Asunto(s)
Edad Gestacional , Recien Nacido Extremadamente Prematuro , Guías de Práctica Clínica como Asunto , Nacimiento Prematuro/fisiopatología , Nacimiento Prematuro/terapia , Anomalías Congénitas/epidemiología , Toma de Decisiones , Femenino , Humanos , Recién Nacido , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Cuidado Intensivo Neonatal/organización & administración , Trabajo de Parto/fisiología , Cuidados para Prolongación de la Vida , Padres/psicología , Comodidad del Paciente , Atención Perinatal/organización & administración , Mortalidad Perinatal , Embarazo , Nacimiento Prematuro/mortalidad , Pronóstico , Medición de Riesgo , Factores SexualesAsunto(s)
Parto Domiciliario/mortalidad , Hospitalización , Mortalidad Perinatal , Femenino , Humanos , EmbarazoRESUMEN
The management of preterm birth has seen major transformations in the last few decades with increasing interest worldwide, due to the impact of preterm birth on neonatal morbidity and mortality. The prevention strategies currently available for asymptomatic women at risk of preterm birth include progesterone, cervical cerclage and cervical pessary. Each approach has varying effects depending on the patient's prior history of preterm birth, cervical length and the presence of multiple gestations. There is a shift in the focus of antenatal treatment, with the use of prenatal magnesium sulphate and corticosteroids, to reduce neonatal intensive care admissions and longer-term disabilities associated with preterm birth, consequently relieving emotional and economical burden. This article provides an update on the recent advances in prevention and management approaches available for women at risk of preterm birth.
RESUMEN
Cervical cerclage is commonly used in the management of women considered to be at high risk of second-trimester loss and spontaneous preterm birth. Insertion is dictated by factors such as multiple pregnancy, uterine anomalies, a history of cervical trauma through destructive procedures or forced dilatation, and cervical shortening seen on transvaginal ultrasound examination. However, its use and efficacy in these different groups is highly controversial as there is contradiction in the results of individual studies and meta-analyses. This review examines the contemporary evidence on cervical cerclage and its current role in obstetrics.
Asunto(s)
Cerclaje Cervical , Medicina Basada en la Evidencia , Incompetencia del Cuello del Útero/cirugía , Femenino , Fibronectinas/análisis , Humanos , Embarazo , Segundo Trimestre del Embarazo , Nacimiento Prematuro/prevención & control , Progesterona/uso terapéutico , Ultrasonografía Prenatal , Incompetencia del Cuello del Útero/diagnóstico , Incompetencia del Cuello del Útero/diagnóstico por imagenRESUMEN
OBJECTIVE: To assess the feasibility of foetal cerebral lactate detection and quantification by proton magnetic resonance spectroscopy ((1)H-MRS) in pregnancies at increased risk of cerebral hypoxia, using a clinical 1.5 T magnetic resonance imaging (MRI) system. METHOD: Localised (1)H-MRS was performed in four patients with pregnancies in their third trimester complicated by intrauterine growth restriction (IUGR). A long echo time (TE) of 288 ms was used to maximise detection and conspicuity of the lactate methyl resonance, together with a short TE MRS acquisition to check for the presence of lipid contamination. Individual peaks in the resulting spectra were measured, corrected for relaxation and referenced to the unsuppressed water signal to provide metabolite concentrations. RESULTS: A resonance peak consistent with the presence of lactate was observed in all cases. In one subject, this was confounded by the identification of significant lipid contamination in the short TE MRS acquisition. The range of measured lactate concentrations was 2.0-3.3 mmol/kg and compared well with preterm neonatal MRS studies. CONCLUSION: The non-invasive detection and quantification of foetal cerebral lactate by MRS is achievable on a clinical 1.5 T MRI system.
