Ovulation induction disrupts luteal phase function

Luteal phase support in assisted reproductive technology centers: Italian survey

BACKGROUND

In assisted reproductive cycles (ART), the fine balance of controlling corpus luteum function is severely disrupted. To challenge this iatrogenic deficiency, clinicians aim to provide exogenous support. Several reviews have investigated progesterone route of administration, dosage and timing.

METHODS

A survey about luteal phase support (LPS) after ovarian stimulation was conducted among doctors in charge in Italian II-III level ART centers.

RESULTS

With regards to the general approach to LPS, 87.9% doctors declare to diversify the approach; the reasons for diversifying (69.7%) were based on the type of cycle. For all the most important administration routes (vaginal, intramuscular, subcutaneous) it appears that in frozen cycles there is a shift towards higher dosages. The 90.9% of the centers use vaginal progesterone, and when a combined approach is required, in 72.7% of cases vaginal administration is combined with injective route of administration. When Italian doctors were asked about the beginning and duration of LPS, 96% of the centers start the day of the pickup or the day after, while 80% of the centers continue LPS until week 8-12. The rate of participation of the centers confirms the low perceived importance of LPS among Italian ART centers, while may be considered quite surprising the relatively higher percentage of centers that measures P level. Tailorization to women's needs is the new objective of LPS: self-administration, good tolerability are the main aspects for Italian centers.

CONCLUSIONS

In conclusion, results of Italian survey are consistent to results of main international surveys about LPS.

Effect of acupuncture on the opening time of implantation window and endometrial receptivity in controlled ovarian hyperstimulation rats during peri-implantation period

PURPOSE

To investigate the effect of acupuncture for improving the pregnancy rate of COH rats from the viewpoint of regulating the opening time of the implantation window and endometrial receptivity.

METHODS

Experimental rats were randomly divided into normal group (N), model group (M) and acupuncture group(A), and samples were collected on Day 4, 5 and 6 after mating. COH rats were treated with acupuncture at SP6, LR3, and ST36 once a day for 7 times. The pinopodes were observed under a scanning electron microscope. Serum estrogen and progesterone levels were measured via ELISA. The protein and mRNA levels of estrogen receptor (ER), progesterone receptor (PR), leukemia inhibitory factor (LIF), integrin β3, vascular endothelial growth factor (VEGF), and fibroblast growth factor 2 (FGF-2) in the endometrium were evaluated via West-blot, immunohistochemistry, and PCR.

RESULTS

Compared with group N, the pregnancy rate of group M was significantly decreased (P<0.05), and the abnormal serum hormone levels and implantation window advancement were observed. Compared with group M, the pregnancy rate of group A was significantly increased (P<0.05), the supraphysiological serum progesterone levels were restored to normalcy (P<0.05), and the advanced implantation window was restored to a certain extent. Further, the abnormal ER, PR, LIF, integrin β3, VEGF, and FGF-2 expression levels of the endometrium got recovered to varying degrees.

CONCLUSION

Acupuncture may restore the estrogen and progesterone balance in COH rats and the forward shift of the implantation window to a certain extent, improving the endometrial receptivity and finally improving the pregnancy rate of COH rats.

Luteal phase deficiency during the early trimester in a case with secondary hypopituitarism following craniopharyngioma resection

A 31‐year‐old woman, who had been diagnosed with craniopharyngioma (CP) at the age of 13, suffered secondary hypopituitarism after two surgical resections of CP, receiving supplement of levothyroxine, cortisone, and sequential estrogen and progesterone because of primary amenorrhea. She managed to conceive after ovulation induction with human menopausal gonadotropin. Luteal phase deficiency (LPD) was found during the first trimester, as the progesterone stayed at a low level between 0.07 and 1.63 ng/ml within seven gestational weeks, followed by a gradual rise from 4.01 up to 34.70 ng/ml in the 11th week, which was mainly secreted by the placenta. Estrogen and progesterone were administered to the patient as luteal support until the 12th week, who succeeded in delivering a healthy baby at term. In conclusion, the patient with hypopituitarism who develops severe LPD during the early pregnancy may need luteal support until 12th week.

Progesterone use in assisted reproductive technology

Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred. In assisted reproduction treatments, there is usually a luteal phase deficiency, so it is necessary to supplement this critical phase to obtain the best results, not only of implantation but also of ongoing pregnancy. Among all the available options, exogenously administered progestogens are the most used, as they have proven their efficacy and safety. This review will address the most relevant aspects of luteal phase support with progesterone in the different scenarios an embryo transfer can be performed, such as the stimulated cycle, the artificial cycle, or the natural cycle. Although there is no evidence of the perfect protocol for all patients, recent studies point to the need of individualizing luteal phase support according to the needs of each patient.

