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203 Cervical length and the etiologic heterogeneity of preterm birth
SMFM Abstracts S137
¢'oluine 185, N u m b e r 6 AinJ Obstet Gynecol 201
202
IS THERE AN ASSOCIATION BETWEEN MATERNAL FOLATE STATUS IN THE SECOND TRIMESTER AND PRETERM BIRTH? ANNA SIEGA-RIZ ~, DAVID 8AV1TZt, J O H N T H O R P JR. 2, STEVEN ZEISEL ~, KATHERINE HARTMANN 2, BARBARA EUCKER2; 1University of North Carolina at Chapel Hill, Epidemiotogy, Chapel Hill, NC: 2University of North Carolina at Chapel Hill Obstetrics/Gynecology, Chapel Hill, NC; 3University of N o r t h Carolina at Chapel Hill, Nutrition, Chapel Hill, NC OBJECTIVE: P o o r m a t e r n a l folate status d u r i n g p r e g n a n c y has b e e n suggested as a cause o f p r e t e r m birth (PTB). The goal of this study was to assess the associatiou between folate status (serum, red b l o o d cell, a n d dietary intake) during the second trimester a n d PTB. STUDY DESIGN: 1734 women who were recruited into the study at 24-29 weeks gestation provided a blood sample a n d completed a food frequency health behavior questionnaire. Both serum (n = 1734) a n d red blood cell (n = 837) folate were analyzed via radioassay. RESULTS: DietaxT fotate was correlated with serum (r = 0.41) a n d red b l o o d cell (r ~ 0.25) folate, even after accounting for supplement use a n d bioavailability. Serum folate correlated with red b l o o d cell folate r = 0.50. Women who were in the lowest 2 / 3 of the sample of folate intake (<502 mg) were at higher risk of PTB (AOR = 1.9, 95% CI = 1.3, 3.1). The lowest tertile of serum folate was also consistently associated with PTB (AOR - 1.9, 95% CI = 1.4, 2.7), with a stronger association a m o n g non-supplement users (AOR = 2.6, 95% CI = 1.1, 6.3). Both models adjusted for supplement use, maternal age, smoking, pregravid BMI a n d total energy (for dietary folate only). The risk ratios were slightly attenuated when the sample was restricted to spontaneous PTBs. CONCLUSION: The results support the hypothesis that p o o r folate status during pregnancy increases the risk of PTB. O u r results with the red blood cell folate (long-term measure) warrantS further investigation.
ASSOCIATION BETWEEN CERVICAL LENGTH AND MARKERS OF IMMUNE STATUS OF THE CERVICO-GENITAL TRACT DURING pREGNANCY RUKMINI BALU 1, J O H N T H O R P JR.2, DAVID 8AVITZ 1, PH1LLIP HEINE 3, MICHAEL MCMAHON 2, KATHERINE HARTMANN 2, BARBARA EUCKER4; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC: "~Duke University, Obstetrics/Gynecology, D u r h a m , NC; aUniversity of North Carolina, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To examine the association between short cervical length a n d markers of i m m u n e status of the lower genital tract during pregnancy STUDY DESIGN: Vaginal fluid specimens obtained from 749 women at 2429 weeks were tested for bacterial vaginosis, presence of leukocytes a n d assayed for defensins. Bacterial vaginosis was studied as a categorical variable while defensin concentrations were dichotomized at the 25th, 50th a n d 75th percentiles. CerviCal length was d i c h o t o m i z e d at the 5th, 25th a n d 50th percentiles (26 mm, 34 mm, a n d 39 ram, respectively). Logistic a n d linear regression models were c o n s t r u c t e d to assess the relationship between bacterial vaginosis, vaginal fluid defensins a n d the presence of leukocytes a n d short cervical length after adjusting lbr marital status, maternal age, race, education, smoking history a n d alcohol consumption during pregnancy. RESULTS: Cervical length <5th percentile was associated with defensins >25th percentiles with adjusted odds ratios [AOR] = 1.4 (95% CI - 0.9, 1.9). Cervical length <25th percentile was associated with defensins >25th a n d 50th percentiles with AOR = 1.5 (95% CI = 1.1, 2.1) a n d AOR ~ 1.4 (95% CI = 1.0, 1.8), respectively. There was a small association between positive BV status a n d cervical length <5th percentile (AOR = 1.3, 95% CI = 0.8, 1.9). There was no association between short cervical length a n d presence of leukocytes in celwico-vaginal fluids. CONCLUSION: A short cervical length at mid-pregnancy is associated with elevated vaginal fluid defensin concentration.
