Assessment of fetal distress based on magnetic resonance examinations: preliminary report.

RATIONALE AND OBJECTIVES: Hypoxia is the main cause of injuries and intrauterine death of the fetus. Therefore, the main aim of monitoring and assessment of the fetus should be diagnosis of fetal distress before irreversible changes occur. Besides the fetal condition assessment methods used so far, in recent years in obstetrics new non-invasive imaging methods were introduced such as magnetic resonance (MR). This method enables morphologic evaluation of brain and brain tissue metabolism using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: Twenty pregnant women with pregnancy-induced hypertension (11 cases, including 3 with coexisting diabetes mellitus and 2 with intrauterine growth retardation), chronic hypertension (2 cases), gestational diabetes mellitus (6 cases), and suspected intrauterine fetal growth retardation (IUGR) participated in the study. Cardiotocography (CTG) and Doppler ultrasound examination of the blood flow in the umbilical artery and in the middle cerebral artery were performed. RESULTS: In case of abnormal CTG and Doppler study records that indicated fetal hypoxia, MR studies showed the existence of ischemic focus in 5 patients and abnormal spectral images in 6 patients. CONCLUSION: The results of the preliminary study suggests that the use of MR in prenatal diagnosis may revolutionize the early detection of fetal injury in fetal distress. It is a valuable component of the diagnostic process, supplementing other examinations. The use of MR to assess fetal condition gives additional information and helps to make decisions about therapeutic actions.

Evaluation of interleukin concentrations in amniotic fluid in preterm and term parturition and in oligohydramnios.

BACKGROUND: The goal of our work was to evaluate the activity of interleukin 1 beta, 6, 8, 12, and 18 in the amniotic fluid in preterm and term deliveries, and to specify the dependency between the amniotic fluid index (AFI) and the concentration of these interleukins. MATERIAL AND METHODS: Amniotic fluid (27 samples from preterm deliveries and 49 from term deliveries) was collected during cesarean section or in the course of amnioinfusion performed when the pregnancy was accompanied by oligohydramnios (AFI< or = 5cm). The amniotic fluid thus obtained was centrifuged at 1000 xg for 15 min. at a temperature of 4 degrees C, and the filtrate was kept at a temperature of -80 degrees C until assayed. The assays were done by the ELISA method, using ready antibody kits from 'R&D Systems'. A comparative analysis was done for the concentrations (expressed in pg/ml) of the individual interleukins found in the amniotic fluid from preterm and term deliveries, and for the amniotic fluid index (AFI< or = L5 and >5). The statistical analysis was performed using the Wilcoxon test. RESULTS: The increased level of IL-12 we found in the amniotic fluid from preterm deliveries and those complicated by oligohydramnios may indicate the participation of immunological mechanisms in the pathogenesis of oligohydramnios.

[The amniotic fluid of term and preterm delivery and its influence on contractions of human myometrium in vitro]. / Ocena wplywu plynu owodniowego z ciaz donoszonych i niedonoszonych na czynnosc skurczowa myometrium ludzkiego w warunkach in vitro.

Initiation of labour is a complex process that involves fetal-maternal communication. Although the mechanism of the initiation of preterm labour has not been elucidated fully, it may differ from that in normal labour. The aim of this research was to study the effect of amniotic fluid from term and preterm deliveries on human myometrial contractions. The amniotic fluid was obtained from 45 women, who underwent caesarean section preterm (18) and at term (27) for routine obstetric indications. The influence of preterm and term amniotic fluid on spontaneous and oxytocin stimulated by in vitro isometric myometrial contractions was evaluated. Repeated measured ANOVA was performed for statistical analysis. Amniotic fluid from preterm delivery successfully inhibits myometrial contractions stimulated by oxytocin, so it may play role in maintaining normal pregnancy and preventing preterm delivery.

Permeability of fetal membranes to calcium and magnesium: possible role in preterm labour.

Calcium (Ca(2+)) and magnesium (Mg(2+)) are co-factors in the synthetic activity of a variety of enzymes and in the secretory process. Both the binding to fetal membranes and the diffusion through the membranes of these two cations could be important factors in the synthesis and/or action of prostaglandins and generation of nitric oxide (NO) which are believed to regulate myometrial activity particularly for the induction of labour. In the present study, the permeability to Ca(2+) and Mg(2+) of chorioamniotic membranes obtained from women who had undergone term or preterm labour was examined. Diffusion of Ca(2+) and Mg(2+) were measured using a system of Plexiglas chambers separated by the mounted fetal membrane. Permeability of Mg(2+) and Ca(2+) through fetal membranes was calculated using non-linear regression analysis. The data show highly significant differences in the diffusion of Ca(2+) and Mg(2+) across fetal membranes between preterm and term labour. Transport coefficient K for Ca(2+) was 0.203 h(-1) and 0. 0223 h(-1) in term and preterm labour respectively. The corresponding values for Mg(2+) were -0.017 h(-1) and 0.051 h(-1) respectively. It is proposed that a considerable reduction in Ca(2+) available to myometrium and placenta would result in down-regulation of nitric oxide synthase (NOS) activity and thereby a reduction in NO production. This together with an effect on intracellular Ca(2+) transport resulting from a reduced availability of Mg(2+) would lead to increased myometrial activity in preterm labour.

