Pregnanediol Glucuronide Concentrations Research Articles

A pilot study on the utility of reduced urine collection frequency protocols for the assessment of reproductive hormones in adolescent girls.

The objectives of this study were to assess the feasibility of and compliance to collecting urine samples in pre- and postmenarcheal girls and to determine if a less than daily collection frequency was sufficient for assessing ovarian function. Twenty-five postmenarcheal girls (11-17 years) collected samples using either a two or a three samples/week protocol during one menstrual cycle. Exposure and mean estrone-1-glucuronide (E1G) and pregnanediol glucuronide concentrations were calculated, and evidence of luteal activity (ELA) was evaluated. Sixteen premenarcheal girls (8-11 years) collected one sample/month for six consecutive months. Samples were analyzed for E1G concentration. Participant compliance was calculated using dates on the urine samples and paper calendars. Participants collecting three samples/week were more compliant to the protocol than those collecting two samples/week (83.6%±2.6% vs. 66.8%±6.6%; p=0.034). There were no differences (p>0.10) regarding paper calendar return (81.8%±12.2% vs. 92.9%±7.1%), recording menses (55.6%±17.6% vs. 92.3%±7.7%) or sample collection (88.9%±11.1% vs. 84.6%±10.4%) between the two protocols. The average cycle length was 30.5±1.3 days and 32% of cycles had ELA. The premenarcheal girls were 100% compliant to the protocol. Only 68.8% of participants returned the paper calendar and 81.8% of those participants recorded sample collection. The average E1G concentration was 15.9±3.8 ng/mL. Use of a less than daily collection frequency during one menstrual cycle in postmenarcheal, adolescent girls is feasible and provides informative data about ovarian function. Collection of one sample/month in premenarcheal girls is feasible and detects the expected low E1G concentrations. Alternate strategies to the use of a paper calendar should be considered.

Endocrine pregnancy monitoring in the two-toed sloth (Choloepus didactylus): “Pregnant or not pregnant”

Progesterone (P4), pregnanediol glucuronide (PdG), estradiol-17β (E2), and estrone sulfate (E1S) were measured in the feces of four female two-toed sloths (Choloepus didactylus) for early pregnancy diagnosis. For individual feces assignment, the examined female sloths were fed with a turquoise food colorant every second day. Fecal samples were collected one to four times per week, depending on the defecation rate throughout the pregnancies and the postpartum periods. The complete course of pregnancy was subdivided into three 16-week intervals (trimester of pregnancy, TP1-3) and a 5-week post-partum period after birth. Progesterone and PdG concentrations started to increase above luteal phase levels 3 weeks after conception (P = 0.028 and 0.005, respectively). At the beginning of TP1, P4 concentrations averaged 345.0 ± 283.0 ng/g and increased approximately 100- to 300-fold to a peak of 7588.0 ± 6717.0 ng/g over the TP3. Progesterone concentrations were considerably lower than PdG concentrations that started with 3206.0 ± 1500.0 ng/g at TP1 and increased up to 12.8556.0 ± 53.744.0 ng/g until birth. In contrast, mean concentrations of E2 (8.2 ± 2.4–11.7 ± 4.2 ng/g) and E1S (12.2 ± 6.7–22.9 ± 13.0 ng/g) elevated insignificantly and were not suitable for pregnancy detection. All hormones analyzed decreased rapidly within the first weeks after birth. Progesterone and PdG, as well as E2 and E1S, highly significantly correlated (r = 0.602, P < 0.001 and r = 0.497, P < 0.001, respectively) at TP1. During the TP2, only P4 and PdG significantly correlated (TP2: r = 0.661, P < 0.001 and postpartum period: r = 0.616, P = 0.009). In summary, only P4 metabolite concentrations were suitable to determine the status of reproduction in the two-toed sloth. Thereby, PdG was ideally suited to diagnose early pregnancy because it was more sensitive and detected pregnancy 2 weeks earlier than P4.

Reductions in urinary collection frequency for assessment of reproductive hormones provide physiologically representative exposure and mean concentrations when compared with daily collection.