Asunto(s)
Encéfalo/metabolismo , Feto/metabolismo , Hipoxia Encefálica/metabolismo , Ácido Láctico/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Adulto , Biomarcadores/análisis , Encéfalo/embriología , Química Encefálica , Femenino , Retardo del Crecimiento Fetal/metabolismo , Hipoxia Fetal/diagnóstico , Hipoxia Fetal/metabolismo , Humanos , Hipoxia Encefálica/embriología , Ácido Láctico/análisis , Imagen por Resonancia Magnética/instrumentación , Insuficiencia Placentaria/diagnóstico , Insuficiencia Placentaria/metabolismo , Embarazo , Tercer Trimestre del EmbarazoRESUMEN
BACKGROUND: Physiological and biochemical studies suggest that normal parturition at term is dependent on programmed development of the uterus in early pregnancy. It is recognized that a short cervix in mid-pregnancy is associated with an increased risk of spontaneous preterm birth. We hypothesized that a long cervix in mid-pregnancy would be associated with an increased risk of cesarean delivery during labor at term. METHODS: We studied 27,472 primiparous women who had a cervical length of 16 mm or more at a median of 23 weeks of gestation and who ultimately delivered a live infant in labor at term. RESULTS: The rate of cesarean delivery at term was lowest (16.0%) among women with a mid-pregnancy cervical length in the lowest quartile (16 to 30 mm) and was significantly greater in the second quartile (18.4%, 31 to 35 mm), third quartile (21.7%, 36 to 39 mm), and fourth quartile (25.7%, 40 to 67 mm) (P<0.001 for trend). The odds ratio for cesarean delivery among women in the fourth quartile, as compared with the first quartile, was 1.81 (95% confidence interval [CI], 1.66 to 1.97), and the odds ratio adjusted for maternal age, body-mass index, smoking status, race or ethnic group, gestational age at birth, spontaneous or induced labor, birth-weight percentile, and hospital of delivery was 1.68 (95% CI, 1.53 to 1.84; P<0.001). The increased risk of cesarean delivery was attributable to procedures performed for poor progress in labor. CONCLUSIONS: The cervical length at mid-pregnancy is an independent predictor of the risk of cesarean delivery at term in primiparous women.
Asunto(s)
Medición de Longitud Cervical , Cuello del Útero/anatomía & histología , Cesárea , Adulto , Cuello del Útero/diagnóstico por imagen , Femenino , Edad Gestacional , Humanos , Recién Nacido , Modelos Logísticos , Embarazo , Segundo Trimestre del Embarazo , RiesgoRESUMEN
The efficacy of Shirodkar cerclage was compared with that of the McDonald procedure for the prevention of preterm birth (PTB) in women with a short cervix. Secondary analysis using data from all published randomized trials including women with a short cervical length (CL) was performed comparing the use of Shirodkar versus McDonald sutures. Analysis was limited to singletons with short CL on transvaginal ultrasound. The primary outcome measure was PTB < 33 weeks. Statistical analysis was performed using bivariate and multivariable techniques. From 607 women randomly assigned in the study, 277 met our inclusion criteria; 127 received Shirodkar and 150 women received McDonald sutures. The mean ( +/- standard deviation) gestational age at delivery was 35.0 +/- 5.3 versus 36.3 +/- 4.7 for the Shirodkar versus McDonald groups, respectively ( p< 0.02). PTB < 33 weeks was seen in 61 (22%) of 277 women; 26 (20%) of 127 in the Shirodkar and 35 (23%) of 150 in the McDonald groups, respectively (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.5 to 1.6). On adjusting for confounders using logistic regression modeling, no significant difference in PTB < 33 weeks was found between the two groups (OR, 0.55; 95% CI, 0.2 to 1.3). In women with short cervical length randomly assigned to receiving cerclage, no significant difference in prevention of PTB was observed using Shirodkar or McDonald's procedures.
Asunto(s)
Cerclaje Cervical/métodos , Cuello del Útero/patología , Nacimiento Prematuro/prevención & control , Incompetencia del Cuello del Útero/cirugía , Adolescente , Adulto , Femenino , Humanos , Embarazo , Atención Prenatal , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoRESUMEN
OBJECTIVE: The purpose of this study was to examine the value of combining maternal characteristics and measurement of cervical length at 22 to 24 weeks in the prediction of spontaneous early preterm delivery. STUDY DESIGN: Cervical length was measured by transvaginal sonography at 22 to 24 weeks in 1163 twin pregnancies attending for routine antenatal care. Logistic regression analysis was used to examine the effect of maternal demographic characteristics and cervical length on the risk of spontaneous early preterm delivery. RESULTS: The rate of spontaneous delivery before 32 weeks was 6.5%. The rate of early delivery was inversely related to cervical length, and for a false-positive rate of 10%, the detection rate of early delivery was 65.3%. The respective detection rate for maternal characteristics and obstetric history was 26.4%. Logistic regression analysis demonstrated that the only significant independent predictor of spontaneous early delivery was cervical length. CONCLUSION: In twins, the prediction of spontaneous early preterm delivery by measurement of cervical length at 22 to 24 weeks is not improved by maternal characteristics.
