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.

Addition of sildenafil citrate for treatment of severe intrauterine growth restriction: a double blind randomized placebo controlled trial.

Background: Severe intrauterine growth restriction complicates approximately 0.4% of the pregnancies. It increases the risk of perinatal morbidity and mortality.Subjects and methods: A double blind placebo controlled trial was conducted in Beni Suef University hospitals during 2017. It included 46 pregnant women with severe intrauterine growth restriction. Women were randomly allocated into two groups each included 23 patients. Intervention group received sildenafil citrate 20 mg orally three times a day, in addition to fish oil and zinc supplementation. Control group received tablets similar to sildenafil and the same treatment as intervention group. Primary outcomes included improvement in umbilical and middle cerebral arteries pulsatility indices and abdominal circumference.Results: Umbilical and middle cerebral arteries Doppler indices showed significant difference between groups after intake of sildenafil. Umbilical artery pulsatility index decreased significantly (p value = .001) while middle cerebral artery pulsatility index increased significantly in intervention group (p value0.001). Moreover, abdominal circumference growth velocity improved after two weeks of sildenafil intake (p value = .001).Conclusions: Sildenafil citrate may improve uteroplacental and fetal cerebral perfusion in pregnancies complicated by severe intrauterine growth restriction. It also improves abdominal circumference growth velocity. A wide scale randomized trials are needed for evaluation of neonatal and long term morbidity and mortality outcomes of pregnancies treated by sildenafil citrate.

Reference ranges for Doppler indices of umbilical and fetal middle cerebral arteries and cerebroplacental ratio: systematic review.

OBJECTIVE: To assess studies reporting reference ranges for umbilical artery (UA) and fetal middle cerebral artery (MCA) Doppler indices and cerebroplacental ratio (CPR), using a set of predefined methodological quality criteria for study design, statistical analysis and reporting methods. METHODS: This was a systematic review of observational studies in which the primary aim was to create reference ranges for UA and MCA Doppler indices and CPR in fetuses of singleton gestations. A search for relevant articles was performed in MEDLINE, EMBASE, CINAHL, Web of Science (from inception to 31 December 2016) and references of the retrieved articles. Two authors independently selected studies, assessed the risk of bias and extracted the data. Studies were scored against a predefined set of independently agreed methodological criteria and an overall quality score was assigned to each study. Linear multiple regression analysis assessing the association between quality scores and study characteristics was performed. RESULTS: Thirty-eight studies met the inclusion criteria. The highest potential for bias was noted in the following fields: 'ultrasound quality control measures', in which only two studies demonstrated a comprehensive quality-control strategy; 'number of measurements taken for each Doppler variable', which was apparent in only three studies; 'sonographer experience', in which no study on CPR reported clearly the experience or training of the sonographers, while only three studies on UA Doppler and four on MCA Doppler did; and 'blinding of measurements', in which only one study, on UA Doppler, reported that sonographers were blinded to the measurement recorded during the examination. Sample size estimations were present in only seven studies. No predictors of quality were found on multiple regression analysis. Reference ranges varied significantly with important clinical implications for what is considered normal or abnormal, even when restricting the analysis to the highest scoring studies. CONCLUSIONS: There is considerable methodological heterogeneity in studies reporting reference ranges for UA and MCA Doppler indices and CPR, and the resulting references have important implications for clinical practice. There is a need for the standardization of methodologies for Doppler velocimetry and for the development of reference standards, which can be correctly interpreted and applied in clinical practice. We propose a set of recommendations for this purpose. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Intervalos de referencia para los índices Doppler de la arterias umbilical y cerebral media del feto y la relación cerebroplacentaria: una revisión sistemática OBJETIVO: Evaluar los estudios que informan sobre intervalos de referencia para los índices Doppler y la relación cerebroplacentaria (RCP) de la arteria umbilical (AU) y la arteria cerebral media (ACM) del feto, mediante un conjunto de criterios de calidad metodológica predefinidos para el diseño del estudio, el análisis estadístico y los métodos de notificación. MÉTODOS: Esta fue una revisión sistemática de estudios observacionales en los que el objetivo principal fue crear intervalos de referencia para los índices Doppler de la AU y la ACM y la RCP de fetos de gestaciones con feto único. Se realizó una búsqueda de artículos relevantes en MEDLINE, EMBASE, CINAHL, Web of Science (desde el inicio hasta el 31 de diciembre de 2016) y en las referencias de los artículos recuperados. Dos autores, de forma independiente, seleccionaron los estudios, evaluaron el riesgo de sesgo y extrajeron los datos. Los estudios se calificaron según un conjunto predefinido de criterios metodológicos acordados de forma independiente y se asignó una puntuación de calidad global a cada estudio. Se realizó un análisis de regresión múltiple lineal para evaluar la asociación entre las puntuaciones de calidad y las características del estudio. RESULTADOS: Un total de 38 estudios cumplieron los criterios de inclusión. El mayor potencial de sesgo se observó en los siguientes casos: 'medidas de control de calidad del ultrasonido', donde sólo dos estudios demostraron una estrategia integral de control de calidad; 'número de mediciones tomadas para cada variable Doppler', que solo fue aparente en tres estudios; 'experiencia del ecografista', puesto que ningún estudio sobre la RCP informó claramente sobre la experiencia o la formación de los ecografistas, y tan solo lo hicieron tres estudios sobre el Doppler de la AU y cuatro sobre el Doppler de la ACM; y 'mediciones a ciegas', donde tan sólo un estudio sobre el Doppler de la AU comunicó que los ecografistas no tuvieron acceso a la medición registrada durante el estudio. Las estimaciones del tamaño de la muestra sólo se comunicaron en siete estudios. No se encontraron predictores de calidad en el análisis de regresión múltiple. Los intervalos de referencia variaron significativamente con implicaciones clínicas importantes para lo que se considera normal o anómalo, incluso cuando se restringió el análisis a los estudios con mayor puntuación. CONCLUSIONES: Existe una heterogeneidad metodológica considerable en los estudios que informan sobre los intervalos de referencia para los índices Doppler de la AU y la ACM y la RCP, y las referencias resultantes tienen implicaciones importantes para la práctica clínica. Es necesario estandarizar las metodologías de la velocimetría Doppler y desarrollar estándares de referencia que puedan ser interpretados y aplicados correctamente en la práctica clínica. Se propone una serie de recomendaciones para este fin.

