Richard J. Paulson

Pharmacokinetics and endometrial tissue levels of progesterone after administration by intramuscular and vaginal routes : a comparative study

OBJECTIVE To determine pharmacokinetic and endometrial effects of vaginally delivered micronized P. DESIGN Functionally agonadal estrogen-replacement recipients received either micronized P administered vaginally or bi-daily IM injections of P. Hourly blood samples were obtained, from baseline to 6 hours after the initial dose of P and again on simulated cycle day 21 when transvaginal ultrasound (US) measurements and tissue samples of the endometrium were performed. Blood and tissue samples were assayed for P. Endometrial histology, estrogen receptor (ER) and P receptor (PR) contents were evaluated. SETTING University of Southern California School of Medicine, Los Angeles, California. PARTICIPANTS Twenty functionally agonadal and four normally ovulating women. MAIN OUTCOME MEASURE Delivery differences were assessed by [1] endometrial P concentrations; [2] USs; [3] histologic datings; [4] ER and PR contents, and [5] serum P levels. RESULTS Endometrial P concentrations were higher with vaginally administered P than endometrial concentrations observed in normal ovulatory women or women who consistently had the highest serum P after IM administration (11.50 +/- 2.60 versus 1.40 +/- 0.40 versus 0.30 +/- 0.10 ng/mg protein [36.56 +/- 8.27 versus 4.45 +/- 1.27 versus 0.95 +/- 0.32 nmol/L], respectively). After 7 days of P, no differences between either treatment regimen and control groups were detected by histologic, ultrasonographic, or immunocytochemical receptor analyses. CONCLUSION Vaginal micronized P enhances P delivery to the uterus compared with a standard IM regimen and results in a synchronous secretory endometrial histology in agonadal women preparing for embryo donation.

Embryo implantation after human in vitro fertilization: importance of endometrial receptivity

To study the effects of controlled ovarian hyperstimulation (COH) on endometrial receptivity during human in vitro fertilization (IVF), we compared embryo implantation data obtained from our nonanonymous donor oocyte program with those obtained from standard IVF. To control for embryo quality, IVF patient characteristics were matched to those of the oocyte donors with regard to age and previous gravidity. All cycles were performed in an identical manner, using standardized ovarian stimulation protocols, transvaginal follicle aspiration, fertilization and culture in vitro, and transcervical embryo transfer. A similar number of oocytes per cycle were obtained, fertilization rates were similar, and similar numbers of embryos were transferred in both groups. Transferred embryos had similar numbers of blastomeres and were morphologically judged to be of similar quality in both groups. Implantation rates per individual embryo were significantly higher in donor than in standard IVF (35% versus 10.7%) as were ongoing per embryo implantation rates (23% versus 8%). Clinical and ongoing pregnancy rates per cycle were likewise higher in the donor group than in the standard IVF group (67% versus 39%, and 61% versus 30%, respectively). We conclude that COH inhibits embryo implantation after IVF by decreasing endometrial receptivity, which is an important factor in IVF pregnancy success.

A Preliminary Report on Oocyte Donation Extending Reproductive Potential to Women over 40

Abstract Background. Fertility in women 40 years of age or older is decreased, and in those with ovarian failure it is thought to be irrevocably lost. The donation of oocytes to young (<35 years old) women with ovarian failure has allowed many considered infertile a chance to become pregnant. In these women gonadal hormone replacement results in an endometrium receptive to implantation. It is not known whether the endometrial response to such replacement is decreased in women over the age of 40. Methods. To test the efficacy of oocyte donation to older women, we enrolled seven women 40 to 44 years old with ovarian failure in a trial of hormone replacement and embryo transfer, using oocytes obtained from women undergoing ovarian hyperstimulation solely for gamete donation. Results. Seven stimulated cycles in the donors that were synchronized with nine cycles in the recipients resulted in eight embryo transfers. Five viable pregnancies were established, one with twins. A sixth pregnancy ended in miscarriage...

Limitations of direct estradiol and testosterone immunoassay kits.