To determine if reducing the frequency of urinary sample collection from daily to 5, 3, or 2 days per week during a menstrual cycle or 28-day amenorrheic monitoring period provide accurate representations of the reproductive hormone metabolites estrone-1-glucuronide (E1G) and pregnanediol glucuronide (PdG) exposure and mean concentrations. Exercising women presenting with eumenorrhea or exercise-associated menstrual disturbances collected daily urine samples for the assessment of E1G and PdG concentrations. After enzyme immunoassay analysis of the daily samples, E1G and PdG data were systematically removed from each menstrual cycle or amenorrheic monitoring period to mimic three reduced collection frequencies, representing 5, 3, and 2 days per week. Exposure and mean concentration were calculated for both hormones and all four urinary collection frequencies. E1G and PdG exposure and mean cycle concentrations derived from reduced collection frequencies were not different from daily collection (P > 0.05), independent of whether menstrual cycles and monitoring periods were analyzed together or separately. Bland-Altman analysis indicated acceptable agreement between each reduced collection frequency and daily collection. Compared with daily urinary collection, a reduced collection frequency of 5, 3, or 2 days each week provides accurate E1G and PdG profiles of collection periods of various lengths and types of menstrual function. Reduction of urinary sample collection frequency may enable researchers to reduce participant burden and costs, increase compliance, and study a wider range of study populations.

Characterization of the ovarian cycle in the two-toed sloths (Choloepus didactylus): An innovative, reliable, and noninvasive method using fecal hormone analyses

Little is known about reproductive physiology in the two-toed sloth (Choloepus didactylus). Therefore, the aim of this study was to obtain detailed information about the ovarian cycle. Measurements of reliable gonadal steroids in the feces of this species were undertaken. For this purpose, fecal samples were collected one to three times per week from nonpregnant captive females (n = 2) over a 16-month period. Before assay analysis, the fecal samples were extracted with methanol. Radioimmunoassays and enzyme immunoassays for fecal progesterone, estradiol-17β, pregnanediol-glucuronide (PdG), and estrone sulfate were tested for their ability to detect the ovarian activity. Using the lowest and highest progesterone values, the ovarian cycle length was comparatively analyzed. The ovarian cycle (n = 26) averaged between 31.4 ± 9.1 days (lowest progesterone) and 32.5 ± 7.5 days (highest progesterone) throughout the whole year. The length of the follicular phase, as indicated by low progesterone levels, was 18.1 ± 4.4 days (range 12–25 days), and the length of the luteal phase, as characterized by elevated progesterone levels, was 13.2 ± 1.8 days (range 11–16 days). In contrast, estradiol-17β and estrone sulfate were not suitable to detect the cycle due to irregular collection intervals. Fecal progesterone and PdG, as well as estradiol-17β and estrone sulfate, significantly correlated (r = 0.621, P < 0.01 and r = 0.606, P < 0.01). PdG concentrations (dilution factor (DF) 1:40) were considerably higher than progesterone concentrations (DF 1:10), PdG amounted in the range of 1326.7 ± 320.2 ng/g wet feces (animal S1) and 1373.8 ± 468.3 ng/g wet feces (animal S2) compared with progesterone concentrations in the range of 98.0 ± 17.0 ng/g (S1) and 105.9 ± 30.0 ng/g (S2). The estrone sulfate levels (DF 1:2) were similar to estradiol-17β (DF 1:22). The mean fecal estradiol-17β concentrations were 6.7 ± 0.9 ng/g for animal S1 and 7.5 ± 1.6 ng/g for animal S2. In conclusion, the ovarian activity of the two-toed sloth was studied using the noninvasive method by means of the fecal steroid monitoring. Progesterone was the most reliable fecal steroid hormone to determine the duration of the ovarian cycle independent of the weekly defecation rate. The course of progesterone concentrations resulted in a cycle length of 4–5 weeks length in the two-toed sloth. Thus, the reproductive activity of the two-toed sloth does not show any seasonality like the three-toed sloth.

Progesterone and pregnanediol-glucuronid concentrations in saliva, milk and urine of female alpacas and their application in pregnancy diagnosis

