Serum progesterone concentration on pregnancy test day might predict ongoing pregnancy after controlled ovarian stimulation and fresh embryo transfer.

Progesterone (P4) is essential for pregnancy. A controlled ovarian stimulation (COS) leads to a iatrogenic luteal defect that indicates a luteal phase support (LPS) at least until pregnancy test day. Some clinicians continue the LPS until week 8 or later, when P4 is mainly secreted by syncytiotrophoblast cells.Measuring serum P4 on pregnancy test day after a fresh embryo transfer could help to identify women who might benefit from prolonged LPS. In women with LPS based on P4 administered by the rectal route, P4 concentration on pregnancy test day was significantly higher in patients with ongoing pregnancy than in patients with abnormal pregnancy.This monocentric retrospective study used data on 99 consecutive cycles of COS, triggered with human chorionic gonadotropin, followed by fresh embryo transfer resulting in a positive pregnancy test (>100 IU/L) (from November 2020 to November 2022). Patients undergoing preimplantation genetic screening or with ectopic pregnancy were excluded. All patients received standard luteal phase support (i.e. micronized vaginal progesterone 600 mg per day for 15 days). The primary endpoint was P4 concentration at day 15 after oocyte retrieval (pregnancy test day) in women with ongoing pregnancy for >12 weeks and in patients with miscarriage before week 12 of pregnancy.The median P4 concentration [range] at pregnancy test day was higher in women with ongoing pregnancy than in women with miscarriage (55.9 ng/mL [11.6; 290.6] versus 18.1 ng/mL [8.3; 140.9], p = 0.002). A P4 concentration ≥16.5 ng/mL at pregnancy test day was associated with higher ongoing pregnancy rate (OR = 12.5, 95% CI 3.61 - 43.33, p <0.001). A P4 concentration ≥16.5 ng/mL at pregnancy test day was significantly associated with higher live birth rate (OR = 11.88, 95% CI 3.30-42.71, p <0.001).After COS and fresh embryo transfer, the risk of miscarriage is higher in women who discontinue luteal support after 15 days, as recommended, but with P4 concentration <16.5 ng/mL. The benefit of individualized prolonged luteal phase support should be evaluated.

Effects of two protocols of ovulation synchronization on corpus luteum size and blood flow, progesterone concentration, and pregnancy rate in beef heifers.

The objective of this study was to evaluate the effect of 7-day estradiol-progesterone-based [Treat(C)] and 5-day Co-Synch plus progesterone [Treat(Co-Sy)] protocols on ovulation time, pre-ovulatory follicle diameter, corpus luteum (CL) size and blood flow, progesterone (P4) concentration and pregnancy rate (PR) in beef heifers. In Experiment 1, a crossover design was applied (n = 9). For Treat(C), a progesterone intravaginal (PI) device was inserted, plus 2 mg of estradiol benzoate (day 0). On day 7, 500 µg of cloprostenol plus 0.5 mg of estradiol cypionate were administered, and PI was removed. For Treat(Co-Sy), on day 0, a PI was inserted plus 100 µg gonadotropin-releasing hormone (GnRH). On day 5, PI was removed, plus 500 µg of cloprostenol and 100 µg of GnRH were administered at 69-70 h later. From day one to ovulation day, dominant follicle was evaluated by ultrasonography. On days 4 and 8 post-ovulation, CL was evaluated by color Doppler, and P4 concentration was determined by chemiluminescence. In Experiment 2, a split-plot experimental design was used. Protocols followed were the same as in Experiment 1 [Treat(C); n = 310 and Treat(Co-Sy); n = 314]. Heifers were fixed-time artificially inseminated. Pregnancy was determined on day 41. In Experiment 1, the interval between PI removal and ovulation time was different between protocols (P < 0.01). In addition, P4 concentration was related to the CL size (P < 0.001), CL blood flow (P < 0.01) and protocols (P < 0.03). In Experiment 2, PR did not differ between protocols.

Low Luteal Serum Progesterone Levels Are Associated With Lower Ongoing Pregnancy and Live Birth Rates in ART: Systematic Review and Meta-Analyses.

