Carlos Alberto Hernández Nieto

• MD, OBGYN, Reproductive Endocrinologist
• Reproductive Endocrinology and Infertility at Icahn School of Medicine at Mount Sinai

Study question: What is the rate of euploidy and the reproductive potential of embryos biopsied after 6 days of development? Summary answer: Embryos biopsied after 6 days of development have higher rates of aneuploidy; however, day 7 euploid embryos selected at transfer can achieve acceptable pregnancy rates and live birth (LB) outcomes. What i...

Objective: Genetic carrier screening has the potential to identify couples at risk of having a child affected with an autosomal recessive or X-linked disorder. However, the current prevalence of carrier status for these conditions in developing countries is not well defined. This study assesses the prevalence of carrier status of selected genetic...

Background Rates of cesarean section continue to increase worldwide. Previous work suggests an association between prior cesarean section and reduced fertility in natural and in vitro fertilization treatment cycles. To our knowledge, there is no published research exploring the relationship between a prior cesarean section and clinical outcomes aft...

Study question: What is the impact of a late follicular phase progesterone elevation (LFPE) during controlled ovarian hyperstimulation (COH) on embryonic competence and reproductive potential in thaw cycles of preimplantation genetic testing for aneuploidy (PGT-A) screened embryos? Summary answer: Our study findings suggest that LFPE, utilizing...

Objective To analyze outcomes of IVF treatment among women diagnosed with an ovarian dermoid cyst (DC). Methods Retrospective analysis of women with an ovarian DC who underwent IVF with fresh blastocyst transfer at a single center in New York from January 2010 to March 2018. Outcomes were compared between women with conservative treatment and thos...

Context Carriers of a CYP21A2 pathogenic variant exhibit distinct hormonal differences, yet their impact on assisted reproductive technology outcomes remains unknown. Objective To evaluate whether carriers of a CYP21A2 pathogenic variant exhibit differences in ovarian stimulation response and in vitro fertilization outcomes compared with non-carri...

Objective: Utilization of fertility preservation treatments has increased since the American Society for Reproductive Medicine lifted the "experimental" label for oocyte cryopreservation in 2012. This study characterizes changes in insurance coverage, clinical outcomes, and live birth probabilities over a span of a decade (2012-2022) in patients wh...

Purpose This study is to evaluate duration of oocyte cryostorage and association with thaw survival, fertilization, blastulation, ploidy rates, and pregnancy outcomes in patients seeking fertility preservation. Methods Retrospective cohort study to evaluate clinical outcomes in patients who underwent fertility preservation from 2011 to 2023 via oo...

To determine whether the embryonic euploidy rate and live birth outcomes following single, euploid embryo transfer (SEET) differ among women of self-reported racial and ethnic backgrounds. This retrospective cohort study included all infertile patients of different self-reported racial backgrounds who underwent In vitro fertilization (IVF) with pre...

OBJECTIVE: The prevalence of embryo mosaicism does not seem to be determined by the same rules that govern embryo aneuploidy, as it is neither associated with meiotic errors nor maternal age. Recent publications found higher mosaicism rates in patients with severe male factor infertility, although the underlying biological mechanism remains unknown...

Study question Does hysteroscopic endometrial peeling improve reproductive outcomes in women with implantation failure (IF) undergoing a single euploid embryo transfer (SEET)? Summary answer Women with IF may benefit from intraoperative endometrial peeling prior to a SEET. What is known already Preimplantation genetic testing for embryonic aneupl...

Purpose What is the rate of euploidy and clinical viability of embryos resulting from micro 3 pronuclei zygotes? Methods Retrospective cohort analysis in a single, academic in vitro fertilization (IVF) center from March 2018 to June 2021. Cohorts were separated by fertilization as either a 2 pronuclear zygote (2PN) or micro 3 pronuclear zygote (mi...

Study question: Do infertile couples who recently utilized clomiphene citrate (CC) for ovulation induction or ovarian stimulation (<90 days previously) followed by a single euploid embryo transfer (SEET) have lower implantation potential compared with patients who were not exposed to CC within 90 days before embryo transfer (ET)? Summary answer:...

Objective: To assess whether open and minimally invasive myomectomy are associated with changes in postoperative ovarian reserve as measured by serum anti-müllerian hormone (AMH) level. Methods: This prospective cohort study included patients who were undergoing open abdominal myomectomy that used a tourniquet or minimally invasive (robot-assist...

