N.D. Tran

Fibroids and reproductive outcomes: a systematic literature review from conception to delivery

We examined the published relationship between uterine fibroids and reproductive outcomes. Submucosal fibroids had the strongest association with lower ongoing pregnancy rates, odds ratio, 0.5; 95% confidence interval, 0.3-0.8, primarily through decreased implantation. Cumulative pregnancy rates appeared slightly lower in patients with intramural fibroids 36.9% vs 41.1%, which may reflect biases in the literature; however, patients with intramural fibroids also experienced more miscarriages, 20.4% vs 12.9%. Adverse obstetric outcomes are rare and may reflect age or other differences in fibroid populations. Increased risk of malpresentation (odds ratio, 2.9; 2.6-3.2), cesarean (odds ratio, 3.7; 3.5-3.9), and preterm delivery (odds ratio, 1.5; 1.3-1.7) are reported; however, the incidence of labor dystocia was low (7.5%). There was no conclusive evidence that intramural or subserosal fibroids adversely affect fecundity. More prospective, controlled trials are needed to assess the effects of myomectomy. Good maternal and neonatal outcomes are expected in pregnancies with uterine fibroids.

The role of embryonic origin in preeclampsia: a comparison of autologous in vitro fertilization and ovum donor pregnancies.

OBJECTIVE: To compare the risk of gestational hypertension and preeclampsia in pregnancies conceived through standard in vitro fertilization (IVF) using autologous oocytes with pregnancies conceived using donated oocytes. METHODS: We conducted a retrospective, matched cohort study of women undergoing IVF using autologous compared with donor oocytes between 1998 and 2005. Women with live births resulting from oocyte donor pregnancies were matched for age and plurality (singleton or twin) with women undergoing autologous IVF. Primary outcomes were the incidence of preeclampsia or gestational hypertension (with and without proteinuria) in the third trimester. Data on preterm delivery, low birth weight, and embryo cryopreservation were also recorded. RESULTS: Outcome data were available for 158 pregnancies, including 77 ovum-donor recipient pregnancies and 81 pregnancies using autologous oocytes. There were no differences in age, parity, and gestational type between the two cohorts. The incidence of gestational hypertension and preeclampsia was significantly higher in ovum-donor recipients compared with women undergoing autologous IVF (24.7% compared with 7.4%, P<.01, and 16.9% compared with 4.9%, P=.02, respectively). Ovum-donor recipients were more likely than women undergoing autologous IVF to deliver prematurely (34% compared with 19%). This association remained after controlling for multiple gestation (odds ratio 2.6, 95% confidence interval 1.04–6.3). Sixteen pregnancies from cryopreserved embryos were more likely to have hypertensive disorders of pregnancy (odds ratio 5.0, 95% confidence interval 1.2–20.5). CONCLUSION: Pregnancies derived from donor oocytes and cryopreserved–thawed embryos may be at a higher risk for hypertensive disorders of pregnancy. These findings inform future research and help counsel women using assisted reproductive technology. LEVEL OF EVIDENCE: II

The role of anti-müllerian hormone (AMH) in assessing ovarian reserve.

CONTEXT Anti-müllerian hormone (AMH) has been suggested as a marker for the quantity of oocytes remaining within the ovaries (ovarian reserve). It was shown to correlate with antral follicle counts (AFC), outcomes from ovarian stimulation, and onset of menopause. Thus, AMH was previously considered to be the ideal marker of ovarian reserve because it is exclusively produced by granulosa cells and is the only marker that was thought to be stable throughout the menstrual cycle. However, recent studies demonstrate fluctuations in AMH levels during the menstrual cycles, questioning the utility of AMH as a marker of oocyte quantity. OBJECTIVE We report the case of a 32-yr-old Gravida 0 woman with idiopathic hypogonadotropic hypogonadism who presented for fertility treatment with unstable AMH levels. PATIENT AND METHODS The patients initial FSH and LH levels were both below 1.0 mIU/ml. Estradiol was 28 pg/ml. Her initial AMH and AFC were 0.20 ng/ml and 0, respectively. She underwent three cycles of fertility treatment. RESULTS During the 16-wk course of treatment with human menopausal gonadotropins, normal follicular development was observed. Both AMH and AFC gradually increased during treatment and peaked at 1.26 ng/ml and 6, respectively. On the third cycle of treatment, she successfully conceived. CONCLUSION In the case of idiopathic hypogonadotropic hypogonadism, AMH concentration increases because human menopausal gonadotropin stimulates the growth of FSH-dependent follicles. Thus, AMH has limitations because it only reflects the growing follicular pool that is responsive to gonadotropins. Therefore, AMH may not be solely reflective of the underlying primordial pool.

