Aim: The objective of this study was to compare the use of clomiphene citrate and letrozole in an IVF setting in which the objective was to produce only one or two embryos. Either clomiphene citrate or letrozole was used in conjunction...
moreAim: The objective of this study was to compare the use of clomiphene citrate and letrozole in an IVF setting in which the objective was to produce only one or two embryos. Either clomiphene citrate or letrozole was used in conjunction with gonadotropins without the use of GnRH antagonists. Methods: Sixty-two patients received either clomiphene citrate or letrozole with low dose gonadotropins in 128 non-randomized treatment cycles. HCG was given when one follicle was at least 17 mm. Oocyte retrieval was done 34 hours later and fertilization was performed using ICSI. Results: There were no statistically significant differences in the number of large follicles produced, oocytes fertilized, endometrial thickness, clinical pregnancy rates, or delivery rates in patients taking letrozole compared to clomiphene citrate. More mature oocytes were retrieved after clomiphene citrate, but a subset analysis of patients undergoing both treatments did not support this difference. The only statistically different finding in both analyses was the peak estradiol levels during treatment, which averaged 516 pg/ml with letrozole and 797 pg/ml with clomiphene citrate (p = 0.005). Overall, the cancellation rate due to a premature LH surge was 5%. An average of 2.8 mature oocytes were recovered, 2.1 oocytes fertilized and 1.6 embryos were transferred. The overall clinical pregnancy rate per transfer was 25% (95% confidence interval 17.7% to 33.3%) and the overall live birth rate per transfer was 19.2% (95% confidence interval of 11.6% to 26.8%). Conclusions: Other than peak estradiol levels, there were no clinically significant differences when letrozole or clomiphene citrate was used for mild ovarian stimulation for IVF. There were only rare cancellations because of premature LH surges.
Fragile X and fragile X-associated tremor-ataxia syndrome (FXTAS) are caused by mutations of the FMR1 gene. The mutations causing FXTAS can expand in a generation to a “full mutation” causing fragile X syndrome. The mutations causing...
moreFragile X and fragile X-associated tremor-ataxia syndrome (FXTAS) are caused by mutations of the FMR1 gene. The mutations causing FXTAS can expand in a generation to a “full mutation” causing fragile X syndrome. The mutations causing FXTAS and the phenotype, fragile X-associated premature ovarian insufficiency (FXPOI), are referred to as the FMR1 premutation (PM). The objective of this paper was to formulate a theory to explain the Mechanism for FXPOI.Recent research on fragile X syndrome and FXTAS has led to sophisticated theories about the mechanisms underlying these diseases. It has been proposed that similar mechanisms underlie FXPOI. Utilizing recent research on FXTAS, but a more detailed application of ovarian physiology, we present a more ovarian specific theory as to the primary mechanism explaining the development of FXPOI.The FXPOI phenotype may best be viewed as derivative of the observation that fragile X PM carriers experience menopause an average of 5 years earlier than non-carriers. Women carrying the PM experience an earlier menopause because of an accelerated activation of their primordial follicle pool. This acceleration of primordial follicle activation occurs, in part, because of diminished AMH production. AMH production is diminished because of accelerated atresia of early antral follicles. This accelerated atresia likely occurs because the fragile X PM leads to a slowing of the rate of granulosa cell mitosis in some follicles.
To compare in vitromaturation (IVM) to conventional in vitro fertilization (IVF) with a focus on what is required of patients in order to complete cycles, the differences in work required from the clinic providing the service, and the...
moreTo compare in vitromaturation (IVM) to conventional in vitro fertilization (IVF) with a focus on what is required of patients in order to complete cycles, the differences in work required from the clinic providing the service, and the difference in the cost of cycles. This was a retrospective cohort-control study. With IVM as compared to IVF: office visits were reduced by an average of 3.2, the number of venipunctures was decreased by an average of 4.5, transvaginal ultrasound examinations were decreased by an average of 2.3, the number of injections given by the patient to herself was decreased by an average of 48.7, the interval from starting gonadotropins to receiving hCG was decreased by an average of 4.6 days, the number of endocrine tests was reduced by an average of 11.4, the number of minutes required for oocyte retrieval was increased by an average of 20.1 minutes, and the number of intracytoplasmic sperm injection procedures increased by an average of 1.7, medication costs...
