Ovarian aging: mechanisms and clinical consequences.

Menopause is the final step in the process referred to as ovarian ageing. The age related decrease in follicle numbers dictates the onset of cycle irregularity and the final cessation of menses. The parallel decay in oocyte quality contributes to the gradual decline in fertility and the final occurrence of natural sterility. Endocrine changes mainly relate to the decline in the negative feedback from ovarian factors at the hypothalamo-pituitary unit. The declining cohort of antral follicles with age first results in gradually elevated FSH levels, followed by subsequent stages of overt cycle irregularity. The gradual decline in the size of the antral follicle cohort is best represented by decreasing levels of anti-Mullerian hormone. The variability of ovarian ageing among women is evident from the large variation in age at menopause. The identification of women who have severely decreased ovarian reserve for their age is clinically relevant. Ovarian reserve tests have appeared to be fairly accurate in predicting response to ovarian stimulation in the assisted reproductive technology (ART) setting. The capacity to predict the chances for spontaneous pregnancy or pregnancy after ART appears very limited. As menopause and the preceding decline in oocyte quality seem to have a fixed time interval, tests that predict the age at menopause may be useful to assess individual reproductive lifespan. Especially genetic studies, both addressing candidate gene and genome wide association, have identified several interesting loci of small genetic variation that may determine fetal follicle pool development and subsequent wastage of his pool over time. Improved knowledge of the ovarian ageing mechanisms may ultimately provide tools for prediction of menopause and manipulation of the early steps of folliculogenesis for the purpose of contraception and fertility lifespan extension.

Ovulation detection methods for urinary hormones: precision, daily and intermittent sampling and a combined hierarchical method.

BACKGROUND: We evaluate the performance of ovulation detection methods and present new approaches, including evaluation of methods for precision, combining multiple markers into a hierarchical system and using ovulation markers in intermittent sampling designs. METHODS: With serum LH peak day as the 'gold standard' of ovulation, we estimated accuracy and precision of ovulation day algorithms using 30 ovulatory menstrual cycles with daily urinary and serum hormones and transvaginal ultrasound. Sensitivity and specificity for estimating the presence of ovulation were tested using visually assessed ovulatory (30) and anovulatory (22) cycles. RESULTS: Sensitivity and specificity ranged from 70 to 100% for estimating presence of ovulation with twice-per-cycle, weekly, twice weekly, every-other-day and daily specimens. A combined hierarchical method estimated ovulation day using daily specimens within +/-2 days of the gold standard in 93% of cases. Accuracy of estimating ovulation day within +/-2 days using intermittent sampling ranged from 40% (weekly sampling) to 97% (every-other-day). CONCLUSIONS: A combined hierarchical algorithm using precise and accurate markers allows maximal use of available data for efficient and objective identification of ovulation using daily specimens. In intermittent sampling designs, the presence and the timing of ovulation can be estimated with good sensitivity, specificity and accuracy.

Short-term calcium supplementation has no effect on biochemical markers of bone remodeling in early postmenopausal women.

INTRODUCTION: This study was designed to assess changes in biochemical markers of bone remodeling in early postmenopausal women receiving calcium supplementation. MATERIALS AND METHODS: In a randomized cross-over study of eighteen weeks duration, the effect of a 6-week calcium supplementation (1000 mg calcium carbonate) on biochemical markers of bone resorption (collagen type I cross-linked C- and N-telopeptides) and bone formation (osteocalcin, total and bone-specific alkaline phosphatase), and total serum calcium was assessed in 27 early postmenopausal women. RESULTS: While total serum calcium levels increased significantly due to calcium supplementation (p<0.05), biochemical markers of both bone resorption and formation remained virtually unchanged. CONCLUSION: In contrast to other investigations, there was no significant short-term effect of calcium supplementation on biochemical markers of either bone resorption or formation.

Bone remodeling and bone mineral density during pregnancy.

