remains a leading cause of morbidity and mortality. Its prevention and treatment are limited by an incomplete understanding of the relevant pathophysiologic mechanisms. Current technology using mass spectrometry allows for the evaluation of the complement of proteins present in a given matrix. Proteins present can then be correlated with a disease state, such as PTB, and candidates mediating the disease can be evaluated. Our objective was to determine whether there were differences in serum protein expression between women who were and were not in preterm labor by a cLC-mass spectral proteomic approach. STUDY DESIGN: Sera obtained from women in spontaneous, preterm labor (N = 4), term labor (N = 5), and non-laboring controls (N = 5) were treated with acetonitrile to precipitate bulk proteins. Remaining proteins were fractionated by cLC interfaced with an electrospray-ionization, quadrupleorthogonal, time-of-flight mass spectrometer. Molecular species were considered unique to a single group if they occurred in at least 3 specimens of one group but in none of the specimens from the other two groups. RESULTS: A 4-min, well-defined region of the 44-min cLC chromatogram (representing only a small portion of the data available) has been evaluated to test this approach. There were 6 molecular species present only in preterm labor but not in term laboring or non-laboring women. There also were 11 molecular species found only in women in term labor but not preterm labor or nonlaboring women. Ten molecular species were found in more than 50% of the preterm and term laboring samples but not in any of the non-laboring samples. There were 29 molecular species unique to non-laboring patients. CONCLUSION: These preliminary results in a small number of subjects suggest that proteomics can identify species unique to a given labor classification, allowing them to be identified and evaluated as potential mediators of normal and abnormal labor.
537
THE USE OF CDNA MICROARRAY TO IDENTIFY AND CHARACTERIZE THE TIME COURSE AND PATTERNS OF GENE EXPRESSION OVER THE FINAL THIRD OF GESTATION AND DURING SPONTANEOUS LABOR ANTONIO E. FRIAS JR.1, MICHAEL S. ESPLIN1, STEVEN HAMBLIN1, STIRLING SMITH1, JONATHAN ENGLISH1, MORGAN R. PELTIER1, ROBERT M. SILVER1, ELI Y. ADASHI1, 1University of Utah, Obstetrics and Gynecology, Salt Lake City, UT OBJECTIVE: The initiation of labor is complex, involving multiple mechanisms and gene regulatory phenomena. We used serial cDNA microarray assessments of the uterine transcriptome to identify the time course and patterns of differential gene expression during the final days of murine pregnancy through spontaneous birth. STUDY DESIGN: cDNA microarray analysis was performed at consecutive time points during the last 6 days of murine gestation. Four C57Bl mice were sacrificed at gestational days 14 and 18, as well as during spontaneous birth. Total myometrial RNA was extracted from each mouse. cDNA microarray analysis was performed on pooled samples at each time point so as to compare each transcriptome to a common pooled counterpart. Statistical analysis was performed to identify significantly up- or down-regulated gene expression for each day relative to controls. A linear mixed model that follows the two-stage process detailed in Wolfinger et al. (2001) was used for the analysis of gene expression data. Differential gene expression was considered statistically significant if P < 6.5 3 107 (Bonferroni correction). RESULTS: At each time point, 15,000 genes were screened by cDNA microarray analysis. Table 1 shows the number of genes significantly up- or down-regulated at each time point. There were 50 genes whose expression pattern was significantly different from control across the entire time period. These 50 genes clustered into the following known or inferred functions based on their mRNA sequence (see Table 2). CONCLUSION: cDNA microarray analysis successfully identified temporal patterns and clusters of gene expression before and during murine labor. The identification of well-characterized genes with known function may lead to improved diagnostic and therapeutic interventions for labor. Equally important, an additional set of novel genes has been identified as a target for future studies. Table 1. Number of genes with differential gene expression at gestational days 14 and 18 and during birth (DB) Gestational Day 14 18 DB
Up-regulated (n)
Down-regulated (n)
30 43 34
63 72 59
Table 2. The 50 genes with differential gene expression at all time points separated by known or inferred gene function Function Unknown Signal Transduction Matrix/Structural Energy/Metabolism Transcription Cell Cycle Apoptosis Inflammation Translation Membrane Transport/Ion Channel Heat Shock 536
