Preterm Labor Patients Research Articles

Can myometrial electrical activity identify patients in preterm labor?

The objective of the study was to determine whether myometrial electrical activity can differentiate false from true preterm labor. Electrical uterine myography (EUM) was measured prospectively on 87 women, gestational age less than 35 weeks. The period between contractions, power of contraction peaks and movement of center of electrical activity (RMS), was used to develop an index score (1-5) for prediction of preterm delivery (PTD) within 14 days of the test. The score was compared with fetal fibronectin (fFN) and cervical length (CL). Patients delivering within 14 days from testing showed a higher index and mean RMS (P = .000). No patients with EUM index scores of 1-2 delivered in this time frame. Combining EUM with CL or fFN increased predictability. Logistic regression revealed that history of PTD and EUM index had 4- to 5-fold increased risk for PTD. Gestational age at testing, body mass index, fFN, and CL were nonsignificant contributors to PTD risk. Measuring myometrial electrical activity may enhance identification of patients in true premature labor.

Adverse neonatal outcomes: examining the risks between preterm, late preterm, and term infants

There is a relative paucity of data regarding neonatal outcomes in the late preterm cohort (34 to 36 6/7 weeks). This study sought to assess differences in adverse outcomes between infants delivering 32 to 33 6/7, 34 to 36 6/7 weeks, and 37 weeks or later. Data were collected as part of a retrospective cohort study of preterm labor patients (2002-2005). Patients delivering 32 weeks or later were included (n = 264). The incidence of adverse outcomes was assessed. Significant associations between outcomes and gestational age at delivery were determined using chi(2) analyses and Poisson regression modeled cumulative incidence and controlled for confounders. Late preterm infants have increased risk of adverse outcomes, compared with term infants. Controlling for confounders, there was a 23% decrease in adverse outcomes with each week of advancing gestational age between 32 and 39 completed weeks (relative risk 0.77, P < .001, 95% confidence interval, 0.71-0.84). Further investigation regarding obstetrical management and long-term outcomes for this cohort is warranted.

Magnesium Sulfate Compared With Nifedipine for Acute Tocolysis of Preterm Labor: A Randomized-controlled Trial

Lyell, D.J.; Pullen, K.; Campbell, L.; Ching, S.; Druzin, M.L.; Chitkara, U.; Burrs, D.; Caughey, A.B.; El-Sayed, Y.Y.Author Information

Is routine infectious and toxicologic screening in preterm labor effective in predicting preterm birth?

Our objective was to evaluate whether a significant association exists between cocaine use, cervical, urine, and/or Group B streptococcus (GBS) infections and preterm birth (PTB) in patients admitted with active preterm labor (PTL). A retrospective cohort study of PTL patients < 34 weeks (n = 400) admitted to a large, urban tertiary care hospital (2002-2005) was performed. Pertinent history and screening test results were collected. The prevalence of a positive result for each test was determined. Pearson chi-square and Poisson regression were used to evaluate the significance of associations between screening tests and PTB and to control for confounders. The percentage of patients that delivered at < 37 and < 34 weeks was 63.5% (n = 254) and 44.5% (n = 178), respectively. Only cocaine use was significantly associated with PTB at < 34 weeks (RR 1.86, 95%CI 1.03, 2.08). This laboratory test panel is not an effective adjunctive means to predict PTB in PTL patients.

Proteomic profiling of amniotic fluid in preterm labor using two-dimensional liquid separation and mass spectrometry

