Effect of estradiol supplementation on luteal support following a significant reduction in serum estradiol levels after hCG triggering: a prospective randomized controlled trial.

OBJECTIVE: This study aimed to evaluate the impact of adding 4 mg estradiol valerate to progesterone for luteal support on pregnancy rates in IVF cycles following a long protocol with reduced luteal serum estradiol levels post-hCG triggering. DESIGN, SETTING, AND PARTICIPANTS: The prospective randomized controlled trial was conducted at a public tertiary hospital reproductive center with 241 patients who experienced a significant decrease in serum estrogen levels post-oocyte retrieval. INTERVENTIONS: Participants received either a daily 4 mg dose of estradiol valerate in addition to standard progesterone or standard progesterone alone for luteal support. RESULTS: The ongoing pregnancy rate did not show a significant difference between the E2 group and the control group (56.6% vs. 52.2%, with an absolute rate difference (RD) of 4.4%, 95% CI -0.087 to 0.179, P = 0.262). Similarly, the live birth rate, implantation rate, clinical pregnancy rate, early abortion rate, and severe OHSS rate were comparable between the two groups. Notably, the E2 group had no biochemical miscarriages, contrasting significantly with the control group (0.0% vs. 10.7%, RD -10.7%, 95% CI -0.178 to -0.041, P = 0.000). In the blastocyst stage category, the clinical pregnancy rate was notably higher in the E2 group compared to the control group (75.6% vs. 60.8%, RD 14.9%, 95% CI 0.012 to 0.294, P = 0.016). CONCLUSION: Adding 4 mg estradiol valerate to progesterone for luteal support does not affect the ongoing pregnancy rate in embryo transfer cycles using a long protocol with a significant decrease in serum estradiol levels after hCG triggering. However, it may reduce biochemical miscarriages and positively impact clinical pregnancy rates in blastocyst embryo transfer cycles. TRIAL REGISTRATION: ChiCTR1800020342.

Optimisation of Early Pregnancy Diagnosis and Resynchronisation in Beef Cows.

The objectives of this study were (1) to investigate the effects of the preovulatory follicle (POF) size on the accuracy of Doppler-based early pregnancy detection, and (2) to determine whether the removal of PGF2α (PGF) treatment during the resynchronisation protocol would affect fertility in beef cows. In Experiment 1, Nelore suckling cows (n = 224) were enrolled in an estradiol-progesterone-based timed artificial insemination (TAI) protocol. At TAI, cows were separated based on the range of POF diameters, as follows: ≤11.0 mm (n = 50), 11.1-12.9 mm (n = 64), 13.0-14.4 mm (n = 62) and ≥14.5 mm (n = 48). On day 22 after TAI, the corpus luteum (CL) blood flow (CLBF) of all cows was examined by colour Doppler ultrasonography to diagnose nonpregnant cows. The cows with the largest POF had the greatest positive predictive value (88.6%; 31 of 35) and diagnostic accuracy (91.7%; 44 of 48). In Experiment 2, Nelore cows (n = 233) were subjected to the same TAI protocol. Fourteen days after TAI, all cows were started on a resynchronisation protocol. Cows diagnosed as nonpregnant based on CLBF, on day 22, received 0.5 mg estradiol cypionate intramuscular (im) and were assigned to receive either 150 µg of PGF (PGF; n = 50) or 2 mL of saline (control; n = 47). Cows treated with PGF had a P/AI of 30.0% compared with a 48.9% P/AI in controls (p = 0.06). Our findings demonstrate that the POF size affects the accuracy of a CLBF-based early pregnancy diagnosis and that the removal of PGF treatment from the resynchronisation protocol tended to increase P/AI of the second TAI.

Comparing the outcomes of in-vitro fertilization in patients receiving vaginal, subcutaneous, and intramuscular progesterone for luteal phase support: a three-armed randomized controlled trial.

BACKGROUND: The optimal approach to luteal-phase support in infertility treatment remains a subject of debate. This study was conducted to investigate the clinical outcomes, side effects, and patient satisfaction associated with vaginal, subcutaneous, and intramuscular progesterone administration in infertile women undergoing Frozen Embryo Transfer (FET). METHODS: This three-armed randomized clinical trial assigned infertile patients eligible for FET to three progesterone treatment groups: vaginal suppositories (400 mg twice daily; n = 100), subcutaneous injections (25 mg daily; n = 102), and intramuscular injections (50 mg daily; n = 108). The primary outcomes were chemical and clinical pregnancy rates per embryo transfer cycle, with chemical pregnancy defined as beta-human chorionic gonadotropin levels > 50 IU/mL two weeks post-transfer and clinical pregnancy confirmed by ultrasound four weeks later. Exploratory outcomes included progesterone-related adverse effects and participant satisfaction, assessed via a Likert-scale survey 12 weeks post-transfer. Statistical analyses included Chi-square tests for categorical data, one-way analysis of variances, and Kruskal-Wallis tests for continuous data. RESULTS: The intramuscular progesterone group had significantly higher chemical pregnancy rates compared to the vaginal and subcutaneous groups (41.7% vs. 26.0% and 27.5%, respectively; p = 0.026). Although the clinical pregnancy rate was also higher in the intramuscular group (32.4%) compared to the vaginal (23.0%) and subcutaneous groups (21.6%), this difference was not statistically significant (p = 0.148). Additionally, patient satisfaction was greater with vaginal and subcutaneous applications than with intramuscular injections (p < 0.001), likely due to a significantly higher incidence of side effects, such as pain and edema at the injection site, in the intramuscular group (p < 0.001). CONCLUSIONS: We found that intramuscular progesterone resulted in higher chemical pregnancy rates than vaginal or subcutaneous routes, but this did not translate into higher clinical pregnancy rates. Despite its effectiveness, intramuscular administration was associated with more adverse effects and lower patient satisfaction. Future research should explore optimizing progesterone regimens to balance efficacy and patient comfort. TRIAL REGISTRATION: The trial protocol was registered on December 6, 2020, in the Iranian Registry of Clinical Trials (IRCT), a primary registry in the World Health Organization (WHO) Registry Network, under the registration number IRCT20141217020351N12.

