The effect of Gonadotropin releasing hormone administration on fertility and embryonic loss in goats during the anoestrus period

Following the induction of oestrus out of season in small ruminants, low fertility and variations in fertility rates are associated with embryonic losses. One of the main causes of embryonic loss is luteal dysfunction. Gonadotropin Releasing Hormone (GnRH) supports the luteal structure, and increasing progesterone levels may be beneficial in terms of promoting embryonic life. The main objective of the present study was to evaluate the efficacy of GnRH administration following an oestrus induction protocol in the anoestrus season for preventing embryonic loss in goats having failure to conceive during the season. In the study, 106 Damascus goats aged 3-5 years and weighing 45-60 kg were used. The oestrus of 106 goats in the anoestrous group was stimulated with progesterone and pregnant mare serum gonadotropin (PMSG) treatment. Out of breeding season, goats were divided into the 4 following groups: GnRH0 (n = 27), GnRH7 (n = 26), GnRH0+7 (n = 27) and control (n = 26). In each goat, an intravaginal sponge (IS) containing 20 mg of fluorogestone acetate (FGA) was placed into the vagina and left for 9 days. With the withdrawal of the sponge, 550IU PMSG and 125 µg of d-cloprostenol were injected intramuscularly. Oestrus detection was made via teaser bucks for 3 days starting 24 h after withdrawal of the IS. Eighteen bucks known to be fertile were used for breeding. Goats in the oestrus period were mated via natural breeding. The GnRH analogue lecirelin was injected intramuscularly at breeding in the GnRH0 group, on day 7 post-breeding in the GnRH7 group, and both at breeding and on day 7 post-breeding in the GnRH0+7 group. No injections were given to the control group. Blood samples for progesterone measurement were taken by jugular vena puncturing on days 3, 6, 7, 10, 13, 16, and 19 after breeding from 10 randomly chosen goats in all groups. The goats with a level of > 3.5 ng/mL of progesterone on day 21 post-breeding were evaluated as pregnant. Pregnancy was also viewed on day 50 after breeding by real-time ultrasonography (USG) with a 5-7.5 MHz convex probe. The oestrus rate was 96.23% (102/106) in the goats. The rates of onset of oestrus between 36-48 h, 48-60 h and 60 h and beyond were 38.7% (41/106), 21.7% (23/106) and 35.8% (38/106), respectively. The total pregnancy rate was 35.8% (38/106). There were no statistically significant differences (P > 0.05) found for the pregnancy rate, embryonic death rate or progesterone concentration of the groups. However, serum progesterone levels were statistically different in the GnRH7 group compared with the control group (P < 0.05). After synchronisation, various anti-luteolytic strategies can be used to support corpus luteum development and elevate progesterone concentration in the luteal phase to decrease embryonic loss and increase reproductive performance. Therefore, application of GnRH to support the luteal structure and to increase progesterone levels may be beneficial in terms of supporting embryonic life. The results showed that GnRH treatment on the day 7 post-breeding following oestrus induction, including FGA and PMSG, can increase serum progesterone levels in Damascus goats in the anoestrus period. However, following oestrus induction in the anoestrus period, it was seen that GnRH treatment at breeding or on day 7 after breeding did not have any positive effect on embryonic loss or reproductive performance. In conclusion, it was considered that this protocol could be implemented successfully, yielding a 35% pregnancy rate in Damascus goats in the anoestrus period, but embryonic loss must be deeply studied in detail.(AU)

Relationship between seasons and pregnancy rates during intrauterine insemination. A historical cohort

ABSTRACT BACKGROUND: The underlying cause of seasonal infertility in humans is unclear, but is likely to be ­multifactorial. OBJECTIVE: The aim of our study was to compare the pregnancy rates among infertile women who underwent induced ovulation and intrauterine insemination (IUI) with the season in which the fertility treatment was performed. DESIGN AND SETTING: This retrospective cohort study was conducted on 466 patients who were treated in the reproductive endocrinology and infertility outpatient clinic of a tertiary-level women's healthcare and maternity hospital. METHODS: Retrospective demographic, hormonal and ultrasonographic data were obtained from the patients' medical records. Clomiphene citrate or gonadotropin medications were used for induced ovulation. The patients were divided into four groups according to the season (spring, winter, autumn and summer) in which fertility treatment was received. Clinical pregnancy rates were calculated and compared between these four groups. RESULTS: There were no significant differences between the seasonal groups in terms of age, infertility type, ovarian reserve tests, duration of infertility, medications used or length of stimulation. A total of 337 patients (72.3%) were treated with clomiphene citrate and 129 (27.7%) with gonadotropin; no significant difference between these two groups was observed. The clinical pregnancy rates for the spring, winter, autumn and summer groups were 15.6% (n = 24), 8.6% (n = 9), 11.5% (n = 13) and 7.4% (n = 7), respectively (P = 0.174). CONCLUSIONS: Although the spring group had the highest pregnancy rate, the rates of successful IUI did not differ significantly between the seasonal groups.

