The traditional view in respect to female reproduction is that the number of oocytes at birth is fixed and continuously declines towards the point when no more oocytes are available after menopause. In this review we briefly discuss the embryonic development of female germ cells and ovarian follicles. The ontogeny of the hypothalamic-pituitary-gonadal axis is then discussed, with a focus on pubertal transition and normal ovulatory menstrual cycles during female adult life. Biochemical markers of menopausal transition are briefly examined. We also examine the effects of age on female fertility, the contribution of chromosomal abnormalities of the oocyte to the observed decline in female fertility with age and the possible biological basis for the occurrence of such abnormalities. Finally, we consider the effects of maternal age on obstetric complications and perinatal outcome. New data that have the potential to revolutionize our understanding of mammalian oogenesis and follicular formation, and of the female reproductive ageing process, are also briefly considered.

Ovarian hyperstimulation syndrome (OHSS) can be a severe and potentially life-threatening complication of ovarian stimulation for IVF. Coasting or withholding gonadotrophin stimulation relies on frequent estimation of serum oestradiol to identify patients at risk. A modified coasting protocol was developed in which identification of patients at risk of severe OHSS was based on ultrasound monitoring. Serum oestradiol concentrations were measured only in patients with >20 follicles on ultrasound (high risk). If serum oestradiol concentrations were <3000 pmol/l, the gonadotrophin dose was maintained; if concentrations were ≥3000 pmol/l but <13200 pmol/l and ≥25% of the follicles had a diameter of ≥13 mm, the gonadotrophin dose was halved; and if serum oestradiol concentrations were ≥13 200 pmol/l and ≥25% of the follicles had a diameter of ≥15 mm, patients were coasted. In the latter group, human chorionic gonadotrophin (HCG) 10000 IU was administered when at least three follicles had a diameter of ≥18 mm and serum oestradiol concentrations were <10000 pmol/l. Over a 10 month period, serum oestradiol concentrations were measured in 123 out of 580 cycles (24%) and in 50 cycles, gonadotrophins were withheld. Overall, moderate OHSS occurred in three patients (0.7%) and severe OHSS in one patient (0.2%). The pregnancy rates in the cycles where the gonadotrophin dose was reduced or withheld were 39.6 and 40% per cycle respectively; corresponding implantation rates were 30.7 and 25.6%. It is concluded that the modified coasting strategy is associated with a low risk of moderate and severe OHSS to a minimum without compromising pregnancy rates. Identification of patients at risk by ultrasound reduces the number of serum oestradiol measurements and thus inconvenience to patients as well as costs and workload.

SummaryPlatelet activation occurs in early pregnancy in women at risk of developing pre-eclampsia. Cytokines have been implicated in the pathogenesis of pre-eclampsia, so we determined the effects of interleukin- 1β (IL-1β) and tumor necrosis factor-α (TNF-α) on the in vitro aggregation of human platelets. IL-1β increased aggregation of platelets from non-pregnant and pre-eclamptic women, and inhibited the aggregation of platelets from normal pregnant women. This latter effect was linked to a diminished P-selectin expression on ADP-stimulated whole blood platelets in normal pregnant women (p = 0.011). Platelet aggregation in response to ADP was found to be inhibited after preincubation with TNF-α in non-pregnant (38%, p = 0.01) and in normal pregnant women (54%, p = 0.001) and not affected in pre-eclamptic women. The inhibitory effects of TNF-α were mediated through the P75 receptor for TNF-α.

No abstract

No abstract