Evaluation of the effect of sustained-release progesterone injection on the expression of interferon-related genes in repeat-breeder dairy cows.

BACKGROUND: Repeat-breeder cows repeatedly fail to conceive after at least three attempts and return to oestrus at apparently normal intervals. Repeat-breeder cows cause economic losses in dairy farms in different ways. OBJECTIVE: In the present study, we investigated the effect of sustained-release progesterone injection in two different doses on the expression of interferon-related genes in repeat-breeder dairy cows. METHODS: A total of 96 repeat-breeder primiparous and multiparous cows were assigned among three groups: control group, inseminated and do not receive progesterone treatment; P400 and P600 groups, inseminated and received a single-intramuscular injection of 400 and 600 mg slow-release progesterone 5 days after insemination, respectively. Blood sampling was carried out on Day 20 after AI for progesterone measurement and evaluation of gene expression for ISG15, MX1 and MX2 genes. RESULTS: One injection of sustained-release progesterone increased the expression of ISG15, MX1 and MX2 genes with differences between two different progesterone concentrations. For all three genes, the level of gene expression was higher in progesterone-supplemented group than in control group, when P400 and P600 groups considered together. The level of MX2 gene expression was significantly higher in pregnant cows than non-pregnant cows. There was a significant positive correlation between expression level of all three genes and blood progesterone concentration. The expression level of ISG15 gene showed a significant positive correlation with MX1 and MX2 gene expression. CONCLUSION: The use of this sustained-release progesterone is simple and can be used in repeat-breeder cows to improve fertility.

[Prevention of Spontaneous Premature Birth With Cervical Pessary: A Single-Center Prospective Cohort Study]. / å®«é¢ˆæ‰˜é¢„é˜²è‡ªå‘æ€§æ—©äº§çš„å•ä¸­å¿ƒå‰çž»æ€§é˜Ÿåˆ—ç ”ç©¶.

Objective: To study and compare the clinical effects of cervical pessary and progesterone for preventing preterm birth in singleton pregnant women with a short cervical length (CL). Methods: This study was a prospective cohort study. A total of 148 pregnant women with CL≤25 mm, as determined by ultrasound examination performed before 28 weeks of pregnancy, were included in the study. All subjects were admitted to West China Second Hospital, Sichuan University between August 2020 and December 2022. According to their treatment plans, the pregnant women were divided into a cervical pessary group (n=55) and a progesterone group (n=93). Spontaneous preterm birth before 37 weeks of pregnancy was defined as the main outcome index. Preterm birth (abortion) or spontaneous preterm birth (abortion) before 37, 34, 32, 30, and 28 weeks of pregnancy, mean extended gestational age, neonatal morbidity, and neonatal mortality were the secondary outcome indicators. The pregnancy outcomes and the neonatal outcomes of the two groups were compared and statistically analyzed. Results: There was no statistically significant difference in the incidence of preterm birth (including iatrogenic preterm birth, spontaneous preterm birth, and abortion) before 37, 34, 32, 30, and 28 weeks between the cervical pessary group and the progesterone group. When iatrogenic preterm birth was excluded, the incidence of spontaneous preterm birth before 37 weeks was lower in the cervical pessary group (23.6%) than that in the progesterone group (41.9%), with the difference between the two groups being statistically significant (P=0.024). There was no statistically significant difference in the incidence of spontaneous preterm birth (including miscarriage) before 34, 32, 30, and 28 weeks. There was no statistically significant difference in the incidence of neonatal morbidity, the rate of transfer to the neonatal care unit after birth, and the neonatal mortality rate between the two groups. Multivariate logistic analysis showed that treatment with cervical pessary was a protective factor for spontaneous preterm birth before 37 weeks compared to progesterone therapy. Conclusion: Using cervical pessary to prevent spontaneous preterm birth in singleton pregnant women with a short cervical length in the second trimester can significantly reduce the incidence of spontaneous preterm birth before 37 weeks.