Minimal Stimulation Using Gonadotropin Combined with Clomiphene Citrate or Letrozole for Intrauterine Insemination

PURPOSE: To evaluate the efficacy of minimal stimulation using discretely administered gonadotropin combined with clomiphene citrate (CC) or letrozole (LTZ) for intrauterine insemination (IUI) cycles. MATERIALS AND METHODS: Total 257 IUI cycles from 158 infertile couples were assessed. A CC dose of 100 mg/day (n=126 cycles) or a LTZ dose of 5 mg/day (n=131 cycles) was administered on days 3-5 of the menstrual cycle for 5 days. Each group received human menopausal gonadotropin at a dose of 150 IU by two or three alternative day: CC combined with alternate-day regimen for 2 or 3 days (CC+300, n=37; CC+450, n=89) and LTZ combined with alternate-day regimen for 2 or 3 days (LTZ+300, n=36; LTZ+450, n=95). RESULTS: The clinical pregnancy rate was comparable between the CC and LTZ groups (18.3% vs. 13.0%, p=0.243). The clinical pregnancy rate also showed no significant difference among the 4 groups (21.6% vs. 16.9% vs. 11.1% vs. 12.6%, p=0.507). The multiple pregnancy rate was significantly higher in LTZ compared to CC group (37.5% vs. 8.7%, p=0.028) and in the LTZ+450 compared to CC+450 group (50% vs. 13.3%, p=0.038). Overall, there were 15 cases of ovarian hyperstimulation syndrome (OHSS), with the prevalence being significantly lower in the LTZ compared to CC group (1.5% vs. 10.3%, p=0.003). OHSS was more prevalent in the CC+450 compared to the LTZ+450 group (12.4% vs. 1.1%, p=0.002). CONCLUSION: Our findings suggest that minimal stimulation using two alternate-day gonadotropin with LTZ decreases the development of OHSS and multiple pregnancies, while maintaining comparable pregnancy rates in IUI cycles.

Minimal Stimulation Using Gonadotropin Combined with Clomiphene Citrate or Letrozole for Intrauterine Insemination

PURPOSE: To evaluate the efficacy of minimal stimulation using discretely administered gonadotropin combined with clomiphene citrate (CC) or letrozole (LTZ) for intrauterine insemination (IUI) cycles. MATERIALS AND METHODS: Total 257 IUI cycles from 158 infertile couples were assessed. A CC dose of 100 mg/day (n=126 cycles) or a LTZ dose of 5 mg/day (n=131 cycles) was administered on days 3-5 of the menstrual cycle for 5 days. Each group received human menopausal gonadotropin at a dose of 150 IU by two or three alternative day: CC combined with alternate-day regimen for 2 or 3 days (CC+300, n=37; CC+450, n=89) and LTZ combined with alternate-day regimen for 2 or 3 days (LTZ+300, n=36; LTZ+450, n=95). RESULTS: The clinical pregnancy rate was comparable between the CC and LTZ groups (18.3% vs. 13.0%, p=0.243). The clinical pregnancy rate also showed no significant difference among the 4 groups (21.6% vs. 16.9% vs. 11.1% vs. 12.6%, p=0.507). The multiple pregnancy rate was significantly higher in LTZ compared to CC group (37.5% vs. 8.7%, p=0.028) and in the LTZ+450 compared to CC+450 group (50% vs. 13.3%, p=0.038). Overall, there were 15 cases of ovarian hyperstimulation syndrome (OHSS), with the prevalence being significantly lower in the LTZ compared to CC group (1.5% vs. 10.3%, p=0.003). OHSS was more prevalent in the CC+450 compared to the LTZ+450 group (12.4% vs. 1.1%, p=0.002). CONCLUSION: Our findings suggest that minimal stimulation using two alternate-day gonadotropin with LTZ decreases the development of OHSS and multiple pregnancies, while maintaining comparable pregnancy rates in IUI cycles.

Development of in vitro produced porcine embryos according to serum types as macromolecule

This study was conducted to establish an in vitro maturation (IVM) system by selection of efficient porcine serum during porcine in vitro production. To investigate the efficient porcine serum (PS), different types of PS [newborn pig serum, prepubertal gilt serum (PGS), estrus sow serum, and pregnancy sow serum] were used to supplement IVM media with or without gonadotrophin (GTH) and development rates of parthenogenetic activation (PA) and in vitro fertilization (IVF) embryos were then compared. The maturation rates of the PGS group was significantly higher when GTH was not added. Additionally, during development of PA embryos without GTH, the PGS group showed significantly higher cleavage and blastocyst formation rates. Moreover, the cleavage rates of IVF embryos were significantly higher in the PGS group, with no significant differences in the blastocyst formation. However, when GTH was supplemented into the IVM media, there were no significant differences among the four groups in the cleavage rates, development rates of the blastocyst, and cell number of the blastocyst after PA and IVF. In conclusion, PGS is an efficient macromolecule in porcine IVM, and GTH supplementation of the IVM media is beneficial when PS is used as macromolecule, regardless of its origin.

