Ultrasound parameters of early pregnancy and Doppler indices of blood vessels in the placenta and umbilical cord throughout the pregnancy period in sheep.

BACKGROUND: Ultrasonography is one of the most important techniques that enable the detection and monitoring of pregnancy. One such study using this technique is the assessment of the hemodynamics of fetal and umbilical blood vessels. However, there is little data on blood flow in the placentomes, which is the basic structural unit of the sheep's placenta. Therefore, the aim of this study was to determine the Doppler parameters in the arterial vessels of the caruncles, cotyledons and the umbilical cord as well as measuring venous flow rates during the entire gestation period of the sheep. Additionally, the usefulness of various other ultrasound parameters in the early diagnosis of pregnancy in sheep was analyzed. RESULTS: Most of the Doppler parameters in umbilical, cotyledonary and caruncular arteries were significantly correlated with the day of pregnancy (p < 0.01). In the early stages of pregnancy, the peak systolic velocity (PSV), regardless of the location of the artery, was significantly lower than that in the later stages of pregnancy (p < 0.01). PSV was also found to be significantly higher in the umbilical artery than in the cotyledonary and caruncular arteries (p < 0.01). Until the 50th day of pregnancy, the end diastolic velocity (EDV) was not found in the umbilical and cotyledonary arteries. EDV was significantly higher in the caruncular arteries than in the cotyledonary and umbilical arteries (p < 0.01). The resistance index (RI) and pulsatility index (PI) in the early stages of pregnancy were found to be significantly higher than that in the later stages of pregnancy (p < 0.01). The RI and PI were significantly lower in the caruncular arteries than in the arteries of the cotyledons and umbilical cord (p < 0.01). In the umbilical vein, all Doppler parameters were observed to be significantly higher than those in the placentomal veins (p < 0.01 or p < 0.05). Using transrectal ultrasound, pregnancy was detected between 20 and 28 days after mating. The ovaries were observed to have corpora lutea, the diameter of which was fairly consistent from the 17th to the 56th day of pregnancy. CONCLUSIONS: It has been demonstrated that both the location of the arterial vessel in the placental-umbilical circulation and the gestational age have a significant impact on hemodynamic parameters. The results also provide new insights about the blood flow in caruncular and cotyledonary arteries, which could contribute to a more holistic understanding of hemodynamic changes in the placentas of sheep. Analyzing haemodynamic parameters in the umbilical and placental veins are preliminary studies in sheep, but it could inspire further research in this field. Furthermore, the research conducted confirms the practicality and convenience of transrectal ultrasonography in the early diagnosis of pregnancy in sheep and also indicates that the identification and imaging of the corpus luteum using B-mode ultrasonography can be a very early and simple method of confirming effective mating in sheep.

Risk Factors for the Development of Refeeding Syndrome-Like Hypophosphatemia in Very Low Birth Weight Infants.

BACKGROUND: Refeeding syndrome is characterized by metabolic disturbance including hypophosphatemia and hypokalemia upon reinstitution of nutrition in severely malnourished patients. OBJECTIVE: The present study sought to identify the risk factors for the development of refeeding syndrome-like metabolic disturbance in very low birth weight infants. METHODS: The correlations of severe hypophosphatemia with the serum levels of potassium and ionized calcium, daily calorie and phosphate intake, and umbilical cord blood flow on ultrasonography were analyzed in 49 very low birth weight infants. RESULTS: Fifteen infants (36%) presented with hypophosphatemia during the first postnatal week. Hypophosphatemia was significantly associated with birth weight z score (odds ratio, 1.60; 95% confidence interval, 1.04-2.47; p = 0.034) and umbilical artery resistance index (odds ratio, 7.72E-04; 95% confidence interval, 1.14E-06-0.523; p = 0.031). Multiple regression analysis revealed that umbilical artery resistance index was independently associated with hypophosphatemia. CONCLUSIONS: Umbilical artery resistance index may serve as a useful marker for future development of refeeding syndrome-like hypophosphatemia in very low birth weight infants. Close monitoring of serum phosphorus and potassium levels and early intervention are important for the management of very low birth weight infants with intrauterine growth restriction due to placental dysfunction.