Is it possible to replace eCG by GnRH in the hormonal protocol for timed artificial insemination in ewes during the breeding season?

Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0-5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.

Reproductive outcomes in Holstein heifers synchronized with timed-AI protocols that provide for a lengthened proestrus.

This study compared reproductive outcomes among two protocols for synchronization of ovulation that provide for a lengthened proestrus with the conventional oestradiol-based protocol currently used for timed-AI (TAI). Holstein heifers (13-15 months) at one location were assigned randomly to one of three TAI protocols. Heifers (n = 150) in the 7-day oestradiol benzoate (EB) group received a progesterone device (Cue-Mate) and 2 mg EB on Day 0; 500 µg of cloprostenol (PGF) and Cue-Mate removal on Day 7; 1 mg of EB on Day 8 and TAI on Day 9 (54 h after Cue-Mate removal). Heifers (n = 150) in the 5-day CO-Synch (CO) group received a Cue-Mate and 100 µg of gonadotropin-releasing hormone (GnRH) on Day 2; Cue-Mate removal and PGF (twice, 12 h apart) on Day 7; and GnRH along with TAI on Day 10 (72 h after Cue-Mate removal). Heifers (n = 150) in the J-Synch (JS) group received a Cue-Mate and 2 mg of EB on Day 1; PGF and Cue-Mate removal on Day 7; GnRH and TAI on Day 10 (72 h after Cue-Mate removal). Heifers were inseminated by one technician with frozen-thawed conventional semen from one of four commercially available sires. Plasma progesterone (P4) concentrations (ng/mL) were determined at Cue-Mate removal and TAI. Ovarian ultrasonography was done in a subset of 217 heifers at the initiation of protocols, at Cue-Mate removal; TAI; and 7 days after TAI. Approximately, 28 and 50 days after TAI pregnancy status was determined by ultrasonography. Mean (±SEM) plasma P4 concentration at Cue-Mate removal was greater (p < .01) in CO (6.02 ± 0.2) and JS (6.51 ± 0.2) compared to EB heifers (4.53 ± 0.2). Mean (±SEM) plasma P4 concentration at TAI was lowest in the JS (0.28 ± 0.05), intermediate in CO (0.46 ± 0.02), and greatest in EB heifers (0.66 ± 0.05, p < .01). The diameter of the ovulatory follicle (mean ± SEM) was the smallest in the JS group compared to that in the CO and EB groups (15.8 ± 0.5; 13.9 ± 0.5; and 12.7 ± 0.5 mm for EB, CO and JS, respectively). More (p < .01) heifers in the JS group had their oestrous cycle synchronized (50.0, 78.8 and 82.4% for EB, CO and JS groups), and were pregnant at 28 (40.3, 51.3 and 63.3% for EB, CO and JS groups) and 50 days after TAI (32.6, 46.0 and 60.0% for EB, CO and JS groups). In summary, heifers subjected to the J-Synch TAI protocol had lower P4 at TAI, and better overall response to hormonal treatments, which resulted in increased P/AI at 28 and 50 days after TAI compared to those heifers subjected to either a 7-day EB protocol or a 5-day CO-synch protocol.

Safety and efficacy assessment of a synthetic porcine recombinant corticotrophin for the ACTH stimulation test in healthy cats.

Porcine adrenocorticotrophic hormone (ACTH) has been considered valid for the ACTH stimulation test (ACTHST) in humans and dogs; however, its safety and efficacy for use in cats are unknown. Also, the equivalence between 5 µg/kg and 125 µg/cat dose of synthetic corticotropin (1-24 ACTH - cosyntropin/tetracosactide) is assumed for ACTHST in cats. This study evaluated the safety and effectiveness of different porcine recombinant ACTH doses for the ACTHST in healthy cats and its equivalence with tetracosactide. The study was divided into two arms. The first evaluated safety and equivalence of intravenous 1 µg/kg, 5 µg/kg, or 125 µg/cat porcine ACTH in seven healthy cats for the ACTHST evaluating basal and post-ACTH androstenedione, aldosterone, cortisol, and progesterone concentrations. In the second arm, the equivalence of the 125 µg/cat porcine ACTH dose was evaluated compared to results obtained using 125 µg/cat of tetracosactide in ten healthy cats regarding cortisol responses. In all tests, several cat-friendly strategies were adopted, and the ACTHST protocol involved basal and 60-minute post-ACTH blood sampling and intravenous ACTH injection. No adverse reactions were documented, and no tested cat showed any complications during the study. No porcine ACTH tested dose significantly increased androstenedione secretion. In contrast, all tested doses were able to increase progesterone concentration significantly (P < 0.05), and Δ-progesterone in response to 5 µg/kg or 125 µg/cat was considered equivalent (P > 0.99). The 125 µg/cat dose promoted greater responses for both cortisol and aldosterone, characterized by Δ-cortisol (P = 0.009) and Δ-aldosterone (P = 0.004). Despite equivalent Δ-cortisol results in response to 5 µg/kg or 125 µg/cat (P = 0.18); post-ACTH results of cortisol in response to 5 µg/kg only approximate statistical significance when compared with basal (P = 0.07). Porcine ACTH and tetracosactide significantly increased post-ACTH cortisol concentration (P < 0.0001) while the Δ-cortisol was slightly greater in response to the porcine ACTH (P = 0.006). These results suggest porcine ACTH could be an alternative source of corticotropin for the ACTHST in cats; however, maximum corticoadrenal stimulation seemed more reliable in response to a 125 µg/cat regarding cortisol and aldosterone.

