Maternal magnesium therapy, neonatal serum magnesium concentration and immediate neonatal outcomes.

OBJECTIVE: The fetus is exposed to magnesium administered to the pregnant mother. However, there is controversy regarding magnesium-related neonatal adverse outcomes, largely driven by a limited understanding of the factors that influence neonatal serum magnesium concentrations and associated outcomes. The objective of this study was to examine the relationship between antenatal maternal magnesium dose and serum concentrations, neonatal serum magnesium concentration and immediate neonatal outcomes. STUDY DESIGN: A retrospective study was conducted at a community-based teaching hospital. Neonatal serum magnesium concentrations within 48 h of birth were used to stratify magnesium-exposed neonates into three groups: group 1: <2.5 mg dl-1, group 2: ⩾2.5 to <4.5 mg dl-1, and group 3:⩾4.5 mg dl-1. Immediate neonatal outcomes were compared between the three groups. Total maternal magnesium dose and serum magnesium concentrations before the delivery were correlated with neonatal serum magnesium concentrations and outcomes. RESULTS: Of the 304 mother-baby dyads between 24 and 34 weeks gestation, 237 received antenatal magnesium. Neonatal serum magnesium concentration was 3.14±0.83 mg dl-1 in exposed and 1.96±0.42 mg dl-1 in unexposed neonates (P<0.001). Compared with group 2, neonates had higher odds of grade 3 or 4 intraventricular hemorrhage in group 1 (adjusted odds ratio (AOR) 5.95 (95% confidence interval (CI) 1.05 to 33.66)) and group 3 (AOR 8.42 (95% CI 1.35 to 52.54)). Group 3 neonates also had increased odds of periventricular leukomalacia (AOR: 5.37 (95% CI 1.02 to 28.28) compared with group 2 neonates. Predictors of neonatal serum magnesium concentrations included maternal magnesium dose (r=0.66, P<0.0001), duration of therapy (r=0.70, P<0.0001) and serum concentration (r=0.72, P<0.001). CONCLUSION: The between-group differences highlight that there is a therapeutic range of neonatal serum magnesium concentrations for neuroprotective effects of antenatal magnesium sulfate, while concentrations outside of this range may be associated with adverse neonatal outcomes. Further studies are needed to determine the optimal dose and duration of maternal magnesium to minimize adverse neonatal outcomes.

Prospective multicenter study of ultrasound-based measurements of fetal head station and position throughout labor.

OBJECTIVES: To assess the relationship between fetal head position and head station during labor, as measured using an ultrasound-based system, and the occurrence of occiput posterior (OP) position at delivery. METHODS: This was an international prospective observational study including women who delivered between January 2009 and September 2013 in four centers: one in Brooklyn, NY, USA; one in Haifa, Israel; and two in Paris, France. We used an ultrasound-based system (LaborPro) to monitor fetal head station and position non-invasively throughout labor. We collected data on demographics, labor parameters and outcome. RESULTS: A total of 595 women were included. In 563 (94.6%) women, fetal head position at delivery was occiput anterior (OA), in 31 (5.2%) it was OP and in one (0.2%) it was occiput transverse. In 89% of pregnancies with intrapartum OP when fetal head station was above -2, the head position turned to OA at delivery; the equivalent figures were 74% and 63% OA at delivery when intrapartum OP was diagnosed at head stations of -2 to < 0, and 0 and below, respectively. Cesarean delivery was performed in 35% of pregnancies with fetal head in OP position at delivery, as opposed to 10% of those with non-OP position at delivery. On retrospective analysis, all deliveries in OP were already in OP at station -2 and below. CONCLUSIONS: In this first assessment of fetal head position at delivery according to fetal head position at various station levels, our data show that 100% of OP positions at delivery were already in OP position at station -2 and below. We did not observe rotation from a non-OP to an OP position from station -2 and below. Nearly two-thirds of fetuses in OP at station 0 and below will rotate to an OA position for delivery.

Association between ultrasound-based assessment of fetal head station and clinically assessed cervical dilatation.

OBJECTIVES: To describe the association between ultrasound-based determination of fetal head station and clinical assessment of cervical dilatation during active labor. METHODS: From 427 women with singleton uncomplicated term pregnancies we obtained, during the active phase of labor, 907 pairs of measurements. Fetal head station and position were determined using the LaborPro system, based on position tracking and ultrasound imaging technology, and degree of cervical dilatation was determined by digital vaginal examination. The association between them was analyzed. RESULTS: The overall correlation between cervical dilatation and fetal head station was 0.64 (P < 0.001). Complete dilatation was observed in 78% of women with fetal head engagement, and in all women with a fetal head station of + 1.5 or more. CONCLUSIONS: There is good association between non-invasive ultrasound-based determination of fetal head station and clinically assessed cervical dilatation.

