Journal of maternal-fetal investigation : the official journal of French Society of Ultrasound in Medicine and Biology ... [et al.]最新文献

>Objective: To evaluate longitudinally the renal circulation from late gestation to the first year of life in order to understand fundamental changes within this vascular bed as the fetus adapts to major circulatory changes occurring during this time period.Methods: Sixteen healthy human fetuses were studied during the last trimester of the pregnancy, within 2 days of birth, at 6 weeks, at 6 months, and at 1 year. Using noninvasive color pulsed Doppler, blood flow velocities of the renal artery, the tricuspid and mitral valves in the fetus, and in the ascending aorta in the newborn/infants were obtained at each study. Diameters of these respective areas were also obtained. Total cardiac output and renal blood flow were calculated using the time velocity integral, the area of the structure of interest, and heart rate.Results: 1) Renal artery dimensions, time velocity integral, peak flow velocity, systolic to diastolic ratio, absolute volume blood flow (RVBF) were all significantly correlated with advancing gestational age; 2) RVBF relative to body weight and percent RVBF were not.Conclusions: In spite of an overall increase in renal blood flow, flow to the kidney appears to be constant during the time period of this study. Most of the "maturational" changes that occur within this vascular bed appear to be related to changes within the vascular resistance and the renal artery diameter.

>The characterization of the nature and time of onset of intervillous blood flow has been the subject of much recent debate. This review advances several hypotheses regarding the physiology of intervillous flow and summarizes the human and monkey evidence that currently exists. As foundational to the discussion, the historical light microscopic data is presented, and this is then coupled with illustrations from current ultrasound work that involves pulsed wave Doppler, color amplitude imaging, and color Doppler imaging. The evidence clearly suggests that intervillous flow is a normal and consistent finding in the early first trimester pregnancy.

>Objective: To describe the fetal heart rate (FHR) patterns of 300 term brain-damaged infants.Methods: The fetal monitor strips of 300 singleton term neurologically impaired neonates were retrospectively analyzed.Results: Of the 300 infants, the admission FHR patterns were: reactive, 152 (51%); nonreactive, 135 (45%); bradycardia, 9 (3%); or unclassifiable, 4 (1%). In the reactive group, the FHR did the following: 1) remained reactive throughout labor [24 (16%)]; 2) developed an elevated baseline FHR in association with repetitive FHR decelerations and, in most instances, a loss of variability [67 (22%)]; or 3) developed a sudden prolonged FHR deceleration that lasted until delivery [61 (20%)]. Finally, the nonreactive admission group exhibited the following: 1) a persistent fixed baseline rate from admission (149 +/- 16 beats/min) [97 (72%)]; 2) a prolonged FHR deceleration that lasted until delivery [12 (9%)]; or 3) a stair steps to death pattern [26 (19%)].Conclusions: While term infants later found to be neurologically impaired do not manifest a uniform FHR pattern, these fetuses do manifest distinct FHR patterns intrapartum that can be easily categorized and identified on the basis of the fetal admission test and subsequent changes in the baseline heart rate. This distinction should prove helpful in the management of obstetrical patients in labor.

>Objective: Administration of purified human IgG from antiphospholipid syndrome patients has not consistently caused murine pregnancy loss despite the presence of significant anticardiolipin antibody (ACA) activity. We evaluated whether a correlation exists between ACA activity and the degree of fetal resorption in murine pregnancy and also determined whether pooled IgG from multiple ACA-positive patients increases the likelihood of fetal resorption compared with injection of single-donor IgG.Methods: Affinity chromatography followed by anisotropic ultrafiltration was used to extract and concentrate IgG from individual serum samples with and without ACA activity (ACA-positive IgG activity, 35-85 GPL versus ACA-negative IgG activity, <1 GPL) and from pooled aliquots derived from the same sera. On Day 8 of gestation, pregnant mice randomly received intraperitoneal injections of ACA-positive or ACA-negative, purified IgG (15 mg/mouse) or saline (1 ml). Laparotomies were performed on day 15, and uteri were harvested for gross evaluation and histologic study. Rates of fetal resorption were derived for each murine pregnancy (resorbed fetuses/resorbed fetuses + live pups) and compared between experimental groups.Results: A significant increase in fetal resorption rate was observed in ACA-positive IgG-treated animals (n = 19, 19.3%) compared with either ACA-negative (n = 5, 6.4%; P = 0.008) or saline-treated pregnancies (n = 8, 4.6%; P = 0.004). However, differences in resorption rates among the ACA-positive IgG-treated pregnancies did not correlate with initial ACA activity of the whole serum or with antibody activity measured in the purified, concentrated IgG preparations. A comparison of fetal resorption between single donor ACA-positive IgG and pooled ACA-positive IgG revealed similar rates of fetal resorption (20.5 versus 17.9%, respectively) but a lower mean birth weight among non-resorbed pups in the single-donor IgG-treated pregnancies (340 versus 430 mg; P = 0.05).Conclusions: Although greater murine fetal resorption resulted from ACA-positive IgG administration compared with ACA-negative IgG or saline injection, marked variability in pregnancy outcome was observed among ACA-positive animals. These differences were not attributable to initial antibody activity in whole serum or to activity associated with the purified immunoglobulins. Combining multiple ACA-positive sera did not augment the rate of fetal resorption.