Factors predicting clinical pregnancy rate of in vitro fertilization-embryo transfer (a STROBE-compliant article)

The aim of this study was to investigate the factors predicting clinical pregnancy rate of in vitro fertilization-embryo transfer (IVF-ET).The data of 9960 patients receiving IVF-ET fresh cycle at our Reproductive Center from January 2009 to December 2017 were first divided into pregnant group and non-pregnant group to find the clinical pregnancy rate-related factors. According to the serum HCG levels at 36 hours and 12 hours after HCG trigger, all patients were divided into 4 groups including <50 mIU/ml, ≥50 and <100 mIU/ml, ≥100 and <200 mIU/ml, and ≥200 mIU/ml groups to know whether the HCG levels at 36 hours and 12 hours affect the pregnancy rate. According to the serum HCG ratio at 36 hours to 12 hours (36 h/12 h) after HCG trigger, all patients were divided into three groups including <0.88, 0.88-1.06 and >1.06 groups to observe whether the serum HCG ratio (36 h/12 h) affects the clinical pregnancy rate. According to different assisted pregnancy modes, all patients were divided into 3 groups including IVF, ICSI, and IVF/ICSI groups to observe whether the assisted pregnancy mode affects the clinical pregnancy rate. The correlation of the clinical pregnancy rate with pregnancy rate-related factors obtained above was analyzed using logistic regression analysis model.The clinical pregnancy rate significantly increased (P < .01) in the HCG ratio (36 h/12 h) >1.06 group as compared with the HCG ratio (36 h/12 h) < 0.88 and 0.88-1.06 groups. The serum estrogen (E2) level at 36 hours was significantly lower and the number of retrieved oocytes was significantly higher in the HCG ratio (36 h/12 h) >1.06 group than in the HCG ratio (36 h/12 h) <0.88 and 0.88-1.06 groups (P = .000).The serum HCG ratio (36 h/12 h) may be used as a predictor of IVF-ET clinical pregnancy rate. High clinical pregnancy rate is probably associated with E2 down-regulation in the HCG ratio (36 h/12 h) >1.06 group.

The endometrium during and after ovarian hyperstimulation and the role of segmentation of infertility treatment

Controlled ovarian hyperstimulation (COH) is a crucial part of assisted reproductive technologies (ART) that resulted in a substantial increase in pregnancy rates from in vitro fertilization (IVF). However, in spite of the apparent benefit of COH on an increase in the number of follicles and the number of oocytes retrieved, allowing for extended embryo culture and enabling the selection of the best quality embryo for transfer, several reports has shown that the supraphysiologic hormonal levels may indeed have a detrimental effect at the endometrial level. The current article revises the pathophysiological mechanisms through which ovarian stimulation may negatively affect endometrial receptivity. Also, the evidence is analyzed explaining how segmentation of IVF treatment may allow us to overcome the deleterious effects of hyperstimulation on endometrial receptivity. Deferred embryo transfer may be performed in a more physiologic uterine environment in a subsequent cycle, improve endometrial receptivity, decrease uterine contractility, diminishes the impact of premature luteinization and allow individualized stimulation according to the level of response.

Early stop of progesterone supplementation after confirmation of pregnancy in IVF/ICSI fresh embryo transfer cycles of poor responders does not affect pregnancy outcome

Previous studies indicated that progesterone can be withdrawn at the time of the first positive β-hCG test without compromising the clinical pregnancy outcome in normal ovarian responder. However, the effect of early stop of progesterone supplementation for patients with poor ovarian response (POR) has not been investigated. This study retrospectively collected data from patients with POR in 156 IVF/ICSI fresh embryo transfer (ET) cycles in single tertiary center from January 2010 to June 2016. All the patients met ESHRE consensus, the Bologna criteria, of POR and had hCG injection for luteal phase support (LPS) on day 2, 5 and 8 after ovum pick-up. The pregnant patients were divided into two groups: early stop group represented those who stopped LPS from day of positive pregnancy test; control group represented those who kept progesterone supplementation till gestational age of 9 weeks. There were no significant differences in age, BMI, parity, hormone data, number of follicles>10(mm), endometrial thickness and number of embryos transferred between the two groups. After adjustment for possible confounders with multivariate logistic regression analysis, the clinical pregnancy rates (55.0% vs. 57.1%, P = 0.35), ongoing pregnancy rates (47.0% vs. 46.4%, P = 0.66), miscarriage rates (34.0% vs. 26.7%, P = 0.66) and live-birth rates (44.0% vs. 46.4%, P = 0.41) were not statistically different between early stop group and the control group. Our study indicates that early stop of progesterone supplementation on the day of positive pregnancy test for patients of POR using hCG as LPS in fresh ET cycles does not affect pregnancy outcome.

