Ultrasound and plasma 17β-oestradiol in the follicular phase, particularly in IVF cycles

The first part of the study described in this thesis was commenced in 1982. At that time, accuracy and reproducibility of ultrasonographic follicle measurements were largely unknown. This part, therefore, has primarily been designed to assess these aspects with respect to static B-compound equipment (Section 2.2.3) and mechanical sector scanners (Section 2.2.4). The ultrasonographical aspects of follicular growth in the spontaneous menstrual cycle have been well documented, as discussed in Section 1.1.1. Little information was available on follicular growth in stimulated cycles for IVF, which therefore comprised the second part of the study. Ovarian stimulation for IVF purposes was initially accomplished using CC. We studied follicular growth in normally cycling women using this compound both in the late follicular phase (Section 3.3.3), and in the 24 h period following the administration of HCG (Section 3.3.4). It was anticipated that the results from these studies might allow more precise planning ofthe administration ofHCG preceding follicle aspiration. Urinary and plasma oestrogens reflect follicular maturation both in the spontaneous and induced menstrual cycle, as described in Sections 1.2.1. and 1.2.2. The question as to whether any predictive value on the prospects of a forthcoming pregnancy can be attributed to absolute plasma E2 levels on each treatment day or to changes in plasma E2 levels during treatment (E2 profiles) led to the third part of the study which is presented in Chapter 4. This Chapter comprises three studies on the significance of plasma E2 determinations and profiles in both CC and HMG stimulated cycles for IVF.