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

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, …