Can we alter pregnancy outcome by adjusting progesterone treatment at mid-luteal phase: a randomized controlled trial

Our study aimed to determine whether mid-luteal serum P concentrations can serve as a predictive factor for in vitro fertilization (IVF) outcomes and whether increasing P dosage for patients with low levels at mid-luteal phase may improve pregnancy rates. It was a prospective, randomized controlled study. A total of 146 patients undergoing IVF treatment were prospectively enrolled and received routine luteal phase support (LPS) regimen of Endometrin® (progesterone) 200 mg/day. Serum P levels were measured 7 days after embryo transfer (ET). Considering a cutoff level of 15 ng/ml on this day, patients with higher levels continued the same dosage until pregnancy test (control group). Patients with lower levels were randomly allocated to continue Endometrin® 200 mg/day (Group A) or to increase Endometrin® dosage to 300 mg/day (Group B). The Main Outcome Measures were pregnancy rates. Both biochemical and clinical pregnancy and live birth rates were comparable between all groups regardless of P level on day 7 of luteal phase and regardless of dose adjustment. ROC analysis determined that mid-luteal P levels of 17 ng/ml can be a better predictor of cycle outcome. In conclusion raising the P dose at mid-luteal phase to 300 mg daily did not improve cycle outcomes.

Effect of Acupuncture on Endometrial Angiogenesis and Uterus Dendritic Cells in COH Rats during Peri-Implantation Period

This study was to explore the mechanism of acupuncture on regulating the endometrial angiogenesis and uterus dendritic cells (uDCs) during the peri-implantation period. Rats, in early pregnancy, were randomized into five groups: normal (N), model (M), acupuncture (A), progesterone (P), and A + P groups. The COH model was established using pregnant mare serum, combined with human chorionic gonadotrophin. Endometrium was collected on days 4, 6, and 8 (D4, D6, and D8) of gestation. Compared with group M, both VEGF and FGF-2 protein and mRNA levels were significantly lower on D4 and higher on D6 and D8 (P < 0.05), except for VEGF of group P on D8; the proportion of uterus dendritic cells (uDCs) in the endometrium was significantly lower on D4 and D6 and higher on D8 (P < 0.05). In vitro, except for the proliferation of group P on D8, proliferation, tube formation, and migration of uDCs were significantly decreased on D4 and increased on D8 (P < 0.05). In addition, acupuncture or progesterone regulated the secretion levels of VEGF, IL-15, and IL-18 secreted by uDCs instead of soluble sFLT-1. In conclusion, acupuncture may regulate angiogenesis of the endometrium and the number and roles of uDCs after COH, and the specific mechanism may be different with progesterone.

Progesterone luteal support after ovulation induction and intrauterine insemination: an updated systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of progesterone (P) for luteal phase support after ovulation induction (OI) and intrauterine insemination (IUI).

DESIGN

An updated systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Patients undergoing OI-IUI for infertility.

INTERVENTION(S)

Exogenous P luteal support after OI-IUI.

MAIN OUTCOME MEASURE(S)

Live birth.

RESULT(S)

Eleven trials were identified that met inclusion criteria and constituted 2,842 patients undergoing 4,065 cycles, more than doubling the sample size from the previous meta-analysis. In patients receiving gonadotropins for OI, clinical pregnancy (relative risk [RR] 1.56, 95% confidence interval [CI] 1.21-2.02) and live birth (RR 1.77, 95% CI 1.30-2.42) were more likely in P supplemented patients. These findings persisted in analysis of live birth per IUI cycle (RR 1.59, 95% CI 1.24-2.04). There were no data on live birth in clomiphene citrate or clomiphene plus gonadotropin cycles. There was no benefit on clinical pregnancy with P support for patients who underwent OI with clomiphene (RR 0.85, 95% CI 0.52-1.41) or clomiphene plus gonadotropins (RR 1.26, 95% CI 0.90-1.76).

CONCLUSION(S)

Progesterone luteal phase support is beneficial to patients undergoing ovulation induction with gonadotropins in IUI cycles. The number needed to treat is 11 patients to have one additional live birth. Progesterone support did not benefit patients undergoing ovulation induction with clomiphene citrate or clomiphene plus gonadotropins.

Addition of gonadotropin releasing hormone agonist for luteal phase support in in-vitro fertilization: an analysis of 2739 cycles

OBJECTIVE

Luteal phase is defective in in vitro fertilization (IVF) cycles, and many regimens were tried for the very best luteal phase support (LPS). Gonadotropin releasing hormone (GnRH) agonist use, which was administered as an adjunct to the luteal phase support in IVF cycles, was suggested to improve pregnancy outcome measures in certain randomized studies. We analyzed the effects of addition of GnRH agonist to standard progesterone luteal support on pregnancy outcome measures, particularly the live birth rates.

MATERIAL AND METHODS

This is a retrospective cohort study, including 2739 IVF cycles. Long GnRH agonist and antagonist stimulation IVF cycles with cleavage-stage embryo transfer were included. Cycles were divided into two groups: Group A included cycles with single-dose GnRH agonist plus progesterone LPS and Group B included progesterone only LPS. Live birth rates were the primary outcome measures of the analysis. Miscarriage rates and multiple pregnancy rates were the secondary outcome measures.

RESULTS

Live birth rates were not statistically different in GnRH agonist plus progesterone (Group A) and progesterone only (Group B) groups in both the long agonist and antagonist stimulation arms (40.8%/41.2% and 32.8%/34.4%, p<0.05 respectively). Moreover, pregnancy rates, implantation rates, and miscarriage rates were found to be similar between groups. Multiple pregnancy rates in antagonist cycles were significantly higher in Group A than those in Group B (12.0% and 6.9%, respectively).