Objective. Simultaneous analysis of the protein composition of biological fluids is now possible. Such an approach can be used to identify biological markers of disease and to understand the pathophysiology of disorders that have eluded classification, diagnosis, and treatment. The purpose of this study was to analyze the differences in protein composition of the amniotic fluid of patients in preterm labor.Study design. Amniotic fluid was obtained by amniocentesis from three groups of women with preterm labor and intact membranes: (1) women without intra-amniotic infection/inflammation (IAI) who delivered at term, (2) women without IAI who delivered a preterm neonate, and (3) women with IAI. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin (IL)-6 (≥2.3 ng/mL). Two-dimensional (2D) chromatography was used for analysis. The first dimension separated proteins by isoelectric point, while the second, by the degree of hydrophobicity. 2D protein maps were generated using different experimental conditions (reducing agents as well as protein concentration). The maps were used to discern subsets of isoelectric point/hydrophobicity containing differentially expressed proteins. Protein identification of differentially expressed fractions was conducted with mass spectrometry. Enzyme-linked immunosorbent assays (ELISA) as well as surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS)-based on-chip antibody capture immunoassays were also used for confirmation of a specific protein that was differentially expressed.Results. (1) Amniotic fluid protein composition can be analyzed using a combination of 2D liquid chromatography and mass spectrometry for the identification of proteins differentially expressed in patients in preterm labor. (2) While total insulin-like growth factor-binding protein-1 (IGFBP-1) concentration did not change, IGFBP-1 fragments at about 13.5 kDa were present in patients with IAI. (3) Proteins that were over-expressed in group 1 included von Ebner gland protein precursor, IL-7 precursor, apolipoprotein A1, tropomyosin sk1 (TPMsk1) fragment, ribosomal protein S6 kinase alpha-3, and alpha-1-microglobulin/bikunin precursor (AMBP). (4) Proteins that were over-expressed in group 3 included fibrinopeptide B, transferrin, major histocompatibility complex (MHC) class 1 chain-related A antigen fragment, transcription elongation factor A, sex-determining region Y (SRY) box 5 protein, Down syndrome critical region 2 protein (DSCR2), and human peptide 8 (HP8). (5) One protein, retinol-binding protein, was over-expressed in women who delivered preterm, regardless of the presence of IAI.Conclusions. A combination of techniques involving 2D chromatography, mass spectrometry, and immunoassays allows identification of proteins that are differentially regulated in the amniotic fluid of patients with preterm labor. Specifically, the amount of the IGFBP-1 fragments at approximately 13.5 kDa was found to be increased in patients with IAI, while the amount of the intact form of IGFBP-1 was decreased.

141: Accuracy of digital measurement of the cervical portio length

RICHARD BURWICK, GENE LEE, JENNIFER BENEDICT, MARGARET POURTEMOUR, MICHAEL G. ROSS, Harbor-UCLA Med. Ctr. (LABioMed), Dept. of Ob/Gyn, Torrance, California OBJECTIVE: To evaluate the accuracy of clinician-performed cervical length measurements using digital exams, as compared to an objective measure using the Cervilenz device in women presenting with symptoms of preterm labor. STUDY DESIGN: Informed consent for cervical exams was obtained from women presenting in preterm labor between 24-34 weeks gestation, as part of a prospective trial of factors predictive for preterm delivery. Exclusion criteria included cervical dilation 3cm, ruptured membranes, multiple gestation, vaginal bleeding, or intercourse within the prior 24 hours. Cervical length was measured initially by digital exam, estimated to the nearest 0.1 cm. A second examiner, blinded to the results of the digital exam, measured the cervical portio length (at 3:00 or 9:00) utilizing the Cervilenz measuring device. RESULTS: Digital measures of cervical length varied widely, and did not correlate significantly with the objective Cervilenz measures (r 0.23, p 0.10). Digital measures tended to be less than Cervilenz measurements, with a mean absolute difference of 0.88 cm (range 0.20-2.10cm, p 0.0005). The mean absolute difference between digital exam and Cervilenz measurements trended to be even greater among women with cervices described as “soft” versus “medium” or “firm” (1.08 vs. 0.76cm, p 0.07), and in women with long ( 3.5cm) versus short ( 2.5cm) cervices (1.29 vs. 0.76cm, p 0.09), but these did not reach statistical significance. The mean absolute difference between the two measures did not change in the presence or absence of uterine contractions (0.84 vs. 0.92cm, p 0.36). CONCLUSION: Using the objective Cervilenz measure as the standard, these results illustrate the relative inaccuracy of digital exams for cervical length assessment in preterm labor patients. We propose that if cervical length assessments are used for clinical decisions regarding preterm hospitalization or tocolysis, they be performed by an objective measure.