[The Doppler cerebroplacental ratios and perinatal outcome in post-term pregnancy]. / Dopplerowskie wskazniki mózgowo-lozyskowe a wynik okoloporodowy w ciazy przeterminowanej.

Our purpose was to determine whether the Doppler cerebroplacental ratios predicts perinatal outcome in postterm pregnancy. The middle cerebral to umbilical artery resistant and pulsatility indices (MCA PI/UA PI and MCA RI/UA RI) were measured in 59 postterm pregnancies. We found significant correlation between MCA PI/UA PI, MCA RI/UA RI, nonstress testing and intrapartum fetal heart rate assessment. There was also an association between MCA PI/UA PI and 1- and 5-minute Apgar score. We conclude that the Doppler cerebroplacental ratios provide useful information about perinatal outcome.

Receptor binding of oxytocin and vasopressin antagonists and inhibitory effects on isolated myometrium from preterm and term pregnant women.

OBJECTIVE: To test binding affinities for, and inhibitory effects on, myometrium of some oxytocin and vasopressin antagonists with respect to their therapeutic potential. DESIGN: Receptor binding studies on transfected cell lines. In vitro contractility studies of human myometrium. SETTING: The Research Laboratory of Sanofi Recherche, Centre de Toulouse, France and the Departments of Obstetrics and Gynecology, Lund University Hospital, Sweden and Bialystok University Hospital, Poland. PARTICIPANTS: Nine women delivered by caesarean section preterm and 37 delivered at term for routine obstetric indications. INTERVENTIONS: The binding affinities of oxytocin, arginine vasopressin, atosiban (1-deamino-2-D-Tyr(OEt)-4-Thr-8-Om-oxytocin), SR 49059 and SR 121463 for the human oxytocin and different subtypes of vasopressin receptors were determined. Concentration-response curves with oxytocin and arginine vasopressin were recorded on myometrium from preterm- and term-delivered women in control experiments and in the presence of 2.5 and 10 nmol/L of SR 49059. Furthermore, using term myometrium, the influence of SR 49059 and SR 121463 in concentrations of 3, 10, 30 and 100 nmol/L on responses to the EC50 concentrations of oxytocin and vasopressin were compared. MAIN OUTCOME MEASURES: Receptor binding affinities. In vitro contractile effects and their inhibitions. RESULTS: Oxytocin had a high affinity for the oxytocin receptor (K(i) in mean = 6.8 nmol/L) and bound, to some extent, to the vasopressin V1a receptor (K(i) = 34.9 nmol/L). Vasopressin displayed higher affinities for vasopressin V1a, V1b and V2 receptors (K(i) = 1.4, 0.8 and 4.2 nmol/L, respectively) than for the oxytocin receptor (K(i) = 48 nmol/L). Atosiban and SR 49059 both had a high affinity for the vasopressin V1a receptor (K(i) = 4.7 and 7.2 nmol/L, respectively, and a moderate one for the oxytocin receptor (K(i) = 397 and 340 nmol/L, respectively). SR 121463 exerted a predominant binding to the V2 receptor (K(i) = 3.0 nmol/L). In the concentration-response experiments levels of up to 10 nmol/L of SR 49059 had no influence on the effect of oxytocin on myometrium from women preterm and at term pregnancy. However, a concentration-dependent inhibition of the responses of both these type of tissues to vasopressin was seen. The effects of EC50 concentrations of oxytocin and vasopressin on term pregnant myometrium were markedly inhibited by 10 nmol/L and higher concentrations of SR 49059, the inhibition of the response to vasopressin being more pronounced than that of the oxytocin response. SR 121463 at maximal concentration only caused slight inhibitions of the oxytocin and vasopressin responses. CONCLUSIONS: Atosiban and SR 49059 both have moderate binding affinities for the human oxytocin receptor and high binding affinities for the vasopressin V1a one. We demonstrated that SR 49059 inhibits the response of term myometrium to oxytocin and that of both preterm and term myometrium to vasopressin. These observations suggest a therapeutic potential of SR 49059 in preterm labour. The vasopressin V2 receptor is apparently not involved to any significant degree in the activation of the pregnant human uterus.

Uterine and fetal Doppler flow changes after misoprostol and oxytocin therapy for induction of labor in post-term pregnancies.

OBJECTIVES: To compare the effect of misoprostol vs. oxytocin on blood flow in uteroplacental circulation during labor induction. METHODS: Ninety-one women with indications for induction of labor were assigned to receive either misoprostol 50 microg per vagina every 4 h as needed or intravenous oxytocin by means of a randomization table generated by computer. Doppler velocimetry of umbilical, uterine and arcuate arteries was performed immediately before and 2-3 h after administration of misoprostol or oxytocin. Pulsatility index (PI), resistance index (RI) and systolic/diastolic (S/D) ratios were measured for these arteries. The SAS system was used to perform statistical analysis. RESULTS: There were no significant changes of PI, RI and S/D ratios in umbilical arteries during misoprostol and oxytocin inductions. Vaginal application of misoprostol significantly increased PI, RI and S/D ratios in arcuate arteries and S/D ratio in uterine arteries. CONCLUSIONS: Our results indicate that intravaginal misoprostol administration increases uteroplacental resistance but probably does not substantially affect placental perfusion.