Acute feTal behavioral Response to prenatal Yoga: a single, blinded, randomized controlled trial (TRY yoga).

BACKGROUND: In 2012, yoga was practiced by 20 million Americans, of whom 82% were women. A recent literature review on prenatal yoga noted a reduction in some pregnancy complications (ie, preterm birth, lumbar pain, and growth restriction) in those who practiced yoga; to date, there is no evidence on fetal response after yoga. OBJECTIVES: We aimed to characterize the acute changes in maternal and fetal response to prenatal yoga exercises using common standardized tests to assess the well-being of the maternal-fetal unit. STUDY DESIGN: We conducted a single, blinded, randomized controlled trial. Uncomplicated pregnancies between 28 0/7 and 36 6/7 weeks with a nonanomalous singleton fetus of women who did not smoke, use narcotics, or have prior experience with yoga were included. A computer-generated simple randomization sequence with a 1:1 allocation ratio was used to randomize participants into the yoga or control group. Women in the yoga group participated in a 1-time, 1 hour yoga class with a certified instructor who taught a predetermined yoga sequence. In the control group, each participant attended a 1-time, 1 hour PowerPoint presentation by an obstetrician on American Congress of Obstetricians and Gynecologists recommendations for exercise, nutrition, and obesity in pregnancy. All participants underwent pre- and postintervention testing, which consisted of umbilical and uterine artery Doppler ultrasound, nonstress testing, a biophysical profile, maternal blood pressure, and maternal heart rate. A board-certified maternal-fetal medicine specialist, at a different tertiary center, interpreted all nonstress tests and biophysical profile data and was blinded to group assignment and pre- or postintervention testing. The primary outcome was a change in umbilical artery Doppler systolic to diastolic ratio. Sample size calculations indicated 19 women per group would be sufficient to detect this difference in Doppler indices (alpha, 0.05; power, 80%). Data were analyzed using a repeated-measures analysis of variance, a χ(2), and a Fisher exact test. A value of P < .05 was considered significant. RESULTS: Of the 52 women randomized, 46 (88%) completed the study. There was no clinically significant change in umbilical artery systolic to diastolic ratio (P = .34), pulsatility index (P = .53), or resistance index (P = .66) between the 2 groups before and after the intervention. Fetal and maternal heart rate, maternal blood pressure, and uterine artery Dopplers remained unchanged over time. When umbilical artery indices were individually compared with gestational age references, there was no difference between those who improved or worsened between the groups. CONCLUSION: There was no significant change in fetal blood flow acutely after performing yoga for the first time in pregnancy. Yoga can be recommended for low-risk women to begin during pregnancy.

The vascular effects of sodium tanshinone IIA sulphonate in rodent and human pregnancy.

Danshen, in particular its derivative tanshinone IIA (TS), is a promising compound in the treatment of cardiovascular diseases and has been used for many years in traditional Chinese medicine. Although many actions of TS have been researched, its vasodilator effects in pregnancy remain unknown. There have been a few studies that have shown the ability of TS to reduce blood pressure in women with hypertensive pregnancies; however, there are no studies which have examined the vascular effects of TS in the pregnant state in either normal or complicated pregnancies. Our aim was to determine the vasoactive role of TS in multiple arteries during pregnancy including: rat resistance (mesenteric and uterine) and conduit (carotid) arteries. Further, we aimed to assess the ability of TS to improve uterine blood flow in a rodent model of intrauterine growth restriction. Wire myography was used to assess vascular responses to the water-soluble derivative, sodium tanshinone IIA sulphonate (STS) or to the endothelium-dependent vasodilator, methylcholine. At mid-pregnancy, STS caused direct vasodilation of rat resistance (pEC50 mesenteric: 4.47±0.05 and uterine: 3.65±0.10) but not conduit (carotid) arteries. In late pregnancy, human myometrial arteries responded with a similar sensitivity to STS (pEC50 myometrial: 3.26±0.13). STS treatment for the last third of pregnancy in eNOS-/- mice increased uterine artery responses to methylcholine (Emax eNOS-/-: 55.2±9.2% vs. eNOS-/- treated: 75.7±8.9%, p<0.0001). The promising vascular effects, however, did not lead to improved uterine or umbilical blood flow in vivo, nor to improved fetal biometrics; body weight and crown-rump length. Further, STS treatment increased the uterine artery resistance index and decreased offspring body weight in control mice. Further research would be required to determine the safety and efficacy of use of STS in pregnancy.