Progesterone plays a key role in implantation. Several studies reported that lower luteal progesterone levels might be related to decreased chances of pregnancy. This systematic review was conducted using appropriate key words, on MEDLINE, EMBASE, and the Cochrane Library, from 1990 up to March 2021 to assess if luteal serum progesterone levels are associated with ongoing pregnancy (OP) and live birth (LB) rates (primary outcomes) and miscarriage rate (secondary outcome), according to the number of corpora lutea (CLs). Overall 2,632 non-duplicate records were identified, of which 32 relevant studies were available for quantitative analysis. In artificial cycles with no CL, OP and LB rates were significantly decreased when the luteal progesterone level falls below a certain threshold (risk ratio [RR] 0.72; 95% confidence interval [CI] 0.62-0.84 and 0.73; 95% CI 0.59-0.90, respectively), while the miscarriage rate was increased (RR 1.48; 95% CI 1.17-1.86). In stimulated cycles with several CLs, the mean luteal progesterone level in the no OP and no LB groups was significantly lower than in the OP and LB groups [difference in means 68.8 (95% CI 45.6-92.0) and 272.4 (95% CI 10.8-533.9), ng/ml, respectively]. Monitoring luteal serum progesterone levels could help in individualizing progesterone administration to enhance OP and LB rates, especially in cycles without corpus luteum. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=139019, identifier 139019.

A lateral flow-based portable platform for determination of reproductive status of cattle.

Our objective was to develop and validate a tool integrating a disposable fluorescence-based lateral flow immunoassay (LFIA) coupled with a portable imaging device for estimating circulating plasma concentrations of progesterone (P4). First, we developed and optimized a competitive LFIA test strip to measure P4 in bovine plasma. The LFIA design included a sample pad, a conjugate pad that stores R-phycoerythrin-anti-P4 conjugates, a glass-fiber spacer pad, a nitrocellulose membrane with printed test and control lines, and a cellulose-fiber absorbent pad. To perform a test, 20 µL of plasma and 50 µL of running buffer were added on the sample pad. After 3 min, 45 µL of running buffer was added to initiate sample flow. After allowing 15 min to stabilize the colorimetric signal, strips were introduced in an LFIA portable reader wirelessly linked to a laptop to determine P4 concentration based on test-to-control-line signal (T/C ratio). In a series of experiments (n = 6), the ability of the LFIA to differentiate plasma samples with ≥1 or <1 ng/mL of P4 was evaluated. For each experiment, a calibration curve was constructed using plasma with known concentrations of P4 (0.1 to 3.7 ng/mL; n = 5). The resulting linear equation was then used to determine a T/C ratio cutoff to differentiate samples with ≥1 or <1 ng/mL of P4. In addition, to evaluate the ability of the platform to assign samples to P4 concentration groups without a calibration curve for individual batches, we performed a receiver operating characteristic analysis to identify a single cutoff value for T/C ratio that could potentially be used for all batches. Overall, calibration curves showed a linear relationship between T/C ratio and P4 levels (mean coefficient of determination = 0.74; range 0.42 to 0.99). Next, plasma samples from lactating dairy cows (n = 58) were tested in triplicate to determine the ability of the LFIA system to differentiate plasma samples with ≥1 or <1 ng/mL of P4 using a RIA for P4 as reference test. Overall, the LFIA assay correctly classified 90% of the samples, with 97% sensitivity, 83% specificity, 85% positive predictive value, and 96% negative predictive value. Agreement between the tests was substantial (kappa = 0.79; 95% confidence interval 0.64 to 0.95). When using a single cutoff value for T/C ratio selected by receiver operating characteristic analysis, sensitivity and specificity to determine CL presence were 97 (95% confidence interval 82 to 99) and 79% (95% confidence interval 60 to 92), respectively. These data suggest that the developed portable LFIA system can accurately differentiate plasma samples with ≥1 or <1 ng/mL of P4.

Effect of the administration of alfaprostol 3 or 6 days after ovulation in jennies: ultrasonographic characteristic of corpora lutea and serum progesterone concentration.