The objective of the present study was the measurement of the pregnancy associated hormones progesterone (P4) and pregnanediol-glucuronide (PdG) in saliva, milk and urine of alpacas and their potential use in pregnancy diagnosis. Sample of blood, saliva, milk and urine were obtained from 36 female alpacas before mating and throughout the pregnancy. Concentrations of P4 and PdG were determined using an enzyme immunoassay (EIA). Pregnancy was checked by ultrasonography at any sampling time. The milk samples were also tested using a commercial on-farm progesterone kit which was designed for dairy cattle. EIA-Concentrations of P4 in blood, milk and urine and urine PdG concentrations were significantly higher in pregnant than in not pregnant alpacas. There was no difference in concentrations of P4 or PdG in saliva. The accuracy of the progesterone kit was 90% for diagnosis of pregnancy and 69% for non-pregnancy. However, 70% of the false positive results also showed relatively high P4 milk concentrations in the EIA. Values of P4 in blood and PdG in urine are comparable to previous reports in alpacas and therefore can be confirmed as an indicator for pregnancy. Saliva seems unsuitable in pregnancy diagnosis in alpacas, whereas milk seems to be an adequate alternative. The use of milk and urine would simplify the pregnancy diagnosis in alpacas since in contrast to the current methods (e. g. blood progesterone) the owners can take the samples. The avoidance of blood sampling results in a considerable stress reduction for the animals. P4 measurement in milk and PdG measurement in urine are good alternatives in pregnancy diagnosis during the first month of pregnancy, when a trans-abdominal ultrasonographic examination is not yet reliable. However, since high values of P4 and PdG only show the presence of active luteal tissue and therefore are indirect markers of pregnancy the diagnosis should be confirmed using ultrasound later in pregnancy.

Relation of Daily Urinary Hormone Patterns to Vasomotor Symptoms in a Racially/Ethnically Diverse Sample of Midlife Women: Study of Women’s Health Across the Nation

The associations of urinary pregnanediol-glucuronide (PdG) levels and menstrual bleeding and their modification of associations of other risk factors with vasomotor symptoms (VMS) are examined. Daily urine samples were collected for 1 menstrual cycle or 50 days if no bleeding occurred. Participants (n = 742) were aged 43 to 54 years, not using exogenous hormones, not pregnant, had an intact uterus and > 1 ovary, and menstruated in the prior 3 months. Multivariate analyses were performed of urinary hormone metabolites and within-woman proportion of days reporting VMS. VMS reporting was 4-fold greater (P = .0005) in women whose urine collections ended without bleeding. In collections with PdG levels suggestive of ovulatory activity according to the work of Kassam et al, VMS are significantly associated with obesity, early perimenopause, and increasing PdG levels. In collections with lower PdG concentrations, VMS are significantly increased with no bleeding, smoking, higher age, physical activity, follicle-stimulating hormone, and luteinizing hormone and are significantly reduced with increasing estrogen concentrations.

Influence of the mother's reproductive state on the hormonal status of daughters in marmosets (Callithrix kuhlii).

Behavioral and endocrine suppression of reproduction in subordinate females produces the high reproductive skew that characterizes callitrichid primate mating systems. Snowdon et al. [American Journal of Primatology 31:11-21, 1993] reported that the eldest daughters in tamarin families exhibit further endocrinological suppression immediately following the birth of siblings, and suggested that dominant females exert greater control over subordinate endocrinology during this energetically challenging phase of reproduction. We monitored the endocrine status of five Wied's black tufted-ear marmoset daughters before and after their mother delivered infants by measuring concentrations of urinary estradiol (E(2)), pregnanediol glucuronide (PdG), testosterone (T), and cortisol (CORT). Samples were collected from marmoset daughters 4 weeks prior to and 9 weeks following three consecutive sibling-litter births when the daughters were prepubertal (M=6.1 months of age), peripubertal (M=11.9 months), and postpubertal (M=17.6 months). The birth of infants was associated with reduced ovarian steroid excretion only in the prepubertal daughters. In contrast, ovarian steroid levels tended to increase in the postpubertal daughters. Urinary E(2) and T levels in the postpubertal daughters were 73.8% and 37.6% higher, respectively, in the 3 weeks following the birth of infants, relative to prepartum levels. In addition, peak urinary PdG concentrations in peri- and postpubertal daughters were equivalent to luteal phase concentrations in nonpregnant, breeding adult females, and all of the peri- and postpubertal daughters showed clear ovulatory cycles. Cortisol excretion did not change in response to the reproductive status of the mother, nor did the concentrations change across age. Our data suggest that marmoset daughters of potential breeding age are not hormonally suppressed during the mother's peripartum period or her return to fertility. These findings provide an additional example of species diversity in the social regulation of reproduction in callitrichid primates.

