Degree Of Fetal Research Articles

Dysmorphologic features of the fetal pelvis in Down syndrome: prenatal sonographic depiction and diagnostic implications of the iliac angle.

To determine whether the axial pelvic profile is morphologically different in fetuses with Down syndrome from those with a normal karyotype. Pelvic images were selected from ultrasound studies in 27 fetuses with trisomy 21 and in 135 fetuses with a normal karyotype. An observer blinded to study results measured the angle formed by the convergence of lines drawn tangent to the wing of the ilium. This angle was measured prospectively in 20 normal fetuses by four independent observers to estimate variability. The iliac bones could be assessed in 19 fetuses with trisomy 21 and in 87 fetuses with a normal karyotype. Between 15 and 20 weeks of gestation, the mean iliac angle was 60 degrees in normal fetuses and 75 degrees in fetuses with Down syndrome (P < .001). Intra- and interobserver correlation coefficients were .70 and .62, respectively. The greatest variability in results was among fetuses (estimated variance, 72.5); smaller variance was seen with repeat measurements in the same fetus (34.7) and with measurements by different observers (9.1). The mean iliac angle in fetuses with Down syndrome is larger than that in fetuses without Down syndrome and may aid in weighing the risks of trisomy 21 against the risks of performing amniocentesis.

Levorotation of the fetal cardiac axis: A clue for the presence of congenital heart disease

To evaluate the use of the cardiac axis within the chest for the prenatal detection of congenital heart defects. We reviewed retrospectively the sonographic findings of all fetuses scanned between 17 and 40 weeks' gestation and diagnosed prenatally as having heart defects. The cardiac diagnoses were confirmed postnatally. The control group consisted of 75 consecutive fetuses with normal fetal surveys and newborn follow-up examinations. The cardiac axes were measured retrospectively using an image of the four-chamber view of the heart and measuring the angle between the interventricular septum and a line bisecting the chest. Mean and standard deviations (SDs) of the axis measurements in normal and abnormal fetuses were compared by Student t test. The 75 fetuses with heart defects diagnosed by prenatal sonogram had a mean cardiac axis of 56 +/- 13 degrees, compared with 43 +/- 7 degrees in normal fetuses (P < .001). Using 57 degrees (two SDs above the mean for normal fetuses) as the upper limit of normal, 33 of 75 (44%) abnormal fetuses versus none of 75 normal fetuses were identified. The frequency of cardiac rotation was greater in fetuses with truncus arteriosus, Ebstein's anomaly, pulmonic stenosis, coarctation of the aorta, and tetralogy of Fallot. The presence of a cardiac axis exceeding 57 degrees in the fetal chest is associated with a substantial risk of congenital heart defects. The finding of an abnormal axis should prompt further evaluation of the fetal heart.

Antenatal bleeding and fetal heart rate.

Objective of the paper was to determine the fetal heart rate (FHR) changes that occur in preterm fetuses whose mothers have suffered antepartum bleeding, versus uncomplicated controls. Over a 12-year span, 91 patients with significant antenatal bleeding (bleeding requiring inhospital observation) were examined and compared to 75 controls with uncomplicated normal pregnancies. None of the women were in labor and all were evaluated at 25-37 weeks' gestation. Excluded were: patients with any other complication (i.e., premature rupture of membranes, intrauterine growth retardation, diabetes, hypertension, collagen vascular disease, postuterine surgery, substance abuse and twins). Analysis of the FHR tracings included baseline heart rate, long-term FHR variability, and number and amplitude of FHR accelerations in 20-min segments. There was no difference in baseline heart rate in the preterm fetuses of pregnancies complicated by antepartum bleeding versus controls. However, the parameters associated with FHR reactivity (number of accelerations in 20 min, and amplitude of accelerations) were higher to a statistically significant degree in fetuses of pregnancies complicated by antenatal bleeding than in controls. Fetuses of mothers suffering antenatal bleeding exhibited significant higher rates of reactive FHR patterns at earlier gestational ages than did controls. In conclusion, there is a significant increase in FHR reactivity in pregnancies in which significant antenatal bleeding occurs, suggesting a probable acceleration in fetal central nervous system maturation in these fetuses.

Effects of morphine and naloxone on spontaneous activity of fetal rats

Morphine causes a dose-dependent decrease in 18-day fetal rat spontaneous activity. This decrease in activity is reversed by naloxone. Spontaneous activity begins on the 15th day of gestation and ends with parturition on day 22. It is not known if morphine and naloxone are effective to the same degree in fetuses throughout this period. The efficacy of morphine is predicted to change because of increasing amounts of drug reaching the fetus, increasing opiate receptors in the spinal cord, ingrowth of supraspinal fibers, and initiation of function of enkephalinergic systems in the central nervous system. Spontaneous activity was measured in rat fetuses (15.7 to 21 days) during a control period, after maternal injection of 10 mg/kg morphine, and after injection of 0.5 mg/kg naloxone. The depression of activity caused by morphine was identical at all ages examined and was reversed by naloxone. Spinal transection at a high cervical level had no influence on the fetal response to morphine and naloxone indicating that morphine-induced depression of fetal activity is mediated at least in part by the spinal cord. Naloxone alone at different ages and in various dosages had no effect on activity indicating that the normal level of fetal activity is not modulated by endogenous opiates.