Comparison of two intravaginal progesterone-releasing devices in lactating Holstein cows synchronized with a 5-d GnRH-based timed-AI protocol.

The objective of the study was to compare the effectiveness of CIDR vs. PRID-Delta devices for use in a 5-day Ovsynch protocol for TAI in lactating Holstein cows that were either not in estrus after the end of the voluntary waiting period or non-pregnant and not returning to estrus following the previous AI. Cows fitted with a collar-mounted automated activity monitoring system (Alta Cow Watch) were subjected to a standard 5-d Ovsynch protocol [100 µg of gonadorelin (GnRH) on Day 0 and 500 µg of cloprostenol on Days 5 and 6] and allocated randomly to receive either an intravaginal device containing 1.35 g (CIDR; n = 304) or 1.55 g (PRID ® DELTA; n = 304) of progesterone between Day 0 and 5. All cows received a second administration of GnRH at approximately 56 h and timed-AI (TAI) 72 h after intravaginal device removal. Inseminations were done using conventional frozen-thawed semen. Estrus events prior to TAI were recorded and transrectal ultrasonography was done on Day 0 to determine presence of a corpus luteum (CL) and 33 and 61 d post-TAI, respectively, to diagnose and confirm pregnancy. Cows had an average of 2.2 lactations, 124.3 days in milk, and a milk yield of 43.6 kg/d at enrollment. The overall percentage of cows with a CL at initiation of treatment was 68.8 % and did not differ between treatment groups. Cows with a CL had greater pregnancy per AI (P/AI) at 33 and 61 d post-TAI than cows without a CL (P < 0.01; 46.9 and 42.3 % vs. 32.1 and 27.4 %, respectively). The overall percentage of cows that expressed estrus prior to TAI was 24.8 % and did not differ between treatment groups; however, estrus expression prior to TAI affected P/AI at 33 and 61 d post-TAI (P < 0.01; 53.6 and 49.0 % vs. 38.5 and 33.9 % for those expressing or not expressing estrus, respectively). Pregnancy per AI at 33 d post-TAI tended to differ between treatment groups (P = 0.08; 46.1 vs. 38.5 % for PRID and CIDR groups, respectively) and P/AI at 61 d post-TAI was greater (P < 0.01) for PRID-treated cows (43.8 %) compared to CIDR-treated cows (31.6 %). Thus, PRID-treated cows had lower pregnancy loss than CIDR-treated cows (P < 0.01; 5.0 vs. 17.9 %). Also, treatment with a PRID tended (P = 0.08) to result in fewer twin pregnancies (7.9 vs. 14.5 % for PRID and CIDR treated cows, respectively). In conclusion, lactating dairy cows subjected to a 5-d Ovsynch TAI protocol plus a PRID-Delta had greater P/AI at 61 d post-TAI, lower pregnancy loss between 33 and 61 d post-TAI, and fewer twin pregnancies compared to cows subjected to a 5-d Ovsynch protocol plus a CIDR.

Impact of different progesterone timings on live birth rates for blastocyst frozen embryo transfer cycles.

RESEARCH QUESTION: Do different timings of progesterone administration for day 5 and day 6 blastocysts affect the live birth rate (LBR) of artificial frozen embryo transfer (FET) cycles? DESIGN: This retrospective cohort study included 1362 patients who underwent artificial FET cycles. The effects of 6 and 7 days of progesterone administration prior to blastocyst transfer on clinical outcomes were compared in day 5 and day 6 blastocysts. Univariable and multivariable regression analyses were undertaken. RESULTS: In all patients, LBR was comparable between the two groups (51.8% versus 47.9%, P = 0.165). For day 6 blastocysts, after adjusting for confounders, the 7-day progesterone regimen resulted in a significantly higher LBR (44.8% versus 36.4%, P = 0.039, adjusted OR = 1.494, 95% CI 1.060-2.106) and lower pregnancy loss rate (15.4% versus 25.2%, P = 0.031, adjusted OR = 0.472, 95% CI 0.260-0.856) compared with the 6-day progesterone regimen. For day 5 blastocysts, there were no significant differences in pregnancy outcomes between the two regimens, but the rate of low birthweight was higher with the 7-day progesterone regimen than with the 6-day progesterone regimen (13.9% versus 6.7%, P = 0.032). CONCLUSIONS: In all blastocyst analyses, no difference in LBR was found between the 6- and 7-day progesterone regimens in artificial FET cycles. For day 6 blastocysts, LBR was significantly higher with the 7-day progesterone regimen than with the 6-day progesterone regimen, whereas for day 5 blastocysts, pregnancy outcomes were comparable between the two regimens.