Monitoring the Reproductive Status of Dairy Cows by Urinary Pregnanediol Glucuronide

This study was undertaken with the aim to establish a reliable radioimmunoassay (RIA) system for urinary pregnanediol glucuronide (PdG) and to employ it for monitoring the reproductive status of dairy cows. Urine and blood samples were collected from the Holstein cows both pregnant and non-pregnant. The samples were then investigated for evaluating the relationship between progesterone (P4) in blood and PdG in urine adjusted with or without urinary creatinine basis. Biweekly urine collection was employed for three cows in estrous and those artificially inseminated, while urine from pregnant cows was collected on a monthly basis. P4 and PdG levels were measured by enzymeimmunoassay (EIA) and RIA techniques, respectively. Our results indicated the sensitivity of PdG for RIA being 35 pg/tube and the recovery rate of 100%. Urinary creatinine concentrations also fluctuated within a day, but change at midday was not noteworthy. Regardless of the time of urination the change in concentrations of PdG was relatively smaller and did not vary significantly. The urinary PdG concentration showed periodic changes as that with serum P4 levels during the cow's estrus cycle. The correlation coefficient rose when creatinine level in urine was adjusted but the change was also not significant. The concentrations of PdG during the luteal phase were detected between 8.2 and 17.4 ng/ml, three to five times higher than that in the follicular phase. The concentration of PdG from pregnant cows (21 days after conception) was three to four times higher than in the non- pregnant cows. Our finding suggests that the determination of urinary PdG could be reliably employed for early pregnancy detection. The urinary PdG level continued to raise until 30 days pre-partum while the concentration reached its peak at 30 ng/ml, after which it started to fall 18 to 30 days before parturition and finally fell to its nadir value one week after parturition. As the correlation coefficient between the urinary PdG and serum P4 was higher than that corrected by urinary creatinine it can be suggested that the adjustment is not needed. The concentrations of urinary PdG could be maintained stably for 2 days in urine samples stored at room temperature and extended to 8 days when the samples were pretreated by boiling for 30 minutes. In conclusion urinary PdG concentration even without the need for creatinine basis adjustment can be used directly for monitoring the reproductive status of dairy cows. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 4 : 460-466)

Reproductive monitoring of free-ranging female mountain gorillas by urinary hormone analysis.

Frequent urine samples from three habituated free-ranging adult female mountain gorillas were collected during a four-week period in order to characterize, by analysis of urinary hormones, their ovarian cycle, and to diagnose pregnancy. A conceptive cycle and two cycles that did not result in full term pregnancy were monitored. Behavioral and physiological observations of mating and labial swellings were correlated to urinary hormone results. Mating occurred on days with elevated estrogens. Labial swelling was maximum near or at peak estrogen levels. Pregnancy was diagnosed at the field site by measurement of chorionic gonadotropin using commercially available human pregnancy detection kits. In one pregnancy, gestation length was 254 days. The pregnanediol glucuronide concentrations of the mountain gorilla did not change during the nonconceptive cycle. During the conceptive cycle, the concentrations did not increase until the approximate time of implantation. This finding suggests marked differences in steroid production or metabolism between the mountain gorilla and the captive lowland gorilla.

Functional significance of behavioral, morphological, and endocrine correlates across the ovarian cycle in semifree ranging female Tonkean macaques.

The role of sexual displays in mating strategies and their reliability in indicating the time of ovulation has given rise to multiple explanations in nonhuman primates. In order to discriminate among hypotheses, socio-sexual behaviors were recorded in a semifree ranging group of Tonkean macaques (Macaca tonkeana), together with sexual skin swelling volumes and measurements of urinary concentrations of estrone conjugates and pregnanediol glucuronide. A clear preovulatory peak of urinary estrogen levels occurred 2 days before a defined rise in pregnanediol glucuronide concentrations, indicating that both hormones pointed out the female's ovulatory period. The concept of estrus rightly could be applied to female Tonkean macaques since fluctuations in estrogen levels correlated with cyclic changes in genital swelling sizes and rates of female behavioral attractivity and proceptivity. Males proved to be capable of recognizing the optimal conception period as judged from the occurrence of maximal rates of following behavior, serial matings, and ejaculations during the peri-ovulatory phase. During this time, males succeeded in maintaining exclusive and enduring associations with females. However, consortships occurred precociously, with males starting to affiliate with females, follow, and mount them 1 week before the presumed time of ovulation. These long-lasting consortships appear to be a consequence of the female extended follicular phase. This presumably sexually selected character allowed females to extend conspicuous sexual displays: genital swelling and utterance of an estrous call, which might attract males' attention and arouse them. With regard to female mating tactics, the combination of reliably indicating the time of ovulation to the male and durable periods of competitor exclusion led to reject explanations assuming manipulation about paternity or long-lasting intermale competition incitement in Tonkean macaques. Competition for mates between females also turned out to be an irrelevant factor as it was very low in the species. We conclude that the main function of sexual displays is to herald the approach of ovulation toward available mates.