Estradiol (E2) and testosterone (T) are biologically active hormones that serve as important diagnostic markers in serum of premenopausal and postmenopausal women and in men. These hormones are measured frequently by immunoassay in clinical laboratories and the test results are used in the diagnosis and treatment of patients. For measuring the hormones by immunoassay, most laboratories utilize commercially available reagents that are packaged in the form of a kit and are used either in an automated instrument or manually. However, both the diagnostic kit manufacturer and testing laboratory seldom thoroughly validate the assay methods generated with these kits. This deficiency may lead to unreliable test results that could affect clinical evaluation and treatment of patients. The purpose of the present study was to assess the reliability of immunoassays that quantify serum E2 and T levels with commercial diagnostic kits. The data generally show wide differences in the apparent levels of each hormone in a given sample obtained with kits from different manufacturers. This was especially true when measuring postmenopausal E2 and T levels. However, a purification step, which included organic solvent extraction, prior to radioimmunoassay (RIA) of E2 gave values that compared well with those obtained by conventional RIA (with preceding extraction/chromatographic steps). Our results point out the importance of more thoroughly validating assays performed with commercial immunoassay kits, especially with respect to sensitivity and specificity, prior to their use for measuring hormone levels in patient samples.

Antiphospholipid antibodies and in vitro fertilization success: a meta-analysis

OBJECTIVE To evaluate whether the presence of antiphospholipid antibodies among women undergoing IVF affects the likelihood of IVF success. DESIGN A meta-analysis of seven eligible studies on antiphospholipid antibodies and IVF outcome. MAIN OUTCOME MEASURE(S) Odds ratios (ORs) and 95% confidence intervals (CIs) of an association between the presence of antiphospholipid antibodies and both clinical pregnancy and live birth from IVF. RESULT(S) There was no significant association between antiphospholipid abnormalities and either clinical pregnancy (OR 0.99; 95% CI 0.64-1.53) or live birth (OR 1.07; 95% CI 0.66-1.75) in IVF patients. CONCLUSION(S) The measurement of antiphospholipid antibodies is not warranted in patients undergoing IVF.

Factors affecting embryo implantation after human in vitro fertilization: A hypothesis

In the clinical practice of human in vitro fertilization, pregnancy is dependent on embryo implantation. Pregnancy is a function of the number of embryos transferred, with multiple embryos resulting in a higher likelihood of pregnancy. We formulated a mathematic model of embryo implantation. This model describes embryo implantation as dependent on three factors--transfer efficiency, embryo quality, and endometrial receptivity. Application of existing embryo implantation data to this model allows the calculation of the approximate value of each of these factors. On the basis of historic data, data obtained from our in vitro fertilization program, and these theoretic considerations, it is our hypothesis that (1) there is an inherent inefficiency associated with the mechanical transfer of embryos into the uterine cavity, which limits the maximal embryo implantation rate; (2) the quality of embryos produced by controlled ovarian hyperstimulation, follicle aspiration, and in vitro fertilization is very high and approaches that of embryos produced in natural cycles in vivo; and (3) endometrial receptivity is markedly diminished in stimulated cycles and is the current rate-limiting step of pregnancy success of in vitro fertilization.

Ovarian hyperstimulation inhibits embryo implantation in the mouse.

Embryo implantation is dependent on the synchronous development of the embryo and of the endometrium. Pharmacologic doses of estrogens change endometrial histology and are known to inhibit implantation. During controlled ovarian hyperstimulation, such as occurs during an in vitro fertilization cycle, serum estradiol levels may be elevated to as much as three to six times those found during spontaneous cycles. Serum progesterone levels are also increased and may counteract the elevated estradiol levels. The overall effect of ovarian stimulation on implantation is therefore not known. To study this question, we developed a mouse embryo donation model. Donor embryos were obtained in the late morula to early blastocyst stage from hyperstimulated mated mice. The donated embryos were then transferred to the uteri of two groups of recipient mice. The study group underwent ovarian hyperstimulation with pregnant mares serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) (OHR group), while the controls were allowed to cycle spontaneously (SR group). All recipient mice underwent cervical stimulation to induce a pseudopregnant state. Five embryos were transferred to the left uterine horn of each of nine OHR mice and seven SR mice. A higher implantation rate was noted in the SR group than in the OHR group (50±12 vs 8±4%, P<0.001). Our data suggest that, in the mouse, ovarian hyperstimulation impedes implantation by causing adverse changes in uterine receptivity.