10: Maintenance nifedipine vs. placebo: A prospective, double blind trial

To test whether treatment with nifedipine after arrested preterm labor prolongs pregnancy and improves neonatal outcomes. A prospective, randomized, double-blind, multi-center study was conducted. After successful tocolysis of preterm labor patients were randomized to 20 mg nifedipine or an identical-appearing placebo every 4-6 hours, and treatment was continued until 37 weeks. The primary outcome was attainment of 37 weeks gestation. Patients were included between 24 and 34 weeks if they had 6 or fewer contractions per hour, intact membranes, and <4 cm cervical dilation. Exclusion criteria included placental abruption or previa, fetal anomaly incompatible with life, or maternal medical contraindication to tocolysis. In order to have an 80% power to detect a 50% reduction in birth prior to 37 weeks, with an alpha of .05 and a beta of .2, 66 patients were required. Statistical comparisons were made using 2-sided Fisher’s Exact tests, Student t-tests, and Mann-Whitney tests. 71 patients were randomized, 2 were excluded after randomization, and 1 was lost to follow up. 35 patient received placebo and 33 received nifedipine. There were no maternal demographic differences between groups. Results are shown in the table.Tabled 1Nifedipine vs. placebo outcomesNifedipinePlacebop-valueAchieved 37 weeks13 (39%)13 (37%)1.00Delivery delay (days)31300.81Mean GA delivery35.035.20.82Delivery delay >48 hours33 (100%)33 (94%)0.49 >1 week31 (94%)31 (89%)0.67 >2 weeks28 (85%)27 (77%)0.54 >3 weeks24 (73%)24 (69%)0.54 >4 weeks22 (67)19 (54%)0.33BW (grams)245325310.69Composite neonatal morbidity10 (30%)7 (20%)0.41 Open table in a new tab Prolonged tocolysis following an episode of arrested preterm labor did not significantly prolong pregnancy or improve neonatal outcomes.

Neutropenia induced in a patient by treatment with ritodrine: in vitro evaluation of myeloid progenitor colony‐forming cells

Neutropenia induced in a patient by treatment with ritodrine: <i>in vitro</i> evaluation of myeloid progenitor colony‐forming cells

Magnesium Sulfate Compared With Nifedipine for Acute Tocolysis of Preterm Labor

To compare the efficacy and side effects of intravenous magnesium to oral nifedipine for acute tocolysis of preterm labor. A multicenter randomized trial was performed. Patients in active preterm labor who were at 24 to 33 weeks and 6 days of gestation were randomly assigned to receive magnesium sulfate or nifedipine. The primary outcome was arrest of preterm labor, defined as prevention of delivery for 48 hours with uterine quiescence. One hundred ninety-two patients were enrolled. More patients assigned to magnesium sulfate achieved the primary outcome (87% compared with 72%, P=.01). There were no differences in delivery within 48 hours (7.6% magnesium sulfate compared with 8.0% nifedipine, P=.92), gestational age at delivery (35.8 compared with 36.0 weeks, P=.61), birth before 37 and 32 weeks (57% compared with 57%, P=.97, and 11% compared with 8%, P=.39), and episodes of recurrent preterm labor. Mild and severe maternal adverse effects were significantly more frequent with magnesium sulfate. Birth weight, birth weight less than 2,500 g, and neonatal morbidities were similar between groups, but newborns in the magnesium sulfate group spent longer in the neonatal intensive care unit (8.8+/-17.7 compared with 4.2+/-8.2 days, P=.007). Patients who received magnesium sulfate achieved the primary outcome more frequently. However, delay of delivery, gestational age at delivery, and neonatal outcomes were similar between groups. Nifedipine was associated with fewer maternal adverse effects.