Effect of low daily doses of mifepristone on ovarian function and endometrial development

The effects of low daily doses of the antiprogestin mifepristone (RU 486) on ovarian and endometrial function were studied. The study included one control cycle, three treatment cycles and one follow-up cycle. During the treatment cycles, either 0.1 (n = 5) or 0.5 (n = 5) mg of mifepristone was administered once daily. Urine samples were collected three times weekly during the control and treatment cycles and pregnanediol glucuronide and oestrone glucuronide and luteinizing hormone (LH) were quantified by radioimmunoassay. Blood samples for cortisol measurement were collected once weekly and for serum glycodelin at the onset of menstruation. An endometrial biopsy was obtained in the mid-luteal phase in the control cycle and in the first and third treatment cycles and analysed by morphometric and histochemical methods. Binding of Dolichus biflorus agglutinin (DBA) lectin was measured and expression of progesterone and oestrogen receptors and glycodelin were analysed immunohistochemically. All cycles studied were ovulatory with an LH peak and elevated pregnanediol glucuronide concentrations. Follicular development seemed normal as judged by ultrasound examination. The length of the menstrual cycle and the menstrual bleeding were not significantly altered. Following administration of 0.5 mg mifepristone/day, endometrial development appeared to be slightly retarded and glandular diameter was significantly reduced. Furthermore, significant decreases in DBA lectin binding and endometrial expression of glycodelin were observed. Daily doses of 0.1 mg did not have any significant effect on the endometrium. No differences in oestrogen or progesterone receptor immunoactivity between control and treatment cycles were seen. This study provides further evidence that endometrial function is sensitive even to doses of antiprogestin that are low enough not to disturb ovulation. It remains to be established whether these effects are sufficient to prevent implantation.

Does creatinine adjustment of urinary pregnanediol glucuronide reduce or introduce measurement error?

Correlation between urinary pregnanediol and serum progesterone measurements and the influence of age, race, smoking and urinary creatinine adjustment was determined during the luteal phase of the menstrual cycle in 175 volunteers. A decline in serum progesterone was observed with increasing age. Mean baseline urinary creatinine declined with increasing age in non-smokers and was not affected by race or baseline weight. An excellent correlation between urinary pregnanediol glucuronide and serum progesterone levels existed except when urinary pregnanediol concentrations were adjusted using creatinine measurements in older individuals. Adjustment of urinary pregnanediol glucuronide concentration using creatinine measurement is therefore discouraged.

Effect of Low Weekly Doses of Mifepristone on Ovarian Function and Endometrial Development

Gemzell-Danielsson, K.; Westlund, P.; Johannisson, E.; Swahn, M.-L.; Bygdeman, M.; Seppala, M. Author Information

The effects of infant births on the sociosexual behavior and hormonal patterns of a cooperatively breeding primate (Cebuella pygmaea).

This study examined changes in the behavioral and hormonal patterns of cooperatively breeding pairs in a primate species with the passing of time and with specific reproductive events. We (1) compared patterns of sexual, agonistic, and affiliative behavior of newly paired pygmy marmosets with the same behavioral patterns immediately after the birth of their first set of infants; (2) determined if postpartum behavioral differences existed between pairs whose infants lived and those whose infants died; and (3) examined whether behavioral patterns changed over the course of ovarian cycles in parous pygmy marmosets as had been documented in nulliparous pairs. The behavior of pairs was recorded during daily half-hour focal samples for 60 days after pairing, and 30 or 60 days after the birth of infants for pairs whose litters died or lived, respectively. Daily urine samples from females during the study were analyzed for luteinizing hormone and pregnanediol glucuronide concentrations to determine dates of ovulation. The results indicated that males consistently altered their sexual behavior and olfactory monitoring of mates during periovulatory periods in the females' cycles both postpairing and postpartum, while similar rates of social and sexual behavior were maintained between the conditions. Sexual behavior occurred throughout the females' ovarian cycles. Peaks in sexual behavior during the periovulatory period in nulliparous pairs disappeared after the birth of infants. Pairs whose infants died showed higher rates of sexual behavior than pairs with surviving infants. Social and sexual behavior may function to maintain the relationship both during and outside of ovulation, especially with the loss of infants. © 1996 Wiley-Liss, Inc.