CONCLUSION

A beneficial effect of a single dose of GnRH agonist administration as a luteal phase supporting agent is yet to be determined because of the wide heterogeneity of data present in literature. Well-designed randomized clinical studies are required to clarify any effect of luteal GnRH agonist addition on pregnancy outcome measures with different doses, timing, and administration routes of GnRH agonists.

The influence of IVF/ICSI treatment on human embryonic growth trajectories

STUDY QUESTION

Is in vitro fertilization treatment with or without intracytoplasmatic sperm injection (IVF/ICSI) associated with changes in first and second trimester embryonic and fetal growth trajectories and birthweight in singleton pregnancies?

SUMMARY ANSWER

Embryonic and fetal growth trajectories and birthweight are not significantly different between pregnancies conceived with IVF/ICSI treatment and spontaneously conceived pregnancies with reliable pregnancy dating.

WHAT IS KNOWN ALREADY

IVF/ICSI treatment has been associated with increased risks of preterm birth, fetal growth restriction and low birthweight. Decreased first-trimester crown-rump length (CRL) in the general population has been inversely associated with the same adverse pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

In a prospective periconception birth cohort study conducted in a tertiary centre, 146 singleton pregnancies with reliable pregnancy dating and nonmalformed live borns were investigated, comprised of 88 spontaneous and 58 IVF/ICSI pregnancies.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serial 3D ultrasound scans were performed from 6 to 12 weeks of gestation. As estimates of embryonic growth, CRL and embryonic volume (EV) were measured using the I-Space virtual reality system. General characteristics were obtained from self-administered questionnaires at enrolment. Fetal growth parameters at 20 weeks and birthweight were obtained from medical records. To assess associations between IVF/ICSI and embryonic growth trajectories, estimated fetal weight and birthweight, stepwise linear mixed model analyses and linear regression analyses were performed using square root transformed CRL and fourth root transformed EV.

MAIN RESULTS AND THE ROLE OF CHANCE

In 146 pregnancies, 934 ultrasound scans were performed of which 849 (90.9%) CRLs and 549 (58.8%) EVs could be measured. Embryonic growth trajectories were comparable between IVF/ICSI pregnancies and spontaneously conceived pregnancies (CRL: βIVF/ICSI = 0.10√mm; P = 0.10; EV: βIVF/ICSI = 0.03(4)√cm³; P = 0.13). Estimated fetal weight and birthweight were also comparable between both groups (βIVF/ICSI = 6 g; P = 0.36 and βIVF/ICSI = 80 g; P = 0.24, respectively).

LIMITATIONS, REASONS FOR CAUTION

Variations in embryonic growth trajectories of spontaneously conceived pregnancies with reliable pregnancy dating may partially be a result of less precise pregnancy dating and differences in endometrium receptivity compared with IVF/ICSI pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

The absence of a significant difference in embryonic and fetal growth trajectories suggests safety of IVF/ICSI treatment with regard to early embryonic growth. However, further research is warranted to ascertain the influence of IVF/ICSI treatments in a larger study population, and to estimate the impact of the underlying causes of the subfertility and other periconceptional exposures on human embryonic and fetal growth trajectories.

FUNDING STATEMENT

This study was supported by the Department of Obstetrics and Gynaecology of the Erasmus MC, University Medical Centre.

CONFLICT OF INTEREST

No competing interests are declared.

Progesterone luteal support after ovulation induction and intrauterine insemination: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of luteal phase P support after ovulation induction IUI.

DESIGN

A systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Undergoing ovulation induction IUI.

INTERVENTION(S)

Any form of exogenous P in ovulation induction IUI cycles.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy and live birth.

RESULT(S)

Five trials were identified that met inclusion criteria and comprised 1,298 patients undergoing 1,938 cycles. Clinical pregnancy (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.15-1.98) and live birth (OR 2.11, 95% CI 1.21-3.67) were more likely in P-supplemented patients. These findings persisted in analyses evaluating per IUI cycle, per patient, and first cycle only data. In subgroup analysis, patients receiving gonadotropins for ovulation induction had the most increase in clinical pregnancy with P support (OR 1.77, 95% CI 1.20-2.6). Conversely, patients receiving clomiphene citrate (CC) for ovulation induction showed no difference in clinical pregnancy with P support (OR 0.89, 95% CI 0.47-1.67).

CONCLUSION(S)

Progesterone luteal phase support may be of benefit to patients undergoing ovulation induction with gonadotropins in IUI cycles. Progesterone support did not benefit patients undergoing ovulation induction with CC, suggesting a potential difference in endogenous luteal phase function depending on the method of ovulation induction.