Enhanced coronary blood flow and abnormal blood flow in the aortic isthmus in severe fetal anemia.

Coronary arteries are not normally visualized by fetal echocardiograms. Reversal of flow in the transverse aortic arch is most often seen in association with severe coarctation. We describe a case of a near-term fetus whose fetal echocardiogram showed very prominent coronary arteries and severe reversal of flow in the transverse aorta suggestive of a coarctation who was postnatally confirmed to have normal intracardiac and aortic anatomy. We discuss the pitfalls in clinical diagnosis in this case to alert pediatric cardiologists of transient perturbations in physiology masquerading as heart disease.

Maternal glycemic control and umbilical artery Doppler velocimetry.

OBJECTIVE: To determine whether information from umbilical artery Doppler flow velocity waveforms significantly improves the prediction of adverse perinatal outcome, independently of maternal glycemic control, in pregnancies complicated by diabetes. STUDY DESIGN: The medical records of 277 pregnant women with diabetes were reviewed. Glycemic control was determined by glycosylated hemoglobin concentration and umbilical artery Doppler velocimetry by using systolic/diastolic ratios (S:D), both obtained during the third trimester. Pregnancies with adverse perinatal outcome were compared to those with good outcome. Logistic regression analysis was used to adjust for glycemic control, and to test whether an elevated umbilical artery Doppler S:D ratio was independently associated with pregnancy outcome. RESULTS: Adverse pregnancy outcome occurred in 51.6% of these pregnancies (143/277). The mean third-trimester glycosylated hemoglobin (7.7 +/- 1.9% vs. 6.7 +/- 1.3%, p < 0.001) and the umbilical artery S:D ratio were significantly higher (2.6 +/- 0.6 vs. 2.4 +/- 0.3, p < 0.001) in the pregnancies with adverse outcome. Logistic regression analysis showed that umbilical artery S:D ratio was an independent predictor of adverse perinatal outcome after adjusting for the third-trimester glycosylated hemoglobin level. Forty per cent of patients with normal Doppler findings (S:D ratio of < 3.0) and normal glycemic control values (glycosylated hemoglobin level of < 7.5%) had an adverse pregnancy outcome. Sixty-three per cent of patients with an abnormal result for one of these tests had an adverse pregnancy outcome. Ninety-six per cent of patients with both abnormal Doppler findings and abnormal glycemic control had an adverse pregnancy outcome. CONCLUSION: Umbilical artery Doppler velocimetry improves the predictive value for adverse perinatal outcome, independently of glycemic control, in pregnancies complicated by diabetes. The combination of an abnormal umbilical artery S:D ratio and abnormal glycosylated hemoglobin was strongly associated with adverse pregnancy outcome.

Maternal arrhythmias of normal labor and delivery.

Labor and delivery are associated with significant hemodynamic changes, as well as pain and anxiety, all of which could be fertile ground for arrhythmias. In order to establish whether cardiac arrhythmias occur more frequently during labor and delivery in healthy parturients and whether it clinically affects the mother or the newborn, 100 pregnant women admitted for delivery had Holter monitoring before, during, and up to 1 h postpartum. Our results show that, excluding sinus rhythm variations, only a slight majority of the study subjects had arrhythmia at all, while only 2% had more complex arrhythmias, none of which required any therapeutic intervention. We conclude that cardiac arrhythmias occurring during labor, delivery, and postpartum in the healthy parturient are no more frequent than in the general female population of the same age and are without clinical consequences for the mother and the newborn.

Acute bowel perforation in a fetus with gastroschisis.

Gastroschisis is a congenital anomaly with a reported incidence of 1 in 10,000 live births. Although prenatal diagnosis is more common with the widespread use of biochemical markers and obstetric ultrasound, the role of ultrasound in the identification of the fetus that might need early intervention has not been established. Acute bowel perforation was diagnosed by ultrasound at 34 weeks gestation in a fetus with gastroschisis. An immediate Cesarean section was performed, followed by repair with primary closure. The neonatal outcome was favorable. The post-partum findings, including bowel pathology, confirmed the antenatal diagnosis. Acute bowel perforation can be diagnosed antenatally. Immediate intervention, before further bowel injury occurs, might enhance the ability of the surgeon to perform primary closure and obtain a favorable outcome.