Effectiveness of Fetal Fibronectin Testing Compared with Digital Cervical Assessment of Women With Preterm Contractions

The purpose of this study is to determine the effectiveness of fetal fibronectin (FFN) compared to assessment of cervical dilation (CD) in clinical management of women with symptomatic preterm labor (PTL). Pregnant women presenting to Thomas Jefferson University Hospital between May 1, 2001 and November 30, 2002 with symptomatic PTL underwent FFN sampling and had a complete clinical evaluation including a pelvic bimanual examination. Inclusion criteria were singleton pregnancy, gestational age (GA) between 24 (0) and 33 (6) weeks, CD < 3 cm, and intact amniotic membranes. FFN samples were sent out and results were available within 4-12 hours. Clinical management including tocolysis, antenatal steroids, and hospitalization was determined based on digital CD assessment and FFN status. A dilated cervix was defined as CD > 1 cm. Ninety-three patients were included. Spontaneous preterm delivery (SPTD) at < 37 weeks occurred in 20 of 93 (21.5%) patients. Medical therapy use was significantly higher in patients with dilated cervix than in those with a closed cervix (all P values < 0.05). Tocolysis and steroid use in FFN-negative patients and FFN-positive patients were not significantly different. Furthermore, tocolytic use was higher in FFN-negative patients than in women with positive FFN (50% versus 42.1%; P = 0.53). Use of antenatal steroids was similar in patients with CD >/= 1 cm and a positive FFN (54.5% versus 47.4%; P = 0.92). Compared with FFN-negative patients, women with closed cervix were less likely to undergo interventions. In symptomatic PTL patients, CD determined clinical management more than FFN status. Overall, the use of FFN was not effective in decreasing "unnecessary" clinical interventions.

Corticotrophin releasing hormone and the timing of birth

Corticotrophin-releasing hormone (CRH) is the hypothalamic peptide that controls the function of the pituitary-adrenal axis in response to stress. CRH is also expressed abundantly in the human placenta and is present in high concentrations in maternal and fetal plasma during late pregnancy. During pregnancy, CRH derived from the placenta is thought to play a crucial role in the regulation of fetal maturation and the timing of delivery, and CRH has also been implicated in the control of fetal-placental blood flow. Elevated CRH concentrations, as compared with gestational age matched controls, occur in patients in preterm labour. The exponential curve depicting the CRH increase is shifted to the left in women who will subsequently deliver preterm and to the right in women who will deliver post dates. This has led to the suggestion that CRH production is linked to a placental clock which determines the length of gestation. Clinically, maternal plasma CRH concentrations may be useful in identifying women at high risk of preterm delivery and CRH antagonists may be useful in preventing preterm labour. As significant CRH production by the placenta is restricted to primates, future research must take into account the species specificity of the mechanisms regulating parturition. A number of significant gaps remain in our knowledge of the function of this peptide in pregnancy. This review examines the current evidence regarding the role of CRH in human parturition.

Expression of cytokines and chemokines in cervical and amniotic fluid: Relationship to histological chorioamnionitis

Objective. To correlate cervical and amniotic fluid cytokines and macrophage-related chemokines to the development of histological chorioamnionitis (HCA) in patients with preterm labor (PTL) and preterm prelabor rupture of the membranes (PPROM).Study design. Cervical and amniotic fluid interleukin (IL)-6, IL-8, IL-18, monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 from pregnant women (at ≤34 weeks of gestation) in PTL (N = 42) were analyzed and related to the subsequent occurrence of HCA or inflammatory signs in the placenta. For the patients with PPROM (N = 30) only amniotic fluid proteins were analyzed.Results. Intra-amniotic levels of IL-6, IL-8, IL-18, MCP-1, and MCP-3 were significantly higher in PTL cases with HCA compared to non-HCA controls, whereas no such relationship was obtained in the PPROM group. Cervical IL-8 and IL-6 (but not IL-18, MCP-1, MCP-2, and MCP-3) in PTL patients was associated with HCA, and at a cut-off level of 10.0 ng/mL cervical IL-8 was a strong predictor of HCA in the PTL cases (sensitivity 100%, specificity 67%, positive predictive value 63%, negative predictive value 100%). The cytokine and chemokine levels in the group with inflammatory signs were generally higher than in controls but lower compared to the concentrations in the HCA group.Conclusions. The amniotic levels of IL-6, IL-8, IL-18, and the CC-chemokines MCP-1 and MCP-3 in PTL patients all predicted HCA, whereas only IL-8 was a clinically useful marker of HCA in the cervical fluid. In addition there is indication that the levels of inflammatory proteins are related to the degree of inflammatory infiltration in placental tissue samples.