THE IMPACT OF MATERNAL OBESITY AND WEIGHT GAIN ON VBAC SUCCESS CELESTE DURNWALD1, HUGH EHRENBERG1, BRIAN MERCER1, 1MetroHealth Medical Center at CWRU School of Medicine, Maternal Fetal Medicine, Cleveland, OH OBJECTIVE: To determine the impact of maternal obesity on VBAC success after a single low transverse cesarean delivery (CD). STUDY DESIGN: We reviewed individual charts of women with low transverse CD in their 1st viable pregnancy who underwent a trial of labor (TOL) in their 2nd viable pregnancy at our urban tertiary care institution over 12 years. Maternal BMI was classified as ‘‘underweight’’ ( < 19.8 kg/m2), ‘‘normal’’ (19.8-25 kg/m2), ‘‘overweight’’ (25.1-30 kg/m2) and ‘‘obese’’ (>30 kg/m2). Clinical characteristics and labor outcomes were assessed. Factors potentially affecting VBAC success such as maternal age, race, BMI, gestational age, labor induction, infant sex, and birthweight were analyzed by univariate analysis. The impact of maternal BMI on VBAC success was evaluated after controlling for race, gestational age, labor induction, and infant birthweight (P < 0.05 considered significant). RESULTS: Of 510 women attempting a TOL, 337 (66%) were successful (sVBAC) and 173 (34%) failed VBAC (fVBAC). Women with sVBAC and fVBAC were similar in clinical characteristics. Decreased VBAC success was seen in obese (54.6%) but not overweight (66.1%) women compared with normal BMI women (70.5%), P = 0.003 and 0.43, respectively. Underweight women had more VBAC success than normal BMI women (84.7% vs 70.5%, P = 0.04). Controlling for other factors, the association between increasing pregravid BMI (P = 0.03) and obesity>30 kg/m2 (P = 0.006) with decreased VBAC success persisted. Normal BMI women who became overweight after the 1st pregnancy had decreased VBAC success compared with those whose BMI remained normal (56.8% vs 73.9%, P = 0.009). However, overweight women who decreased their BMI to normal after the 1st CD did not improve VBAC success (65.2% vs 58.4%, P = 0.65). CONCLUSION: Increasing pregravid BMI and weight gain between pregnancies reduce VBAC success after a single low transverse cesarean delivery.
538
Number (%) 17 10 9 4 3 2 1 1 1 1 1
(34%) (20%) (18%) (8%) (6%) (4%) (2%) (2%) (2%) (2%) (2%)
PRIOR CESAREAN DELIVERY INCREASES THE NEED FOR DILATATION AND CURETTAGE DURING MID-TRIMESTER LABOR INDUCTIONS DAVID KMAK1, JERRIE REFUERZO2, ANTHONY JOHNSON1, SEAN BLACKWELL1, GENE MCNEELEY1, FAISAL QURESHI1, SUZANNE JACQUES1, 1Wayne State University, Obstetrics/Gynecology, Detroit, MI 2 Wayne State University, Obstetrics and Gynecology, Detroit, MI OBJECTIVE: Recently, the American College of Obstetrics and Gynecology recommended that ‘‘Misoprostol should not be used in patients with previous cesarean delivery or prior major uterine surgery.’’ However, this recommendation did not address misoprostol use for labor induction specifically in the midtrimester. The purpose of our study was to determine the delivery outcomes of women with a prior cesarean delivery who received misoprostol for secondtrimester induction of labor. STUDY DESIGN: A prospective, randomized trial was performed including women electing misoprostol induction of labor between 14 and 24 weeks’ gestation. Patients were randomized to receive vaginal, oral, or combination (oral and vaginal) misoprostol, 400 lg every 6 hours until delivery. Delivery complications were compared between patients with and without a prior cesarean delivery. Also, the length of induction was compared between groups. RESULTS: 91 women received misoprostol for labor induction in the midtrimester; oral 35.2%, vaginal 33.3%, and combination 31.8%. Eighteen patients (19.8%) had a prior cesarean delivery. Patients with a prior cesarean delivery had a significantly higher rate of retained placenta and need for a dilatation and curettage (D&C) (44.8% vs 18%, P = 0.027). There were no differences in the rate of fever, antibiotic use, emesis, diarrhea, blood transfusions, or length of induction between women with and without a prior cesarean delivery. Also, there were no cases of uterine rupture. CONCLUSION: The use of misoprostol for labor induction in the second trimester is associated with an increased risk of D&C for retained placenta in patients with a prior cesarean delivery. Although there were no cases resulting in uterine ruptures, precautions should be taken when administering misoprostol in the second trimester in patients with a prior cesarean delivery.