A patient with Wilson's disease treated with penicillamine developed severe hirsutism. After treatment with oral contraceptives, her breasts enlarged rapidly, and she experienced cyclic mastodynia. Around the time of her breast...
moreA patient with Wilson's disease treated with penicillamine developed severe hirsutism. After treatment with oral contraceptives, her breasts enlarged rapidly, and she experienced cyclic mastodynia. Around the time of her breast enlargement she also developed gingival hyperplasia.
Objective: To compare the pregnancy rates with two different methods of priming for in vitro maturation cycles (IVM). Cycles using letrozole together with hCG were compared to cycles using FSH together with hCG in 75 cycles in patients...
moreObjective: To compare the pregnancy rates with two different methods of priming for in vitro maturation cycles (IVM). Cycles using letrozole together with hCG were compared to cycles using FSH together with hCG in 75 cycles in patients being treated for infertility by IVM. Study design: Retrospective cohort non-inferiority trial Results: Using letrozole for priming was found to not be inferior to using FSH for priming cycles. The live birth rate per transfer was 31.6% in letrozole primed cycles compared to 20.8% in FSH primed cycles (not significant). However, FSH priming produced more oocytes that were mature on the day of retrieval (p = 0.004) and also resulted in more high quality embryos than did letrozole priming (p = 0.004). Conclusion: Letrozole may be used for priming in IVM cycles in which the clinician views the characteristics of letrozole as more desirable than FSH.
Abdominal fluid retention after the instillation of lactated Ringer's solution into the abdomen after operative laparoscopy was evaluated by comparing the serial weights of patients receiving lactated Ringer's after surgery to those of...
moreAbdominal fluid retention after the instillation of lactated Ringer's solution into the abdomen after operative laparoscopy was evaluated by comparing the serial weights of patients receiving lactated Ringer's after surgery to those of patients treated with the abdominal instillation of high-molecular-weight dextran and to those of negative controls. Twenty-four patients were randomized to receive either lactated Ringer's or high-molecular-weight dextran after operative laparoscopy. Patients undergoing only diagnostic laparoscopy served as negative controls. Patients receiving either lactated Ringer's or high-molecular-weight dextran had increased weights as compared to the negative controls for at least 36 hours (P less than .5), although the weight gain in the treatment groups did not differ statistically significantly. The weight gain remained significantly greater than in the negative controls on postoperative days 3 and 4 in patients treated with dextran. Since the "flotation" effect of dextran in preventing pelvic adhesions is likely to be most pronounced in the immediate postoperative period, the findings suggest the need for a reinterpretation of adhesion prevention studies in which the use of dextran was compared to that of lactated Ringer's solution or to saline as a negative control.
This review looks at the problem of pregnancy loss after in vitro maturation IVF (IVM) cycles as it may relate to the development of the endometrium during that cycle. The management of the endometrial lining in IVM cycles is currently...
moreThis review looks at the problem of pregnancy loss after in vitro maturation IVF (IVM) cycles as it may relate to the development of the endometrium during that cycle. The management of the endometrial lining in IVM cycles is currently primarily informed by what has worked in the past rather than by designed experimental studies. The IVF literature on the use of estradiol in artificial cycles prior to cryopreserved embryo transfer cycles and fresh donor-recipient cycles can provide some context in which to evaluate practices in IVM. Endogenous estradiol, exogenous estradiol, and estradiol induced by FSH priming all potentially effect the development of the endometrium during an IVM cycle. These vary in part between programs based on patient selection and cycle management choices, making it harder to use the medical literature to guide decision making in this area. In particular, the short duration of functional estrogen exposure and the diminished endometrial thickness typical of many IVM cycles may contribute to an increased pregnancy loss rate and a lower implantation rate than seen with conventional IVF.
Recent meta-analyses suggest that flushing follicles during the oocyte retrieval is not beneficial for patients with a normal response to ovarian stimulation. The rate at which oocytes are recovered after flushing is not mathematically...
moreRecent meta-analyses suggest that flushing follicles during the oocyte retrieval is not beneficial for patients with a normal response to ovarian stimulation. The rate at which oocytes are recovered after flushing is not mathematically compatible with cumulus oocyte complexes always being free floating in the follicle. Furthermore, some residual fluid always remains in the follicle after aspiration. For patients with a small number of follicles, follicle flushing is likely to increase oocyte yield and the potential for pregnancy enough to be clinically significant.
