1. Reports that maternal anaemia in pregnancy is associated with a greater placental: birth weight ratio, which predisposes towards high postnatal blood pressure in the human, led us to examine the effects of maternal anaemia during pregnancy on placental size, fetal and neonatal growth, and blood pressure development in the rat. 2. Nutritional anaemia was induced in female rats prior to mating and maintained throughout pregnancy and up until weaning of the pups. Fetuses were studied at 20 days of gestation (E20). Pups were studied on postnatal days 20 (P20) and 40 (P40), having been weaned onto normal rat chow at 21 days. 3. In the anaemic group placental: fetal body weight ratios were lower compared with controls. Body weights at all ages were lower in the anaemic group than in controls, despite a greater rate of growth in the anaemic group between P20 and P40. 4. At P20 heart weights of the anaemic group were almost twice that of controls, suggesting an alteration in their cardiovascular development. However, paradoxically, the systolic blood pressure of the anaemic group was lower than that of controls. 5. By P40 the systolic blood pressure of the anaemic group (136 +/‐ 3 mmHg) had increased and was greater than that in control pups (126 +/‐ 3 mmHg). 6. In conclusion, we have shown that there is a pronounced postnatal rise in systolic blood pressure associated with maternal anaemia during pregnancy, which is not related to a greater placental: birth weight ratio. Before weaning, anaemic pups have a lower systolic blood pressure than controls and there is an important association between the rate of postnatal growth and blood pressure.

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Extracellular matrices (ECM) present around unfertilized and fertilized mammalian oocytes were studied ultrastructurally in samples prepared in the presence of ruthenium red to facilitate stabilization of extracellular materials. Unfertilized mouse, hamster, and human oocytes have an ECM comprising granules and filaments in their perivitelline spaces (PVS). This matrix is more abundant in the human than in hamsters and mice. The granule/filament matrix appears identical to the matrix seen between cumulus and corona radiata cells following ruthenium red processing and previously shown to comprise protein and hyaluronic acid. By including ruthenium red during fixation, it is possible to demonstrate the existence of cortical granule exudate in the PVS of fertilized oocytes from hamsters, mice, and humans. Much of the cortical granule exudate is trapped in the PVS and forms a new coat around the fertilized oocyte. This material is particulate when stained with ruthenium red and appears to be uniformly dispersed around the entire oocyte surface. We refer to this new coat as the cortical granule envelope. This envelope is observed in the PVS of all developmental stages up to and including blastocysts in all three species. Following hatching of mouse and hamster blastocysts, the cortical granule envelope is no longer present. Possible functions of this envelope are discussed.

The effect of sperm concentration on the fertilization of preovulatory and immature human eggs was studied in the context of an ongoing in vitro fertilization-embryo transfer (IVF-ET) program. Fertilization success was independent of the follicular recruitment protocol used, and with preovulatory eggs, was inversely related to sperm concentration over the range of 2.5 - 50 X 10(4) motile sperm/ml. Maximum fertilization (80.8%) occurred at a concentration of 2.5 X 10(4) motile sperm/ml. The incidence of polyspermic fertilization was directly related to the sperm concentration, decreasing from 5.5% at 10 X 10(4) to 0% at 1-2.5 X 10(4) motile sperm/ml. Immature eggs cultured in vitro, then inseminated, also demonstrated an inverse relationship between fertilization and sperm concentration with a maximum fertilization rate of 66.6% at 5 X 10(4) motile sperm/ml. The percentage of motile sperm in the inseminating population had no influence on fertilization rates unless the value dropped below 40%. Fertilization success using sperm from oligospermic and polyzoospermic males was also examined. In contrast to males with normal semen parameters, oligospermic males demonstrated highest fertilization success at 50 X 10(4) motile sperm/ml. The IVF of preovulatory eggs using sperm from polyzoospermic males was comparable to that for males with normal semen parameters at equivalent sperm concentrations. The implications of these findings to the application of IVF-ET technology to the infertile couple is discussed.

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