Cervical length in women in preterm labor with intact membranes: relationship to intra‐amniotic inflammation/microbial invasion, cervical inflammation and preterm delivery

Intra-amniotic infection, diagnosed by microbial invasion of the amniotic cavity (MIAC) and/or the presence of intra-amniotic inflammation (IAI), is related to adverse perinatal outcome in women with preterm labor. Due to the subclinical nature of IAI, a correct diagnosis depends on amniocentesis, which is an invasive method not performed as a clinical routine. The aim of this study was to evaluate if cervical length measured by transvaginal sonography could assist in the identification of women at high risk for IAI. Cervical length was assessed by transvaginal sonography in 87 women with singleton pregnancies in preterm labor (<34 weeks of gestation). Cervical (n=87) and amniotic (n=55) fluids were collected. Polymerase chain reactions for Ureaplasma urealyticum and Mycoplasma hominis, and culture for aerobic and anaerobic bacteria, were performed. Interleukin (IL)-6 and IL-8 were analyzed by enzyme-linked immunosorbent assay. IAI was present in 25/55 (45%) of the patients presenting with preterm labor who underwent amniocentesis. Women with IAI had a significantly shorter cervical length (median, 10 (range, 0-34) mm) than had those without IAI (median, 21 (range, 11-43) mm) (P<0.0001). Receiver-operating characteristics curve analysis showed that a cervical length (cut-off of 15 mm) predicted IAI (relative risk, 3.6; CI, 1.9-10.0) with a sensitivity of 72%, specificity of 83%, positive predictive value of 78% and negative predictive value of 78%. Cervical length was also significantly associated with preterm birth up to 7 days from sampling and at <or=34 weeks. Cervical length assessed by transvaginal sonography predicts IAI as well as preterm birth and could thereby be a useful clinical tool in the management of patients in preterm labor.

Expression of RND Proteins in Human Myometrium1

RHO GTPases are key regulators of the actin cytoskeleton and stress fiber formation. In the human uterus, activated RHOA forms a complex with RHO-associated protein kinase (ROCK) which inhibits myosin light chain phosphatase (PPP1R12A), causing a calcium-independent increase in myosin light chain phosphorylation and tension (Ca2+ sensitization). Recently discovered small GTP binding RND proteins can inhibit RHOA and ROCK interaction to reduce calcium sensitization. Very little is known about the expression of RND proteins in the human uterus. We tested the hypothesis that the uterine quiescence observed during gestation is mediated by an increase in RND protein expression inhibiting RHOA-ROCK-mediated PPP1R12A phosphorylation. Immunohistochemistry and immunoblotting were used to determine RHOA and RND protein expression and localization in nonpregnant, pregnant nonlaboring, and laboring patients at term and patients in spontaneous preterm labor. Changes in protein expression estimated by densitometry between different patient groups were measured. A significant increase of RND2 and RND3 protein expression was observed in pregnant relative to nonpregnant myometrium associated with a loss of PPP1R12A phosphorylation. RND transfected myometrial cells demonstrated a dramatic loss of stress fiber formation and a "rounding" phenotype. RND upregulation in pregnancy may inhibit RHOA-ROCK-mediated increase in calcium sensitization to facilitate the uterine quiescence observed during gestation.

Effects of Abdominal Breathing on Preterm Labor Anxiety

Purpose: The purpose of this study was to explore the effects of abdominal breathing on relieving anxiety in women diagnosed with preterm labor. Method: This was a pilot study, which was based on a repeated pre-post experiment design without a control group. Seven patients with preterm labor who were admitted to Y university medical center, Seoul, Korea, participated in the experiment. They were under receiving ritodrine hydrochloride(Yutopa) as tocolytic therapy and did not have any other complications. The patients were taught abdominal breathing, which is a modified version of Mason's breathing technique. The experimental treatments were done 33 times from February 18 to June 19 in 2005. Result: After abdominal breathing, the average psychological anxiety level decreased significantly. The physical anxiety levels of preterm labor patients were measured by blood pressure, pulse, and skin temperature. After abdominal breathing, the average systolic and diastolic blood pressure decreased from 117.3mmHg to 107.6 mmHg (z=-3.85, p