Space travel has different effects on the reproductive capacity of women compared to men. The radiation exposure intrinsic to deep space travel causes destruction of some of a woman's primordial follicles. Data suggests that a typical...
moreSpace travel has different effects on the reproductive capacity of women compared to men. The radiation exposure intrinsic to deep space travel causes destruction of some of a woman's primordial follicles. Data suggests that a typical Mars mission may reduce a women's ovarian reserve by about 50%. This has consequences to a woman's reproductive capacity and, more significantly, decreases the time interval to her menopause. A reduced time interval to menopause is associated with earlier mortality. Estrogen replacement therapy and cryopreservation of a female astronaut's oocytes may be used to address these issues. However, cortical tissue freezing provides advantages to more directly compensate for these workplace complications. Cortical tissue freezing especially provides advantages if there are plans to reproduce in an extraterrestrial location.
In this note we show that taking a scalar extension of two elementarily equivalent finite-dimensional algebras over the same field preserves elementary equivalence. The general question of whether or not tensor product preserves...
moreIn this note we show that taking a scalar extension of two elementarily equivalent finite-dimensional algebras over the same field preserves elementary equivalence. The general question of whether or not tensor product preserves elementary equivalence was originally raised in [4]. In [3] Feferman relates an example of Ersov which answers the question negatively. Eklof and Olin [7] also provide a counterexample to the general question in the context of two-sorted structures. Thus the result proved below is a partial positive answer to a general question whose status has been resolved negatively. From the viewpoint of applied model theory it seems desirable to find contexts in which positive statements of preservation can be obtained. Our result does have an application; a corollary to it increases our understanding of what it means for two division algebras to be elementarily equivalent.All algebras are finite-dimensional algebras over fields. All algebras contain an identity element...
Recent meta-analyses suggest that flushing follicles during the oocyte retrieval is not beneficial for patients with a normal response to ovarian stimulation. The rate at which oocytes are recovered after flushing is not mathematically...
moreRecent meta-analyses suggest that flushing follicles during the oocyte retrieval is not beneficial for patients with a normal response to ovarian stimulation. The rate at which oocytes are recovered after flushing is not mathematically compatible with cumulus oocyte complexes always being free floating in the follicle. Furthermore, some residual fluid always remains in the follicle after aspiration. For patients with a small number of follicles, follicle flushing is likely to increase oocyte yield and the potential for pregnancy enough to be clinically significant.
Ovarian drilling is a laparoscopic treatment for polycystic ovary syndrome. As with wedge resection, it is unclear why women with this syndrome ovulate after the procedure. Studies describing the clinical response of over 600 patients to...
moreOvarian drilling is a laparoscopic treatment for polycystic ovary syndrome. As with wedge resection, it is unclear why women with this syndrome ovulate after the procedure. Studies describing the clinical response of over 600 patients to this treatment have appeared in the medical literature. Attention to detailed steps can guide experienced laparoscopic surgeons to apply this technique to appropriate patients who are experiencing infertility due to polycystic ovary disease.
Most obstetricians share the belief that an estimate of gestational age based on several clinical measures that agree with one another is more accurate than an estimate based on a single measurement. This paper presents a formal...
moreMost obstetricians share the belief that an estimate of gestational age based on several clinical measures that agree with one another is more accurate than an estimate based on a single measurement. This paper presents a formal justification for this belief by applying Bayes' theorem to calculate the probability of a fetus being a certain gestational age by using information from several clinically established single predictors. The application of Bayes' theorem justifies the use of multiple measures of gestational age in individual ultrasound examinations and the use of serial ultrasound studies in the third trimester to more accurately estimate gestational age. The same technique could be applied to obstetric research studies that need to establish accurate gestational dating.
