Clinical significance of absent or reversed end diastolic velocity waveforms in umbilical artery

Blood gases, pH, and lactate in appropriate- and small-for-gestational-age fetuses.

Placental Regulation of Fatty Acid Delivery and its Effect on Fetal Growth—A Review

when concentrations of luteinising hormone are high throughout the follicular phase, as in some women with polycystic ovaries, the hormone penetrates the follicle and allows the oocyte to mature prematurely, resulting in ovulation of an oocyte that is physiologically \"aged.\" Such oocytes are unlikely to be fertilised or will tend to produce embryos that implant poorly and therefore abort. Data that support this model were reported in studies of pigs in which premature ovulation (and presumably maturation of oocytes) was induced with human chorionic gonadotrophin'° and in studies of rats in which insemination was delayed.\" In both studies the interval between maturation of the oocytes and fertilisation was extended and rates of fertilisation and embryo survival were impaired. In women extension of the interval between ovulation and insemination was associated with a striking increase in the rate of miscarriage.'2 Moreover, Stanger and Yovitch, Howles et al, and Punnonen et al have reported that high concentrations of luteinising hormone in the few days before oocytes were collected from women for in vitro fertilisation were associated with impaired rates of fertilisation and conception. Our results show that high concentrations of luteinising hormone during the follicular phase, found in many women with the polycystic ovary syndrome, have a deleterious effect on the success of induction of ovulation and conception and may be a causal factor in early pregnancy loss. As recent studies suggest that the polycystic ovary syndrome is common, both in patients attending infertility clinics and in the general population ,\"6 \" many patients may perhaps experience early miscarriage because of an endocrine disturbance. A potential treatment for these patients is to induce ovulation with exogenous gonadotrophins after desensitisation of the pituitary with a superactive analogue of luteinising hormone releasing hormone.7 The urinary excretion of interstitial cell and follicle stimulating hormone activity by women with diseases of the reproductive system. luteinising hormone releasing hormone therapy in women with polycystic ovary syndrome. 13 Stanger JD, Yovitch JL. Reduced in vitro fertilisation of human oocytes from patients with raised basal luteinising hormone levels during the follicular phase. of high tonic levels of luteinising hormone on outcome of in vitro fetilisation. Spontaneous luteinizing hormone surge and cleavage of in vitro fertilized embryos. Absence of end diastolic frequencies in umbilical artery: a sign of fetal hypoxia and acidosis One of the main challenges of antenatal management is distinguishing between normal small fetuses and growth retarded fetuses, …

https://www.bmj.com/content/bmj/297/6655/1026.full.pdf

Absence of end diastolic frequencies in umbilical artery: a sign of fetal hypoxia and acidosis.

Fetal growth restriction (FGR) is challenging because of the difficulties in reaching a definitive diagnosis of the cause and planning management. FGR is associated not only with a marked increased risk in perinatal mortality and morbidity but also with long-term outcome risks. Combinations of fetal biometry, amniotic fluid volume, heart rate patterns, arterial and venous Doppler, and biophysical variables allow a comprehensive fetal evaluation of FGR. However, no evidence supports that the use of cardiotocography or the biophysical profile improves perinatal outcome. Therefore, obstetricians aim to identify fetuses with early FGR so delivery can be planned according to gestational age and severity of the condition. The balance of risks and the need for the availability of services mean that the involvement of neonatologists in FGR management is vital. In this review, the focus is on the pathophysiology and management of FGR caused by placental diseases.

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Management of fetal growth restriction

Relation of fetal hypoxia in growth retardation to mean blood velocity in the fetal aorta

Apres un rappel sur la physiopathologie de l'isoimmunisation fœto-maternelle et son mode habituel de surveillance, les auteurs decrivent les resultats qu'ils ont obtenus en etudiant par enregistrement Doppler des ultrasons, la circulation au niveau des arteres ombilicales et uterines et au niveau de differents vaisseaux du fœtus (veines ombilicales et veine cave inferieure, aorte, carotides) ainsi que du cœur Les enregistrements ont ete effectues aux differents stades de la maladie fœtale et apres transfusion in utero

Doppler studies in red cell isoimmunization.

The technique of doppler ultrasound has revolutionized our understanding of the changes in uteroplacental blood flow impedance that occur in human pregnancy. Several reports in the last few years have examined the use of doppler ultrasound to detect blood velocity changes in maternal (Campbell et al., 1983), umbilical (Trudinger et al., 1986), and fetal vessels (Griffin et al., 1984). Both pulsed (Erskine and Ritchie, 1985) and continuous wave doppler (Trudinger et al., 1985) have been used to study the flow velocity waveforms in normal and abnormal pregnancies. These studies have concentrated on the latter half of pregnancy, in an attempt to assess the potential clinical value of this non invasive test for the screening and subsequent management of high risk pregnancies.

Doppler Measurement of Uterine Blood Flow in the First Trimester of Normal and Complicated Pregnancies

Umbilical venous blood pO2, pCO2, pH, erythroblast count, and plasma lactate were measured in twenty-nine fetuses with growth retardation. There were significant negative correlations between the severity of fetal hypoxia, hypercapnoea, acidosis, and hyperlactaemia and the mean velocity of blood in the fetal aorta measured by doppler ultrasound.

C. M. Bilardo

Papers

Relation of fetal hypoxia in growth retardation to mean blood velocity in the fetal aorta

Doppler studies in red cell isoimmunization.

Doppler Measurement of Uterine Blood Flow in the First Trimester of Normal and Complicated Pregnancies

Relation of Fetal Hypoxia in Growth Retardation to Mean Blood Velocity in the Fetal Aorta