INTRODUCTION: The effect of pregnancy upon the maternal skeleton is not fully understood. The information that has been gathered by recent studies is conflicting with regard to overall loss or gain of bone during pregnancy. The aim of the present longitudinal, controlled study, therefore, was to investigate the effect of pregnancy on lumbar spine, wrist, and hip bone mineral density, and to describe bone remodeling during pregnancy as indicated by biochemical markers of both bone resorption and formation. MATERIALS AND METHODS: Thirty healthy women (15 subjects seeking pregnancy and 15 non-pregnant controls) were studied. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry before conception and within 2 weeks after parturition. Markers of bone resorption (urinary cross-linked type I collagen N-telopeptides, serum type I collagen C-telopeptides) and bone formation (total and bone specific alkaline phosphatase, osteocalcin), and total serum calcium were analyzed before, during (once in each trimester), and after pregnancy. RESULTS: During pregnancy, BMD decreased significantly by 3.4+/-4.1% at the lumbar spine and 4.3+/-3.9% at the trochanter, while there was a slight but significant increase in BMD at the proximal 1/3 of the forearm (1.3+/-1.9%). Total hip and femoral neck BMD did not change significantly, nor did total and ultradistal forearm BMD. Bone resorption increased during pregnancy with peak levels in the third trimester (N-telopeptides) or post partum (C-telopeptides), respectively. The increase in bone resorption was accompanied by a significant decrease in serum calcium in the third trimester. Markers of bone formation showed a biphasic pattern with decreases from baseline to the first (total and bone specific alkaline phosphatase) or second trimester (osteocalcin), respectively, followed by a significant increase in the third trimester and post partum. There was no change in any parameter in the control group throughout the study. CONCLUSION: In conclusion, pregnancy is characterized by high bone turnover with resorption preceding formation. During the first and second trimester bone remodeling is uncoupled. Serum calcium decreases as bone resorption peaks in late pregnancy. There are significant decreases in bone mineral density at sites rich in trabecular bone, such as the lumbar spine and the trochanter.

Stages of Reproductive Aging Workshop (STRAW).

A select group of clinicians and investigators met recently for the express purpose of developing a staging system for female reproductive aging. The group also addressed the confusing and redundant nomenclature that is commonly used to describe the late reproductive years. A summary and recommendations are presented.

The future of human ovarian cryopreservation and transplantation: fertility and beyond.

OBJECTIVE: To review the current progress in ovarian cryopreservation and transplantation and to discuss the obstacles with the clinical application of this technique. DESIGN: The literature on ovarian cryopreservation and transplantation was reviewed to facilitate understanding and predict future directions. The studies related to this topic were identified through MEDLINE and other bibliographic databases, focusing on the most recent developments. CONCLUSION(S): The experimental evidence for low-temperature storage of ovarian tissue is encouraging. Although restoration of fertility with cryopreserved ovarian grafts has been successful in various animals, there are uncertainties about the optimum use of stored ovarian tissue in humans. Autotransplantation appears to be promising, but the potential risk of transmitting malignant cells in women with cancer is of great concern. The maturation of primordial follicles with xenotransplantation is encouraging, but the efficacy and the safety of this method need further investigation. Furthermore, the quality of oocytes that have been matured in a host animal is unknown. The development of in vitro culture systems for oocyte maturation is still in its infancy. There are many issues to be resolved in ovarian transplantation before the full clinical use of this emerging technique. Most of all, there is an urgent need to optimize the freeze/thaw procedure and to find the means to protect grafts from ischemia-reperfusion injury. Nevertheless, ovarian transplantation should prove to be clinically useful for women at risk for premature ovarian failure.

Executive summary: Stages of Reproductive Aging Workshop (STRAW).

A select group of investigators attended a structured workshop, the Stages of Reproductive Aging Workshop (STRAW), at Park City, Utah, USA, in July 2001, which addressed the need in women for a staging system as well as the confusing nomenclature for the reproductive years.

Bacteria in the transfer catheter tip influence the live-birth rate after in vitro fertilization.