Indução da puberdade e sincronização do cio subsequente em leitoas pré-púberes utilizando gonadotrofinas exógenas / Induction of puberty and following estrus synchronization in prepubertal gilts using exogenous gonadotropins

A utilização de gonadotrofinas exógenas na indução da puberdade e sincronização do estro e ovulação é uma prática que influencia positivamente no manejo das marrãs, para a mais efetiva e econômica inclusão no plantel de matrizes em Sistemas Intensivos de Produção de Suínos. No entanto, poucos estudos têm sido desenvolvidos com a finalidade de avaliar o grau de sincronização do estro seguinte à indução da puberdade. Assim sendo, o objetivo do presente estudo foi, justamente, o de verificar a taxa de sincronização do estro subseqüente à puberdade induzida hormonalmente, e a comparação das características dos estros, induzido e subseqüente a este. Sessenta e seis leitoas pré-púberes tiveram a puberdade induzida através de combinação hormonal utilizando gonadotrofinas (eCG e LH) aos 145 dias de idade em média. Das 66 fêmeas que iniciaram o experimento, 35 (53,03%) apresentaram cio até sete dias após a aplicação do LH, e 40 (60,60%) das 66 fêmeas tiveram o estro subseqüente sincronizado, ou seja, até o 25° dia após a aplicação do LH. Vinte e seis (39,39%) fêmeas manifestaram o primeiro e segundo cios. As 26 (39,39%) leitoas que não manifestaram o 2° cio de maneira sincronizada foram abatidas, sendo que 15 apresentaram corpos lúteos e/ou corpos albicans e 11 não apresentaram as estruturas mencionadas anteriormente, sendo consideradas imaturas. Não houve diferença significativa da duração do cio na puberdade com o cio subseqüente (P>0,05), tampouco da dispersão dos mesmos.

The utilization of exogenous gonadotropins in the puberty induction and estrus/ovulation synchronization is a management that influence positive1y gilts handle, to the better effectiveness and economic inclusion of gilts in the Intensive Swine Production System herd. However, few researches have been deve10ped to evaluate the subsequent estrus synchronization after puberty induction. Thus, the aim of this study was to verify the subsequent estrus synchronization after the hormonal puberty induction and to evaluate the inducted and the following one estrus characteristics. Sixty six prepubertal gilts had their puberty inducted by a hormonal combination using gonadotropins (eCG and LH) at 145 days old, in average. A total of 35 (52,03%) of the 66 initially gilts showed estrus up to seven days after LH administration, and 40 (60,60%) had the subsequent estrus synchronized (synchronization was defined as the gilts which showed estrus up to day 25 after LH administration). Twenty six gilts (39,39%) showed the first and second estrus. The 26 (39,39%) remaining gilts that didn't show the second estrus synchronized were slaughtered, which 15 presented corpus albicans and/or corpora lutea and 11 were considered immature because they didn't present any structure mentioned above in the ovaries. There was no significant difference between the puberty estrus duration and the subsequent estrus duration (P>0,05), neither their dispersion.

Valor de los niveles basales de gonadotropinas para predecir la respuesta folicular en ciclos de FIV-TE y GIFT / Baseline values of gonadotrophins for predecting follicle response in FIVTE and GIFT cycles

El objetivo del trabajo es determinar el valor predictivo que pueden tener los nivles séricos basales de gonadotropinas hipofisiarias en relación a la respuesta folicular a esquemas de estimulación folicular múltiple en un programa de reproducción asistida. Se estudiaron 35 paciente tratadas con FSH pura y mentropinas, haciéndose la monitorización de la respuesta mediante determinación sérica de estradiol y medición ultrasonográfica vaginal de los diámetros foliculares a partir del día 8 del ciclo. Las cuantificaiones basales de gonodotropinas hispofisiarias y estradiol se realizaron en el día 3 del ciclo de tratamiento. En función de la respuesta folicular se formaron 2 grupos y en cambio las diferencias en los niveles basales de FSH y de LH fueron notorias y estadísticamente significativas llegándose a la conclusión de que los niveles basales de las hormonas gonadotrópicas hipofisiarias tomadas en el día 3 del ciclo, predicen sensiblemente la cálidad de la respuesta folicular distinguiéndose dos patrones diferentes.

Review article GnRH analogues physiology and clinical applications in the female

A number of disorders in gynaecology are amenable to alterations of ovarian steroid hormones or pituitary gonadotrophin secretion. The availability of gonadotrophin-releasing hormone [GnRH] analogues and their ability to specifically inhibit pituitary gonadotrophin secretion has allowed these agents to be investigated as new treatment modalities in a broad spectrum of gynaecological and reproductive endocrine disorders. GnRH analogues have a well-established role to play in the treatment of endomethosis, uterine fibroids [pre-operatively], dysfunctional uterine haemorrhage, ovulation induction and polycystic ovary syndrome. They are also being investigated in premenstrual syndrome, precocious puberty and as an alternative approach to contraception. This article reviews these various applications and any problems encountered in their use