POESIT recommendations on management of body-identical hormones in menopausal symptoms.

Many women seek treatment to improve menopausal vasomotor symptoms (VMS). The selection of women most likely to benefit from menopause hormone therapy (MHT) is crucial in clinical practice. There is general agreement that women younger than 60 years or who initiate MHT within the first 10 years of menopause, with no contraindications, have greater benefits considering symptomatic relief and additional advantages. This group may have the advantage of protection from osteoporosis and from other chronic diseases that affect postmenopausal women, namely cardiovascular disease (CVD). Cumulating evidence supports MHT for symptomatic women. However, inadequate use according to the needs of symptomatic women led to a burden of suffering worldwide. In recent years, the emergent use of non-regulated body-identical hormones (non-rBHT) can expose patients to potential harms. These hormone preparations are not regulated through the same tests of safety, efficacy or dosing consistency as regulated-BHT (r-BHT). The POESIT (Portugal + Spain + Italy) recommendations highlight the use of 17ß-estradiol (E2) and micronized progesterone (P4) as the real r-BHT. In addition, the group emphasizes as an example the data from the REPLENISH study with 1 mg E2/100 mg P4. The combination of the two hormones in one convenient pill showed a clear reduction or elimination of hot flashes and an improvement in sleep quality and, consequently, quality of life. At the same time, this combination has shown high rates of amenorrhea and no significant impact on lipid, glucose or coagulation parameters. Both the REPLENISH study and a real-life retrospective study pointed to the possibility of a lower risk of venous thromboembolism (VTE) with this formulation than with other combinations.

The use of a recombinant equine chorionic gonadotropin (reCG) in fixed-time AI programs in beef cattle.

The aim of the current study was to evaluate the effect of a novel recombinant eCG (reCG) on pregnancy rates to AI (P/AI) in suckled beef cows of different breeds that were synchronized with an estradiol/progesterone (P4)-based protocol for fixed-time AI (TAI). In experiment 1, 1244 Bos taurus suckled cows were used. On Day 0 all cows received an intravaginal P4 device (600 mg P4) and 2 mg of estradiol benzoate. On Day 7, devices were removed, and all cows received 0.150 mg of D-cloprostenol plus 1 mg of estradiol cypionate and were randomly divided to receive 140 IU or 105 IU of reCG or no reCG treatment (controls) at that time. Cows were tail painted for estrus detection and those in estrus by 48 h after P4 device removal were inseminated; whereas those not showing estrus were also inseminated and received GnRH at the same time. In experiment 2, 818 Bos taurus x Bos indicus crossbred suckled cows received the same FTAI protocol used in Experiment 1. Cows were randomly divided at the time of P4 device removal into 4 groups to receive 140 IU, 105 IU or 84 IU of reCG or no reCG treatment. In experiment 3, 345 Bos indicus suckled cows were submitted to the same FTAI protocol as those in previous experiments and were randomly divided into three groups to receive 140 IU or 105 IU of reCG, or 300 IU of serum derived eCG (PMSG). In Experiment 1, estrus rate and P/AI was greater (P < 0.05) in cows treated with reCG (79.9 and 53.5 %, 76.9 and 52.3 % for the 105 UI and 140 UI reCG groups, respectively) than those in the control group (69.9 and 44.4 %, respectively). In Experiment 2, cows treated with reCG tended (P < 0.1) to achieve a greater P/AI than control cows (38.6 %, 37.1 %, 36.2 % and 28.2 % for those receiving 84 IU, 105 IU,140 IU of reCG, and those in the control group); but when P/AI of all cows treated with reCG was contrasted to that of control cows, the difference was significant (P < 0.01). In Experiment 3, P/AI in cows treated with 84 IU of reCG (54 %) did not differ from that of cows treated with serum derived eCG (59 %) but both were greater (P < 0.05) than cows treated with 105 UI of reCG (41 %). In conclusion, treatment with reCG improved fertility in suckled Bos taurus and Bos taurus x Bos indicus beef cows. In suckled Bos indicus cows, although treatment with reCG and serum derived eCG were comparable, the higher dosage of reCG was detrimental to their P/AI.

Effect of an equine chorionic gonadotrophin-like recombinant glycoprotein treatment on fertility in Angus cattle.