OBJECTIVE: To assess the impact of individual bacteria isolated from the vagina and tip of the embryo transfer catheter on live-birth rates. DESIGN: Prospective clinical study. SETTING: Infertility outpatient clinic of a university hospital. PATIENT(S): Ninety-one women undergoing IVF-ET. INTERVENTION(S): Cultures were obtained from the vagina for aerobic and anaerobic bacteria at the time of both sonographic egg retrieval and embryo transfer and from the tip of the embryo transfer catheter. Doxycycline treatment was started after egg retrieval. MAIN OUTCOME MEASURE(S): The live birth of one or more neonates. RESULT(S): Doxycycline had no substantial impact on the recovery of individual vaginal bacteria or on bacterial vaginosis. An increase in live-birth rate was associated with the recovery of hydrogen peroxide-producing Lactobacillus from the vagina (P=0.01) and from the embryo transfer catheter (P=0.01). In contrast, a reduction in live-birth rate was associated with recovery of Streptococcus viridans (S. viridans) from the embryo transfer catheter tip (P=0.04). CONCLUSION(S): In the setting of IVF-ET, prophylactic doxycycline had little effect on vaginal bacteria. Specific bacteria recovered from the embryo transfer catheter appear associated with a detrimental or beneficial effect or with no effect on live-birth rates.

Ovarian follicular concentrations of activin, follistatin, inhibin, insulin-like growth factor I (IGF-I), IGF-II, IGF-binding protein-2 (IGFBP-2), IGFBP-3, and vascular endothelial growth factor in spontaneous menstrual cycles of normal women of advanced reproductive age.

Previous studies indicate that the menstrual cycles of older reproductive age women are characterized by a selective elevation of FSH associated with early development and ovulation of a dominant follicle. Several intraovarian hormones and growth factors have been identified that appear to serve important paracrine roles. The purpose of this study was to examine follicular fluid (FF) hormones and growth factors in the dominant follicle of unstimulated cycles of older, ovulatory women. We aspirated FF from the preovulatory dominant follicle in natural menstrual cycles of older subjects (age, 40-45 yr; n = 20) and younger controls (age, 20-25 yr; n = 19). FF was analyzed for estradiol, progesterone, testosterone, androstenedione, inhibin A and B, total activin A, total follistatin, insulin-like growth factor I (IGF-I), IGF-II, IGF-binding protein-2 (IGFBP-2), IGFBP-3, and vascular endothelial growth factor (VEGF) concentrations. We found that the dominant follicles from older women contain normal concentrations of steroids, inhibin A and B, IGF-II, IGFBP-2, and IGFBP-3; increased concentrations of follistatin, activin A, and VEGF; and decreased concentrations of IGF-I. Therefore, under the influence of elevated FSH, the dominant follicle in older women is highly competent in terms of hormone and growth factor secretion. We postulate that elevated FF activin may be related to the early ovulation observed in older women, whereas elevated VEGF may be related to the meiotic spindle abnormalities observed in the oocytes of older reproductive age women.

Inhibin-B as a test of ovarian reserve for infertile women.

The objective of the study was to compare a standard clomiphene citrate challenge test with inhibin-B serum concentrations also obtained on cycle days 3 and 10 as a negative predictor of pregnancy in a group of 106 women at risk for compromised ovarian function. Mean duration of follow-up was 8.25 months in 95 patients with 30 pregnancies recorded (plus one biochemical). Inhibin-B concentrations on cycle days 3 and 10 were correlated only with each other and not with serum oestradiol, follicle stimulating hormone (FSH) and/or pregnancy rates. Pregnancy occurred in 34.5% (10/29) of all patients with inhibin-B values >/=45 pg/ml on cycle day 3 and in 31.8% (21/66) of those with values <45 pg/ml. For FSH >11 mIU/ml on either day, pregnancy rate was 13.6% versus 38.4% for FSH of

The pattern of infertility diagnoses in women of advanced reproductive age.