Volume 189, Number 6 Am J Obstet Gynecol 535
PROTEOMICS AND MECHANISTIC CANDIDATES OF TERM AND PRETERM LABOR CRAIG D. THULIN1, MICHAEL S. ESPLIN2, STEVEN W. GRAVES1, ANTONIO FRIAS2, ROBERT M. SILVER2, MICHAEL W. VARNER2, KATIE SOUTHWICK1, 1Brigham Young University, Chemistry and Biochemistry, Provo, UT 2University of Utah, Obstetrics and Gynecology, Salt Lake City, UT OBJECTIVE: Preterm birth (PTB) remains a leading cause of morbidity and mortality. Its prevention and treatment are limited by an incomplete understanding of the relevant pathophysiologic mechanisms. Current technology using mass spectrometry allows for the evaluation of the complement of proteins present in a given matrix. Proteins present can then be correlated with a disease state, such as PTB, and candidates mediating the disease can be evaluated. Our objective was to determine whether there were differences in serum protein expression between women who were and were not in preterm labor by a cLC-mass spectral proteomic approach. STUDY DESIGN: Sera obtained from women in spontaneous, preterm labor (N = 4), term labor (N = 5), and non-laboring controls (N = 5) were treated with acetonitrile to precipitate bulk proteins. Remaining proteins were fractionated by cLC interfaced with an electrospray-ionization, quadrupleorthogonal, time-of-flight mass spectrometer. Molecular species were considered unique to a single group if they occurred in at least 3 specimens of one group but in none of the specimens from the other two groups. RESULTS: A 4-min, well-defined region of the 44-min cLC chromatogram (representing only a small portion of the data available) has been evaluated to test this approach. There were 6 molecular species present only in preterm labor but not in term laboring or non-laboring women. There also were 11 molecular species found only in women in term labor but not preterm labor or nonlaboring women. Ten molecular species were found in more than 50% of the preterm and term laboring samples but not in any of the non-laboring samples. There were 29 molecular species unique to non-laboring patients. CONCLUSION: These preliminary results in a small number of subjects suggest that proteomics can identify species unique to a given labor classification, allowing them to be identified and evaluated as potential mediators of normal and abnormal labor.
537
THE USE OF CDNA MICROARRAY TO IDENTIFY AND CHARACTERIZE THE TIME COURSE AND PATTERNS OF GENE EXPRESSION OVER THE FINAL THIRD OF GESTATION AND DURING SPONTANEOUS LABOR ANTONIO E. FRIAS JR.1, MICHAEL S. ESPLIN1, STEVEN HAMBLIN1, STIRLING SMITH1, JONATHAN ENGLISH1, MORGAN R. PELTIER1, ROBERT M. SILVER1, ELI Y. ADASHI1, 1University of Utah, Obstetrics and Gynecology, Salt Lake City, UT OBJECTIVE: The initiation of labor is complex, involving multiple mechanisms and gene regulatory phenomena. We used serial cDNA microarray assessments of the uterine transcriptome to identify the time course and patterns of differential gene expression during the final days of murine pregnancy through spontaneous birth. STUDY DESIGN: cDNA microarray analysis was performed at consecutive time points during the last 6 days of murine gestation. Four C57Bl mice were sacrificed at gestational days 14 and 18, as well as during spontaneous birth. Total myometrial RNA was extracted from each mouse. cDNA microarray analysis was performed on pooled samples at each time point so as to compare each transcriptome to a common pooled counterpart. Statistical analysis was performed to identify significantly up- or down-regulated gene expression for each day relative to controls. A linear mixed model that follows the two-stage process detailed in Wolfinger et al. (2001) was used for the analysis of gene expression data. Differential gene expression was considered statistically significant if P < 6.5 3 107 (Bonferroni correction). RESULTS: At each time point, 15,000 genes were screened by cDNA microarray analysis. Table 1 shows the number of genes significantly up- or down-regulated at each time point. There were 50 genes whose expression pattern was significantly different from control across the entire time period. These 50 genes clustered into the following known or inferred functions based on their mRNA sequence (see Table 2). CONCLUSION: cDNA microarray analysis successfully identified temporal patterns and clusters of gene expression before and during murine labor. The identification of well-characterized genes with known function may lead to improved diagnostic and therapeutic interventions for labor. Equally important, an additional set of novel genes has been identified as a target for future studies. Table 1. Number of genes with differential gene expression at gestational days 14 and 18 and during birth (DB) Gestational Day 14 18 DB
Up-regulated (n)