This study determined the effects of administering a glycoprotein with equine chorionic gonadotropin (eCG)-like activity (eCG-like) on corpus luteum (CL) area, serum progesterone concentrations, incidence of multiple ovulations (MOV), estrus expression rate (EER), and pregnancy to timed AI (P/TAI) in Angus cattle synchronized with a 5-d Co-Synch protocol. On Day -8, cattle were body condition scored (BCS), and received a 1.0 g progesterone intravaginal device (IVD) and 100 µg GnRH. On Day -3, the IVDs were removed and 500 µg cloprostenol was administered intramuscularly (i.m.). Cattle were randomly assigned into one of two groups: eCG-like (heifers, n = 232, primiparous, n = 148, and multiparous cows = 485; 300 IU (heifers) and 400 IU (cows) eCG-like i.m. on Day -3), or Control (heifers, n = 240, primiparous, n = 151, and multiparous cows, n = 478; no eCG-like). On Day -2, cattle received a second dose of 500 µg cloprostenol, and on Day 0, 100 µg GnRH was given concurrently with TAI. Estrus expression rate was assessed by observing the tail paint rubbed off in a subset of heifers (n = 372) and all cows on Day 0. Transrectal ultrasonography was used to evaluate the presence of CL on Day -8 and to diagnose P/TAI on Day 30-35. In a subset of cattle (heifers = 194 and multiparous cows = 87), CL area, serum progesterone concentrations, and incidence of MOV were evaluated on Day 7. Heifers, primiparous, and multiparous cows were analyzed separately. Treatment with eCG-like did not affect (P > 0.1) EER in heifers. Estrus expression rate was increased (P ≤ 0.03) in primiparous (68.9 % vs 45.0 %) and multiparous (75.5 % vs. 68.8 %) cows treated with eCG-like compared with Controls. Pregnancy/TAI was increased (P < 0.01) in heifers (65.2 % vs 48.3 %) and primiparous cows (48.3 % vs. 35.1 %) treated with eCG-like than Controls. In multiparous cows with a BCS ≤4 P/TAI was increased (P = 0.03) in the eCG-like group (47.7 %) than the Control group (34.8 %) but was similar (P > 0.1) between treatment groups in multiparous cows with a BCS ≥4.5. The eCG-like treatment increased (P < 0.05) CL area in heifers and multiparous cows and tended (P = 0.10) to elevate serum progesterone concentrations only in heifers. However, it did not affect (P > 0.1) the incidence of MOV in heifers and multiparous cows. Glycoprotein eCG-like administration increased fertility in heifers and primiparous cows, but in multiparous the effect of eCG-like on fertility was associated with BCS.

Treatment alternatives to induce follicular wave emergence for timed-AI in lactating dairy Cows.

Two experiments evaluated the effect of different hormonal treatments to synchronize follicle wave emergence on follicle dynamics and pregnancies per AI (P/AI) in estradiol (E2)/progesterone (P4) timed-AI (TAI) protocols in lactating dairy cows. In Experiment 1, lactating, primiparous Holstein cows (n = 36) received a P4 releasing device (Day 0) and were allocated at random to one of the following three treatment groups: Group EB received 2 mg E2 benzoate (EB) intramuscularly (i.m.), Group EB + GnRH received 2 mg EB+20 µg buserelin (GnRH) i.m., or Group EB + P4 received 2 mg EB + 100 mg of injectable P4 (iP4) in oil i.m. All cows received 0.150 mg D-Cloprostenol on Days 7 and 8 followed by P4 device removal, 400 IU eCG and 1 mg ECP on Day 8. Daily ultrasound examinations revealed that although the interval from P4 device removal to ovulation was not affected by treatment, cows that received EB + GnRH had an earlier (P < 0.05) emergence of the new follicular wave (Day 2.6 ± 0.2) than the other two treatment groups (Days 3.5 ± 0.3 and 6.1 ± 0.3, for EB and EB + P4, respectively). In Experiment 2, 808 lactating cows were assigned randomly to the three treatments evaluated in Experiment 1, and all the cows were TAI to determine P/AI. Cows in the EB + GnRH group had greater P/AI (57.4 %, P < 0.01) than those in the EB (44.6 %) or EB + P4 (45.7 %) groups. In conclusion, the administration of GnRH, but not iP4, on the day of insertion of a P4 device improves P/AI in lactating dairy cows synchronized for TAI with an estradiol/P4-based protocol.

Vaginal Progesterone for Pregnancy Prolongation After Arrested Preterm Labor: A Randomized Clinical Trial.

Importance: Women with arrested preterm labor (APTL) are at very high risk for spontaneous preterm delivery (SPTD), the leading cause of neonatal mortality and morbidity. To date, no maintenance therapy has been found to be effective for pregnancy prolongation. A few clinical trials with considerable methodological limitations have demonstrated some efficacy for 400 mg vaginal micronized progesterone (VMP) in women with APTL. Objective: To investigate the effectiveness of daily 400 mg VMP for the prolongation of pregnancy after APTL. Design, Setting, and Participants: This randomized clinical trial was conducted between December 19, 2018, and February 27, 2023, in 3 university-affiliated medical centers in Israel. Participants included women with singleton and twin pregnancies after APTL following tocolysis at 24 weeks 0 days to 34 weeks 0 days' gestation. Women with a history of preterm delivery or asymptomatic cervical shortening in the current pregnancy were excluded. Interventions: Participants were randomly allocated to receive VMP 200 mg twice a day or no treatment until 36 weeks 6 days' gestation. Main Outcomes and Measures: The primary end points were mean number of days from study enrollment to delivery and the rate of SPTD prior to 37 weeks' gestation. Results: A total of 129 participants were enrolled (65 in the VMP group and 64 in the no-treatment group). Mean (SD) age was 27.6 (5.1) years. Between the VMP and no-treatment groups, there was no difference in pregnancy prolongation (mean [SD], 40.0 [17.8] vs 37.4 [20.3] days; P = .44) and the rate of SPTD (16 [25%] vs 19 [30%]; relative risk, 0.8; 95% CI, 0.5-1.5; P = .52). In twin pregnancies, including 12 and 15 pairs in the VMP and no-treatment groups, respectively, VMP prolonged pregnancy (mean [SD], 43.7 [18.1] vs 26.1 [15.2] days; P = .02), postponed the delivery week (36.5 [1.4] vs 34.7 [2.2] weeks; P = .01), shortened the length of stay in the neonatal intensive care unit (4.9 [10.6] vs 13.2 [18.5] days; P = .03) and overall hospital stay (8.3 [9.6] vs 15.1 [17.2] days; P = .03), and was associated with a higher birth weight (2444 [528] vs 2018 [430] g; P = .01). Conclusions and Relevance: These findings show that VMP given in a dosage of 200 mg twice a day following APTL is not an effective treatment to prolong pregnancy or prevent SPTD. However, VMP demonstrated beneficial effects in twin pregnancies, warranting further investigation. Trial Registration: ClinicalTrials.gov Identifier: NCT02430233.