Fetal thymic involution: A sonographic marker of the fetal inflammatory response syndrome

The purpose of this study was to evaluate whether there is a relationship between the sonographic fetal thymus size and the presence of an intrauterine infection in patients with preterm labor. Thirty-one women who had been admitted with preterm labor and intact membranes between 24 and 32 weeks of gestation were included. Fetal thymus perimeter was measured sonographically, and amniocentesis for the microbiologic assessment of the amniotic cavity was performed. Placentas and umbilical cords were examined for the presence of chorioamnionitis/funisitis. The prevalence of preterm delivery and intra-amniotic infection was 51.6% (16/31 women) and 32.3% (10/31 women), respectively. In all cases with intrauterine infection and in 23.8% of cases without intrauterine infection, the fetal thymus perimeter was below the 5th percentile for gestational age (10/10 women vs 5/21 women; P < .01). Isolated histologic chorioamnionitis and funisitis were found in 22.6% and 25.8% of fetuses, respectively. The fetal thymus was below the 5th percentile for gestational age in 100%, 71.4%, and 12.5% of patients with histologic signs of funisitis and isolated chorioamnionitis and without histologic signs of infection, respectively. Fetal thymus involution in preterm labor patients is strongly associated with funisitis, which is the histologic manifestation of the fetal inflammatory response syndrome.

Preterm labor (PTL) is associated with changes in progesterone receptor, estrogen receptor and cycloxygenase-2 expression

There are changes in progesterone receptor, estrogen receptor-alpha (ER-α), and cycloxygenase-2 (COX-2) expression associated with term labor. We sought to determine if there are similar changes in total progesterone receptor (total PR-A & PR-B), progesterone receptor B (PR-B), ER-α, and COX-2 expression in patients in PTL.

Women's Health Kaiser Permanente--Improving Women's Lives through Health Care Research, Innovation, and Education

What is “Women's Health”? Women's Health is medical practice that touches all aspects of women's lives—from daily wellness and “thriving” to access to quality medical care. It includes medical research that takes into account gender differences—both biologic and sociologic. It includes innovative programs that constantly push the envelope to provide the highest quality and service. It includes providing superior health education materials that are easy to access and assists women in caring for themselves and their families. It includes providing the best evidence-based education for the doctors and nurses who take care of women when they are sick. KP is uniquely capable of translating research into clinical practice that directly improves patient care. Permanente physicians are committed to evidence-based medicine. But sometimes the evidence doesn't exist in the literature—and we must do our own research to answer our questions about how to best manage our patients. Throughout the Kaiser Permanente (KP) Regions, research studies are designed, the data are analyzed, the answers are applied to our clinical practice, and new innovative programs are born. KP is uniquely capable of translating research into clinical practice that directly improves patient care. Innovative programs are often piloted in single medical centers. Through ongoing quality analysis and our rich communications network, programs that are successful are then recreated and restyled from one medical center to the next—and often from one region to the next. Excellent examples of this process can be seen in the article by Leslie Lieberman, MSW; Cosette Taillac, LCSW; and Nancy Goler, MD, on the Early Start Program (page 62). The clinical need to develop a new way to care for pregnant women with substance abuse problems was identified more than 15 years ago. The key component to Early Start is recognizing that all women need to be screened—both with surveys and toxicology screening. Once women are identified as being at risk, they are managed within the prenatal clinics—using on-site specialists that are part of the obstetrical care team to provide the unique counseling that pregnant women need. Well-constructed research studies showed that this type of identification and intervention could not only help pregnant women stay off drugs but could save money by decreasing hospital admissions for newborns. This program has now been successfully implemented throughout KP Northern California—and is being considered by several other KP Regions for adoption. The Perinatal Nursing Service is another fine example of how provocative research can translate into groundbreaking clinical practice. Yvonne Crites, MD; Jenny Ching, RN; Connie Lessner, RN; and Deborah Ray, MD, describe this program, which was born at a time when commercial home-monitoring technologies were taking over the management of preterm labor patients (page 37). Permanente researchers suspected that there must be a better way to care for these women. Once the best strategy for managing preterm labor was identified, the Perinatal Nursing Service was created to provide case management. During the past decade, the program has grown to include many medical centers—and has expanded to include different high-risk obstetrical conditions. Because of ongoing outcome assessment, the program is now positioned to be expanded as an interregional program. Early Start and the Perinatal Nursing Service are just two examples of the fantastic research and innovation that is going on within KP around the country. As you look through this collection of articles from our colleagues, keep in mind that you are only seeing the tip of the iceberg. Permanente researchers and clinicians are constantly striving to create an even better product for our members and patients. It's what we do best.