Study question Can implantation failure (IF) and pregnancy loss be predicted in serum prior to in vitro fertilization (IVF)? Summary answer Tumor necrosis factor (TNFα) and milk fat globule-epidermal growth factor 8 (MFG-E8) levels may serve as serum markers to predict IF and pregnancy loss. What is known already In a normal pregnancy, mediators...

Study question Do progesterone (P) levels the day after trigger for oocyte maturation impact the oocyte recovery rate? Summary answer A progesterone cutoff value of ≤ 5.0 ng/ml the day after trigger for oocyte maturation is associated with a lower oocyte recovery rate. What is known already Oocyte maturation and embryo development are controlled...

Objective To analyze the correlation between TE grading and initial β-hCG serum level after single euploid embryo transfer. Secondarily, to explore the association between TE grading with subsequent IVF outcomes. Design Retrospective cohort analysis. Setting Single, academic, private infertility and assisted reproductive care institute. Patients...

Objective: Compare maternal and perinatal outcomes between emergency and electively scheduled cesarean-hysterectomy for placenta accreta spectrum (PAS) disorders. Methods: Single-center retrospective cohort study including 125 cases of antenatally suspected and pathologically confirmed PAS disorders. Maternal and perinatal outcomes were analyzed...

Objective: To assess whether coronavirus disease 2019 (COVID-19) mRNA vaccination is associated with controlled ovarian hyperstimulation or early pregnancy outcomes. Methods: This retrospective cohort study included patients who underwent controlled ovarian hyperstimulation or single euploid frozen-thawed embryo transfer at a single academic cen...

Obstetric care in the context of COVID-19 must be supported by the best clinical practices and the most recent scientific evidence available, therefore, the development of recommendations must be based on clinical research, in order to obtain policies and practices that reduce the risk of contagion and the spread of the disease. The update of this...

Objective: Compare maternal and perinatal outcomes between emergency and elective caesarean-hysterectomy for placenta accreta spectrum (PAS) disorders managed by a multidisciplinary team. Design and setting: Single-centre retrospective cohort study Population: 125 cases of antenatally suspected and pathologically confirmed PAS disorder. Methods: Ma...

Study question Does the use of double dose of GnRH antagonists during COH in women with risk of premature LH surge alter luteinization after final oocyte maturation induction? Summary answer The use of double dose of GnRH antagonist in women with risk of premature luteinizing hormone surge dosent affect luteinization after final oocyte maturation...

Purpose: To assess whether utilization of a mathematical ranking algorithm for assistance with embryo selection improves clinical outcomes compared with traditional embryo selection via morphologic grading in single vitrified warmed euploid embryo transfers (euploid SETs). Methods: A retrospective cohort study in a single, academic center from S...

Study question Does hysteroscopic endometrial peeling improve reproductive outcomes in women with implantation failure? Design In this case series, 66 women underwent an hysteroscopic endometrial peeling and subsequently, a single frozen embryo transfer. Results After the exclusion of patients with intraoperative incidental findings, pregnancy wa...

Protocolo Mexicano actualizado Enero 2021 de infección por SARS-CoV-2 en Embarazo.

Objective: Although chromosomal heteromorphisms are commonly found in the general population, some researchers have suggested a correlation with higher rates of embryo aneuploidy. This study aimed to assess the rates of embryo aneuploidy in couples who carry a chromosome heteromorphism. Methods: The study included couples who had G-banding karyo...

Objective The current study aimed to evaluate perinatal outcomes from transfers of euploid embryos that required trophectoderm (TE) biopsy on day 7 due to delayed cavitation. Design Retrospective study Materials and Methods This study included euploid embryos that underwent IVF and preimplantation genetic testing for aneuploidy (PGT-A) from 2011 to...

Objective Recent studies have demonstrated that extended culture of blastocysts to day 7 leads to satisfactory pregnancy outcomes in patients with slow-growing embryos.1,2 However, even when confirmed to be euploid by preimplantation genetic testing for aneuploidy (PGT-A), day 7 embryos have lower rates of implantation, clinical pregnancy, and live...

Objective The coronavirus (COVID-19) pandemic has forever reshaped the United States health care system. However, assisted reproductive technology (ART) treatment remains an essential form of medicine. Reproductive practices have since incorporated vigilant practices regarding social distancing, ample use of Personal Protective Equipment (PPE), and...