Donkey jenny's corpus luteum (CL) response to PGF2α analogues has not been investigated in depth. Aim of this study was to evaluate the donkey jenny's corpus luteum (CL) ultrasonographic characteristics (diameter, area and vascularized area) by B-Mode, Color Doppler and serum progesterone concentration ([P4]) after treatment with the prostaglandins F2α analogue alfaprostol at day 3 or day 6 after ovulation (groups PG3 and PG6, respectively). [P4] was positively correlated (P < 0.0001) with CL diameter: r2 = 0.17; area: r2 = 0.21 and vascularized area: r2 = 0.54. The interovulatory interval was significantly reduced in the PG6 group (15 ±â€¯1.8 days), compared to the control group (24.5 ±â€¯2.9 days; P < 0,05), while there were no significant differences in interovulatory interval between PG3 (21.7 ±â€¯7.9 days) and control or PG6 group. [P4], in the 6 jennies of the PG6 group, dropped under 1 ng/mL within 2 days after treatment, remaining under this concentration until [P4] raised again to levels comparable with those of the control group until spontaneous luteolysis. After alfaprostol administration, one of the 2 remaining PG3 group jennies showed a complete luteolysis, and the other one underwent a partial luteolysis and ovulated in diestrus.

Effect of education on ability of AI professionals and herd-owner inseminators to detect cows not in oestrus and its relation with progesterone concentration on day of re-insemination.

The effect of training background of persons performing artificial insemination (AI) (herd-owner inseminators (OWNER), AI technicians (AI-T), and fertility consultants (FC)) on pregnancy rate and their ability to detect cows not in oestrus were studied. A total of 1584 re-AI occasions on 754 dairy farms were included. Milk samples for progesterone (P4) analysis in all cases were collected, as were data on the herd, previous breeding attempts, oestrous signs, uterine tone, slipperiness of cervix, and co-operation of the cow. Further breeding attempts and next calving or culling date were sought from registers. The cases were distributed into three categories based on P4 concentrations; <6 nmol/l (no luteal activity, could be in oestrus), 6-10 nmol/l (some luteal activity), and >10 nmol/l (high luteal activity, not in oestrus). Of cows offered for re-AI 7.7% had P4 concentration >10 nmol/l, with no difference between OWNER farms and farms using AI service. OWNERs chose for AI more cows having intermediate P4 than farms using AI service (9.8% vs. 5.9%, p < 0.05). AI-Ts recommended no AI significantly less often than FCs (1.6% vs. 4.9%, p < 0.01). Both groups were equally right: 71% and 68% of cows that were recommended to have no AI had high P4 concentration. Due to courageous and correct rejection of cows with high P4, FCs inseminated proportionally more cows in low P4 and less cows in intermediate P4 than OWNERs (p < 0.05). Of cows finally inseminated, 36.7% became pregnant, with no difference between OWNER farms and farms using AI service. Fertility consultants had higher pregnancy rates than AI-Ts (39.6% vs. 32.6%, p < 0.05). Toneless uterus and sticky cervix at AI significantly correlated with AI occurring at the wrong time (p < 0.001). Behaviour of the cow at AI did not predict P4 concentration. In conclusion, 7.7% of cows offered for re-AI had high P4 concentration. Training of AI personnel increased their ability to detect and reject these cows.

Effects of gonadotropin-releasing hormone administration or a controlled internal drug-releasing insert after timed artificial insemination on pregnancy rates of dairy cows.

This study investigated the effects of gonadotrophin-releasing hormone (GnRH) administration (Experiment 1) and a controlled internal drug-releasing (CIDR) insert (Experiment 2) after timed artificial insemination (TAI) on the pregnancy rates of dairy cows. In Experiment 1, 569 dairy cows that underwent TAI (day 0) following short-term synchronization with prostaglandin F2α were randomly allocated into two groups: no further treatment (control, n = 307) or injection of 100 µg of gonadorelin on day 5 (GnRH, n = 262). In Experiment 2, 279 dairy cows that underwent TAI (day 0) following Ovsynch were randomly allocated into two groups: no further treatment (control, n = 140) or CIDR insert treatment from days 3.5 to 18 (CIDR, n = 139). The probability of pregnancy following TAI did not differ between the GnRH (34.4%) and control (31.6%, p > 0.05) groups. However, the probability of pregnancy following TAI was higher (odds ratio: 1.74, p < 0.05) in the CIDR group (51.1%) than in the control group (39.3%). Overall, CIDR insert treatment at days 3.5 to 18 increased pregnancy rates relative to non-treated controls, whereas a single GnRH administration on day 5 did not affect the pregnancy outcomes of dairy cows.