Uterine infusion of melatonin or melatonin receptor antagonist alters ovine feto-placental hemodynamics during midgestation.

Dietary melatonin supplementation from mid- to late gestation increases umbilical artery blood flow and causes disproportionate fetal growth. Melatonin receptors have been described throughout the cardiovascular system; however, there is a paucity of data on the function of placental melatonin receptors. The objectives of the current experiment were to determine fetal descending aorta blood flow, umbilical artery blood flow, and placental and fetal development following a 4-wk uterine infusion of melatonin (MEL), melatonin receptor 1 and 2 antagonist (luzindole; LUZ), or vehicle (CON) from Day 62 to Day 90 of gestation. After 4 wk of infusion, umbilical artery blood flow and umbilical artery blood flow relative to placentome weight were increased (P < 0.05) in MEL- versus CON- and LUZ-infused dams. Fetal descending aorta blood flow was increased (P < 0.05) in MEL- versus CON- and LUZ-infused dams, while fetal descending aorta blood flow relative to fetal weight was increased in MEL- versus CON-infused dams and decreased in LUZ- versus CON-infused dams. Following the 4-wk infusion, we observed an increase in placental efficiency (fetal-placentome weight ratio) in MEL- versus LUZ-infused dams. The increase in umbilical artery blood flow due to chronic uterine melatonin infusion is potentiated by an increased fetal cardiac output through the descending aorta. Moreover, melatonin receptor antagonism decreased fetal descending aorta blood flow relative to fetal weight. Therefore, melatonin receptor activation may partially mediate the observed increase in fetal blood flow following dietary melatonin supplementation.

Acute and chronic modulation of placental chorionic plate artery reactivity by reactive oxygen species.

Control of vascular resistance and blood flow in the fetoplacental circulation is incompletely understood. Reactive oxygen species (ROS), physiological and pathophysiological regulators of vascular tone, are elevated in preeclampsia (PE), a disease of pregnancy characterized by increased fetoplacental vascular resistance. We tested the hypothesis that ROS modulate vascular reactivity in placental chorionic plate arteries. Wire myography was used to examine (1) the effects of acute exposure to ROS on arterial function in normal pregnancy and (2) the effects of maternal antioxidant supplementation on arterial reactivity in women at high risk for PE participating in the Vitamins in Pre-eclampsia (VIP) trial. ROS generated by xanthine plus xanthine oxidase enhanced basal tension, vasoconstriction in response to the thromboxane mimetic U46619, and relaxation in response to sodium nitroprusside. Hydrogen peroxide and peroxynitrite increased basal tone and relaxed preconstricted arteries (U44619), respectively. In women at risk for PE, chorionic plate artery constriction in response to U46619 was greater in the women receiving placebo compared to the women supplemented with the antioxidant vitamins C and E. ROS may regulate fetoplacental vascular resistance and blood flow in the short term, and chronic exposure to raised ROS could contribute to elevated fetoplacental vascular resistance in PE and fetal growth restriction (FGR).

[Changes in resistance of the umbilical artery, foetal movements and short time variation through clinical hypnosis--preliminary results]. / Veränderung des Gefässwiderstands der Arteria umbilicalis, der fetalen Bewegung und der Herzzeitvariation durch Hypnose - Erste Ergebnisse.