Ovarian stimulation for IVF and endometrial receptivity--the missing link

The contemporary approach to ovarian stimulation for IVF treatment results in supraphysiological concentrations of steroids during the follicular and luteal phases of the menstrual cycle. These sex steroids act directly and indirectly to mature the endometrium, influencing receptivity for implantation. Corpus luteum function is distinctly abnormal in IVF cycles, and therefore luteal support is widely used. Various reasons may underlie the defective luteal phase, including (i) ovarian hyperstimulation per se, (ii) gonadotrophin-releasing hormone (GnRH) analogue co-treatment and (iii) the use of human chorionic gonadotrophin (HCG) to induce final oocyte maturation. The recent introduction of GnRH antagonist co-treatment for the prevention of a premature LH rise during the late follicular phase allows for different approaches to ovarian stimulation for IVF. However, a recent meta-analysis showed that implantation rates may be compromised by using GnRH antagonists in currently employed regimens. The development of endometrium receptive to embryo implantation is a complex process and may be altered by inappropriate exposure to sex steroids in terms of timing, duration and magnitude. New approaches to the assessment of endometrial receptivity are now required. Novel approaches to ovarian stimulation aimed at adjusted GnRH antagonist regimens and achieving a more physiological luteal phase endocrinology are now appearing in the literature and may represent an important step in the improvement of the overall health economics of IVF.

Unpredicted ovulations and conceptions during early pregnancy: an explanatory mechanism of human superfetation

In this bioessay, a literature review on human superfetation was performed in order to find epidemiological variables associated with this phenomenon. Thereafter, an explanatory mechanism of superfetation compatible with the endocrinological, histological and physiological changes undergone by women during early pregnancy is proposed. Superfetation can be defined as the ovulation, fertilisation and implantation of a second or additional embryo(s) during pregnancy. The literature review evidences a small discordance in gestational age between dizygotic twins in humans (range: 2–4 weeks; mean ± s.e.m.: 3.3 ± 0.3 weeks). This difference is compatible with a luteal out-of-phase (LOOP; i.e. atypical increase in E2 levels in the mid-luteal phase)-like event occurring between 1 and 3 weeks after the ovulation that allowed the first pregnancy to take place. The LOOP-like event may allow passive sperm transport from the vaginal fornix to the Fallopian tube ipsilateral to the ovulatory ovary and trigger a LH peak and ovulation. Furthermore, during very early pregnancy, the decidual reaction is not yet completed and at least one proximal Fallopian ostium may be opened, allowing the passage of the spermatozoa ascending to the fertilisation site and the extra embryo(s) descending to the implantation site(s).

Defective soil for a fertile seed? Altered endometrial development is detrimental to pregnancy success

Background

Synchronous development of the endometrium (to achieve a receptive state) and of the embryo is essential for successful implantation and ongoing pregnancy. Endometrial receptivity exists only for a finite time in a menstrual cycle and the endometrium is refractory to embryo implantation outside of this window. Administration of hormones to stimulate multifollicular development within the ovary, integral to the majority of assisted reproduction (ART) protocols, dramatically alters the hormonal milieu to which the endometrium is exposed versus normal menstrual cycles. Endometrial maturation may be profoundly affected by this altered endocrine environment.

Aim

Compare endometrial histology in fertile women, fertile women undergoing hormonal stimulation for oocyte donation and infertile women undergoing fresh embryo transfers in an ART cycle with further comparisons between women who did or did not become pregnant. Examine the presence of leukocytes and markers of endometrial maturation.

Methods

Endometrial histology was examined by hematoxylin and eosin staining with a semi quantitative scoring method developed to compare histological appearance of tissues. The presence of leukocytes and developmental markers was examined by immunohistochemistry and scored.

Results

Endometrial histology was dramatically altered upon stimulation for ART. However, those women who became pregnant presented with significantly less alterations in histological endometrial maturation. Numbers and activation status of leukocyte populations were also altered within the endometria stimulated for ART, with neutrophils undergoing degranulation, usually observed only pre-menstrually.

Conclusion

We propose that such developmental changes render the endometrium hostile to the embryo and that modifications to ART protocols should be considered to take account of the requirement for endometrial receptivity and hence increase pregnancy rates.

[Ovarian hyperstimulation syndrome: pathophysiology, risk factors, prevention, diagnosis and treatment]

The ovarian hyperstimulation syndrome is a major complication of ovulation induction for in vitro fertilization, with severe morbidity and possible mortality. Whereas its pathophysiology remains ill-established, the VEGF may play a key role as well as coagulation disturbances. Risk factors for severe OHSS may be related to patients characteristics or to the management of the ovarian stimulation. Two types of OHSS are usually distinguished: the early OHSS, immediately following the ovulation triggering and a later and more severe one, occurring in case of pregnancy. As no etiologic treatment is available, the therapeutic management of OHSS should focus on its related-complications. Thrombotic complications that can occur in venous or arterial vessels represent the major risk of OHSS, possibly conducting to myocardial infarction and cerebrovascular accidents. Once the OHSS is diagnosed, prevention of thrombotic accidents remains the major issue.