Effects of gonadotropin-releasing hormone administration or a controlled internal drug-releasing insert after timed artificial insemination on pregnancy rates of dairy cows

This study investigated the effects of gonadotrophin-releasing hormone (GnRH) administration (Experiment 1) and a controlled internal drug-releasing (CIDR) insert (Experiment 2) after timed artificial insemination (TAI) on the pregnancy rates of dairy cows. In Experiment 1, 569 dairy cows that underwent TAI (day 0) following short-term synchronization with prostaglandin F(2α) were randomly allocated into two groups: no further treatment (control, n = 307) or injection of 100 µg of gonadorelin on day 5 (GnRH, n = 262). In Experiment 2, 279 dairy cows that underwent TAI (day 0) following Ovsynch were randomly allocated into two groups: no further treatment (control, n = 140) or CIDR insert treatment from days 3.5 to 18 (CIDR, n = 139). The probability of pregnancy following TAI did not differ between the GnRH (34.4%) and control (31.6%, p > 0.05) groups. However, the probability of pregnancy following TAI was higher (odds ratio: 1.74, p < 0.05) in the CIDR group (51.1%) than in the control group (39.3%). Overall, CIDR insert treatment at days 3.5 to 18 increased pregnancy rates relative to non-treated controls, whereas a single GnRH administration on day 5 did not affect the pregnancy outcomes of dairy cows.

Natural influence of season on follicular, luteal, and endocrinological turnover in Indian crossbred cows.

The study was aimed at investigating the effect of seasonal changes on follicular and luteal dynamics in vivo in normally cycling crossbred cows during summer and winter months of the year. Six healthy regularly cycling Jersey crossbred nonlactating pluriparous cows were used for the study. Follicular and luteal developmental pattern was studied every other day throughout the estrous cycle by scanning the ovaries during two periods of a year viz., hot season (April to June; n = 16) and cold season (December to February; n = 12). Plasma progesterone (P4) concentrations were measured on Days 0 (estrus), 6, and 12 of the estrous cycle. Among the 12 cycles studied during the cold season, 11 (91.7%) had three waves and one had two waves. Of 16 cycles studied during the hot season, eight (50%) had two waves, four (25%) had three waves, and the remaining four cycles had single (n = 2) and four waves (n = 2). High P4 concentrations during the midcycle would have suppressed the dominant follicle of the second follicular wave and induced the emergence of the third wave during the cold season. The first follicular wave (wave I) of the cycle emerged much earlier (Day 0.5 ± 0.3) during the cold season than that in the hot season (Day 1.7 ± 0.4). The ovulatory wave emerged significantly earlier during the hot season (Day 11.5 ± 1.3) than in the cold season (Day 14.8 ± 0.4), and hence, the growth phase of ovulatory follicle significantly increased during the former season (11.0 ± 1.4 days) than the latter (5.8 ± 0.2 days). The ovulatory follicle attained a significantly larger diameter (12.8 ± 0.8 mm) to express the estrus during the hot season when compared to the cold season (11.3 ± 0.4 mm), which might be indicative of alterations in steroidogenic activity within the follicular microenvironment. During the midphase of the cycle, a period critical for embryonic sustenance, the P4 level was significantly reduced in the hot months indicating suppression of luteal activity during hot period of the year. Thus, it could be concluded that increased incidence of two follicular waves associated with a prolonged growth phase of the ovulatory follicle, and altered luteal endocrine activity during the hot season might be associated with decreased fertility in crossbred cattle.