BACKGROUND: The aim of this study was to determine whether there are any changes in short time variation (STV), foetal movements, and blood flow in the umbilical artery in the trance state. METHODS: Six pregnant patients who had already attended two hypnoreflexogenous birth preparation course units had a standardised hypnosis intervention under cardiotocography (CTG). Using the CTG-Player ((R)) STVs and foetal movements were calculated from the electronically saved CTG traces and evaluated against control CTGs recorded before and after hypnosis. Before and after the induction of hypnosis, blood flow in the umbilical artery was measured. RESULTS: Using the Wilcoxon test there is a significant lowering of blood flow resistance in the umbilical artery after hypnosis (p=0.042). There was a trend that the foetal movements increas at the beginning of the trance (Wilcoxon test, p=0.075). There was no significant difference in the STVs before, during and after trance. CONCLUSIONS: Preliminary results showed that blood flow of the umbilical artery can be improved by hypnosis. Further clinical studies are required to verify this hypothesis. The subjective impression of participants that foetal movements increase at the beginning of the trance seems to be correct.

Effects of oral L-arginine on the foetal condition and neonatal outcome in preeclampsia: a preliminary report.

Estimation of the influence of oral supplementation with low dose of L-arginine on biophysical profile, foeto-placental circulation and neonatal outcome in preeclampsia. Randomized, placebo-controlled, double-blind, clinical trial. Oral therapy with 3 g of L-arginine daily or placebo as a supplement to standard therapy. Eighty-three preeclamptic women, randomly assigned to the L-arginine (n=42) or placebo (n=41) groups; [n=30 (L-arginine) and n=31 (placebo) ended the study, respectively]. Foetal gain chances due to ultrasound biometry, biophysical profile, Doppler velocimetry of pulsatility indices of umbilical and middle cerebral arteries, cerebro-placental ratio, as well as differences in duration of pregnancy and clinical data of newborn. L-arginine treatment transitory accelerated foetal gain and improved biophysical profile. Starting from 3rd week of therapy, the umbilical artery pulsatility indices values were significantly lower in L-arginine than in placebo group. Moreover, treatment with L-arginine caused significant increase of middle cerebral artery pulsatility indices and cerebro-placental ratio values. Latency was longer in L-arginine group. Neonates delivered in the L-arginine group revealed higher Apgar score. Supplementary treatment with oral L-arginine seems to be promising in improving foetal well-being and neonatal outcome as well as in prolonging pregnancy complicated with preeclampsia. However, these benefits require confirmation in more-powered, larger studies.

Neurologic condition of healthy term infants at 18 months: positive association with venous umbilical DHA status and negative association with umbilical trans-fatty acids.

Prenatal long-chain polyunsaturated fatty acids (LCPUFAs) and trans-fatty acids may affect neurodevelopment. In healthy term children, we determined relationships between relative fatty acid contents of umbilical arteries and veins and neurodevelopment at 18 mo. The study comprised a mixed group of 317 breast-fed, formula-fed, and LCPUFA formula-fed children. Study endpoints were the Hempel neurologic examination resulting in a neurologic classification and neurologic optimality score (NOS), and the Bayley Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI). Fifteen children showed minor neurologic dysfunction (MND). The umbilical vein trans, trans-18:2n-6 content was higher in children with MND than in the normal group. The NOS was significantly reduced in infants with an umbilical vein docosahexaenoic acid (DHA) content within the lowest quartile. Umbilical vein arachidonic acid (AA) was related to NOS in univariate statistics but not in multivariate analyses. The sum of trans-fatty acids and that of C18 trans-fatty acids showed a negative association with NOS in both univariate and multivariate analyses. No associations were found between AA, DHA and total trans-fatty acids with PDI or MDI. In conclusion, neonates with a relatively low DHA status and those with high trans-fatty acid levels have a less favorable neurologic condition at 18 mo.

[Intracellular calcium-dependent contractile effects of serotonin in the human umbilical artery]. / Efectos contráctiles dependientes del calcio intracelular inducidos por la serotonina en la arteria umbilical humana.