Asunto(s)
Cuello del Útero/diagnóstico por imagen , Trabajo de Parto Prematuro/etiología , Embarazo Múltiple , Gemelos , Adolescente , Adulto , Femenino , Humanos , Incidencia , Modelos Logísticos , Registros Médicos , Persona de Mediana Edad , Trabajo de Parto Prematuro/epidemiología , Valor Predictivo de las Pruebas , Embarazo , Curva ROC , Factores de Riesgo , UltrasonografíaRESUMEN
OBJECTIVE: Preterm birth is the main cause of perinatal morbidity and mortality. A short cervical length on transvaginal ultrasonography predicts preterm birth. Our aim was to estimate by meta-analysis of randomized trials whether cerclage prevents preterm birth in women with a short cervical length. DATA SOURCES: MEDLINE, PubMed, EMBASE, and the Cochrane Library were searched with the terms "cerclage," "cervical cerclage," "short cervix," "ultrasound," and "randomized trial." We included randomized trials involving the use of cerclage in women with short cervical length on transvaginal ultrasonography using patient-level data. TABULATION, INTEGRATION, AND RESULTS: Four properly conducted trials were identified. In the total population, preterm birth at less than 35 weeks of gestation occurred in 29.2% (89/305) of the cerclage group, compared with 34.8% (105/302) of the no-cerclage groups (relative risk [RR] 0.84, 95% confidence interval [CI] 0.67-1.06). There was no significant heterogeneity in the overall analysis (P = .29). There was a significant reduction in preterm birth at less than 35 weeks in the cerclage group compared with the no-cerclage groups in singleton gestations (RR 0.74, 95% CI 0.57-0.96), singleton gestations with prior preterm birth (RR 0.61, 95% CI 0.40-0.92), and singleton gestations with prior second-trimester loss (RR 0.57, 95% CI 0.33-0.99). There was a significant increase in preterm birth at less than 35 weeks in twin gestations (RR 2.15, 95% CI 1.15-4.01). CONCLUSION: Cerclage does not prevent preterm birth in all women with short cervical length on transvaginal ultrasonography. In the subgroup analysis of singleton gestations with short cervical length, especially those with a prior preterm birth, cerclage may reduce preterm birth, and a well-powered trial should be carried out in this group of patients. In contrast, in twins, cerclage was associated with a significantly higher incidence of preterm birth.
Asunto(s)
Cerclaje Cervical/métodos , Resultado del Embarazo , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/prevención & control , Incompetencia del Cuello del Útero/diagnóstico por imagen , Incompetencia del Cuello del Útero/cirugía , Adulto , Intervalos de Confianza , Femenino , Estudios de Seguimiento , Edad Gestacional , Humanos , Incidencia , Recién Nacido , Edad Materna , Paridad , Embarazo , Probabilidad , Ensayos Clínicos Controlados Aleatorios como Asunto , Medición de Riesgo , Sensibilidad y Especificidad , Resultado del Tratamiento , Ultrasonografía PrenatalRESUMEN
BACKGROUND: Cervical cerclage has been widely used in the past 50 years to prevent early preterm birth and its associated neonatal mortality and morbidity. Results of randomised trials have not generally lent support to this practice, but this absence of benefit may be due to suboptimum patient selection, which was essentially based on obstetric history. A more effective way of identifying the high-risk group for early preterm delivery might be by transvaginal sonographic measurement of cervical length. We undertook a multicentre randomised controlled trial to investigate whether, in women with a short cervix identified by routine transvaginal scanning at 22-24 weeks' gestation, the insertion of a Shirodkar suture reduces early preterm delivery. METHODS: Cervical length was measured in 47?123 women. The cervix was 15 mm or less in 470, and 253 (54%) of these women participated in the study and were randomised to cervical cerclage (127) or to expectant management (126). Primary outcome was the frequency of delivery before 33 completed weeks (231 days) of pregnancy. FINDINGS: The proportion of preterm delivery before 33 weeks was similar in both groups, 22% (28 of 127) in the cerclage group versus 26% (33 of 126) in the control group (relative risk=0.84, 95% CI 0.54-1.31, p=0.44), with no significant differences in perinatal or maternal morbidity or mortality. INTERPRETATION: The insertion of a Shirodkar suture in women with a short cervix does not substantially reduce the risk of early preterm delivery. Routine sonographic measurement of cervical length at 22-24 weeks identifies a group at high risk of early preterm birth.