Dinâmica ovariana e concentração de progesterona de vacas Nelore submetidas a IATF / Ovarian dynamics and progesterone concentration in nellore cows artificially inseminated in fixed time

Objetivando-se subsidiar pesquisas envolvendo sincronização de estros e ovulação em bovinos, pretende-se com este estudo, avaliar a dinâmica folicular e a concentração de progesterona em vacas Nelore submetidas a um protocolo de sincronização e IATF. Para tanto, sete vacas adultas foram submetidas à IATF, seguindo o protocolo: implante intravaginal de progesterona no dia zero (D0) e aplicação de benzoato de estradiol; D7 retirada do implante e aplicação de PGF2alfa; D8 administração de hCG, e D9 IATF. Da retirada do implante até a IATF, as vacas foram submetidas, duas vezes ao dia (manhã e tarde) à ultrassonografia transretal, para avaliação do número e diâmetro folicular em cada ovário. O sangue foi coletado para dosagem de progesterona nos dias: implante, retirada, dois, 10, 15, 18 e 23 dias após a retirada do implante. O diagnóstico de gestação foi realizado 60 dias da IATF por palpação transretal. Após análise de variância, o número e diâmetro folicular entre os ovários direito (OD) e esquerdo (OE) foi comparado pelo Teste F, e a concentração de progesterona pelo SNK (5% de significância). A dinâmica de crescimento folicular durante o período estudado foi semelhante entre os ovários (p>0,05). Observaram-se queda no número médio de folículos na manhã do dia da retirada do implante até a tarde da IATF (5,50 + 2,99 e 4,36 + 2,00 folículos, respectivamente) (p<0,05). O diâmetro médio do maior folículo foi superior no OE que no OD (7,35 + 6,34 mm e 5,49 + 4,59, respectivamente) (p<0,05), embora o OE tenha apresentado diâmetro médio diário semelhante ao observado no OD. No entanto, no dia da IATF à tarde o diâmetro folicular médio diminuiu (3,32 + 3,39 mm) (p<0,05). Já a concentração média de progesterona foi semelhante (p>0,05). Concluí-se que vacas Nelore submetidas a sincronização de estro utilizada nesse estudo apresentaram maior folículo no OE, cujo diâmetro diminuiu no momento da IATF.

The purpose of this study is to evaluate the follicular dynamics and progesterone concentration of Nellore cows artificially inseminated in fixed time. Seven Nellore cows were submitted to FTAI on the following protocol: animals received an intravaginal progesterone device on day zero (D0) and injection of estradiol. After 7 days (D7), the device was removed and PGF2alpha administered. On the eighth day (D8) of hCG were administered, and, on the ninth Day (D9), the FTAI. The animals had their blood collected for the dosage of serum progesterone by the solid-phase radioimmunoassay technique, which was conducted on the days of the insertion, on the removal, on days 2, 10, 15, 18, and 23 after the insertion removal. The same animals were submitted, twice a day (morning and afternoon), to transrectal ultrasonography for the assessment of the moment of the removal of the device until the FTAI, the amount of follicles in each ovarium (right and left) and the diameter of the longest follicle in each of them. The diagnosis of gestation through transrectal palpation was carried out 60 days later. The progesterone concentration was submitted to analysis of variance (AV) and compared throughout the days with Student Newman Keuls test (SNK). The amount of follicles and the diameter of the longest follicle were also submitted to AV, but compared to with the F test. They all considered a 5% significance. The dynamics of follicular growth during the studied period was similar between the ovaries (p>0.05). Decrease of the average amount of follicles in the morning of the day of the device removal until the afternoon of the day of FTAI, from 5.50 + 2.99 to 4.36 + 2.00 follicles, respectively (p<0.05), were noticed. The average diameter of the longest follicle was higher for the left ovarium, 7.35 + 6.34 mm and 5.49 + 4.59, respectively (p<0.05), even though the left ovarium presented daily average diameter similar to that noticed for the right ovarium follicles.