Assessment of female reproductive status in captive-housed Hanuman langurs (Presbytis entellus) by measurement of urinary and fecal steroid excretion patterns.

The study reports on the use of urinary and fecal hormone measurements for monitoring female reproductive status in captive-housed Hanuman langurs (Presbytis entellus). Matched urine and fecal samples collected throughout 7 complete menstrual cycles of two females, and during part of one pregnancy in a third female were analyzed. Estrone conjugates (E1C) and immunoreactive pregnanediol glucuronide (PdG) in urine and immunoreactive estradiol (E2), progesterone (P4), pregnanediol (Pd) and 20α-hydroxyprogesterone (20αOHP) in feces were measured by enzymeimmunoassay. E1C and PdG in urine were excreted in a cyclic pattern with E1C levels increasing 3- to 4-fold during the follicular phase to reach preovulatory peak values 2 days before a defined rise in PdG concentrations. Cycle lengths ranged between 20 and 34 days comprising a variable follicular phase of 7-21 days and a more consistent luteal phase of 12-14 days. High pressure liquid chromatography (HPLC) analysis of fecal extracts confirmed the presence of all fecal hormones measured, but indicated large amounts of additional immunoreactivity in the three progestin assays. The patterns of excretion of fecal E2 and all three fecal progestins corresponded well with those of steroid metabolites in urine in showing a clear and well defined follicular phase E2 rise followed by a luteal phase progestin increase. Measurement of 20αOHP immunoreactivity revealed the most stable baseline and the highest follicular/luteal phase differential. Levels of all hormones were clearly elevated during pregnancy although urinary E1C and PdG showed a more pronounced increase compared to fecal metabolites. The results indicate that urinary and fecal hormone analysis can be applied to noninvasive monitoring of reproductive status in the Hanuman langur. © 1995 Wiley-Liss, Inc.

Endocrine monitoring of the ovarian cycle and pregnancy in the saddle-back tamarin (Saguinus fuscicollis) by measurement of steroid conjugates in urine.

Direct measurements of urinary immunoreactive estrone conjugates (E1C) and pregnanediol glucuronide (PdG), were applied to monitoring the ovarian cycle (n = 9) and pregnancy (3 full term pregnancies, 2 mid-term abortions) in Saguinus fuscicollis. During the ovarian cycle, urinary E1C concentrations revealed a high degree of day-to-day variability and appeared to be uninformative in reflecting cyclic ovarian function. In contrast, PdG was a reliable indicator of ovarian cyclicity with excretion patterns corresponding well with plasma progesterone profiles. Luteal phase PdG concentrations were on average 4-7-fold higher than corresponding follicular phase values. On the basis of changes in circulating progesterone, a mean cycle length of 25.7 ±1.0 days with an average follicular phase of 7.1 ± 0.6 days and a mean luteal phase of 18.6 ± 0.7 days, was found (n = 14 cycles). Following conception, both urinary steroid conjugate concentrations increased and elevated levels were maintained beyond the normal luteal phase length, allowing pregnancy to be determined at around day 25-30. During mid- to late pregnancy, PdG levels declined while E1C concentrations continued to be elevated until approximately 6 weeks before parturition when a decrease occurred. Both hormones showed a clear and rapid fall to follicular phase values following termination of pregnancy at either parturition or mid-term abortion. Post partum ovulations (n = 5) occurred on average 17-18 days following birth with four ovulations leading to conceptions. The results demonstrate the potential of urinary steroid conjugate analysis as a practical and reliable method for non-invasive monitoring of reproductive status in the female saddle-back tamarin. © 1995 Wiley-Liss, Inc.

The postpartum llama: fertility after parturition.