Very high serum estradiol levels are not detrimental to clinical outcome of in vitro fertilization

The use of gonadotropin-releasing hormone agonists as adjuncts to ovulation induction for in vitro fertilization (IVF) has resulted in increases in oocyte recovery rates. Along with increased oocyte number, greatly increased estradiol (E 2 ) levels have been found. We sought to determine the clinical effect of very high E 2 levels on the outcome of IVF cycles. Estradiol levels were measured in 141 patients undergoing controlled ovarian hyperstimulation with leuprolide acetate and human menopausal gonadotropin for IVF. Whereas the number of oocytes recovered and fertilized and the number of embryos available for cryopreservation were directly proportional to the E 2 level, the fertilization rate and embryo cleavage rates were unrelated to the E 2 level. When the patients were grouped in thirds according to E 2 levels, pregnancy rate (PR) was highest in the patients with the highest E 2 levels (E 2 >2,777pg/mL, PR=37% ). One mild, one moderate, and one severe case of ovarian hyperstimulation syndrome occurred in patients with E 2 ≥3,000pg/mL (n=21), but in general, high E 2 levels were attained with few complications. We conclude that high E 2 levels are not detrimental to the pregnancy outcome of IVF. Our experience further suggests that cycles with E 2 levels of ≤5,000pg/mL need not be canceled and can proceed to oocyte recovery and embryo transfer.

The luteal phase of cycles utilizing controlled ovarian hyperstimulation and the possible impact of this hyperstimulation on embryo implantation.

OBJECTIVE Our purpose was to evaluate the early luteal phase of assisted reproductive cycles utilizing controlled ovarian hyperstimulation and to compare these results with those obtained in unstimulated cycles. STUDY DESIGN We undertook a descriptive study analyzing luteal phase serum progesterone levels, endometrial histologic features, and endometrial surface ultrastructure by scanning electron microscopy of cycles utilizing controlled ovarian hyperstimulation. Study samples were obtained from 7 oocyte donors undergoing controlled ovarian hyperstimulation for the purpose of follicle aspiration in oocyte donation. Control (unstimulated) serum progesterone samples were obtained from 19 patients undergoing in vitro fertilization in unstimulated cycles. Prospective recipients of oocyte donation (n = 20) undergoing mock cycles of exogenous estradiol and progesterone acted as controls for the endometrial biopsies. RESULTS Serum progesterone levels on the day of human chorionic gonadotropin administration were twofold higher in the study group than in the unstimulated group (1.1 +/- 0.6 vs 0.5 +/- 0.2 ng/ml, mean +/- SD, p < 0.01). On the day of follicle aspiration, progesterone levels were much higher in the study group (8.5 +/- 2.2 vs 0.5 +/- 0.1 ng/ml, p < 0.001). Histologic dating of endometrial biopsies revealed that the study group was advanced by nearly 2 days as compared with the group having artificial cycles. Pinopods, ultrastructural markers of the implantation window, were present in only one of seven study cycles as compared with all of the four artificial cycles. CONCLUSIONS The early luteal phase of cycles undergoing controlled ovarian hyperstimulation is characterized by markedly elevated serum progesterone levels during the periovulatory period, advanced endometrial histologic features, and an absence of endometrial pinopods at the time of embryo implantation. We speculate that these high levels of progesterone in the early luteal phase cause premature endometrial luteinization and a premature appearance of the implantation window, thus providing an explanation for the observed decrease in endometrial receptivity.

Hormonal induction of endometrial receptivity

OBJECTIVE To review and synthesize information from the scientific literature pertaining to the hormonal induction of endometrial receptivity before ET. DESIGN Critical review of selected scientific literature, synthesis and formulation of opinion. SETTING Not applicable. PATIENT(S) Prospective recipients of oocyte donation or candidates for frozen embryo transfer. INTERVENTION(S) Hormonal treatment for the purpose of induction of endometrial receptivity. MAIN OUTCOME MEASURE(S) Successful induction of endometrial receptivity, as substantiated by live birth rates, pregnancy rates, implantation rates or by measuring putative markers of endometrial receptivity. RESULT(S) The practice of assisted reproductive technology, particularly third-party parenting, in which the source of oocytes is separated from the endometrium, has allowed a separate assessment of embryo and endometrial development. Endometrial receptivity can be induced by exogenously administered E(2) and P in a variety of regimens. The degree of synchrony between embryo and endometrium influences the probability of embryo implantation and may be controlled by initiating P stimulation at different times relative to the stage of embryo development. Many substances have been investigated as adjuncts to E(2) and P in the induction of endometrial receptivity, but at the present time, their value is unproven. CONCLUSION(S) Estrogen and P are the only hormones necessary to prepare the endometrium for implantation.