Relative ability of modified versions of the hamster oocyte penetration test, incorporating hyperosmotic medium or the ionophore A23187, to predict IVF outcome.

This study was designed to assess the relationship between IVF outcome and the results obtained with two modified versions of the zona-free hamster oocyte penetration test in which the spermatozoa were pre-incubated with either hyperosmotic medium or the divalent cation ionophore A23187. When the former system was used, a poor correlation with IVF outcome was observed. Samples screened prior to IVF exhibited a 60% false negative rate (failed penetration test, successful IVF), while for those assessed concurrently with IVF, the equivalent figure was 85.

Induction of ovarian activity by pulsatile infusion of LHRH in women with lactational amenorrhoea.

Four fully breast-feeding women at 6 weeks post partum were injected with LHRH (0.1 microgram/kg) every 94 min by pulsatile infusion pump. While follicular development occurred in all women, and evidence of luteinization was apparent in three out of four, normal ovulation and luteal function did not occur.

The prolactin response to suckling.

Changes in prolactin concentration during single suckling episodes in twenty breast-feeding women from four to 40 weeks post partum have been investigated. Basal prolactin concentration and the increase in prolactin secretion in response to single suckling episodes and amount of milk taken by the infant were both independent of time post partum until the introduction of supplementary feeds, when a significant decrease with time was apparent. Basal concentrations of prolactin were dependent upon the interval between suckling episodes, and the magnitude of the prolactin response varied with the time of day when suckling took place.

Pulsatile secretion of LH in relation to the resumption of ovarian activity post partum.

Changes in the pulsatile pattern of LH secretion in relation to the resumption of ovarian activity post partum have been studied in breast feeding mothers. Basal concentrations of LH were significantly lower than normal both when ovarian activity was completely suppressed and when there was evidence of some follicular development prior to the resumption of menstruation. Once menstruation resumed basal concentrations of LH were unchanged whether ovulation occurred or not.

Fertility after childbirth: changes in serum gonadotrophin levels in bottle and breast feeding women.

Changes in basal serum gonadotrophin levels during the resumption of ovarian activity post partum have been studied longitudinally in breast and bottle feeding mothers. On the basis of urinary steroid levels, ovarian activity was classified as showing complete suppression, follicular activity only, deficient luteal phases or normal menstrual cycles. Complete suppression of ovarian activity during lactation was associated with normal levels of FSH but low levels of LH.

Fertility after childbirth: pregnancy associated with breast feeding.

During studies on the resumption of fertility postpartum in 12 breast feeding mothers who were using no contraception, eight pregnancies occurred. In seven cases these pregnancies occurred while the mothers continued to breast feed while in one it occurred within 2 weeks of weaning. In two cases pregnancy occurred prior to first postpartum menstruation but followed an abrupt decline in suckling frequency and duration resulting in resumption of follicular development and ovulation.