>Objective: Variability of the fetal heart rate (FHR) is used clinically to assess fetal well being. Approximate entropy (ApEn) is a statistic that quantifies the regularity of a time series. This study was designed to test whether ApEn changed in the FHR of the hypoxic ovine fetus.Methods: Five time-bred ewes at 130 days of gestation were surgically prepared with fetal arterial catheters, fetal electrodes, and a maternal common uterine artery snare occluder. After recovery, a continuous fetal electrocardiogram recording was started, and control blood gas measurements were made. The uterine blood flow was then reduced with the occluder, and blood gas measurements were repeated at fetal pH 7.20 and 7.00. The FHR tracing (1,000 beats) was extracted from the fetal electrocardiogram tracing at the time of each blood gas. For each heart rate tracing, the ApEn was calculated. The significance of changes was assessed using analysis of variance for repeated measures.Results: The snare occluder produced significant fetal hypoxia and acidosis. Although FHR variability was increased, approximate entropy was significantly decreased during periods of hypoxia in the ovine fetus.Conclusions: Approximate entropy of the ovine fetus is directly related to the degree of hypoxia. The decreased ApEn indicates increased regularity in the FHR during hypoxia in spite of the increased variability. ApEn may provide insight into the regulatory feedback mechanisms of the fetal heart rate during periods of hypoxia.

>Objective: Cytokines are associated with the systemic inflammatory response syndrome that occurs after cardiopulmonary bypass. We hypothesized that the placental dysfunction which has been found to complicate fetal cardiac bypass may be in part a function of a cytokine-mediated acute phase reaction. To test this hypothesis, we designed a study to investigate the effect of cardiac bypass on interleukin-1beta (IL-1beta), IL-6, and IL-8 in fetal sheep.Methods: Nine mixed-breed pregnant ewes at 118-122 days of gestation were assigned randomly to either the "fetal cardiac bypass group" (n = 5) or the "control group" (n = 4). After surgical exposure and instrumentation, cardiac bypass was performed for 30 min in study group fetuses, whereas control group fetuses were exposed and instrumented identically but did not undergo bypass. Placental and systemic hemodynamics were monitored in both groups. Pre- and post-bypass blood samples were analyzed for IL-1beta, IL-6, and IL-8 using enzyme-linked immunosorbent assays.Results: IL-6 levels were undetectable before bypass in all fetuses. IL-6 increased after bypass in all bypass group fetuses to 53.0 +/- 24.2 pg/ml, whereas IL-6 levels remained undetectable in all control animals. Fetal cardiac bypass produced no significant changes in IL-1beta and IL-8 in either group. Following bypass, placental blood flow decreased by 23% in the bypass group, which was significantly more (P = 0.0002) than the 6% decrease in the control group; placental vascular resistance increased significantly more in the bypass group (20%) than in control fetuses (1%; p = 0.004).Conclusions: Fetal cardiac bypass produces significant and consistent increases in fetal plasma IL-6, which correlate with increased placental vascular resistance and decreased placental blood flow. IL-6 may have an important role in placental dysfunction following fetal cardiac bypass, but further investigation will be necessary to elucidate its specific role in the impairment of placental function or as a marker of placental injury.