The relationship of maternal position to the results of brief nonstress tests: a randomized clinical trial.

OBJECTIVE: This study was undertaken to determine whether maternal posture (left lateral recumbent vs semi-Fowler position) had any effect on nonstress test results when the test was performed for a shortened period (10 minutes). STUDY DESIGN: In this randomized clinical trial of 108 patients with singleton pregnancies at 32 to 42 weeks' gestation, patients were randomly assigned to a "sitting first" (semi-Fowler position) or a "supine first" (left lateral recumbent position) group at the initial visit. The order of position was alternated at subsequent visits. Ten minutes of fetal heart rate monitoring was performed in each position at each visit. Computer analysis of the nonstress test was used to interpret each 10-minute segment for reactivity. Statistical analyses were performed on the paired nonstress test unit (sitting and supine). RESULTS: There were no adverse clinical outcomes among the participants. Logistic regression analysis showed that both the sequence of the nonstress test and the position were significant and independent factors related to nonstress test reactivity. Tests performed during the second 10 minutes and tests performed with the patient in the semi-Fowler position were more likely to have reactive results. CONCLUSION: The semi-Fowler position is a superior position for conducting a nonstress test in a short period. Use of this position could decrease the need for prolonged monitoring, thus leading to a more time-effective evaluation of patients at risk.

Multigated simultaneous spectral Doppler imaging: a new ultrasound modality.

BACKGROUND: Spectral Doppler ultrasound, an important diagnostic tool for the functional assessment of various organs, as yet has no major use in prenatal diagnosis due to the conventional technique's limitation of analyzing only one site at a time. Our aim was to develop a new modality that shows simultaneous studies of multiple sites in a vascular area, which should provide improved assessment of hemodynamic status of vascular systems. TECHNIQUE: The new Doppler modality features automatic acquisition and analysis of blood flow in multiple sites over a large area. The quantitative Doppler data are presented as color-coded maps of the spectral Doppler indices overlaid on the gray-scale sonographic images and as histograms of indices distribution. EXPERIENCE: Serial sequences of Doppler measurements in the umbilical artery were taken in 14 women. The reproducibility of the new modality was confirmed. CONCLUSION: Our new Doppler modality provides reproducible and reliable data. This method is a viable alternative to the traditional Doppler ultrasound and might offer better assessment of feto-placental circulation.

Weighing in college students' diet and exercise behaviors.

A questionnaire was used to investigate the nutritional health behaviors of 302 college students at a large urban university. Body mass index (BMI) was calculated for each student, using self-reported heights and weights. Eight percent of the surveyed students were categorized as overweight on the basis of their BMIs. However, 50% of the students who were rated underweight on the basis of their BMIs classified themselves as overweight. Only 39% of the students reported exercising 3 or more times per week; 76% of the students reported that they ate the same foods day after day. Recommendations are presented for colleges and universities that are offering or are considering offering nutritional education programs for students.

Intraplacental spectral Doppler scanning: fetal growth classification based on Doppler velocimetry.

The purpose of the study was to develop a Doppler modality for effective assessment of the fetoplacental circulation. Calculations based upon a theoretical model were employed to predict downstream pulsatility values in the fetoplacental circulation. The clinical study included 83 pregnancies between 32 and 36 weeks of gestation. Sixty-nine women were recruited from our low-risk clinic and had uncomplicated pregnancies. Fourteen patients had complications suspected to be associated with placental pathology. All 83 patients demonstrated UA Doppler indices within the normal limits for the gestational age. The study induced intraplacental and UA Doppler waveform analyses. The ratios between intraplacental and UA PI values (at the cord insertion to the placenta) were calculated. Nineteen patients with intraplacental to UA (placental cord insertion) PI ratios > 1 (abnormal) had adverse pregnancy outcome. The study demonstrates the importance of detailed scanning of the intraplacental pulsatile waveforms and the importance of using the ratio between the intraplacental and UA Doppler indices as an additional method for evaluation of the fetoplacental circulation. The method might be proven more effective mainly in the early stages of placental disease when a relatively small number of the placental terminal arterioles are affected with a negligible effect on the UA Doppler indices, and also in the evaluation of the large placenta. A fetal growth classification based on detailed intraplacental velocimetry and cord to intraplacental flow gradient is proposed.

Significance of prenatal diagnosis of umbilical cord cyst in a fetus with trisomy 18.