BACKGROUND: Absence of innervation is a hallmark of human umbilical vessels. Intervillous space blood flow is regulated by vasoactive substances and calcium dependent contractility, both in normal and pathological conditions such as preeclampsia-eclampsia. OBJECTIVE: To obtain additional information on the intracellular calcium contractile effects of serotonin in human umbilical arteries. MATERIALS AND METHODS: Umbilical arteries from normal pregnancies were dissected, cut in 5 mm rings and mounted in a temperature-controlled isolated organ chamber, using calcium-free Krebs solution. The contractile effects of serotonin, lantane, verapamil and cyclopiazonic acid were evaluated at different concentrations using a computer coupled biopac polygraph. RESULTS: No differences in response were observed in the presence and absence of intracellular calcium. The positive contractile effects observed with serotonin were significantly decreased with repeated stimulation. An increase in the basal tone of the vessel was observed after calcium supplementation was added to the solution. This effect was minimized in the presence of verapamil and lantane. The contractile effects of serotonin in the calcium-free solution were not affected by the presence of cyclopiazonic acid. CONCLUSIONS: Serotonin contractile effects in the human umbilical artery depend mainly on intracellular calcium levels which favor the gradual entrance of this ion over time. Calcium influx induced by serotonin is possible through L and Non-L channels apparently insensitive to ciclopiozonic acid.

Efectos contráctiles dependientes del calcio intracelular inducidos por la serotonina en la arteria umbilical humana / Intracellular calcium-dependent contractile effects of serotonin in the human umbilical artery

Antecedentes: Los vasos umbilicales humanos se caracterizan por la ausencia de inervación y por consecuencia, las diferentes sustancias vasoactivas y la respuesta contráctil a través de los iones de calcio son los factores que determinan el flujo sanguíneo al espacio intervelloso en condiciones normales y patológicas, como es el caso de la preeclampsia eclampsia. Objetivo: Aportar información adicional de la respuesta contráctil de la serotonina en relación al calcio intracelular en la arteria umbilical humana. Material y métodos: Se utilizaron vasos umbilicales procedentes de mujeres con embarazo normoevolutivo, los cuales una vez disecados se cortaron en anillos de 5 mm y se montaron en cámara de órgano aislado, utilizando solución de Krebs con y sin calcio, burbujeada con carbógeno y la temperatura controlada. Se evaluó el efecto contráctil inducido por serotonina a diferentes concentraciones molares y se contrastó con verapamil, lantano y ácido ciclopiazónico, cuantificando la respuesta contráctil mediante un polígrafo biopac acoplado a un sistema computacional. Resultados: No se observaron diferencias significativas en la magnitud de la respuesta obtenida en presencia y ausencia de calcio extracelular. Se apreció el efecto contráctil a la serotonina que disminuyó significati vamente como respuesta a la estimulación repetida a la misma; así mismo, se incrementó el tono basal posterior a la adición del calcio al medio de incubación, lo que dependió del tiempo de exposición. También se observó la inhibición parcial del incremento en el tono basal con vera pamil y lantano. Finalmente, el pretratamiento con ácido ciclopiazónico no modificó la respuesta contráctil a la serotonina en un medio sin calcio. Conclusiones: La contracción inducida por serotonina en la arteria umbilical humana, depende principalmente de calcio intracelular y favorece el ingreso capacitativo de este ion, el cual se incrementa gradualmente a través del tiempo. El ingreso capacitativo del calcio secundario al vaciamiento de los depósitos intracelulares de este ion con serotonina se efectúa a través de canales tipo L y no-L, y no parecen ser sensibles al ácido ciclopiazónico.

Background: Absence of innervation is a hallmark of human umbilical vessels. Intervillous space blood flow is regulated by vasoactive substances and calcium dependent contractility, both in normal and pathological conditions such as preeclampsia eclampsia. Objective: To obtain additional information on the intracellular calcium contractile effects of serotonin in human umbilical arteries. Materials and Methods: Umbilical arteries from normal pregnancies were dissected, cut in 5 mm rings and mounted in a temperature controlled isolated organ chamber, using calciumfree Krebs solution. The contractile effects of serotonin, lantane, verapamil and cyclopiazonic acid were evaluated at different concentrations using a computer coupled biopac polygraph. Results: No differences in response were observed in the presence and absence of intracellular calcium. The positive contractile effects observed with serotonin were significantly decreased with repeated stimulation. An increase in the basal tone of the vessel was observed after calcium supplementation was added to the solution. This effect was minimized in the presence of verapamil and lantane. The contractile effects of serotonin in the calcium free solution were not affected by the presence of cyclopiazonic acid. Conclusions: Serotonin contractile effects in the human umbilical artery depend mainly on intracellular calcium levels which favor the gradual entrance of this ion over time. Calcium influx induced by serotonin is possible through L and Non-L channels apparently insensitive to cyclopiozonic acid.