Nifedipine increases fetoplacental perfusion.

AIM: Our aim is to evaluate the effect of nifedipine on fetoplacental hemodynamic parameters. METHODS: A retrospective study was conducted at a tertiary center with 30 patients for whom nifedipine treatment was used as a tocolytic therapy for preterm labor. Initiation of this treatment was at 31.6±2.5 weeks of gestation. We combined the pulse Doppler imaging parameters with grayscale imaging via the Bernoulli theorem, which is called the "continuity equation", to get the fetoplacental perfusion (FPP). Evaluated parameters were the resistance index (RI), the pulsatility index (PI), systole/diastole ratios (S/D), the velocity-time integral of the umbilical artery (VTI), the radius of the umbilical artery, the peak systolic velocity and the mean pressure gradient in the umbilical artery. From these parameters, the FPP was acquired. RESULTS: We found that the RI, the PI and the S/D ratio did not change after treatment with nifedipine. The mean pressure gradient, the VTI and the peak systolic velocity increased after treatment with nifedipine. Nifedipine increases FPP from 166±73.81 beat.cm3/min to 220±83.3 beat.cm3/min. DISCUSSION: Although nifedipine had no effect on the PI, the RI or the S/D, it increased the mean pressure gradient, the VTI and FPP.

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.

Ultrasound parameters and L/S ratio in prediction of perinatal outcome in term-growth restricted newborns.

AIM: The relation between biophysical profile (BPP), cerebroplacental (C/P) ratio, and lecithin/sphingomyelin (L/S) ratio as a predictor perinatal outcome in term intrauterine growth restricted (IUGR) neonates was evaluated. MATERIALS AND METHODS: A retrospective study of the perinatal outcome of 77 term monofetal pregnancies complicated with IUGR fetuses (< 10 percentile) who were terminated by cesarean section in 2010 was performed at the Institute of Gynecology and Obstetrics, Belgrade. RESULTS: The most frequent early neonatal complication was asphyxia. The authors found a strong correlation between the L/S ratio and birth weight (BW) r = 0.609, as well as between BPP and Apgar score 5 r = 0.583. Significant negative correlation was found between asphyxia and BPP r = -0.398, as well as between asphyxia and C/P ratio r = -0.379. CONCLUSION: In serous IUGR neonates, low values of BPP and L/S ratios predicted asphyxia.