203
CERVICAL LENGTH AND THE ETIOLOGIC HETEROGENEITY OF PRETERM BIRTH RUKMINI BALU 1, J O H N T H O R P JR. 2, DAVID SAVITZ 1, MICHAEL MCMAHON 2, KATHERINE HARTMANN 2, BARBARA EUCKER2; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To d e t e r m i n e if cervical length m e a s u r e m e n t s via endovaginal sonography differ in their ability to predict mechanisms of preterm birth (PTB). STUDY DESIGN: Women enrolled in a cohort study between 24-29 weeks h a d endovaginal s o n o g r a m s d o n e in a s t a n d a r d fashion. Records were reviewed by masked clinicians a n d PTBs assigned to one of three categories: p r e t e r m labor (PTL), p r e m a t u r e r u p t u r e of m e m b r a n e s (PROM), a n d medically indicated PTBs using standard definitions. RESULTS: 2295 women h a d cervical length determinations of whom 12% h a d PTBs. Relative risks are shown (see Table). CONCLUSION: Cervical lengths are most predictive of spontaneous PTBs that manifest after PTL and not PTBs preceded by ROM. Table RRPTB RRPTB RRMED RR ANY DUE TO DUE TO IND PTB PTL ROM PTB Cervical length >20 m m 2.8 (1.4,5.5) 7.6 (2.6, 19.8) 20-30 m m 1.1 (.4, 3.4) 2.6 (.6, 12) 30-35 m m Ref. category Ref. category 3540 mm 1.6 (1.0, 2.8) 2.2 (.8, 5.6) 40-45 rnm 0.8 (.5, 1.3) .9 (.4, 2.2) >45 m m 1.0 (.6, 1.6) 1.0 (.4, 2.3)
204
2.5 (.3, 21.2) 3.3 (.9, 11.3) Ref. category .6 (.2, 2.3) 1.0 (.3, 3.6) 1.2 (.3, 4.2)
.7 (.2, 22) .6 (.2, 2.3) Ref. category 1.0 (.3, 3.6) 1.2 (.3, 4.2) .8 (.4, 1.4)
PSYCHOSOCIAL FACTORS AND PRETERM BIRTH AMONG AFRICANAMERICAN AND WHITE WOMEN IN CENTRAL N O R T H CAROLINA NANCY DOLE 1, DAVID SAVITZ 2, ANNA SIEGA-RIZ 3, MICHAEL MCMAH O N 4, BARBARA EUCKER4,JOHN THORPJR.5; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 3University of North Carolina at Chapel Hill, Maternal & Child Health, Chapel Hill, NC; 4University of North Carolina at Chapel Hill, Obstetrics & Gynecology, Chapel Hill, NC; 5University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To determine if stress, discrimination, a n d o t h e r psychosocial factors may explain racial differences in preterm birth (PTB) rates. STUDY DESIGN: From a prospective cohort study examining risk factors for PTB, w o m e n were recruited between 24-29 weeks a n d were asked to complete a self-administered questionnaire assessing life eventS, social support, depression, pregnancy-related anxiety, perceived discrimination a n d neighborh o o d safety. 1827 Afi'ican-American or white w o m e n are included in this analysis. RESULTS: PTB rates were not different by race, with 12.0% of the 692 African-American women delivering preterm c o m p a r e d to 11.7% of the 1107 white women. African-American women were at higher risk if they employed distancing from a problem as a coping mechanism (relative risk = 1.7, [CI] 1.03.1), or if they were in the highest tertile of perceived racial discrimination (RR = 1.7, 95% CI: 1.0-2.8). White women were at risk if they were in the highest quartile for the count of negative events (RR = 1.7, 95% CI: 1.1-2.6), they were not living with a partner (RR = 1.8, 95% CI: 1.2-2.7), or were living in what they perceived as a n unsafe n e i g h b o r h o o d (RR = 1.7, 1.0-2.9). W o m e n were at higher risk, regardless of race, if they were in the highest tertile for pregmancyrelated anxiety which they rated as negative (RR = 2.3 for African Americans and RR = 2.1 for Whites). There was n o association with preterm birth a m o n g either race for measures of depression, social support, or church attendance. CONCLUSION: The association between psychosocial measures a n d p r e t e r m birth were different for African-American a n d White w o m e n for several exposures.