Anti-hypertensive therapy and the feto-placental circulation: effects on umbilical artery resistance.

OBJECTIVE: To investigate and compare the direct effects of compounds used in the treatment of hypertensive disease in pregnancy on human umbilical artery resistance in vitro. METHODS: Isometric tension recordings were performed under physiological conditions on human umbilical arterial rings (n=30). The in vitro effects of labetolol, hydralazine, alpha-methyldopa, nifedepine and magnesium sulphate (at concentration ranges from 1 nanomolar to 1 millimolar), and their respective vehicle controls, were measured. Results were expressed as -logEC50 (pD2) and mean maximal inhibition values for each compound. RESULTS: All compounds investigated, except alpha methyldopa, exerted a significant relaxant effect on umbilical arterial tone. Alpha-methyldopa was significantly less potent when compared to all other compounds (mean maximal inhibition value [20.89+/-7.99%] versus all other agents [range 63.15+/-8.70-84.12+/-3.84%] (P<0.01)). The dose response curve of nifedipine yielded a significantly greater PD2 value when compared to that of hydralazine, labetalol, and magnesium sulphate (PD2 value [5.82+/-0.34] versus the above groups [range 3.10+/-0.09-3.52+/-0.14] (P <0.01)). CONCLUSION: These findings demonstrate that agents commonly used for the treatment of hypertensive disease in pregnancy, excluding alpha-methyldopa, have significant direct effects on the feto-placental circulation. These results suggest that alpha-methyldopa administration during pregnancy is less likely to produce significant direct effects on fetal vasculature then other agents used.

Influence of acupuncture on Doppler ultrasound in pregnant women.

OBJECTIVE: To evaluate the influence of acupuncture on the blood flow in the umbilical artery (UA), fetal aorta and uterine artery and on the fetal heart rate using two different acupuncture points (SP-6 (Sanyinjiao) and LI-4 (Hegu)). METHODS: In group A (n = 50), measurements (Doppler ultrasound and fetal heart rate) were performed at term after an uneventful pregnancy (#1) followed by acupuncture treatment using the acupuncture-point SP-6 bilaterally. The treatment time lasted 15 min after which the next measurement (#2) was carried out. The needles were then inserted into the LI-4 acupuncture point for a further 15 min. A third measurement at the end of acupuncture treatment (#3) completed the session. In group B (n = 25), measurements were made before (#1) and after (#4) acupuncture at LI-4 acupuncture points only. RESULTS: In group A, the mean systolic/diastolic (S/D) ratios of UA #1, UA #2 and UA #3 were 2.45, 2.38 and 2.22, respectively (P = 0.0012). The difference in mean S/D ratios between UA #1 and UA #3 as well as that between UA #2 and UA#3 were statistically significant (P = 0.0002 and P = 0.008, respectively). There was no difference between the mean S/D ratios of the uterine artery and between the mean resistance indices of the fetal aorta. In group B, the only significant difference between measurements following acupuncture treatment was in fetal heart rate (139 vs. 143 bpm, P = 0.02). CONCLUSION: Our study indicates a positive influence of acupuncture treatment on umbilical artery waveforms when using a combination of SP-6 (Sanyinjiao) and LI-4 (Hegu) acupuncture points. Acupuncture performed at these sites either individually or in combination does not seem to affect blood flow in the fetal aorta or uterine artery.

Fetal circulatory responses to maternal blood loss.

We examined the fetal circulatory responses to maternal blood loss in pregnant women during the third trimester. Seven healthy women with placenta previa and singleton pregnancies underwent phlebotomies in an autologous donation program. Four hundred milliliters of blood was collected within 15 min at 34 and 35 weeks of gestation. Continuous electric recordings of fetal heart rate were performed during the first blood collection, and the maternal uterine artery (UtA), umbilical artery (UmA) and fetal middle cerebral artery (MCA) Doppler velocity waveforms were recorded before, immediately after and 24 h after the second collection in each patient. The average fetal heart rate, maternal UtA and UmA pulsatility indices did not change measurably during or after maternal blood collections. However, the average fetal MCA pulsatility index decreased significantly 24 h after maternal blood loss. The observation of a decrease in fetal MCA pulsatility index may indicate delayed fetal asphyxia following mild maternal hemorrhage.