Risk of necrotizing enterocolitis and feeding interventions for preterm infants with abnormal umbilical artery Doppler.

Infants exposed to absent or reversed end-diastolic flow (ARE DF) in utero may be at an increased risk of developing necrotizing enterocolitis (NEC). This article reviews placental function and the development of ARE DF. Studies examining the relationship between AREDF and NEC are reviewed, yet research remains inconclusive regarding this relationship. Recent studies reveal that early minimal enteral feeding does not increase the incidence of NEC in infants with AREDF. Initiation and advancement of enteral feedings should be monitored closely in this subset of the neonatal intensive care unit (NICU) population.

[Interstitial laser coagulation in Twin Reversed Arterial Perfusion sequence]. / Mikroinwazyjna laserowa koagulacja naczyn wewnatrzbrzusznych w zespole odwróconej perfuzji tetniczej.

Twin Reversed Arterial Perfusion (TRAP) sequence complicates about 1% of all monochorionic twin pregnancies and about 1 to 35000 of all pregnancies. It involves an acardiac twin whose structural defects are incompatible with life, and an otherwise normal "pump" co-twin. As the blood flow in the acardiac twin is reversed, it keeps on growing owing to the oxygenated blood from the co-twin. Here we report a case of monochorionic, diamniotic twin pregnancy after ICS/-ET complicated with TRAP sequence, diagnosed at 11 weeks of pregnancy The unusual finding in this case was the residual heart in the so called acardiac twin. Gradually the normal twin developed signs of hemodynamic compromise. Reversed a-wave in ductus venosus was observed. The acardiac twin showed subcutaneous oedema. On 24 November 2011 a successful interstitial ultrasound-guided laser coagulation was performed at 16 weeks of gestation. 17G needle and 0.6 mm laser fibre were used. The needle was introduced into the pelvic region of the acardiac twin through the abdominal wall. A series of laser bursts lasting 5-10 seconds were fired, until cessation of blood flow in the pelvic vessels and umbilical cord of the acardiac twin was confirmed using colour Doppler. The course of the intervention was uneventful. Routine steroid therapy was administered at 27 weeks of gestation. At 32 weeks the patient was hospitalized and oral antibiotics were administered due to premature rupture of the membranes and suspicion of intrauterine growth retardation of the pump twin. The patient delivered spontaneously at completed 33 weeks of pregnancy (weight 1805g, Apgar 10). After the delivery a stage 2 intraventricular hemorrhage and jaundice were observed in the neonate. Phototherapy was administered and the mother and the child were eventually discharged from the hospital, both in good general condition. Since then, two more successful interstitial laser coagulations in TRAP sequence were performed in our institution. The essence of the treatment of TRAP sequence is cessation of the blood flow from the pump to the acardiac twin. Fetoscopic cord ligature or coagulation, and laser or radiofreqency ablations of the acardiac twin vessels, are the possible methods of intervention. The interstitial laser coagulation of the acardiac twin is less invasive than fetoscopic umbilical cord coagulation, as the outer diameter of the 17G needle is much smaller. A meticulous comparison of these methods would require a randomised study but at 16 weeks of MCDA twin pregnancy interstitial laser coagulation seems to be the method of choice. The outcome of the procedure and possible treatment options in case of TRAP together with the review of literature, are presented in the article.

Folic acid is positively associated with uteroplacental vascular resistance: the Generation R study.