OBJECTIVE: Our intention was to determine whether there is a unique pattern of infertility diagnoses in older infertile couples. STUDY DESIGN: The design of this study was a retrospective chart review study. It was performed in a tertiary referral reproductive medicine unit. There were 2 groups of patients-couples: group 1, female partner aged 20-29 (n = 105) at presentation; group 2, female partner aged 40-45 (n = 112) at presentation. All women underwent infertility evaluations between 1989 and 1994. There were no interventions. The prevalence of standard infertility diagnoses was the main outcome measure. RESULTS: The prevalence of 8 major infertility diagnoses in the younger and older groups (each couple could have >/=1 diagnosis) was as follows: (1) ovulatory factor-younger group, 56%; older group, 30%; (2) tubal factor-younger group, 34%; older group, 29%; (3) endometriosis-younger group, 13%; older group, 17%; (4) uterine factor-younger group, 1%; older group, 5%; (5) cervical factor-younger group, 4%; older group, 1%; (6) luteal deficiency-younger group, 4%; older group, 10%; (7) male factor-younger group, 32%; older group, 45%; (8) unexplained-younger group, 5%; older group, 10%. The only significant difference was an increase in ovulatory factor in the younger group. CONCLUSIONS: There is no unique pattern of infertility diagnoses in women of advanced reproductive age as seen at a tertiary referral center. We speculate that a high false-positive rate associated with standard infertility tests and a different referral pattern for older couples obscures any real differences in the etiology of infertility in older couples.

Morphometric analysis of primordial follicle number in pigtailed monkey ovaries: symmetry and relationship with age.

We previously described a modern, three-dimensional counting method for determining primordial follicle (PF) numbers in primate ovaries using a combination of fractionator and physical dissector techniques. The purposes of our current study were 1) to apply our method to describe intraindividual differences in PF numbers between ovaries and 2) perform a linear regression analysis of age versus mean PF number per ovary. Ovaries from 16 pigtailed monkeys (Macaca nemestrina) age 0.85-12.5 yr were examined. Both ovaries were available from 11 subjects. The difference between ovaries ranged from 2% to 22% (mean +/- SD, 10 +/- 7%) and was not statistically significant. Regression analysis of data from all 16 subjects displayed a log-linear relationship according to the equation log N(a) = 4.8542 - 0.0714(age) where N(a) is the number of PF at a given chronological age. The fit for this model was highly significant (r(2) = 0.73, p

Commentary: posthumous harvesting of gametes--a physician's perspective.

Author offers a clinical perspective on problems arising from requests for postmortem sperm and oocyte retrieval.

Endocrine changes of the perimenopause.

Reproductive aging in women is closely tied to the loss of ovarian follicles through atresia. The sentinel endocrinologic finding is the monotropic FSH rise, associated with a decline in ovarian inhibin B secretion. Fertility becomes significantly compromised long before overt clinical signs occur, such as cycle irregularity. Compromised fertility is primarily related to oocyte dysfunction. As women with regular cycles near the end of the reproductive years, the following changes are usually manifested: 1) the selection and development of a dominant follicle occurs earlier; 2) there is earlier ovulation; 3) there is a short follicular phase and total cycle length; and 4) ovarian steroid secretion is normal. The relationships, if any, between the monotropic FSH rise, accelerated follicular atresia, shortened follicular phase, and oocyte quality remain to be determined. The next phase of reproductive aging is the perimenopause. Lack of predictability is the rule with regard to the nature and duration of the perimenopause. Long cycles are interspersed with short ones, and intermittent ovulatory cycles are intermingled with periods that are hormonally indistinct from the postmenopausal state. Even after the last menstrual period, evidence of intermittent ovarian estradiol production may still be detected. Although fertility is severely compromised during the perimenopause, ovulation may occur without warning and contraception must be practiced if pregnancy is not desired. Further studies are needed to elucidate the factors contributing to oocyte abnormalities in women of advanced reproductive age, as well as the factors that determine the rate of follicle atresia and the length of the reproductive life span.