Down-regulated (n)
30 43 34
63 72 59
Table 2. The 50 genes with differential gene expression at all time points separated by known or inferred gene function Function Unknown Signal Transduction Matrix/Structural Energy/Metabolism Transcription Cell Cycle Apoptosis Inflammation Translation Membrane Transport/Ion Channel Heat Shock 536
THE IMPACT OF MATERNAL OBESITY AND WEIGHT GAIN ON VBAC SUCCESS CELESTE DURNWALD1, HUGH EHRENBERG1, BRIAN MERCER1, 1MetroHealth Medical Center at CWRU School of Medicine, Maternal Fetal Medicine, Cleveland, OH OBJECTIVE: To determine the impact of maternal obesity on VBAC success after a single low transverse cesarean delivery (CD). STUDY DESIGN: We reviewed individual charts of women with low transverse CD in their 1st viable pregnancy who underwent a trial of labor (TOL) in their 2nd viable pregnancy at our urban tertiary care institution over 12 years. Maternal BMI was classified as ‘‘underweight’’ ( < 19.8 kg/m2), ‘‘normal’’ (19.8-25 kg/m2), ‘‘overweight’’ (25.1-30 kg/m2) and ‘‘obese’’ (>30 kg/m2). Clinical characteristics and labor outcomes were assessed. Factors potentially affecting VBAC success such as maternal age, race, BMI, gestational age, labor induction, infant sex, and birthweight were analyzed by univariate analysis. The impact of maternal BMI on VBAC success was evaluated after controlling for race, gestational age, labor induction, and infant birthweight (P < 0.05 considered significant). RESULTS: Of 510 women attempting a TOL, 337 (66%) were successful (sVBAC) and 173 (34%) failed VBAC (fVBAC). Women with sVBAC and fVBAC were similar in clinical characteristics. Decreased VBAC success was seen in obese (54.6%) but not overweight (66.1%) women compared with normal BMI women (70.5%), P = 0.003 and 0.43, respectively. Underweight women had more VBAC success than normal BMI women (84.7% vs 70.5%, P = 0.04). Controlling for other factors, the association between increasing pregravid BMI (P = 0.03) and obesity>30 kg/m2 (P = 0.006) with decreased VBAC success persisted. Normal BMI women who became overweight after the 1st pregnancy had decreased VBAC success compared with those whose BMI remained normal (56.8% vs 73.9%, P = 0.009). However, overweight women who decreased their BMI to normal after the 1st CD did not improve VBAC success (65.2% vs 58.4%, P = 0.65). CONCLUSION: Increasing pregravid BMI and weight gain between pregnancies reduce VBAC success after a single low transverse cesarean delivery.
538
Number (%) 17 10 9 4 3 2 1 1 1 1 1
(34%) (20%) (18%) (8%) (6%) (4%) (2%) (2%) (2%) (2%) (2%)
PRIOR CESAREAN DELIVERY INCREASES THE NEED FOR DILATATION AND CURETTAGE DURING MID-TRIMESTER LABOR INDUCTIONS DAVID KMAK1, JERRIE REFUERZO2, ANTHONY JOHNSON1, SEAN BLACKWELL1, GENE MCNEELEY1, FAISAL QURESHI1, SUZANNE JACQUES1, 1Wayne State University, Obstetrics/Gynecology, Detroit, MI 2 Wayne State University, Obstetrics and Gynecology, Detroit, MI OBJECTIVE: Recently, the American College of Obstetrics and Gynecology recommended that ‘‘Misoprostol should not be used in patients with previous cesarean delivery or prior major uterine surgery.’’ However, this recommendation did not address misoprostol use for labor induction specifically in the midtrimester. The purpose of our study was to determine the delivery outcomes of women with a prior cesarean delivery who received misoprostol for secondtrimester induction of labor. STUDY DESIGN: A prospective, randomized trial was performed including women electing misoprostol induction of labor between 14 and 24 weeks’ gestation. Patients were randomized to receive vaginal, oral, or combination (oral and vaginal) misoprostol, 400 lg every 6 hours until delivery. Delivery complications were compared between patients with and without a prior cesarean delivery. Also, the length of induction was compared between groups. RESULTS: 91 women received misoprostol for labor induction in the midtrimester; oral 35.2%, vaginal 33.3%, and combination 31.8%. Eighteen patients (19.8%) had a prior cesarean delivery. Patients with a prior cesarean delivery had a significantly higher rate of retained placenta and need for a dilatation and curettage (D&C) (44.8% vs 18%, P = 0.027). There were no differences in the rate of fever, antibiotic use, emesis, diarrhea, blood transfusions, or length of induction between women with and without a prior cesarean delivery. Also, there were no cases of uterine rupture. CONCLUSION: The use of misoprostol for labor induction in the second trimester is associated with an increased risk of D&C for retained placenta in patients with a prior cesarean delivery. Although there were no cases resulting in uterine ruptures, precautions should be taken when administering misoprostol in the second trimester in patients with a prior cesarean delivery.