An umbilical cord cyst was detected in a fetus who underwent ultrasonography at 38 weeks' gestation for clinical suspicion of intrauterine growth retardation. Such an association should alert the clinician to the possibility of aneuploidy, thus guiding clinical management. This case represents the second report of a cystic umbilical lesion in a fetus with trisomy 18.

Estimates of the British Jewish population 1984-88.

"During the 20th century, estimates of the British Jewish population have been obtained by applying appropriate death-rates to communal mortality data. This death-rate method has become increasingly sophisticated with respect to the death-rates used. The exercise reported here covers more than 22,000 deaths recorded in the community over the 5-year period [1984-88].... An estimate of 308,000 is suggested for the community, in which deaths-related data are augmented by information about births within the community."

Statistical models for the analysis of ordered categorical data in public health and medical research.

In the late 1970s statisticians extended the methods for analysing loglinear and logit models for cross-classified categorical data to incorporate information about the ordinal structure of the categories corresponding to some of the classification variables. In this paper we review one class of such extensions known as association models. We consider association models with and without order restrictions on the parameters and we use these models to answer research questions about several medical examples involving ordered categorical data. We emphasize the interpretation of parameters in the association models and how this relates to the research questions of interest.

A new technique for improved diagnosis of local placental abnormalities: Fourier analysis of intraplacental waveforms.

A new method to diagnose localized placental lesions is introduced. The method involves Fourier analysis of intraplacental and umbilical Doppler velocity waveforms. It is shown, using a theoretical model based on an electrical transmission line approach, that intraplacental waveforms that are of higher pulsatilities than those in the umbilical artery indicate placental abnormalities. The method was applied in a series of cases with normal umbilical waveforms in which placental abnormalities were diagnosed. The method promises to be more sensitive and specific than analyzing umbilical waveforms alone as it does not depend on uncertain threshold values.

The detection of errors in sentences after right hemisphere brain damage.

Several experiments have shown that non-aphasic, right hemisphere-damaged adults encounter difficulty solving syllogistic reasoning problems. In order to confirm and further explore the nature of this deficit with different linguistic material, patients with focal cerebral insult were asked to detect logical errors in sentences describing familiar causal situations. The findings revealed significant impairments in detecting errors after insult to anterior portions of the right hemisphere and to the left hemisphere, but qualitatively different patterns of errors in these two groups of patients. We conclude that the right hemisphere may make a unique contribution to sentence processing.

Arachidonic acid metabolism in human granulosa cells: evidence for cyclooxygenase and lipoxygenase activity in vitro.

In view of the studies demonstrating the involvement of eicosanoids (prostaglandins and hydroxyperoxides, including leukotrienes) in ovulation in several mammalian species, we have examined the activity of the two enzyme systems, lipoxygenase and cyclooxygenase in human granulosa cells obtained from women undergoing in-vitro fertilization--embryo transfer. The activity of cyclooxygenase was assessed by radioimmunoassay of prostaglandin E and of 6-keto-prostaglandin F1 alpha, the conversion product of prostacyclin, accumulated in the culture medium of granulosa cells. Lipoxygenase activity was detected by the conversion of [14C]arachidonic acid into its products (hydroxyperoxides and leukotrienes) separated by reversed phase high-performance liquid chromatography. The results confirmed the activity of cyclooxygenase in human granulosa cells, production in vitro of prostaglandin E and prostacyclin and demonstrated the presence of active lipoxygenase enzymes. These results support the possible involvement of eicosanoids in ovulation of the human.

Size classification of fibers and isometric particles keeping each fraction airborne.

The hazardous properties of airborne fibers are generally thought to be related to size. The purpose of this study was to develop a technique for physically classifying airborne fibers on the basis of diameter, keeping the separated fractions in the suspended state. This would permit either fraction to be further classified, monitored by real-time instrumentation and/or used in size-related inhalation studies. Other fiber classification methods have involved deposition of fibers onto a substrate, which precludes these advantages. Diameter classification was achieved by the use of an opposing-jet aerosol classifier. With isometric aerosols, sharp diameter classification was achieved: D50/D16 = 1.1 for liquid particles, and D50/D16 = 1.3 for solid particles. Diameter classification of fibers was also achieved, but the sharpness of cut was much less; D50/D16 greater than 3. The decreased sharpness of cut for fibers is attributed to the more or less random bounce of fibers from the edge of the separation plate to either outlet flow of the classifier. The sharpness of cut is expected to be better in a classifier in which the thickness of the separation plate is smaller relative to the flow dimensions.