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Department of Obstetrics & Gynecology

Preterm Labor: Can the Initial Cervical Dilation Predict Gestational Age at Delivery? Olga E. Jackson MD, MPH

Joanne N. Quiñones MD, MSCE Lehigh Valley Health Network, [email protected]

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Published In/Presented At Jackson, O. E., & Quiñones, J. N. (2011, April). Preterm labor: Can the initial cervical dilation predict gestational age at delivery? Presented at: The 59th Annual Clinical Meeting (ACM) of the American College of Obstetricians and Gynecologists, Washington, DC.

This Poster is brought to you for free and open access by LVHN Scholarly Works. It has been accepted for inclusion in LVHN Scholarly Works by an authorized administrator. For more information, please contact [email protected]. Preterm Labor: Can the Initial Cervical Dilation Predict Gestational Age at Delivery?

Olga E. Jackson, MD MPH, Joanne N. Quiñones, MD MSCE, Lehigh Valley Health Network, Allentown, Pennsylvania

Methods Preterm Delivery By Dilation Preterm Delivery with Tocolytic Use Abstract • Retrospective cohort study Objective: To determine if the digital cervical Cervical dilation <3cm Cervical dilation >3cm p value Delivery <37 weeks Delivery >37 weeks Total • Inclusion Criteria: Non-anomalous singleton fe­ exam at the time of initial admission for preterm N=170 N=54 N = 75 N = 149 N = 224 tuses between 23–34 gestational weeks, ad­ labor predicts birth at less than 37 weeks ges­ Delivery <34 weeks 25 (73.5%) 9 (26.5%) 0.73 mission for preterm labor or contractions and no Tocolysis–yes 63 (84%) 118 (79.2%) 181 tation. known uterine anomalies Delivery >34 weeks 145 (76.3%) 45 (23.7%) 0.73 Methods: Retrospective cohort study of women Tocolysis–no 12 (16%) 31 (20.8%) 43 • Exclusion Criteria: Singleton fetuses less than 23 Delivery <37 weeks 51 (68%) 24 (32%) 0.05 admitted with a diagnosis of preterm labor be­ gestational weeks or greater than 34 gestational tween June 1, 2004 and June 1, 2009. Inclusion Delivery >37 weeks 119 (80%) 30 (20.1)% 0.05 P - value 0.39 weeks, women presenting with preterm prema­ criteria included singleton gestations between ture rupture of membranes, medically indicat­ Risk ratio 1.48 (1.02 – 2.16), p = 0.05 23 0/7–34 6/7 weeks, intact membranes and ed preterm deliveries, multifetal gestations and no congenital anomalies. Only the initial cervical Adjusted for Tocolytic Use pregnancies complicated by fetal anomalies ­dilation was used for analysis for women ad­ OR p value 95% CI mitted more than once for preterm labor. • Data was collected from the electronic medical Delivery by Early PT Birth, Late PT Birth and Term record and delivery logs. Results: 224 patients met inclusion criteria for Gestation Cervical dilation <3cm Cervical dilation >3cm p value Cervical dilation 1.84 0.06 0.98–3.46 analysis. Mean gestational age on admission at delivery N=170 N=54 >3cm was 30.7 ± 2.7 weeks. Mean cervical dilation <34 weeks 13 (7.65%) 4 (23.6%) 0.10 Tocolysis–no 1.33 0.45 0.63–2.78 was 1.8 cm ± 1.1cm. 80% of women received Baseline Maternal 34–37 weeks 38 (65.5%) 20 (34.5%) 0.10 tocolysis on admission. Mean gestational age at Characteristics delivery for the cohort was 37.2 +/- 2.5 weeks. >37 weeks 119 (79.8%) 30 (20.1%) 0.10 N=224 33.5% admitted for preterm labor delivered at Data is in n ( %) or median range as indicated. PT: Preterm less than 37 weeks. There was a trend towards Age at presentation 25.1±6.0 an increased risk of preterm delivery for women (mean±SD) whose cervix was greater than 2 cm on admis­ Conclusion sion (risk ratio 1.48 [1.02 - 2.16; p=0.05]). Of Ethnicity Tocolytic Use Outcomes by Tocolytic Use Our data suggest that most women admitted for preterm labor deliver at those who delivered preterm, 34.8% received • Caucasian 110 (48.8%) Tocolytic Frequency Percentage Del Del term. However, cervical dilation greater than 2 cm may help discriminate tocolysis whereas 27.9% did not (p=0.39). After • Black 18 (8.0%) <37 weeks >37 weeks those women at the highest risk of preterm birth in need of admission for adjustment for tocolytic use, the risk of preterm Indocin 28 12.5 N=75 N=149 corticosteroids and ­possible tocolysis administration. • Hispanic 9 (40.4%) delivery was similar regardless of cervical dila­ Magnesium 120 53.5 Indomethacin 14 (18.6%) 14 (9.5%) tion on admission (adjusted OR 1.84 [CI 0.98- • Other 3 (1.3%) Nifedipine 25 11.2 Magnesium 43 (57.3%) 77 (51.1%) 3.46; p = 0.06]). • Unknown 3 (1.3%) Terbutaline 6 2.7 Nifedipine 5 (6.7%) 20 (13.5%) Conclusion: Our data suggest that most women History of preterm delivery 49 (22%) admitted for preterm labor deliver at term. How­ Two or More 2 0.9 Terbutaline 1 (1.3%) 5 (3.4%) History of vaginal infection 44 (19.6%) ever, cervical dilation greater than 2 cm may No tocolysis 43 19.2 >Two 0 (0%) 2 (1.4%) help discriminate those women at the highest History of cervical surgery 17 (7.6%) 80.8% of patients in preterm labor received tocolysis No tocolysis 12 (16%) 31 (20.9%) risk of preterm birth in need of admission for Tobacco use 34 (15.1%) corticosteroids and possible tocolysis. Alcohol use 2 (0.9%) Drug use 8 (3.6%)

Data: mean +/- SD or %, Cervical surgery, i.e LEEP/Cone biopsy