II. Cognitive performance of middle-aged female rats is influenced by capacity to metabolize progesterone in the prefrontal cortex and hippocampus

Cognitive decline can occur with aging; however, some individuals experience less cognitive decline than do others. Secretion of ovarian hormones is reduced post-menopause and may contribute to cognitive function. The extent to which hormonal effects may be parsed out from other age-related factors to influence cognition is of interest. Middle-aged (12-month-old) female rats that were retired breeders were categorized as maintaining or declining reproductive function based upon their estrous cyclicity (regular 4-5 day cycles), fertility (> 60 % successful pregnancy), and fecundity (>10 pups/litter). Performance in object recognition, Y-maze, water maze, inhibitory avoidance, and contextual-cued fear conditioning was evaluated. Estradiol, progesterone (P(4)), dihydroprogesterone, and 5α-pregnan-3α-ol-20-one (3α,5α-THP) were assessed in medial prefrontal cortex (mPFC) and hippocampus; corticosterone was assessed in plasma. Rats maintaining reproductive function performed significantly better on the object recognition, Y-maze, water maze, inhibitory avoidance, and cued fear conditioning tasks than did rats with declining reproductive function. Steroid concentrations varied greatly within groups. Higher levels of P(4) in mPFC and hippocampus were associated with better Y-maze performance. In mPFC, higher levels of P(4) were associated with poorer inhibitory avoidance performance; greater levels of 3α,5α-THP were associated with better object memory. Neither estradiol nor corticosterone levels significantly contributed to cognitive performance. Thus, the capacity for cortico-limbic P(4) utilization may influence cognitive performance in aging.

Reproductive ecology and the endometrium: physiology, variation, and new directions

Endometrial function is often overlooked in the study of fertility in reproductive ecology, but it is crucial to implantation and the support of a successful pregnancy. Human female reproductive physiology can handle substantial energy demands that include the production of fecund cycles, ovulation, fertilization, placentation, a 9-month gestation, and often several years of lactation. The particular morphology of the human endometrium as well as our relative copiousness of menstruation and large neonatal size suggests that endometrial function has more resources allocated to it than many other primates. The human endometrium has a particularly invasive kind of hemochorial placentation and trophoblast that maximizes surface area and maternal-fetal contact, yet these processes are actually less efficient than the placentation of some of our primate relatives. The human endometrium and its associated processes appear to prioritize maximizing the transmission of oxygen and glucose to the fetus over efficiency and protection of maternal resources. Ovarian function controls many aspects of endometrial function and thus variation in the endometrium is often a reflection of ecological factors that impact the ovaries. However, preliminary evidence and literature from populations of different reproductive states, ages and pathologies also suggests that ecological stress plays a role in endometrial variation, different from or even independent of ovarian function. Immune stress and psychosocial stress appear to play some role in the endometrium's ability to carry a fetus through the mechanism of inflammation. Thus, within reproductive ecology we should move towards a model of women's fecundity and fertility that includes many components of ecological stress and their effects not only on the ovaries, but on processes related to endometrial function. Greater attention on the endometrium may aid in unraveling several issues in hominoid and specifically human evolutionary biology: a low implantation rate, high rates of early pregnancy loss, prenatal investment in singletons but postnatal support of several dependent offspring at once, and higher rate of reproductive and pregnancy-related pathology compared to other primates, ranging from endometriosis to preeclampsia. The study of the endometrium may also complicate some of these issues, as it raises the question of why humans have a maximally invasive placentation method and yet slow fetal growth rates. In this review, I will describe endometrial physiology, methods of measurement, variation, and some of the ecological variables that likely produce variation and pregnancy losses to demonstrate the necessity of further study. I propose several basic avenues of study that leave room for testable hypotheses in the field of reproductive ecology. And finally, I describe the potential of this work not just in reproductive ecology, but in the resolution of broader women's health issues.

Luteal support: progestogens for pregnancy protection

Following ovulation, the granulosa cells undergo luteinization and form part of the corpus luteum; this then secretes progesterone that causes secretory transformation of the endometrium so that implantation can occur. The ideal time for implantation is 6-10 days after the luteinizing hormone (LH) surge; implantation occurring outside this optimal window is associated with a higher likelihood of miscarriage. Before the placenta takes over progesterone production, the progesterone produced by the corpus luteum also provides the necessary support to early pregnancy. A defect in corpus luteum function is not only associated with implantation failure but also with miscarriage. In assisted reproduction, both the use of gonadotropin-releasing hormone analogues to prevent the LH surge and aspiration of granulosa cells during the oocyte retrieval may impair the ability of the corpus luteum to produce sufficient progesterone. This may be treated effectively with progestational agents such as progesterone or dydrogesterone, which have a very similar pharmacological profile. Studies indicate that an estrogen may be given during the luteal phase to optimise the estrogen:progestogen ratio to facilitate implantation, although the available evidence is inconsistent in its strength for this hypothesis. In addition to assisted reproduction, progestational agents have shown beneficial effects in the management of patients with recurrent spontaneous miscarriage of unknown cause. In conclusion, despite the wide-spread use and many years of clinical experience, the amount of data from well-controlled clinical trials is currently limited. Further studies are therefore required to establish the optimal treatment situation and type and dose of progestational agent.