Search for the most predictive tests of fetal well-being in early labor.

The aim of the study was to evaluate the admission CTG alone and in combination with the following tests: fetal acoustic stimulation test (FAST), maternal perception of sound provoked fetal movement (mpSPFM), amniotic fluid index (AFI), and umbilical artery doppler studies in early labor. 1092 singleton pregnancies in cephalic presentation, and with intact amniotic membranes at 37 weeks gestation or more, were admitted in early labor to the labor ward at the National University Hospital, Singapore. Admission tests were performed, and labor managed according to established labor ward protocol. Of all the tests performed, only the results of the admission CTG and color of the amniotic fluid were known to the obstetrician. If the admission CTG is normal, AFI is > 5 cm and there is an acceleratory responses to FAST the incidence of fetal distress is low. In the presence of a reactive admission CTG and in the absence of thick meconium, fetal heart rate response to FAST and the AFI provided a better selection of the high risk fetus that would require closer monitoring or early delivery. When the admission CTG was suspicious, FAST, AFI, and blood flow velocity waveform studies may allow more confident prediction of the ability of the fetus to withstand the stresses of labor.

Oral magnesium supplementation improves fetal circulation.

It is well known that pregnancy is a condition in which plasma magnesium falls because of accumulation of the ion in the placenta and fetus. Magnesium (Mg) is therefore widely given as a supplement during pregnancy, particularly in cases of preterm labour. In our experience, the combination of oral Mg (magnesium pyrrolidone carboxylic acid) at a dose of 360 mg/day with conventional ritodrine treatment allows a reduction in ritodrine dosage, accompanied by a significant reduction in side effects. We therefore evaluated changes in fetal blood flow, using pulsed Doppler, in women submitted to combined magnesium and ritodrine treatment compared to those treated with ritodrine plus placebo. The Mg-treated group showed a decrease in vessel resistance both in the umbilical artery and in the fetal middle cerebral artery, indicating that fetal vasculature is sensitive to exogenous Mg. Measurement of plasma and mononuclear cell Mg showed an intracellular increase in the cation of about 10 per cent. We conclude that oral magnesium supplementation in pregnancy is safe and that it has a positive effect on the fetal circulation.

[Mechanism and effect of anisodamine on uteroplacental circulation in pregnancy-induced hypertension].

The short term effect of anisodamine, an alkaloid isolated from the chinese herb anisodas tonguticus, on blood flow of uterine and umbilical arteries in 16 pregnant women with pregnancy-induced hypertension (PIH) was investigated by means of pulsed doppler ultrasound technique Results have shown that anisodamine could decrease the A/B ratio, resistant index (RI), and pulsative index (PI) of blood velocity in these arteries with statistical significant difference. Its mechanism of action might be the improving of the rheology in PIH and adjusting the imbalance of TXA2/PGI2. It was suggested that the resistance in uteroplacental circulation was decreased and its perfusion improved, so that favors the fetal growth and development.

Effects of hyperthermia on fetal and maternal plasma prostaglandin concentrations and uterine activity in sheep.

The exposure of pregnant sheep to high ambient temperatures (43 degrees C) for 8 hours, sufficient to significantly elevate maternal and fetal body temperature +2.0 degrees C (p less than 0.001) and +1.9 degrees C (p less than 0.001) respectively, resulted in significant increases in PGE2 plasma concentrations in both the maternal and fetal circulations. Plasma PGF2 alpha concentrations were significantly raised in the fetal circulation but not the maternal during hyperthermia. The increase in prostaglandin concentrations were correlated with the magnitude of the increase in maternal and fetal body temperature. Uterine activity also increased during hyperthermia, probably as a result of the increase in prostaglandin concentrations. We propose that increased synthesis and release of prostaglandins from the uterus and/or placenta is an adaptive response to hyperthermia, and may protect the fetus from the consequences of heat stress.