Purpose: In vitro maturation (IVM) continues its evolution as new ideas are introduced with the objective of making the IVM procedure easier and more effective. This study combines ideas believed likely to improve the IVM outcome or make...
morePurpose: In vitro maturation (IVM) continues its evolution as new ideas are introduced with the objective of making the IVM procedure easier and more effective. This study combines ideas believed likely to improve the IVM outcome or make the IVM oocyte identification process easier. Methods: A cohort of 45 women underwent an IVM cycle in which letrozole was used with the theoretical objective of improving the competence of small antral follicles, the oocyte aspiration technique was modified to minimize the time between oocyte aspiration and oocyte identification, and blastocysts were transferred during a subsequent cycle with controlled endometrial development. Results: Measures of oocyte competence used for these prospectively followed cycles were as follows: the maturation rate was 90.5%, the fertilization rate was 92.4%, the cleavage rate was 94.6%, the usable blastulation rate per zygote was 50.2%, and the implantation rate was 34.2%. In 7.9% of cycles initiated, there was a fai...
Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for...
moreLetrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response to FSH is only a part of the endocrine events occurring in a developing follicle. The health of the small antral follicles is driven primarily by androgens, which contribute to granulosa cell mitosis, sensitivity to FSH, and resistance to atresia. In contrast, elevated androgens in the late antral to pre-ovulatory follicle have a negative impact on follicle health and lead to atresia and cystic follicle formation. This ovarian physiologic data suggests that current applications of letrozole to infertility may be squandering some of the primary benefits available in using letrozole to promote follicle development. Four applications of letrozole to infertility that have appeared in the medic...
Let n ≥ 3. The following theorems are proved.Theorem. The theory of the class of strictly upper triangular n × n matrix rings over fields is finitely axiomatizable.Theorem. If R is a strictly upper triangular n × n matrix ring over a...
moreLet n ≥ 3. The following theorems are proved.Theorem. The theory of the class of strictly upper triangular n × n matrix rings over fields is finitely axiomatizable.Theorem. If R is a strictly upper triangular n × n matrix ring over a field K, then there is a recursive map σ from sentences in the language of rings with constants for K into sentences in the language of rings with constants for R such that K ⊨ φ if and only if R φ σ(φ).Theorem. The theory of a strictly upper triangular n × n matrix ring over an algebraically closed field is ℵ1-categorical.
Matatyahu Rubin pointed out that the proof of Lemma 6.1 [2] works only for rings of prime or zero characteristic. This invalidates the characterization of semiprime rings with the descending chain condition on right or left ideals which...
moreMatatyahu Rubin pointed out that the proof of Lemma 6.1 [2] works only for rings of prime or zero characteristic. This invalidates the characterization of semiprime rings with the descending chain condition on right or left ideals which admit elimination of quantifiers given in [2] and cited in the abstract [1]. Although the correct characterization is easy to derive, it is complex to state.Let be the class of finite fields. Let be the class of 2 × 2 matrix rings over a field with a prime number of elements. Let be the class of rings of the form GF(pn) ⊕ GF(pk) such that either n = k or g.c.d.(n, k) = 1 and p is a prime. Let ′ be the class of algebraically closed fields. Let P denote the set of all prime numbers together with zero. Let be the set of all ordered pairs (f, Q) where Q is a finite subset of P and f: Q → ⋃ ⋃ ⋃ such that the characteristic of the ring f(q) is q. Finally, let be the class of rings of the form ⊕q∈Qf(q) for some (f,Q) in .A corrected version of Theorem 6.2 [...
Laparoscopic treatment of polycystic ovary syndrome has its roots in bilateral wedge resection. Although it is still unclear why surgery is effective in treating this syndrome, more than 600 cases of patients treated laparoscopically have...
moreLaparoscopic treatment of polycystic ovary syndrome has its roots in bilateral wedge resection. Although it is still unclear why surgery is effective in treating this syndrome, more than 600 cases of patients treated laparoscopically have been reported in the literature. Recent publications enhance our understanding of appropriate patient selection as well as the effectiveness of, and the complications associated with, this procedure.
ORIGINAL ARTICLE, Amer J Perinatol 1987; 4(2): 147-151 DOI: 10.1055/s-2007-999760. © 1987 by Thieme Medical Publishers, Inc. Ultrasound in Obstetric Decision Making. How Accurate Are Late Ultrasound Scans in Gestational Age and Fetal...
moreORIGINAL ARTICLE, Amer J Perinatol 1987; 4(2): 147-151 DOI: 10.1055/s-2007-999760. © 1987 by Thieme Medical Publishers, Inc. Ultrasound in Obstetric Decision Making. How Accurate Are Late Ultrasound Scans in Gestational Age and Fetal Weight Assessment? ...