Fertility was evaluated at various times during the postpartum period in the llama. Fifty-six parous female llamas chosen at random were bred at 10, 20, and 30 days postpartum with six intact males. Half of the females copulated only once and the other half twice within an interval of 24 h. Ovarian activity was monitored by ultrasonography and analysis of urinary estrone sulfate and pregnanediol glucuronide (PdG). At the time of copulation, all females had developed ovulatory-size follicles. Ovulation was confirmed by the presence of a CL at 8 days after breeding and PdG concentrations > 1 ng/mg creatinine (Cr). Conception was defined as PdG concentrations > 1 ng/mg Cr at 15 days after breeding and the presence of a CL. Pregnancy was defined as the presence of a CL, PdG concentrations > 1 ng/mg Cr and an embryonic vesicle 20 days postbreeding. There were no significant differences in the proportion of females ovulating after breeding at different times postpartum; however, conception and pregnancy were significantly greater in females bred at Day 20 or 30. Ovarian follicle size was significantly larger at 30 days (9.1 mm) than at 10 and 20 days (7.9 and 8.8 mm, respectively) of breeding, with no difference in concentrations of estrone sulfate. The proportion of females conceiving as a result of breeding at 10 days postpartum (6 out of 10) was significantly less than for females bred at 20 (13 out of 15) or 30 days (16 out of 18).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum and urinary levels of reproductive hormones associated with the estrous cycle in white‐tailed deer (Odocoileus virginianus)

AbstractConcentrations of estradiol‐17β (E2), progesterone (Po), and luteinizing hormone (LH) in serum and estrone glucuronide (E1G) and pregnanediol glucuronide (PdG) in urine were determined by direct radioimmunoassay in five yearling and three adult female white‐tailed deer (Odocoileus virginianus) from 14 October to 20 December 1985. Elevated levels of LH were recorded before the first estrus of the breeding season and immediately preceding or during behavioral estrus. Urinary E1G and PdG concentrations were poorly correlated with serum levels of E2 and Po, respectively. Serum Po levels prior to the first estrus of the breeding season indicate that pubertal yearlings experience silent ovulations and suggest that silent ovulations may be important in the transition from adolescence to cycling adult in white‐tailed deer. © 1992 Wiley‐Liss, Inc.

The Effect of Ovarian Follicle Size on Pituitary and Ovarian Responses to Copulation in Domesticated South American Camelids1

The relation of ovarian follicle size to pituitary and ovarian responses to copulation was studied in domesticated South American camelids (llamas and alpacas). Females from each species were divided into four groups according to follicle size: small (4-5 mm), growing (6-7 mm), mature (8-12 mm), and regressing (10-7 mm). The pituitary response to copulation was determined by analysis of LH and FSH concentrations in plasma. The ovarian response to copulation was determined by ultrasonography and by analysis of estrone sulfate (follicular status) and pregnanediol glucuronide (luteal status) concentrations in urine. Females with small follicles (4-5 mm) released less LH after copulation than did those with larger follicles, and ovulation was not induced. Females with growing and mature follicles (7-12 mm) released LH in response to copulation that was adequate to induce ovulation and to initiate normal luteal activity. While copulation-induced LH release in females with regressing follicles was similar to that released in animals with growing and mature follicles, regressing follicles were luteinized instead of being ovulated. The luteal structure formed as a result of luteinization of follicles had a short life span, i.e., 5.1 days. Copulation-induced LH release was significantly higher in llamas vs. alpacas in animals with mature or regressing follicles, but not in those with small or growing follicles. Urinary estrone sulfate and pregnanediol glucuronide concentrations correlated positively with the presence of follicles and corpora lutea, respectively.

Urinary steroids in the periparturient and postpartum periods through early pregnancy in llamas

Urinary steroids were determined daily in the periparturient and postpartum periods, including early pregnancy, in the female llama. Estrone sulfate (E 1S) and pregnanediol glucuronide (PdG) concentrations were determined by enzyme immunoassay with values corrected for variations in urine concentration by creatinine. Estrone sulfate concentrations, elevated during the last 20 days of gestation through 12 hours before parturition, were declining at the time of delivery. Pregnanediol glucuronide concentrations followed a pattern similar to that of estrone sulfate except that values began to decrease 5 days before parturition. Values for both E 1S and PdG were basal by 24 hours after delivery. The first significant elevation of estrone sulfate, indicative of initial follicle development, was observed 5 days after parturition. Pregnanediol glucuronide concentrations were low during the postpartum period until 4 to 5 days after breeding. The PdG values rose steadily following copulatory-induced ovulation, which was initiated at about 2 weeks postpartum; values continued to increase through the first 15 days of pregnancy.