Asociación entre la cervicometría y el parto prematuro en pacientes con sospecha de trabajo de parto pretérmino inicial

Objetivo: determinar en gestantes que fueron hospitalizadas con diagnóstico clínico de trabajo de parto pretérmino (TPP) inicial, embarazo único entre las 20 y 36 semanas de gestación y membranas íntegras, la asociación de la cervicometría y otros factores de riesgo, con el parto prematuro por TPP idiopático en nuestra comunidad.Metodología: estudio observacional analítico de tipo cohorte prospectiva realizado en los servicios de obstetricia de tres instituciones en el área metropolitana de Medellín, durante los meses de enero a junio de 2004. Las pacientes fueron divididas en dos grupos: el primero con cervicometría positiva (longitud cervical &lt; 30 mm) y un segundo grupo con cervicometría negativa (longitud cervical &gt; 30 mm) y se determinó la frecuencia de parto prematuro en cada uno de ellos.Resultados: se estudiaron 156 pacientes de las cuales 22 fueron excluidas por no tener información acerca del resultado de la gestación. 53 tenían cervicometría positiva y 81 cervicometría negativa. En el análisis bivariado del parto prematuro con las variables independientes estudiadas, sólo la longitud del cérvix menor 30 mm y la infección vaginal tuvieron asociación estadísticamente significativa. La única variable que en presencia de todas las demás presentó un valor estadísticamente significativo en el análisis multivariado fue la longitud cervical menor de 30 mm con OR 11,1 (IC95% 4,55 – 27,05).Conclusiones: en la población en estudio, la detección en la cervicometría de una longitud cervical menor de 30 mm se constituye en un factor asociado a la posibilidad de tener un parto prematuro como desenlace final.

Impact of Ultrasound Cervical Length Assessment on Duration of Hospital Stay in the Clinical Management of Threatened Preterm Labor

Although women with symptoms of preterm labor usually are hospitalized, only 10% to 30% of those admitted to the hospital because of premature contractions deliver before term. Monitoring of contractions and digital examination do not have good predictive value. As a result, the hospital stay may be unnecessarily prolonged when the risk of preterm delivery is actually very low. This prospective study, enrolling 294 women with threatened preterm labor at 3 hospital units, was an attempt to learn whether ultrasound measurements of cervical length have greater predictive value. Patients in preterm labor reportedly are at very low risk when the cervical length is 15 mm or greater. In the initial phase of the study, cervical length was measured by transvaginal ultrasonography and the managing physicians were blinded to the results. In a second phase, physicians at 1 of the 3 units (group A) remained blinded, whereas those at the other 2 units (groups B and C) were able to incorporate the findings into their management plan. Early discharge was considered in group B women if the cervix measured 25 mm or more within 24 hours of admission. Group C women had a repeat scan after 24 to 48 hours and were considered for discharge when cervical length was unchanged. Women in all 3 groups were similar in age, Bishop scores, and ultrasonographic cervical length at admission. Nulliparous women were more frequent in group A than in the other groups. Hospital time averaged 6.1 days overall. In the interventional phase, women in groups B and C had significantly shorter hospital stays than did group A women. Within the same group, hospital time averaged 4.9 days for nulliparas and 5.2 days for parous women. Rates of delivery within 7 days and delivery before 37 weeks gestation were comparable in all units during both phases of the study. There were also no significant group differences in rates of readmission or the use of tocolytic agents. These findings suggest that ultrasound measurements of cervical length may substantially reduce time in the hospital for women with threatened preterm labor. The examination is noninvasive and the findings are reproducible.