Con el objetivo de subsidiar investigaciones involucrando sincronización de estros y ovulación en bovinos, se buscó con este estudio, evaluar la dinámica ovárica y concentración de progesterona en vacas Nelore sometidas a un protocolo de sincronización e IATF. Para esto, siete vacas adultas fueron sometidas a IATF, siguiendo el protocolo: implante intravaginal de progesterona en el día cero (D0) y aplicación de benzoato de estradiol; D7 remoción del implante y aplicación de PGF2alfa; D8 administración de hCG, y D9 IATF. De la remoción del implante hasta IATF, las vacas fueron sometidas, dos veces al día (mañana y tarde) a ecografía transrectal, para evaluación del número y diámetro folicular en cada ovario. La sangre fue recogida para dosificación de progesterona en los días: implante, remoción, 2, 10, 15, 18 y 23 días tras la remoción del implante. El diagnóstico de preñez se realizó 60 días de IATF por palpación transrectal. Tras análisis de variación, el número y diámetro folicular entre los ovarios derecho (OD) e izquierdo (OE) se comparó por Test F, y la concentración de progesterona por SNK (5% de significación). La dinámica de crecimiento folicular durante el período estudiado fue semejante entre los ovarios (p> 0.05). Se observaron caída en el número medio de folículos en la mañana de la remoción del implante, hasta la tarde de IATF (5.50 + 2.99 y 4.36 + 2.00 folículos) respectivamente (p< 0.05). El diámetro medio del mayor folículo fue superior en el OE que en el OD (7.35 + 6.34 mm y 5.49 + 4.59, respectivamente) (p< 0.05), aunque el OE haya presentado diámetro medio diario semejante al observado en el OD.

Concentração sérica de progesterona em bezerras da raça nelore e mestiças tratadas com progesterona em veículo de liberação lenta / Serum progesterone concentration in Nelore and crossbreed heifers treated with long-acting progesterone

Avaliaram-se a eliminação da progesterona em veículo de liberação lenta (P4LA) em animais zebus e mestiços e sua potencial aplicabilidade em programas de sincronização de estro, utilizando-se 60 bezerras, 30 da raça Nelore e 30 mestiças (Gir x Holandês), entre 120 e 150 dias de idade e peso médio de 150kg. Em cada grupo experimental as bezerras foram divididas em três subgrupos (G) de 10 animais, sendo GI = controle (tratado com 5ml de solução fisiológica por via intramuscular); GII = tratado com 450mg P4LA (3ml IM); e GIII = tratado com 750mg P4LA (5ml IM). Amostras de sangue foram coletadas no dia zero, 7 e 13 (D0, D7 e D13) e procedeu-se à análise hormonal por radioimunoensaio de fase sólida. A progesterona de ação prolongada (P4LA), administrada por via intramuscular, manteve-se por 13 dias na corrente sangüínea em concentrações superiores a 1ng/ml. As doses de 450mg e 750mg de P4LA não ocasionaram efeitos adversos sistêmicos clinicamente perceptíveis, e o metabolismo da P4LA foi mais lento nas bezerras Nelore, cuja concentração de progesterona foi maior na corrente sangüínea do que nas bezerras mestiças.

The clearance of long-acting progesterone in microspheres (P4LA) in zebu animals and its potential for use in estrus synchronization were evaluated using 30 Nelore and 30 crossbreed (Holstein x zebu) heifers, with aging between 120 to 150-day-old and weighting 150kg in average. For each breed the animals were divided into three groups of ten animals each, GI= control group treated with saline; GII= treated with 450mg of P4LA; and GIII= treated with 750mg of long-acting progesterone (P4LA). Blood samples were colleted on days 0, 7 and 13 and analysed for progesterone using radioimmunoassay in solid phase. The serum concentration of progesterone was different on days 0, 7 and 13 in relation to the dose of P4LA given. All treated animals presented basal values for progesterone on day 0, increased on day 7 and decreased on day 13, but with values over 1ng/ml. The results show that the drug was absorbed rapidly after its administration and remained in satisfactory concentration in the circulation until day 13. The average total concentration of serum progesterone was higher in Nelore heifers when compared to the concentration in crossbreed ones, indicating difference in the metabolism of the drug between the two genetic groups.