Human corpus luteum physiology and the luteal-phase dysfunction associated with ovarian stimulation

The human corpus luteum is a temporary endocrine gland that develops after ovulation from the ruptured follicle during the luteal phase. It is an important contributor of steroid hormones, particularly progesterone, and is critical for the maintenance of early pregnancy. Luteal-phase dysfunction can result in premature regression of the gland, with a subsequent shift to an infertile cycle. Understanding the mechanism of steroidogenesis during corpus luteum growth and regression is crucial for evaluating the normal physiology and pathophysiology of reproductive cycles. The rate-limiting step in corpus luteum steroidogenesis is the transport of cholesterol to the site of steroid production. Steroidogenic acute regulatory protein is a key player in this process and is positively correlated with progesterone concentrations throughout the early and mid-luteal phase. Changes in the endocrine environment brought on by the gonadotrophins used for ovarian stimulation are thought to underlie the corpus luteum dysfunction associated with IVF cycles. While ovarian hyperstimulation syndrome is associated with human chorionic gonadotrophin (HCG), studies suggest that exogenous progesterone provides necessary luteal support in patients undergoing IVF. The current trend towards simple stimulation protocols and the use of single-embryo transfers provide further opportunity to revisit HCG administration as luteal support.

The effect of luteal phase vaginal estradiol supplementation on the success of in vitro fertilization treatment: a prospective randomized study

OBJECTIVE

To determine whether the use of luteal phase vaginal E(2) supplementation improves clinical pregnancy rates in patients undergoing IVF treatment.

DESIGN

Prospective randomized controlled trial.

SETTING

University-based tertiary fertility center.

PATIENT(S)

One hundred sixty-six patients undergoing their first cycle of IVF treatment.

INTERVENTION(S)

Patients underwent three different protocols for controlled ovarian hyperstimulation for IVF treatment with long GnRH agonist suppression, use of GnRH antagonist, or a microdose GnRH agonist protocol. Luteal phase support was in the form of IM P. Patients randomized into the study group (n = 84) received E(2) supplementation in the form of vaginal estrace 2 mg twice a day starting on the day of ET. Patients randomized to the control group (n = 82) received no E(2) supplementation.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rates.

RESULT(S)

There were no significant differences in the implantation (56/210 [26.7%] vs. 64/203 [31.5%]), clinical pregnancy (42/84 [50%] vs. 52/82 [63.4%]), and ongoing pregnancy rates (40/84 [47.6%] vs. 46/82 [56.1%]) between the study and control groups, respectively. In the subgroup of patients who used the long GnRH agonist suppression protocol, there was a lower clinical pregnancy rate in the study group compared with the control group (27/55 [49.1%] vs. 42/59 [71.2%]). There were, however, no differences in clinical pregnancy rates between the two groups in patients who used either the GnRH antagonist or microdose GnRH agonist protocols.

CONCLUSION(S)

The addition of vaginal E(2) supplementation to routine P supplementation for luteal support does not improve the probability of conception after IVF treatment.

Effects of gonadotropin-releasing hormone agonists and antagonists on luteal function

PURPOSE OF REVIEW

This review addresses the effects of gonadotropin-releasing hormone agonists and antagonists on various aspects of the luteal phase.

RECENT FINDINGS

Recent studies have shown that use of both gonadotropin-releasing hormone agonists and antagonists during in-vitro fertilization cycles leads to alterations in the hormonal profiles of the luteal phase as well as changes in endometrial histology. Gonadotropin-releasing hormone agonists are effective in triggering final oocyte maturation and reducing the incidence of ovarian hyperstimulation syndrome. Ongoing pregnancy rates are excellent after gonadotropin-releasing hormone agonist trigger when luteal phase and early pregnancy supplementation with estradiol and progesterone is provided. Gonadotropin-releasing hormone agonists have recently been used for luteal phase support in in-vitro fertilization cycles.

SUMMARY

Although gonadotropin-releasing hormone agonists and antagonists are clinically useful, they may have adverse effects on luteal function. Luteal phase supplementation significantly improves clinical outcomes in in-vitro fertilization cycles because it may correct some of these detrimental effects. Use of gonadotropin-releasing hormone agonist to induce oocyte maturation is beneficial to patients who are at increased risk for ovarian hyperstimulation syndrome. The key factor in achieving favorable ongoing pregnancy rates with use of gonadotropin-releasing hormone agonist to induce oocyte maturation appears to be adequate luteal phase support.

High Serum Estradiol Levels are not Detrimental to In Vitro Fertilization Outcome

OBJECTIVE

To evaluate the impact of high estradiol (E2) levels and a high number of retrieved oocytes on the outcome of in vitro fertilization (IVF) cycles.

