Normal amino-terminal pro-brain natriuretic peptide (NT-proBNP) values in amniotic fluid.

INTRODUCTION: Brain natriuretic peptide (BNP) is synthesized by human fetal membranes, both the amnion and chorion. This locally produced BNP inhibits the contraction of the human myometrium, contributing to the maintenance of myometrial quiescence during pregnancy. Reference values for NT-proBNP concentrations in amniotic fluid at different gestational ages have not been completely defined. We aimed to investigate the range of fetal NT-proBNP values in amniotic fluid in normal pregnancy between 17 and 41weeks of gestation. METHODS: Samples of amniotic fluid were obtained from women meeting the following inclusion criteria: gestational age defined by early ultrasound, singleton gestation and not in labor. The exclusion criteria were as follows: multiple gestation, clinically evident chorioamnionitis, laboratory signs of infection in the amniotic fluid sample and fetal conditions that may alter NT Pro-BNP levels (anemia, hydrops, etc.). NT-proBNP concentrations in amniotic fluid were measured using the automated Elecsys® proBNP assay. RESULTS: We analyzed 218 samples of amniotic fluid at various gestational ages. Half of the samples were obtained by amniocentesis (118 samples), and the other half (100 samples) were obtained by direct puncture at the time of cesarean section. We found a significant decline in NT-proBNP concentrations with advancing gestational age. DISCUSSION: Gestational age has to be taken into consideration in the assessment of NT-proBNP values. Our data may be used as reference values in fetal medicine, as a possible predictor of preterm delivery risk using the inferior limit (0.5 multiples of the median (MoM)) of our normal curve.

The Synergic In Vitro Tocolytic Effect of Nifedipine Plus Ritodrine on Human Myometrial Contractility.

Many pharmacological agents have been investigated to manage preterm labor; we postulate that a combination of tocolytic drugs may achieve a better effect in the prevention of uterine contractions without dose-dependent adverse effects. The aim of this study was to evaluate the inhibitory effect of dual combinations of tocolytics in vitro. Human myometrium was obtained during elective cesarean sections (term without labor; n = 40). Myometrial strips were placed in organ baths for the measurement of isometric tension. Contractile activity was induced by oxytocin (10-8 mol/L), then a concentration-response curve to single or dual combinations of tocolytics was started. All studied tocolytics (nifedipine, ritodrine, nitroglycerin, atosiban, and NS-1619), when used alone, significantly inhibited myometrial contractions. When combined, nifedipine plus ritodrine produced a significantly greater inhibition of contractility than each drug alone in the midrange of concentrations. The combination of nifedipine plus nitroglycerin or nifedipine plus atosiban produced a significantly greater inhibition than nitroglycerin or atosiban alone but not greater than nifedipine. The combination of nifedipine plus NS-1619 (Ca+2-activated K+ [BKCa] channel opener) reduced the inhibitory effect of each drug. We concluded that a selected combination of tocolytics (nifedipine plus ritodrine) produced a significantly greater inhibitory effect on contractility than each drug alone at intermediate concentrations. Thus, specific combinations of tocolytics with different intracellular signaling pathways may have a synergic effect constituting a provocative new option for preterm labor treatment.

Parto Natural. ¿Qué nos dice la evidencia? / Natural birth. What does the evidence tell us?