BACKGROUND AND AIMS: Periconception folic acid supplementation may influence early placentation processes and thereby the occurrence of hypertensive pregnancy disorders. For this reason we examined the associations between periconception folic acid supplementation and uteroplacental vascular resistance, blood pressure, and the risks of gestational hypertension and preeclampsia, in 5993 pregnant women, participating in a population-based cohort study. METHODS AND RESULTS: Folic acid supplementation was assessed by questionnaire. Mean pulsatility index (PI) and resistance index (RI) of the uterine (UtA) and umbilical arteries (UmA) were measured by Doppler ultrasound in mid- and late pregnancy. Systolic and diastolic blood pressures (SBP, DBP) were measured in early, mid- and late pregnancy. Compared to women who did not use folic acid, preconception folic acid users had a slightly lower UtA-RI in mid-pregnancy [ß -0.02, 95% confidence interval (CI) -0.03, -0.01] and late pregnancy [ß -0.02, 95% CI -0.03, -0.001], a lower UtA-PI in mid-pregnancy [ß -0.06, 95% CI -0.1, -0.03] and late pregnancy [ß -0.03, 95% CI -0.05, -0.01], as well as tendencies towards a lower UmA-PI in mid-pregnancy [ß -0.02, 95% CI -0.04, -0.001] and late pregnancy [ß -0.01, 95% CI -0.02, 0.01]. Additionally, these women had slightly higher SBP and DBP throughout pregnancy. Neither the patterns of blood-pressure change during pregnancy, nor the risk of gestational hypertension and preeclampsia differed between the folic acid categories. CONCLUSION: Periconception folic acid supplementation is associated with lower uteroplacental vascular resistance and higher blood pressures during pregnancy. The effects are small and within physiologic ranges and seem not associated with the risk of hypertensive pregnancy disorders.

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.

Nifedipine therapy for preterm labor: effects on placental, fetal cerebral and atrioventricular Doppler parameters in the first 48 hours.

OBJECTIVE: To assess the effect of nifedipine tocolysis on Doppler parameters of the uterine, umbilical and fetal middle cerebral arteries and atrioventricular valves in the first 48 h of therapy. METHODS: Doppler waveforms of uterine, umbilical and middle cerebral arteries and both atrioventricular valves were measured from 28 pregnant women and fetuses prior to and during nifedipine therapy for preterm labor. Maternal and fetal heart rates (FHR), maternal systolic and diastolic blood pressure, and the Doppler pulsatility index (PI) of the uterine, umbilical and middle cerebral arteries were measured. The cerebroplacental ratio (middle cerebral artery PI/umbilical artery PI) was calculated. The total time velocity integrals (TVIs) of tricuspid and mitral valves and their E- and A-wave peak velocity ratio (E/A) were measured. Friedman repeated-measures analysis of variance was used to compare the variables before and after nifedipine therapy. If significant differences were found, Wilcoxon's signed ranks test was used to analyze the difference between the two variables. A P-value of < 0.05 was considered significant. RESULTS: Nifedipine maintenance was associated with a significant decline in maternal systolic and diastolic blood pressure after 24 h, while maternal heart rate and FHR were unaffected. The uterine artery PI had decreased significantly at 24 and 48 h, while the umbilical artery PI did not change significantly. The middle cerebral artery PI had decreased significantly at 24 and again at 48 h. A significant fall in the cerebroplacental Doppler ratio was maintained beyond 24 h. The mean E/A values, TVIs and TVI x FHR values at 24 and 48 h were unchanged from the baseline values. CONCLUSIONS: Nifedipine maintenance tocolysis is associated with a significant decline in uterine artery and middle cerebral artery Doppler indices 24 h after the first dose. Fetal cardiac diastolic function is unaffected and the significant redistribution observed after 24 h is likely to be attributable to altered cerebral blood flow.

Efficacy of yoga in pregnant women with abnormal Doppler study of umbilical and uterine arteries.

To study the efficacy of yoga on the outcome of complicated pregnancy, 121 women attending antenatal clinic at Gunasheela Surgical and Maternity Hospital (GSMH) in Bangalore, India, were enrolled between 18-20 weeks of pregnancy in a prospective, matched, observational study. Sixty-eight women were in the yoga group and 53 women in the control group. Women were matched for age, gravida and Doppler velocimetry scores of umbilical and uterine arteries. Yoga practices including physical postures, breathing and meditation were practised by the yoga group, one hour daily, from the date of entry into the study until delivery. The control group walked half an hour twice a day during the study period. Compliance in both the groups was ensured. In babies the birth-weight is significantly higher (P < 0.018) in the Yoga group (2.78 +/- 0.52 kg), compared to the control group (2.55 +/- 0.52 kg). Occurrence of complications of pregnancy (pregnancy-induced hypertension, intrauterine growth retardation, pre-term delivery) shows lower trends in yoga group.

