Search

Unlabelled: This paper is based on a Cochrane review published in The Cochrane Library, issue 3, 2002 (see www.CochraneLibrary.net for information) with permission from The Cochrane Collaboration and Update Software. Cochrane reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and The Cochrane Library should be consulted for the most recent version of the review., Background: Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic condition resulting from an excessive ovarian response to superovulation medication. The objective of this review was to evaluate the effectiveness of cryopreservation (embryo freezing) when compared with human i.v. albumin infusion and with fresh embryo transfer for the prevention of OHSS., Methods: This was based on a Cochrane Review. Randomized controlled trials in which either human i.v. albumin or cryopreservation of all embryos was used as a therapeutic approach to OHSS were included. The participants were women down-regulated by GnRH agonist, undergoing superovulation in IVF/ICSI cycles. The interventions compared were cryopreservation versus i.v. human albumin administration and elective cryopreservation of all embryos versus fresh embryo transfer. The primary outcomes were: incidence of moderate and severe OHSS versus nil/mild OHSS, and clinical pregnancies/woman. Statistical analysis was performed in accordance with the Cochrane Menstrual Disorders and Subfertility Group guidelines., Results: Seventeen studies were identified, two of which met our inclusion criteria. One study was included where cryopreservation was compared with i.v. human albumin administration and another where elective cryopreservation of all embryos was compared with fresh embryo transfer. In both interventions no difference was found in all the outcomes examined between the two groups., Conclusions: This review has shown that there is insufficient evidence to support routine cryopreservation and insufficient evidence for the relative merits of i.v. albumin versus cryopreservation.

The Fallopian tube has been reported to undergo cyclical changes. However, many studies of tubal ultrastructure have either examined one segment of the tube only or studied animal oviducts. The aim of this study was to document in detail the combined morphological and ultrastructural features of the epithelial lining along the length of the tube in women at different stages of the menstrual cycle. We report an increase in the proportion of ciliated cells along the tube, being highest in the fimbriae, but no substantial difference between the follicular and luteal phases of the menstrual cycle. In the late follicular phase, fragments of cytoplasmic and cellular material were seen in the isthmic lumen but not in the outer tubal segments. Similarly, surface domes and secretory granules were more prominent in the mid-tube and ampullary sections than in the fimbriae. This surface activity was followed by relative quiescence in the early/mid luteal phase with reversion to a more active surface but with little secretory activity in the late luteal phase. These findings along the Fallopian tube substantiate the concept of functional differentiation between the different segments and necessitate further studies to determine its clinical relevance.

Cyclical ultrastructural changes in the endometrium and Fallopian tube have been reported previously but in different subjects. The aim of this study is to compare cyclical changes in endometrial gland and tubal (isthmic, mid-tube, ampulla, and fimbria) epithelia in the same subjects with a view to identifying any similarities or differences which may have clinical implications for assisted reproduction treatment. Endometrial and Fallopian tube samples were obtained from women undergoing hysterectomy and salpingectomy. We report similar epithelial surface changes taking place in the endometrial glandular and endosalpingeal epithelia with the exception of the fimbriae. Secretions within endometrial gland lumen and the isthmus increase throughout the late follicular phase and before ovulation, then dissipate in these two regions simultaneously in the early/mid luteal phase. Similarly, in the late follicular and pre-ovulatory phases, the process of granule secretion is similar in the glandular epithelium, isthmus and ampulla. In the fimbriae, no comparable activity is noted during these phases of the menstrual cycle. The differences reflect the functional differentiation between these regions. Equally, the observed similarities highlight the need for further comparative studies to determine the role of these secretions in early embryonic development and their clinical relevance.

Oestrogen and progesterone are known to require their corresponding steroid receptors to manifest structural and functional effects in the Fallopian tube, uterus and other target organs. This study compares cyclical variations of these receptors in the uterus and in different segments of the Fallopian tube in the same subjects using an immunocytochemical technique. The results show that in the Fallopian tube, isthmic and ampullary epithelial and stromal oestrogen receptors increased in the follicular phase to a peak at mid cycle and then declined in the late luteal phase. The intensity of immunostaining of oestrogen receptors was less in the Fallopian tube than in endometrial glandular epithelium. The fimbrial end demonstrated an opposite pattern of staining to other segments of the tube. Progesterone receptor immunostaining was more intense than that for oestrogen receptors in the follicular phase, and, whereas it disappeared completely from the endometrial glandular epithelium in the late luteal phase, positive staining was clearly visualized in the tubal epithelium and stroma and endometrial stroma at this stage of the menstrual cycle. These differences in the steroid receptor content may reflect the changing and different functional roles of these regions and may have important implications on human reproduction.

Several treatments for infertility have been promoted with only little supporting objective data demonstrating their therapeutic value. The choice of an assisted reproductive technique depends on a balance between numerous factors. Seldom is the choice absolute as in patients with tubal block. There is conflicting evidence on the efficacy of simpler methods such as ovarian stimulation with or without artificial insemination and the available data suggest that the more invasive methods such as gamete intra-Fallopian transfer or in-vitro fertilization are more effective in the treatment of couples with unexplained infertility. Equally, there is no conclusive evidence that pregnancy rates with any of the invasive techniques are superior to any others. However, a higher implantation rate following tubal embryo transfers is observed in many studies. This review presents a critical assessment of the effectiveness of assisted reproductive techniques.