¢'oluine 185, N u m b e r 6 AinJ Obstet Gynecol 201
202
IS THERE AN ASSOCIATION BETWEEN MATERNAL FOLATE STATUS IN THE SECOND TRIMESTER AND PRETERM BIRTH? ANNA SIEGA-RIZ ~, DAVID 8AV1TZt, J O H N T H O R P JR. 2, STEVEN ZEISEL ~, KATHERINE HARTMANN 2, BARBARA EUCKER2; 1University of North Carolina at Chapel Hill, Epidemiotogy, Chapel Hill, NC: 2University of North Carolina at Chapel Hill Obstetrics/Gynecology, Chapel Hill, NC; 3University of N o r t h Carolina at Chapel Hill, Nutrition, Chapel Hill, NC OBJECTIVE: P o o r m a t e r n a l folate status d u r i n g p r e g n a n c y has b e e n suggested as a cause o f p r e t e r m birth (PTB). The goal of this study was to assess the associatiou between folate status (serum, red b l o o d cell, a n d dietary intake) during the second trimester a n d PTB. STUDY DESIGN: 1734 women who were recruited into the study at 24-29 weeks gestation provided a blood sample a n d completed a food frequency health behavior questionnaire. Both serum (n = 1734) a n d red blood cell (n = 837) folate were analyzed via radioassay. RESULTS: DietaxT fotate was correlated with serum (r = 0.41) a n d red b l o o d cell (r ~ 0.25) folate, even after accounting for supplement use a n d bioavailability. Serum folate correlated with red b l o o d cell folate r = 0.50. Women who were in the lowest 2 / 3 of the sample of folate intake (<502 mg) were at higher risk of PTB (AOR = 1.9, 95% CI = 1.3, 3.1). The lowest tertile of serum folate was also consistently associated with PTB (AOR - 1.9, 95% CI = 1.4, 2.7), with a stronger association a m o n g non-supplement users (AOR = 2.6, 95% CI = 1.1, 6.3). Both models adjusted for supplement use, maternal age, smoking, pregravid BMI a n d total energy (for dietary folate only). The risk ratios were slightly attenuated when the sample was restricted to spontaneous PTBs. CONCLUSION: The results support the hypothesis that p o o r folate status during pregnancy increases the risk of PTB. O u r results with the red blood cell folate (long-term measure) warrantS further investigation.
ASSOCIATION BETWEEN CERVICAL LENGTH AND MARKERS OF IMMUNE STATUS OF THE CERVICO-GENITAL TRACT DURING pREGNANCY RUKMINI BALU 1, J O H N T H O R P JR.2, DAVID 8AVITZ 1, PH1LLIP HEINE 3, MICHAEL MCMAHON 2, KATHERINE HARTMANN 2, BARBARA EUCKER4; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC: "~Duke University, Obstetrics/Gynecology, D u r h a m , NC; aUniversity of North Carolina, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To examine the association between short cervical length a n d markers of i m m u n e status of the lower genital tract during pregnancy STUDY DESIGN: Vaginal fluid specimens obtained from 749 women at 2429 weeks were tested for bacterial vaginosis, presence of leukocytes a n d assayed for defensins. Bacterial vaginosis was studied as a categorical variable while defensin concentrations were dichotomized at the 25th, 50th a n d 75th percentiles. CerviCal length was d i c h o t o m i z e d at the 5th, 25th a n d 50th percentiles (26 mm, 34 mm, a n d 39 ram, respectively). Logistic a n d linear regression models were c o n s t r u c t e d to assess the relationship between bacterial vaginosis, vaginal fluid defensins a n d the presence of leukocytes a n d short cervical length after adjusting lbr marital status, maternal age, race, education, smoking history a n d alcohol consumption during pregnancy. RESULTS: Cervical length <5th percentile was associated with defensins >25th percentiles with adjusted odds ratios [AOR] = 1.4 (95% CI - 0.9, 1.9). Cervical length <25th percentile was associated with defensins >25th a n d 50th percentiles with AOR = 1.5 (95% CI = 1.1, 2.1) a n d AOR ~ 1.4 (95% CI = 1.0, 1.8), respectively. There was a small association between positive BV status a n d cervical length <5th percentile (AOR = 1.3, 95% CI = 0.8, 1.9). There was no association between short cervical length a n d presence of leukocytes in celwico-vaginal fluids. CONCLUSION: A short cervical length at mid-pregnancy is associated with elevated vaginal fluid defensin concentration.
