background: intracytoplasmic sperm injection (icsi) is an advanced technique employed in assisted reproductive clinics for treatment of infertile couples. the reproductive endocrinologists try their level best to identify factors that enhance success rate after icsi. objective: to compare estradiol progesterone ratio on ovulation induction day amongst pregnancy outcome groups following icsi. ma...

The effects on spontaneous ovulation associated with the unilateral or bilateral sectioning of the superior ovarian nerves (SON) were analyzed in guinea pigs at different time intervals of the estrous cycle. Day 1 of the estrous cycle was defined as the day when the animal presents complete loss of the vaginal membrane (open vagina). Subsequent phases of the cycle were determined by counting th...

In mammalian species, olfactory cues are important for within and between species communication. These can be part of multimodal signals indicating, example, female fertility potentially perceived by male conspecifics. However, a large gap exists in our understanding signaling non-human catarrhines. Chimpanzees ( Pan troglodytes ) live fission-fusion societies, mate promiscuously express high l...

In vitro studies suggests that sperm capacitation occurs in the sperm reservoir (SR) of the pig, with spermatozoa progressing towards the ampullary-isthmic junction (AIJ) around ovulation as a consequence of capacitation/hyperactivation. In contrast, in vivo studies are scarce. Consequently, we determined the degree of capacitation in boar spermatozoa that were retrieved from the SR of sows at ...

Inhibition of ovulation by RMI 12,936 was associated with suppression of the pro-oestrous peak of hypothalamic dopamine. The antiovulatory effect was not reversed by administration of oestrogen, was partly reversed by progesterone and was fully reversed by oestrogen and progesterone. Hypophysial sensitivity to LH-RH, known to be reduced by RMI 12,936, remained low when ovulation was restored by...

The times at which post-partum ovulation occurred relative to the times of parturition, were similar for CD-1 mice exposed either to 18L:6D of 10L:14D and comparable to the times reported previously for mice of the same strain kept under 14L:10D. When parturition took place close to 'lights off', ovulation tended to occur 13--14 h after littering (i.e. during the last part of the same dark peri...

I read with interest the letter by Webb et al. about the pitfalls of adapting the Clinical Effectiveness Unit’s guidance on emergency contraception (EC). Their letter discusses, in relation to maximising the pharmacodynamic attributes of ulipristal acetate (UA), the significant inaccuracies inherent in the calculation of the timing of ovulation based on the menstrual history. However, we freque...

The mare, on the average, has an estrous period that lasts around 6.5 days. Most mares will ovulate follicles ranging between 40 and 45 mm, 24–48 h before the end of their standing heat. Therefore, mares can show strong signs of heat up to 48 h after ovulation. Although these parameters are well established for the average mare, follicle size at ovulation and the duration of estrus in mares var...