Transfer of selected embryos that reached the 2-cell stage between 25 and 29 h post-insemination/ICSI is a reliable prognostic tool for patients undergoing assisted reproduction techniques.
SummaryThe aim of the present study was to evaluate the effect of prepartum artificial photoperiod on pregnancy length and reproductive performance in mares. The study included 145 Thoroughbred mares with age between 4 and 23 years. The mares were submitted to a 15 hour light/9 hour dark photoperiod/day (10W/m 2 ) during different lengths of time before foaling, constituting the following groups: <30: less than 30 days of artificial photoperiod; 30-45: from 30 to 45 days of artificial photoperiod; 46-60: from 46 to 60 days of artificial photoperiod; >60: more than 60 days of artificial photoperiod. In the moment of delivery, mares were classified according to body condition score (crescent range from 1 to 5) and, when necessary, submitted to surgical repair of the vulva within 30 minutes. Mating occurred when a follicle larger than 40 mm was detected, associated with decrease of uterine edema. Twin pregnancies were reduced manually. The number of days in which mares were submitted to artificial photoperiod influenced significantly the anoestrus rate postpartum (p=0.033), as well as the interval between parturition and the first ovulation (p=0.019). Mares submitted to a larger artificial photoperiod showed anoestrus postpartum rate significantly smaller than that observed in mares submitted to artificial photoperiod of less than 30 days (>60 -0%; <30 -16.7%). Parturition-ovulation interval was significantly shorter in mares submitted to artificial photoperiod for more than 30 days (p<0.001). Body condition was influenced by photoperiod. Treatment groups submitted to artificial photoperiod for more than 45 days presented better body condition than that submitted for less than 30 days. The body condition influenced anoestrus postpartum rate (p=0.07) and parturition-ovulation interval (p=0.073). Comparing only mares with body condition score 4 (n=81), a reduction in parturition-ovulation interval in mares submitted to a longer artificial photoperiod was seen (p=0.072). Pregnancy length was not influenced (p=0.077) by the length of photoperiod. There was no influence either on pregnancy rate in foal heat (p>0.1), or on embryo death rate (p>0.1), or on number of cycles per pregnancy rate (p=0.798). It was concluded that the use of a 15-hour light/9 hour dark photoperiod/day (10W/m 2 ) during at least 60 days before delivery decreases significantly the incidence of anoestrus postpartum. The use of this photoperiod for more than 30 days decreases parturition-ovulation interval. There is no influence either on pregnancy rate during foal heat, or on embryo death rate, or on number of cycles per pregnancy. Keywords:equine, artificial photoperiod, postpartum, body condition Einfluss eines künstlichen Lichtregimes auf die Gestationsdauer und den postpartalen Reproduktionserfolg bei Stuten
The objective of the present study was to determine if exposure of cervical mucus to air during specular examination could modify mucus pH. Detection of changes is justified because of their possible interference with sperm-mucus interaction, since an acidic pH is unfavorable to sperm penetration and is associated with infertility due to the cervical factor. Twenty women with good quality mucus were evaluated. pH measurements of ecto-and endocervical mucus were made in situ using a glass electrode after 0-, 5-and 10-min exposure to air. There was a progressive alkalinization of mucus pH. Mean values of ectocervical mucus pH were 6.91, 7.16 and 7.27, while mean values of endocervical mucus pH were 7.09, 7.34 and 7.46 at 0, 5 and 10 min, respectively. Significant differences were found between the mean values obtained at 0 and 5 min, and at 0 and 10 min (P<0.05), whereas the differences in mean values at 5 and 10 min were not significant at either site. We conclude that 5 to 10 min of exposure to atmospheric air affects cervical mucus pH in a significant way. Since tests used to evaluate sperm-mucus interaction generally have not considered this possibility, we suggest that they should be performed immediately after mucus collection in order to avoid misinterpretation of the results. Abnormalities of the cervix and its secretion are reported to be responsible for infertility in approximately 5 to 10% of women (1). Evaluation of sperm-cervical mucus interaction is important in infertility investigation. The traditional method for the evaluation of sperm-cervical mucus interaction in vivo is the postcoital test (PCT), but in vitro cervical mucus-sperm penetration tests are also used (2,3).Sometimes, negative or abnormal PCT are attributed to immunological problems in particular. Anyway, recent studies have shown that the incidence of immunological factors in these cases is low, and that 80% of them can be reversed by means of a bicarbonate douche (4). The improvement observed with mucus alkalinization suggests that the low mucus pH (5) causes the poor spermmucus interaction. In addition, it was reported that some cases of negative PCT (absence of progressive sperm) or absent PCT (absence of sperm) involving ovulatory mucus and normal sperm became normal during the performance of in vitro cervical mucussperm penetration tests (6,7). It was suspected that this alteration occurred due to the variation of mucus pH after exposure to air.Previous studies have reported pH variation of mucus exposed to air (8,9), but those
A total of 342 breeding cycles [262 lactating (L), 80 barren (B)] in 237 mares were evaluated. The effect of the following variables on pregnancy (14 and 42 days) was analysed using a general linear model system. Each cycle was randomly assigned to one of the following treatments: untreated control [f1); oxytocin (20 lU, i.v.), admin stered 0 and 12 to 16 h after breeding [f2); intrauterine infusion of leukoc]te enriched plasma (120 ml) 12 to 16 h after breeding (T3); combined treatment of oxytocin (20 lU, j.v.) administered 0 h after breedjng and leu kocyte-enriched plasma infused 12 16 h atter breeding/insemination The early pregnancy rate per cycle was significantly higher (p < 0.05) in barren mares treated with plasma containing leukoc),,tes (78.6%) than in mares treated with oxytocin (50.0%) and in control mares (52.0%), but they did not differ from pregnancy rates obtained n mares treated with the combined treatment (69.27o, T4). The ditferent treatments fI2, T3, T4) did not atfect significantly (p > 0.05) the pregnancy rate per cycle in lactating mares when compared to control group. lt was concluded that the infusion of leukocyte enriched plasma improves pregnancy rate per cycle in barren mares.
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