MATERIALS AND METHODS

We retrospectively reviewed 274 IVF cycles. These patients were divided into five groups according to their peak E2 levels on the human chorionic gonadotropin day: < or = 2,000 pg/mL (130 cycles); 2,001-3,000 pg/mL (53 cycles); 3,001-4,000 pg/mL (46 cycles); 4,001-5,000 pg/mL (29 cycles); > 5,000 pg/mL (16 cycles). Fertilization, pregnancy, and implantation rates were analyzed between these groups. We also compared the outcome of IVF for high responders (> 15 retrieved oocytes) and normal responders (< or = 15 retrieved oocytes).

RESULTS

The oocyte fertilization and embryo cleavage rates were not significantly different among these five groups. Although decrease in pregnancy and implantation rates was observed when E2 levels were > 5,000 pg/mL compared with those having lower E2 levels, there were no statistically significant differences between these five groups. In addition, similar IVF outcome was detected for those cycles with > 15 oocytes and < or = 15 oocytes obtained.

CONCLUSION

High serum E2 levels and high oocyte yield are not detrimental to IVF outcome. More studies are needed to characterize the threshold E2 levels above which implantation rates are reduced.

Estradiol production during controlled ovarian hyperstimulation correlates with treatment outcome in women undergoing in vitro fertilization–embryo transfer

OBJECTIVE

To study the value of E(2) production during controlled ovarian hyperstimulation (COH) in predicting IVF-ET outcome.

DESIGN

Historical cohort.

SETTING

Academic infertility center.

PATIENT(S)

A cohort of 270 patients who completed 324 consecutive IVF-ET treatment cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Area under the curve for E(2) levels (AUC-E(2)) from the first day of COH until the day of hCG administration was calculated and cycles grouped into low, average, and high AUC-E(2) groups. Clinical pregnancy rates per cycle were compared among the three groups, and correlations with AUC-E(2) values were calculated for all patients and after sub-grouping according to age, COH protocol and infertility diagnosis.

RESULT(S)

Cycles with low and high AUC-E(2) values had significantly lower pregnancy rates particularly in patients 35 years or older. There was a positive correlation between AUC-E(2) and pregnancy rates up to a certain AUC-E(2) level above which a negative correlation was found. The turning point between positive and negative correlations occurred at a significantly lower AUC-E(2) level in patients 35 years or older.

CONCLUSIONS

Estradiol production during COH correlates with IVF-ET outcome. Women >35 years of age seem more vulnerable to high E(2) levels.

The science behind 25 years of ovarian stimulation for in vitro fertilization

To allow selection of embryos for transfer after in vitro fertilization, ovarian stimulation is usually carried out with exogenous gonadotropins. To compensate for changes induced by stimulation, GnRH analog cotreatment, oral contraceptive pretreatment, late follicular phase human chorionic gonadotropin, and luteal phase progesterone supplementation are usually added. These approaches render ovarian stimulation complex and costly. The stimulation of multiple follicular development disrupts the physiology of follicular development, with consequences for the oocyte, embryo, and endometrium. In recent years, recombinant gonadotropin preparations have become available, and novel stimulation protocols with less detrimental effects have been developed. In this article, the scientific background to current approaches to ovarian stimulation for in vitro fertilization is reviewed. After a brief discussion of the relevant aspect of ovarian physiology, the development, application, and consequences of ovarian stimulation strategies are reviewed in detail.

GnRH agonist (buserelin) or hCG for ovulation induction in GnRH antagonist IVF/ICSI cycles: a prospective randomized study

BACKGROUND

We aimed to determine the efficacy of ovarian hyperstimulation protocols employing a GnRH antagonist to prevent a premature LH rise allowing final oocyte maturation and ovulation to be induced by a single bolus of either a GnRH agonist or hCG.

METHODS

A total of 122 normogonadotrophic patients following a flexible antagonist protocol was stimulated with recombinant human FSH and prospectively randomized (sealed envelopes) to ovulation induction with a single bolus of either 0.5 mg buserelin s.c. (n = 55) or 10,000 IU of hCG (n = 67). A maximum of two embryos was transferred. Luteal support consisted of micronized progesterone vaginally, 90 mg a day, and estradiol, 4 mg a day per os.

RESULTS

Ovulation was induced with GnRH agonist in 55 patients and hCG in 67 patients. Significantly more metaphase II (MII) oocytes were retrieved in the GnRH agonist group (P < 0.02). Significantly higher levels of LH and FSH (P < 0.001) and significantly lower levels of progesterone and estradiol (P < 0.001) were seen in the GnRH agonist group during the luteal phase. The implantation rate, 33/97 versus 3/89 (P < 0.001), clinical pregnancy rate, 36 versus 6% (P = 0.002), and rate of early pregnancy loss, 4% versus 79% (P = 0.005), were significantly in favour of hCG.

CONCLUSIONS

Ovulation induction with a GnRH agonist resulted in significantly more MII oocytes. However, a significantly lower implantation rate and clinical pregnancy rate in addition to a significantly higher rate of early pregnancy loss was seen in the GnRH agonist group, most probably due to a luteal phase deficiency.