weeks of collection. Active engagement of VEGF in the process of cervical ripening and dilatation and/or increased afﬁnity of extracel- lular matrix components for VEGF may provide explanation for our ﬁndings. Clinical characteristics of enrolled cohort Singletons 96/103 (93%) .......................................................................................................................................................................................... Twin gestations 9/103 (7%) .......................................................................................................................................................................................... Cervical dilation 1 cm 25/103 (24%) .......................................................................................................................................................................................... Short cervix 2.5 cm 42/103 (41%) .......................................................................................................................................................................................... Symptoms of threatened preterm labor 48/103 (47%) .......................................................................................................................................................................................... Days enrollment-to-delivery (median [IQR]) 56 [33-81] .......................................................................................................................................................................................... PTB 37 wks 36 (35%) .......................................................................................................................................................................................... 501 Withdrawn 502 The DUC trial: a pilot randomized controlled trial of immediate vs. delayed umbilical cord clamping in preterm infants born between 24 and 32 weeks gestation Kelly Chu 1 , Wendy Whittle 1 , Rory Windrim 2 , Prakeshkumar Shah 1 , Kellie Murphy 3 1 University of Toronto, Toronto, ON, 2 Fetal Medicine Unit, Mount Sinai Hospital, Toronto, ON, 3 Mount Sinai Hospital, University of Toronto, Toronto, ON OBJECTIVE: Current obstetrical practice is to clamp the umbilical cord immediately at time of birth in preterm infants to allow for immediate neonatal resuscitation. Some evidence suggests that a short delay in umbilical cord clamping may improve neonatal outcomes. STUDY DESIGN: A pilot randomized controlled trial to determine the feasibility of delayed umbilical cord clamping in preterm infants. Fur- thermore, to examine the rates of intraventricular hemorrhage (IVH), sepsis, anemia, and hyperbilirubinemia in anticipation of a large ran- domized controlled trial. RESULTS: Thirty-eight women were recruited with a recruitment rate of 33%. There was one protocol violation with a compliance rate of 97.4%. The average time of cord clamping in the ICC (n=19) and DCC (n=19) groups were 5.4 seconds vs. 39.7 seconds, respectively (p0.05). The incidence of IVH and sepsis were similar between groups (15% and 10%, respectively). Thirty-ﬁve percent in ICC and 21% in the DCC group required blood transfusion. The incidence of hyperbilirubinemia requiring phototherapy was 66.7% and 74% in the ICC and DCC groups, respectively. No infants required exchange transfusion. One neonatal death occurred in the ICC group. CONCLUSIONS: The intervention of a short delay in umbilical cord clamping, 30-45 seconds, is feasible for a larger randomized con- trolled trial and appears safe in preterm infants (24-32 weeks). 503 Rate of sonographic cervical shortening and the risk of spontaneous preterm birth Leslie Moroz 1 , Hy Simhan 2 1 Magee-Women’s Hospital of UPMC, Pittsburgh, PA, 2 University of Pittsburgh School of Medicine, Magee- Women’s Research Institute, Pittsburgh, PA OBJECTIVE: Sonographic measurement of cervical length (CL) identi- ﬁes women at risk for spontaneous preterm birth (SPTB). Current evidence supports a relation between a short cervix at a point in time (e.g.  25 mm) and SPTB. Among women with a short cervix, it is unknown whether subsequent sonographic shortening is related to the risk of SPTB. We hypothesized that change in CL on serial CL ultrasounds is associated SPTB 36wks for women with a short cervix (CL25mm). STUDY DESIGN: This is a secondary analysis of a multicenter prospec- tive observational cohort study designed to study predictors of pre- term birth. Women with singleton gestation from the general obstet- ric population had CL ultrasounds and vaginal FFN detection performed at intervals of 2 weeks between 20-33wks gestation. The relation between change in CL and SPTB was evaluated using logistic regression. RESULTS: 2721 women had CL exams. 412 (15.1%) women had CL25mm and 2309 (84.9%) had CL 25mm. Change in CL (mm) and average daily change in CL (mm/day) were associated with SPTB for women with CL 25mm [OR (95%CI) 0.97 (0.96-0.98) and 0.53 (0.28-0.98)], but not women with for CL 25mm. Among women with a short cervix, for every 1mm of cervical shortening between ultrasounds, there was a 3% increase in odds of SPTB. The association between change in CL and SPTB remained signiﬁcant after control- ling for age, race, BMI, tobacco use, and FFN status. CONCLUSIONS: Among women with a sonographically short cervix, the rate of change in CL is associated with SPTB, independent of FFN and other important risk factors for SPTB. The ﬁndings of this study sup- port the need for prospective studies to evaluate the role of serial cervical sonography among women identiﬁed as having a short cervix. 504 Serial collection of fetal ﬁbronectin and the risk of spontaneous preterm birth among women with a sonographically short cervix Leslie Moroz 1 , Hy Simhan 2 1 Magee-Women’s Hospital of UPMC, Pittsburgh, PA, 2 University of Pittsburgh School of Medicine, Magee- Women’s Research Institute, Pittsburgh, PA OBJECTIVE: The presence of fetal ﬁbronectin (FFN) in vaginal ﬂuid is associated with risk for spontaneous preterm birth (SPTB). The effect of serial FFN samples on risk for SPTB is not known. We hypothesized that FFN status over gestation collected on serial exams is informative with respect to risk of SPTB 36wks for women with a short cervix (CL25mm). STUDY DESIGN: This is a secondary analysis of a multicenter prospec- tive observational cohort study designed to study predictors of pre- term birth. Women with singleton gestation from the general obstet- ric population had CL ultrasounds and vaginal FFN detection performed at intervals of 2 weeks between 20-33wks gestation. The relation between FFN status and SPTB was evaluated using logistic regression. RESULTS: 2721 women had CL exams and serially collected FFN. 412 (15.1%) women had CL25mm and 2309 (84.9%) had CL 25mm. We evaluated FFN status at two visits: visit 1 [median 23.9 week- s(range 28-28 weeks)] and visit 2 [median 28.1 weeks (range 25-33 weeks)]. FFN positivity was associated with SPTB at visits 1 and 2 for women with CL 25mm (OR 2.3 and 5.4, respectively, p0.01 for both) and for visit 2 for women with CL 25mm (OR 1.9, p0.01). Odds ratios for SPTB by FFN status over gestation are shown in the Table for CL25mm. The association was present when controlling for age, race, BMI, and tobacco use. Risk for SPTB in women with CL25mm and a history of prior preterm birth (n=88) was further increased. There was no association between FFN status over gesta- tion and SPTB for women with CL25mm. CONCLUSIONS: Among women with a sonographically short cervix, FFN status assessed over two time points is informative with respect to risk of subsequent SPTB. The ﬁndings of this study support the need for prospective studies to evaluate the role of serial collection of FFN among women identiﬁed as having a sonographically short cervix. FFN status FFN1 FFN2 CL<25 adjOR (95%CI) CL<25  prior SPTB adjOR (95%CI) 1 - - Ref Ref .......................................................................................................................................................................................... 2 + - 2.5 (1.01-6.34) 3.0 (0.6-14.5) .......................................................................................................................................................................................... 3 - + 6.5 (3.0-14.0) 20.1 (2.4-169.3) .......................................................................................................................................................................................... 4 + + 9.2 (2.8-20.9) 6.7 (0.65-68.3) .......................................................................................................................................................................................... www.AJOG.org Doppler Assessment, Fetus, Neonatology, Prematurity Poster Session III Supplement to JANUARY 2011 American Journal of Obstetrics & Gynecology S201