203
CERVICAL LENGTH AND THE ETIOLOGIC HETEROGENEITY OF PRETERM BIRTH RUKMINI BALU 1, J O H N T H O R P JR. 2, DAVID SAVITZ 1, MICHAEL MCMAHON 2, KATHERINE HARTMANN 2, BARBARA EUCKER2; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To d e t e r m i n e if cervical length m e a s u r e m e n t s via endovaginal sonography differ in their ability to predict mechanisms of preterm birth (PTB). STUDY DESIGN: Women enrolled in a cohort study between 24-29 weeks h a d endovaginal s o n o g r a m s d o n e in a s t a n d a r d fashion. Records were reviewed by masked clinicians a n d PTBs assigned to one of three categories: p r e t e r m labor (PTL), p r e m a t u r e r u p t u r e of m e m b r a n e s (PROM), a n d medically indicated PTBs using standard definitions. RESULTS: 2295 women h a d cervical length determinations of whom 12% h a d PTBs. Relative risks are shown (see Table). CONCLUSION: Cervical lengths are most predictive of spontaneous PTBs that manifest after PTL and not PTBs preceded by ROM. Table RRPTB RRPTB RRMED RR ANY DUE TO DUE TO IND PTB PTL ROM PTB Cervical length >20 m m 2.8 (1.4,5.5) 7.6 (2.6, 19.8) 20-30 m m 1.1 (.4, 3.4) 2.6 (.6, 12) 30-35 m m Ref. category Ref. category 3540 mm 1.6 (1.0, 2.8) 2.2 (.8, 5.6) 40-45 rnm 0.8 (.5, 1.3) .9 (.4, 2.2) >45 m m 1.0 (.6, 1.6) 1.0 (.4, 2.3)
204
2.5 (.3, 21.2) 3.3 (.9, 11.3) Ref. category .6 (.2, 2.3) 1.0 (.3, 3.6) 1.2 (.3, 4.2)
.7 (.2, 22) .6 (.2, 2.3) Ref. category 1.0 (.3, 3.6) 1.2 (.3, 4.2) .8 (.4, 1.4)
PSYCHOSOCIAL FACTORS AND PRETERM BIRTH AMONG AFRICANAMERICAN AND WHITE WOMEN IN CENTRAL N O R T H CAROLINA NANCY DOLE 1, DAVID SAVITZ 2, ANNA SIEGA-RIZ 3, MICHAEL MCMAH O N 4, BARBARA EUCKER4,JOHN THORPJR.5; 1University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 2University of North Carolina at Chapel Hill, Epidemiology, Chapel Hill, NC; 3University of North Carolina at Chapel Hill, Maternal & Child Health, Chapel Hill, NC; 4University of North Carolina at Chapel Hill, Obstetrics & Gynecology, Chapel Hill, NC; 5University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, NC OBJECTIVE: To determine if stress, discrimination, a n d o t h e r psychosocial factors may explain racial differences in preterm birth (PTB) rates. STUDY DESIGN: From a prospective cohort study examining risk factors for PTB, w o m e n were recruited between 24-29 weeks a n d were asked to complete a self-administered questionnaire assessing life eventS, social support, depression, pregnancy-related anxiety, perceived discrimination a n d neighborh o o d safety. 1827 Afi'ican-American or white w o m e n are included in this analysis. RESULTS: PTB rates were not different by race, with 12.0% of the 692 African-American women delivering preterm c o m p a r e d to 11.7% of the 1107 white women. African-American women were at higher risk if they employed distancing from a problem as a coping mechanism (relative risk = 1.7, [CI] 1.03.1), or if they were in the highest tertile of perceived racial discrimination (RR = 1.7, 95% CI: 1.0-2.8). White women were at risk if they were in the highest quartile for the count of negative events (RR = 1.7, 95% CI: 1.1-2.6), they were not living with a partner (RR = 1.8, 95% CI: 1.2-2.7), or were living in what they perceived as a n unsafe n e i g h b o r h o o d (RR = 1.7, 1.0-2.9). W o m e n were at higher risk, regardless of race, if they were in the highest tertile for pregmancyrelated anxiety which they rated as negative (RR = 2.3 for African Americans and RR = 2.1 for Whites). There was n o association with preterm birth a m o n g either race for measures of depression, social support, or church attendance. CONCLUSION: The association between psychosocial measures a n d p r e t e r m birth were different for African-American a n d White w o m e n for several exposures.