Testicular Niche Required for Human Spermatogonial Stem Cell Expansion

Prepubertal boys treated with high‐dose chemotherapy do not have an established means of fertility preservation because no established in vitro technique exists to expand and mature purified spermatogonial stem cells (SSCs) to functional sperm in humans. In this study, we define and characterize the unique testicular cellular niche required for SSC expansion using testicular tissues from men with normal spermatogenesis. Highly purified SSCs and testicular somatic cells were isolated by fluorescence‐activated cell sorting using SSEA‐4 and THY1 as markers of SSCs and somatic cells. Cells were cultured on various established niches to assess their role in SSC expansion in a defined somatic cellular niche. Of all the niches examined, cells in the SSEA‐4 population exclusively bound to adult testicular stromal cells, established colonies, and expanded. Further characterization of these testicular stromal cells revealed distinct mesenchymal markers and the ability to undergo differentiation along the mesenchymal lineage, supporting a testicular multipotent stromal cell origin. In vitro human SSC expansion requires a unique niche provided exclusively by testicular multipotent stromal cells with mesenchymal properties. These findings provide an important foundation for developing methods of inducing SSC growth and maturation in prepubertal testicular tissue, essential to enabling fertility preservation for these boys.

Developmental competence of immature and failed/abnormally fertilized human oocytes in nuclear transfer

Somatic cell nuclear transfer holds great promise for basic studies of reprogramming human somatic cells and for the potential development of novel cell-based therapeutics. The aim of this study was to examine experimental aspects of human nuclear transfer via use of an abundant source of oocytes, those that are routinely discarded from assisted reproduction clinics. The results suggest and reinforce several findings based on the analysis of multiple parameters: first, it was observed that supplementation of commercial culture media with hormones promoted embryo development after parthenogenetic activation. Second, the use of the chemical activation reagent puromycin resulted in significant differences in cleavage rates in oocytes that were failed/abnormally fertilized after intracytoplasmic sperm injection relative to those from IVF (P < 0.05). Third, cycloheximide promoted cleavage rates >/=40% in both groups of oocytes; moreover, two blastocysts were produced following cycloheximide treatment. Finally, the use of a subset of oocytes for nuclear transfer resulted in cleaved embryos that expressed green fluorescent protein from a transgene in donor nuclei from human embryonic stem cells. In light of these results, it is suggested that the discarded oocytes can be used to investigate new human nuclear transfer protocols for embryonic stem cell derivation.

CHARACTERIZATION OF HUMAN SPERMATOGONIAL STEM CELL MARKERS IN FETAL, PEDIATRIC, AND ADULT TESTICULAR TISSUES

Autologous spermatogonial stem cell (SSC) transplantation is a potential therapeutic modality for patients with azoospermia following cancer treatment. For this promise to be realized, definitive membrane markers of prepubertal and adult human SSCs must be characterized in order to permit SSC isolation and subsequent expansion. This study further characterizes the markers of male gonocytes, prespermatogonia, and SSCs in humans. Human fetal, prepubertal, and adult testicular tissues were analyzed by confocal microscopy, fluorescence-activated cell sorting, and qRT-PCR for the expression of unique germ cell membrane markers. During male fetal development, THY1 and KIT (C-Kit) are transient markers of gonocytes but not in prespermatogonia and post-natal SSCs. Although KIT expression is detected in gonocytes, THY1 expression is also detected in the somatic component of the fetal testes in addition to gonocytes. In the third trimester of gestation, THY1 expression shifts exclusively to the somatic cells of the testes where it continues to be detected only in the somatic cells postnatally. In contrast, SSEA4 expression was only detected in the gonocytes, prespermatogonia, SSCs, and Sertoli cells of the fetal and prepubertal testes. After puberty, SSEA4 expression can only be detected in primitive spermatogonia. Thus, although THY1 and KIT are transient markers of gonocytes, SSEA4 is the only common membrane marker of gonocytes, prespermatogonia, and SSCs from fetal through adult human development. This finding is essential for the isolation of prepubertal and adult SSCs, which may someday permit fertility preservation and reversal of azoospermia following cancer treatment.