Comparing cervical cerclage, pessary and vaginal progesterone for prevention of preterm birth in women with a short cervix (SuPPoRT): A multicentre randomised controlled trial.

BACKGROUND: Cervical cerclage, cervical pessary, and vaginal progesterone have each been shown to reduce preterm birth (PTB) in high-risk women, but to our knowledge, there has been no randomised comparison of the 3 interventions. The SuPPoRT "Stitch, Pessary, or Progesterone Randomised Trial" was designed to compare the rate of PTB <37 weeks between each intervention in women who develop a short cervix in pregnancy. METHODS AND FINDINGS: SuPPoRT was a multicentre, open label 3-arm randomised controlled trial designed to demonstrate equivalence (equivalence margin 20%) conducted from 1 July 2015 to 1 July 2021 in 19 obstetric units in the United Kingdom. Asymptomatic women with singleton pregnancies with transvaginal ultrasound cervical lengths measuring <25 mm between 14+0 and 23+6 weeks' gestation were eligible for randomisation (1:1:1) to receive either vaginal cervical cerclage (n = 128), cervical pessary (n = 126), or vaginal progesterone (n = 132). Minimisation variables were gestation at recruitment, body mass index (BMI), and risk factor for PTB. The primary outcome was PTB <37 weeks' gestation. Secondary outcomes included PTB <34 weeks', <30 weeks', and adverse perinatal outcome. Analysis was by intention to treat. A total of 386 pregnant women between 14+0 and 23+6 weeks' gestation with a cervical length <25 mm were randomised to one of the 3 interventions. Of these women, 67% were of white ethnicity, 18% black ethnicity, and 7.5% Asian ethnicity. Mean BMI was 25.6. Over 85% of women had prior risk factors for PTB; 39.1% had experienced a spontaneous PTB or midtrimester loss (>14 weeks gestation); and 45.8% had prior cervical surgery. Data from 381 women were available for outcome analysis. Using binary regression, randomised therapies (cerclage versus pessary versus vaginal progesterone) were found to have similar effects on the primary outcome PTB <37 weeks (39/127 versus 38/122 versus 32/132, p = 0.4, cerclage versus pessary risk difference (RD) -0.7% [-12.1 to 10.7], cerclage versus progesterone RD 6.2% [-5.0 to 17.0], and progesterone versus pessary RD -6.9% [-17.9 to 4.1]). Similarly, no difference was seen for PTB <34 and 30 weeks, nor adverse perinatal outcome. There were some differences in the mild side effect profile between interventions (vaginal discharge and bleeding) and women randomised to progesterone reported more severe abdominal pain. A small proportion of women did not receive the intervention as per protocol; however, per-protocol and as-treated analyses showed similar results. The main study limitation was that the trial was underpowered for neonatal outcomes and was stopped early due to the COVID-19 pandemic. CONCLUSIONS: In this study, we found that for women who develop a short cervix, cerclage, pessary, and vaginal progesterone were equally efficacious at preventing PTB, as judged with a 20% equivalence margin. Commencing with any of the therapies would be reasonable clinical management. These results can be used as a counselling tool for clinicians when managing women with a short cervix. TRIAL REGISTRATION: EU Clinical Trials register. EudraCT Number: 2015-000456-15, clinicaltrialsregister.eu., ISRCTN Registry: ISRCTN13364447, isrctn.com.

Rectal versus vaginal progesterone administration for luteal phase support in the hormone replacement therapy frozen embryo transfer (HRT-FET) cycle: protocol for a non-inferiority randomised controlled trial.