>Objective: To investigate if the adverse effects caffeine and nicotine have on the fetus are mediated by placental vascular tone alterations.Study Design: Isolated human placental arteries and veins at resting tone in the presence and absence of endothelium were exposed to cumulative doses of caffeine (0.1 nm-0.1 mm), nicotine, and cotinine (1.0 nm-1.0 mm). Some of the vessels were submaximally precontracted with U44619 prior to exposure to cumulative doses of the drugs. Dose-response curves to serotonin, KCl, U46619, and prostaglandin F2alpha were also obtained in the presence or absence of caffeine, nicotine, and cotinine (0.1 mm).Results: Caffeine did not alter vascular tone in human placental arteries and veins at resting tone (n = 10). Modest relaxations (15-30% of maximal tone) were noted with the addition of the drug to precontracted placental blood vessels. Similarly, nicotine and cotinine had no effect on resting tone in placental blood vessels, whereas small relaxations (6-10% of maximal tone) occurred in vessels precontracted with U46619 (n = 7-10). Additionally caffeine (n = 6-10), nicotine, and cotinine failed to alter the dose-response curves to other contractile agents (n = 7-10).Conclusions: Based on these results caffeine, nicotine, and the nicotine metabolite cotinine do not appear to alter human placental vascular tone in vitro. These results suggest that the adverse effects of these drugs on the fetus during pregnancy are unlikely to be due to changes in placental vascular tone.

>Objective: To determine the relative accuracy of clinical and sonographic estimates of fetal weight (EFW) among parturients with diabetes requiring insulin (White's classifications A2 and higher).Methods: In early labor, clinical EFW was followed by sonographic mensuration of fetal parts. At the completion of the study, sonographic EFW was calculated using abdominal circumference and femur length. Student's t test, Wilcoxan test, and chi square test were used to assess the relative accuracy of the two methods of assessing birth weight.Results: Among 94 parturients with various classifications of diabetes, the clinical estimate of birth weight has a significantly higher simple error (-180.3 + 419.5 g) but not a significantly higher mean standardized absolute error (130.7 +/- 130.1 g/kg) than sonographic prediction (-139.3 +/- 447.1 g, 115.6 +/- 90.8 g/kg, respectively). Analysis of the data, according to gestational age, indicates that clinical EFW is more accurate than sonographic EFW among term (n = 67) parturients with diabetes, but both methods are comparable in preterm (n = 27) parturients. However, when the data are analyzed according to birth weight, EFW by Leopold maneuvers is significantly more accurate than those obtained sonographically in infants weighing 2500-3999 g (n = 66) and >4000 g (n = 12).Conclusion: In term gestations of diabetic mothers and those infants with a birth weight of 2500 g or more, the clinical estimate of birth weight is more accurate; however, in preterm diabetic pregnancies, clinical and sonographic estimates are equal.

>Objective: To determine whether maternal meal ingestion affects amniotic fluid index (AFI) over a short period after maternal meal ingestion in normal growth fetuses with normal amniotic fluid volume in uncomplicated late pregnancies.Methods: Twenty-five women with an appropriate-for-gestational-age fetus with normal AFI were included in a simple crossover, blinded study during late pregnancy. After an overnight fast, two different maternal meal states were prepared. On day A, the subjects had a standard 600-kcal breakfast at 8 a.m. On day B, the fasting state was maintained until 10 a.m. Both states were randomly assigned to each woman within 3 days. On both days, the AFI was measured at 7 a.m. (the fasting state) and at 10 a.m. (the fed state on day A and the continuous fasting state on day B). A change in AFI between 7 and 10 a.m. was compared between the days by paired t test.Results: The mean gestational age (mean +/- SD) was 37.5 +/- 1.5 weeks on day A and 37.4 +/- 1.6 weeks on day B. The change in AFI between 7 and 10 a.m. was 1.1 +/- 3.0 cm on day A (with breakfast) and 2.1 +/- 2.6 cm on day B (keeping fast). These changes were not different between the days (P = 0.19).Conclusions: Maternal meal ingestion had no apparent acute effect on AFI in normal growth fetuses with normal amniotic fluid volume.

>Objective: To obtain a longitudinal gestational reference range for the amniotic fluid index (AFI) among Japanese women and to compare the study with those of previous reports.Methods: A total of 739 measurements of the AFI of 96 Japanese women with normal pregnancies were analyzed. The criteria were singleton pregnancies between 20 and 40 weeks, without fetal anomalies, diabetes mellitus, hypertension, and other maternal complications. Logarithmic transformation was used to obtain the predicted mean AFI values with 95% confidence intervals at each gestational week.Results: The AFI rose from 20 weeks reaching its peak at 30 weeks. After the peak, it declined toward 40 weeks. Comparison of this study with previously published reports revealed differences in the mean AFI values.Conclusions: We obtained the gestational age-specific value of AFI in normal pregnancy for Japanese women.