A novel “delayed start” protocol with gonadotropin-releasing hormone antagonist improves outcomes in poor responders

OBJECTIVE To investigate whether delaying the start of ovarian stimulation with GnRH antagonist improves ovarian response in poor responders. DESIGN Retrospective study. SETTING Academic medical center. PATIENT(S) Thirty patients, who responded poorly and did not get pregnant with conventional estrogen priming antagonist IVF protocol. INTERVENTION(S) Delayed-start antagonist protocol (estrogen priming followed by early follicular-phase GnRH antagonist treatment for 7 days before ovarian stimulation). MAIN OUTCOME MEASURE(S) Number of dominant follicles and mature oocytes retrieved, mature oocyte yield, and fertilization rate. RESULT(S) The number of patients who met the criteria to proceed to oocyte retrieval was significantly higher in the delayed-start protocol [21/30 (70%)] compared with the previous conventional estrogen priming antagonist cycle [11/30 (36.7%)]. The number of dominant follicles was significantly higher in the delayed-start (4.2 ± 2.7) compared with conventional (2.4 ± 1.3) protocol. In patients who had oocyte retrieval after both protocols (n = 9), the delayed start resulted in shorter ovarian stimulation (9.4 ± 1.4 days vs. 11.1 ± 2.0 days), higher number of mature oocytes retrieved (4.9 ± 2.0 vs. 2.2 ± 1.1), and a trend toward increased fertilization rates with intracytoplasmic sperm injection (ICSI; 86 ± 17% vs. 69 ± 21%) compared with conventional protocol. After delayed start, the average number of embryos transferred was 2.8 ± 1.4 with implantation rate of 9.8% and clinical pregnancy rate of 23.8%. CONCLUSION(S) The delayed-start protocol improves ovarian response in poor responders by promoting and synchronizing follicle development without impairing oocyte developmental competence.

Optimizing cryopreservation of human spermatogonial stem cells: comparing the effectiveness of testicular tissue and single cell suspension cryopreservation.

OBJECTIVE To determine whether optimal human spermatogonial stem cell (SSC) cryopreservation is best achieved with testicular tissue or single cell suspension cryopreservation. This study compares the effectiveness between these two approaches by using testicular SSEA-4+ cells, a known population containing SSCs. DESIGN In vitro human testicular tissues. SETTING Academic research unit. PATIENT(S) Adult testicular tissues (n=4) collected from subjects with normal spermatogenesis and normal fetal testicular tissues (n=3). INTERVENTION(S) Testicular tissue versus single cell suspension cryopreservation. MAIN OUTCOME MEASURE(S) Cell viability, total cell recovery per milligram of tissue, as well as viable and SSEA-4+ cell recovery. RESULT(S) Single cell suspension cryopreservation yielded higher recovery of SSEA-4+ cells enriched in adult SSCs, whereas fetal SSEA-4+ cell recovery was similar between testicular tissue and single cell suspension cryopreservation. CONCLUSION(S) Adult and fetal human SSEA-4+ populations exhibited differential sensitivity to cryopreservation based on whether they were cryopreserved in situ as testicular tissues or as single cells. Thus, optimal preservation of human SSCs depends on the patients age, type of samples cryopreserved, and end points of therapeutic applications.

A miR‐372/let‐7 Axis Regulates Human Germ Versus Somatic Cell Fates

The embryonic stem cell cycle (ESCC) and let‐7 families of miRNAs function antagonistically in the switch between mouse embryonic stem cell self‐renewal and somatic differentiation. Here, we report that the human ESCC miRNA miR‐372 and let‐7 act antagonistically in germline differentiation from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs). hESC and iPSC‐derived primordial germ cell‐like cells (PGCLCs) expressed high levels of miR‐372 and conversely, somatic cells expressed high levels of let‐7. Manipulation of miRNA levels by introduction of miRNA mimics or knockdown with miRNA sponges demonstrated that miR‐372 promotes whereas let‐7 antagonizes PGCLC differentiation. Knockdown of the individual miR‐372 targets SMARCC1, MECP2, CDKN1, RBL2, RHOC, and TGFBR2 increased PGCLC production, whereas knockdown of the let‐7 targets CMYC and NMYC suppressed PGCLC differentiation. These findings uncover a miR‐372/let‐7 axis regulating human primordial germ cell (PGC) specification. Stem Cells 2016;34:1985–1991

Fertility preservation for boys and adolescents facing sterilizing medical therapy

Improvements in childhood cancer survival have allowed boys and their families to increasingly focus on quality of life after therapy, particularly their future ability to father children. Treatments should maintain comprehensive cancer care goals and consider the long-term quality of life of these children. While semen cryopreservation is a well-established method of fertility preservation for post-pubertal children, the use of cryopreserved pre-treatment testicular tissue represents a promising, yet experimental method of fertility preservation for prepubertal males facing sterilizing therapy. Healthcare providers should counsel families about the fertility risks of therapy, discuss or refer patients for standard fertility preservation options, and consider experimental approaches to fertility preservation while being mindful of the ethical questions these treatments raise.