INTRODUCTION: This study compares rectal administration with vaginal administration of progesterone as luteal phase support in hormone replacement therapy frozen embryo transfer (HRT-FET) cycles. The reason for comparing the two routes of administration is that rectal administration has been suggested to be more patient friendly. METHODS AND ANALYSIS: This study is a randomised controlled trial comparing the ongoing pregnancy rate (OPR) at week 12 in HRT-FET cycles after rectal administered progesterone as the only administered progesterone compared with a vaginal luteal phase support regimen. All patients are enrolled from a Danish public fertility clinic and randomised to one of two groups, with 305 patients receiving embryo transfer assigned to each group. Endometrial preparation includes 6 mg oestradiol daily. The intervention group receives rectally administered progesterone (400 mg/12 hours) and the control group receives vaginally administered progesterone (400 mg/12 hours). If P4 is <35 nmol/L on blastocyst transfer day an additional rectal luteal phase rescue regimen is started (control group). Thawing and transferring of a single autologous vitrified blastocyst is scheduled on the sixth day of progesterone administration in both groups. The power calculation is based on a non-inferiority analysis with an expected OPR in both groups of 44% and the upper limit of a one-sided 95% CI will exclude a difference in favour of the control group of more than 10.0%. An interim analysis will be conducted once half of the study population has been enrolled. ETHICS AND DISSEMINATION: The trial was approved on 21 November 2023 by the Danish National Ethical Committee and the Danish Medicines Agency and is authorised by the Clinical Trials Information System (EUCT number 2023-504616-15-02). All patients will provide informed consent before being enrolled in the study. The results will be published in an international journal. TRIAL REGISTRATION NUMBER: EUCT number: 2023-504616-15-02.

Individualized luteal phase support in frozen-thawed embryo transfer after intramuscular progesterone administration might rectify live birth rate.

Background: The serum P concentrations are suggested to have an impact on pregnancy outcome. However there is no consensus about the optimal progesterone cut-off during the luteal phase. Few studies evaluated the effectiveness of a "rescue protocol" for low serum P concentrations and most of these studies used vaginal progesterone administration. There is paucity of data on the effectiveness of rescue protocol using intramuscular progesterone (IM-P) in frozen-thawed embryo transfer (FET). Methods: This study is a retrospective cohort study included 637 single or double blastocyst FETs with artificially prepared endometrium receiving 100 mg IM progesterone (P) after incremental estrogen treatment. Serum P concentrations were evaluated using blood samples obtained 117-119 hours after the first IM-P administration and 21 ± 2 hours after the last IM-P administration. Patients with serum P concentrations <20.6 ng/ml on the ET day were administrated 400 mg vaginal progesterone for rescue. Results: Demographic and cycle characteristics were similar between patients receiving rescue vaginal P (embryo transfer (ET)-day P concentration < 20.6 ng/ml) and patients who did not need rescue vaginal P (ET-day P concentration ≥ 20.6 ng/ml). Clinical pregnancy, miscarriage, and live birth rates were similar between two groups: 52.9%(45/85) vs 59.6%(326/552), p=0.287; 11.1%(5/45) vs 14.1%(46/326), p=0.583; and 47.1%(40/85) vs 50.7%(280/552), p=0.526, respectively. Logistic regression analysis revealed that the female age (p = 0.008, OR=0.942, 95% CI = 0.902-0.984) and embryo quality (ref: good quality for moderate: p=0.02, OR=0.469, 95% CI =0.269-0.760; for poor: p=0.013, OR= 0.269, 95% CI = 0.092-0.757) were independent variables for live birth. Following rescue protocol implementation, ET-day P concentration was not a significant predictor of live birth. Conclusions: Rescue vaginal P administration for low ET day serum P concentrations following IM-P yields comparable live birth rates.

Luteal phase support with oral progesterone improves live birth rate in intrauterine insemination cycles using letrozole.

RESEARCH QUESTION: Does luteal phase support (LPS) with oral progesterone improve the live birth rate (LBR) in patients undergoing intrauterine insemination (IUI) cycles with letrozole? DESIGN: This retrospective cohort study included 1199 IUI cycles with letrozole between January 2017 and December 2021. A nearest neighbour random matching approach was employed to pair the LPS group and the control group in a 1:2 ratio. Eight variables were chosen for matching in the propensity score matching (PSM) model: age; body mass index; duration of infertility; cause(s) of infertility; antral follicle count; basal concentration of FSH; rank of IUI attempts; and leading follicle size. LBR was selected as the primary outcome. RESULTS: In total, 427 LPS cycles were matched with 772 non-LPS (control) cycles after PSM. The LBR was significantly higher in the LPS group compared with the control group (19.7% versus 14.5%; P = 0.0255). The clinical pregnancy rate (23.2% versus 17.6%; P = 0.0245) and ongoing pregnancy rate (20.6% versus 15.8%; P = 0.0437) were also significantly higher in the LPS group. The biochemical pregnancy rate, ectopic pregnancy rate and miscarriage rate were similar in the two groups (P > 0.05). The intergroup comparison revealed no significant variances in terms of gestational age, mode of delivery, ectopic pregnancy rate or abortion rate. Furthermore, there were no significant differences in birth weight or birth length between the two groups. CONCLUSIONS: Luteal support with oral progesterone significantly improved the LBR in IUI cycles with letrozole, but did not affect neonatal outcomes.