The short-term effect of nifedipine tocolysis on placental, fetal cerebral and atrioventricular Doppler waveforms.

OBJECTIVE: To evaluate the effect of nifedipine on placental and fetal middle cerebral and atrioventricular Doppler waveforms. METHODS: Doppler waveforms of uterine (UtA), umbilical (UA) and middle cerebral (MCA) arteries and both atrioventricular valves were measured from 21 pregnant women/fetuses prior to and during nifedipine therapy for preterm labor. Maternal and fetal heart rates (FHR), maternal systolic and diastolic blood pressure, the Doppler pulsatility index and systolic/diastolic ratio of the UtA, UA and MCA were measured. The total time velocity integrals (TVI) of tricuspid and mitral valves and their E-wave/A-wave (E/A) TVI ratios were measured. Wilcoxon signed pairs test was used to compare the differences in Doppler parameters before and at 3 h after nifedipine loading up to a maximum dose of 40 mg. RESULTS: Fetal arterial and UtA Doppler parameters were not different before and after nifedipine therapy. Blood flow across the atrioventricular valves and the TVI were equally unaffected by nifedipine. The TVI x FHR product was also unchanged following nifedipine therapy. CONCLUSIONS: In women with otherwise uncomplicated pregnancies, nifedipine loading and tocolysis are generally well tolerated by the mother. Placental and fetal cerebral arterial blood flow, fetal systolic and diastolic cardiac function and downstream distribution of fetal cardiac output are unaffected by nifedipine loading. These results apply to women with unchanged vital parameters. Further studies are necessary to show long-term effects of nifedipine therapy and may help to refine choice of tocolytic agents.

The effect of nifedipine and dipyridamole on the Doppler blood flow waveforms of umbilical and uterine arteries in hypertensive pregnant women.

In a study of 45 hypertensive pregnant women, the systolic velocity/diastolic velocity ratio and pulsatility index of the umbilical and uterine arteries showed good correlation with the maternal blood pressure, and they appeared to provide a good parameter for the fetoplacental condition. Using the pulse Doppler method, we studied the effects of the antihypertensive agent nifedipine and of dipyridamole (an agent used to treat proteinuria) on the blood flow of the umbilical and uterine arteries in 16 hypertensive pregnant women. The results proved that both drugs caused a decrease in the vascular resistance of the umbilical artery and suggested that they increased the blood flow volume of this artery and were useful in the treatment of hypertension during pregnancy.

Antepartum fetal surveillance in the preterm fetus.

Over the past two decades, obstetric and neonatal health care has shifted its attention to the preterm pregnancy. Due to the immaturity of the fetal autonomic nervous system, the usual diagnostic criteria for intervention in the preterm fetus are not available. Alternative methods such as the biophysical profile and Doppler offer the clinician a reasonable alternative in identifying potential fetal compromise.

The effect of nifedipine therapy on fetal and placental Doppler waveforms in preeclampsia remote from term.

Twenty patients with preeclampsia at a gestational age of 26 to 35 weeks were treated with oral nifedipine until delivery. The mean oral daily dose was 45.1 +/- 11 mg/day (range, 40 to 80 mg/day). Fetal aorta, internal carotid artery, umbilical artery, and uteroplacental Doppler flow velocity waveforms were recorded before treatment and then serially. The mean nifedipine concentration at the time of the Doppler studies was 60.3 ng/ml (range, 10 to 90 ng/ml). The use of nifedipine therapy was associated with a significant decrease in both maternal systolic blood pressure (baseline, 154 to 135 mm Hg, p less than 0.001) and diastolic blood pressure (baseline, 100 to 88 mm Hg, p less than 0.001). However, there was no significant difference in the resistance index between baseline and postnifedipine Doppler studies in either the fetal or uteroplacental vessels. The use of oral nifedipine to control blood pressure in preeclampsia does not affect the resistance indices in fetal or uteroplacental vessels as measured by the Doppler technique.