Introducción: Es deseable que el proceso del parto concluya con una madre y un recién nacido sano, y sea un momento especial e íntimo. El Parto Natural, ha sido propuesto como una opción para mejorar la satisfacción de las mujeres con el proceso del parto. Sin embargo, no existen definiciones serias respecto a qué es el Parto Natural, introduciendo dificultades en la atención de mujeres que solicitan un Parto Natural. Métodos: El objetivo de este artículo es revisar la mejor evidencia disponible para entender cómo debe definirse un Parto Natural y analizar si se asocia a riesgos mayores que los de la atención médica habitual del parto. Resultados: Hemos comprobado que no existen definiciones científicas consensuadas para precisar qué es el Parto Natural, dejando espacio para discusión sobre su verdadero significado. No existen estudios de diseño aleatorizado y controlado que comparen el resultado materno/perinatal del parto natural comparado con la atención habitual del parto. Las intervenciones médicas, usadas en la atención médica del parto, y que podrían ser evitadas en el Parto Natural, producen algunos cambios favorables y otros deletéreos respecto de la salud materna y perinatal. Conclusiones: La decisión de optar por el Parto Natural debe ser discutida con las mujeres que lo solicitan, precisando con ella y su pareja cuál es su concepto de parto natural o qué es lo que desean incluir o evitar, los riesgos y beneficios asociados a cada una de las intervenciones deben ser expuestos por el equipo médico, para adoptar un plan de manejo individualizado.(AU)

Introduction: It is desirable that the birth process concludes with a healthy mother and newborn, while at the same time being a special and intimate moment. Natural childbirth has been proposed as a recent option to improve the satisfaction of women with the process of childbirth. However, there are no serious definitions regarding what is or should be a Natural Childbirth, introducing difficulties in the care of women who request a Natural Birth. Methods: The objective of this article is to review the best available evidence to understand how Natural Childbirth should be defined and to analyze if it is associated with greater maternal or perinatal risks than those of usual medical care at birth. Results: We verified that there are no agreed scientific definition to specify what Natural Childbirth is, leaving space for discussion about its true meaning. There are no randomized, controlled trials comparing the maternal/ perinatal outcome of natural childbirth compared to usual medical care during labor/delivery. Medical interventions used in childbirth are that could be avoided in natural birth produce some favorable changes and some deleterious changes in maternal and perinatal health. Conclusions: The decision to choose Natural Childbirth must be discussed with the women who request it, specifying with her and her partner´s concept of natural childbirth or what they wish to include or avoid, the risks and benefits associated with these interventions must be exposed by the medical team, to adopt an individualized management plan.(AU)

Síndrome de HELLP normotensivo: caso clínico / Normotensive HELLP syndrome: Report of one case

HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) represents a severe form ofpreeclampsia associated with serious maternal and fetal morbiditiesand even death. Usually HELLP syndrome appears during the evolution of a severepreeclampsia; however HELLP syndrome can have atypical clinical manifestations.We report a 22-year-old female who consulted at 20 weeks of pregnancy for lumbarpain, dysuria and fever. A urinalysis revealed the presence of white blood cells. Thepatient was admitted to hospital and treated with antimicrobials. Forty eight hoursafter admission a proteinuria of 440 mg/24 h was detected. A severe pre eclampsia-HELLP syndrome was diagnosed. However the patient remained with normal bloodpressure. An elevation of liver enzymes and creatinine were observed. Five dayslater fetal death was confirmed and an abortion was induced. The patient requireda platelet transfusion. Four days after the abortion, the patient was discharged ingood conditions.

[Normotensive HELLP syndrome: report of one case]. / Síndrome de HELLP normotensivo: caso clínico.

HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) represents a severe form of preeclampsia associated with serious maternal and fetal morbidities and even death. Usually HELLP syndrome appears during the evolution of a severe preeclampsia; however HELLP syndrome can have atypical clinical manifestations. We report a 22-year-old female who consulted at 20 weeks of pregnancy for lumbar pain, dysuria and fever. A urinalysis revealed the presence of white blood cells. The patient was admitted to hospital and treated with antimicrobials. Forty eight hours after admission a proteinuria of 440 mg/24 h was detected. A severe pre eclampsia-HELLP syndrome was diagnosed. However the patient remained with normal blood pressure. An elevation of liver enzymes and creatinine were observed. Five days later fetal death was confirmed and an abortion was induced. The patient required a platelet transfusion. Four days after the abortion, the patient was discharged in good conditions.