RESUMO
Introduction: Preterm birth, before 37 weeks of gestation, is the main determinant of neonatal morbidity and mortality and is associated with serious consequences,including compromised quality of life for the affected individual and physical, psychological, and economic costs. Objective: To evaluate the correlation of obstetric history, cervicovaginal infections, and cervical length with preterm birth. A prospective, blind cohort study evaluated 1,370 pregnant women from Ribeirão Preto between 20 and 25 weeks of gestation. Materials and methods: The correlation between obstetric history, cervical length, and gestational age at birth was obtained by calculating the relative risk of the different variables. Results: The distribution of pregnant women according to cervical length (CL) showed a predominance of women with a cervix longer than 2.5 cm (n = 1,308, 95.8%), followed by women with a cervix between 2 and 2.49 cm (n = 42, 3.1%) and < 2 cm (n = 15, 1.1%). Among the 1,370 pregnant women evaluated, 133 had spontaneous preterm birth (< 259 days); 14 (10.5%) preterm births occurred in women under 19 years of age, 105 (79%) in women between 19 and 35 years, and 14 (10.5%) in women older than 35 years. Microbiological analysis showed the growth of Mycoplasma hominis, Ureaplasma urealyticum, and other bacteria in 8, 17, and 16 women with preterm birth, respectively. Among the 133 women with spontaneous preterm birth, CL was < 2.5 cm in 15 women, < 2 cm in 3, < 1.5 cm in 3, and < 1 cm in 2. Conclusion: The identification of pregnant women at high risk for preterm delivery can reduce the incidence of preterm birth. Although no gold standard test exists for the prediction of preterm birth, this study confirms that the measurement of CL is a good individual predictor.
Introducción: El nacimiento pretérmino, antes de las 37 semanas de gestación, es el principal determinante de la morbimortalidad neonatal y se asocia a graves consecuencias,incluyendo el compromiso de la calidad de vida del individuo afectado y costes físicos, psicológicos y económicos. Objetivo: Evaluar la correlación de los antecedentes obstétricos, infecciones cervicovaginales y longitud cervical con el parto prematuro. Estudio de cohorte prospectivo, ciego, evaluando 1.370 gestantes de Ribeirão Preto entre 20 y 25 semanas de gestación. Material y métodos: La correlación entre los antecedentes obstétricos, la longitud cervical y la edad gestacional al nacer se obtuvo calculando el riesgo relativo de las diferentes variables. Resultados: La distribución de las gestantes según la longitud cervical (LC) mostró un predominio de mujeres con cuello uterino mayor de 2,5 cm (n = 1,308, 95.8%), seguidas de mujeres con cuello uterino entre 2 y 2,49 cm (n = 42, 3.1%) y menor de 2 cm (n = 15, 1.1%). De las 1,370 embarazadas evaluadas, 133 tuvieron un parto prematuro espontáneo (< 259 días); 14 (10.5%) partos prematuros se produjeron en mujeres menores de 19 años, 105 (79%) en mujeres de entre 19 y 35 años, y 14 (10.5%) en mujeres mayores de 35 años. Los análisis microbiológicos mostraron la proliferación de Mycoplasma hominis, Ureaplasma urealyticum y otras bacterias en 8, 17 y 16 mujeres con parto prematuro, respectivamente. Entre las 133 mujeres con parto prematuro espontáneo, la CL fue < 2.5 cm en 15 mujeres, < 2 cm en 3, < 1.5 cm en 3 y < 1 cm en 2. Conclusión: La identificación de las gestantes con alto riesgo de parto prematuro puede reducir la incidencia de parto prematuro. Aunque no existe una prueba de referencia para la predicción del parto prematuro, este estudio confirma que la medición de la longitud cervical es una buena predicción individual.
Assuntos
Humanos , Feminino , Gravidez , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Complicações Infecciosas na Gravidez/epidemiologia , Colo do Útero/anatomia & histologia , Nascimento Prematuro/etiologia , Nascimento Prematuro/epidemiologia , Estudos Prospectivos , Fatores de Risco , Idade Gestacional , Medição de RiscoRESUMO
This study evaluated the role of 5-HT7 receptors within the central nervous system in modulating cardiovascular responses to the activation of chemo-, baro- and cardiopulmonary reflexes and in the regulation of mean arterial pressure and heart rate, using intracisternal (i.c.) application of the selective 5-HT7 receptor antagonist SB-269970 in awake rats. Experiments were performed on male Wistar rats (300-320 g). At 4 days before the experiment, rats were anesthetized and placed in a stereotaxic frame implantation of a guide cannula in the direction of the cisterna magna to be used for microinjection of saline or SB-269970 (100 microg/kg). On the day before the experiments a femoral artery and vein were cannulated to record arterial pressure and heart rate and to inject drugs to activate cardiovascular reflexes, respectively. The chemo-, baro- and cardiopulmonary reflexes were activated in different experimental groups before and after i.c. injection of saline or SB-269970. The antagonism of 5-HT7 receptors reduced: (a) the pressor (50+/-4 vs. 19+/-9 mm Hg) and bradycardic (-247+/-13 vs. -69+/-27 bpm) responses to chemoreflex activation; (b) the fall in MAP (-54+/-4 vs. -20+/-6 mm Hg) and the bradycardia (-294+/-12 vs. -98+/-34 bpm) in response to cardiopulmonary reflex activation; and (c) the gain of the baroreflex (-2.3+/-0.1 to -0.9+/-0.2 bpm/mm Hg). Intracisternal application of SB-269970 increased significantly baseline MAP in those rats previously submitted to the activation of a cardiovascular reflex but in naïve rats produced no changes in the baseline MAP were observed. The fact that cardiovascular responses to all reflexes tested were attenuated by the antagonism of 5-HT7 receptors suggests that brainstem 5-HT7 receptors brainstem facilitate the processing of the autonomic responses to cardiovascular reflex activation and that a 5-HT-containing pathway to the brainstem provides a normalizing input during challenges produced by cardiovascular reflex activation which seems to be mediated by 5-HT7 receptors.