Objective Elevation of progesterone (P) during day 3 of a menstrual cycle is an uncommon phenomenon during ovarian stimulation cycles. Incomplete luteolysis, endogenous P production by the adrenals and ovarian aging have been described as potential causes of baseline progesterone elevation (BPE). Some authors have postulated that BPE predicts decre...

Objective Rates of cesarean section (CS) continue to increase worldwide[1]. Although a CS is often a necessary intervention, it presents increased risk for short and long-term sequelae in mother and infant[2]. Previous work suggests an association between prior CS and reduced fertility in both natural and ART cycles [3-5]. To our knowledge, there i...

Objective PGT-A with NGS is broadly utilized by reproductive specialists at modern ART treatment centers to improve embryo transfer selection. However, there are technical limitations to PGT which might prevent formal designation of the embryo as euploid or aneuploid. While re-biopsy of the embryo is possible, some studies suggesting that the selec...

OBJECTIVE: To compare obstetrical and neonatal outcomes following single embryo transfer (SET) versus (vs.) multiple embryo transfer (MET) from frozen-thawed embryo transfer cycles (FET) of autologous pre-implan-tation genetic tested for aneuploidy (PGT-A) embryos. DESIGN: Retrospective cohort study from the SART CORS national database. MATERIALS A...

(Abstracted from Hum Reprod 2020;35:1889–1899) Although the physiologic mechanism remains unclear, late follicular phase progesterone elevation (LFPE) commonly occurs during controlled ovarian hyperstimulation (COH) for assisted-reproductive technology (ART) such as in vitro fertilization (IVF). Late follicular phase progesterone elevation has been...

Los índices elevados de fragmentación del ADN espermático no se asocian con escasa blastulación o aumento de aneuploidía embrionaria en tratamientos de fertilización in vitro Resumen OBJETIVO: Analizar la relación entre el índice de fragmentación del ADN espermático y el desarrollo embrionario; además, las tasas de euploidía embrionaria en una pobl...

Study question: Does hysteroscopic endometrial peeling improve reproductive outcomes in women with implantation failure? Summary answer: Women with implantation failure may benefit from intraoperative endometrial peeling prior to a frozen embryo transfer (FET). What is known already: Trials on endometrial scratching with pipelle and diagnostic h...

Study question: Does endometrial receptivity analysis (ERA) test offer clinical utility in patients with recurrent pregnancy loss (RPL)? Summary answer: Women with RPL may benefit from a personalized adjustment in timing of frozen embryo transfer. What is known already: Successful embryo implantation requires an appropriate embryonic development...

BACKGROUND: A positive association between hyperglycemia and impaired prognosis has been described in patients with stroke. OBJECTIVE: To evaluate whether hyperglycemia has any association with increased mortality rates or prognosis in patients with stroke. MATERIAL AND METHOD: A retrospective cohort multicenter study was performed. All patients wi...

OBJETIVO: Revisar la bibliografía de la prevalencia, factores de riesgo, síntomas, diagnósticos y tratamiento de las pacientes con istmocele. MÉTODO: Búsqueda electrónica en las bases de datos: PubMed, EMBASE y Google Scholar. Se utilizaron los siguientes términos, palabras y sus combinaciones: “Cesarean section defect, uterine niche, isthmocele,...

To assess clinical outcomes of females diagnosed with Inflammatory Bowel Disease (IBD) and infertility, which underwent in vitro fertilization (IVF) with preimplantation genetic testing for aneuploidy. (PGT-A). Retrospective cohort study comparing clinical outcomes of patients with Inflammatory bowel disease who underwent IVF with PGT-A with a subs...

Efecto del tabaquismo en la fertilidad femenina y masculina Resumen El tabaquismo tiene un efecto nocivo en la salud causando daño multisistémico y aumentando el riesgo de distintas enfermedades. La fertilidad es una de las funciones biológicas que puede verse afectada; sin embargo, los mecanismos subyacentes de este problema siguen sin estar claro...

Study question:Do women with baseline hyperandrogenemia have differential ovarian response, oocyte maturation, and/or embryo quality as compared to normoandrogenemic women? Summary answer: Despite greater ovarian reserve, hyperandrogenemic patients had similar oocyte yield, blastulation, and aneuploidy compared to normoandrogenemic women. Hyperandr...

Study question: Does endometrial biopsy (EMB) and chronic endometritis (CE) screening offer clinical utility in patients following euploid embryo implantation failure? Summary answer: Patients, regardless of endometrial biopsy findings, have similar IVF outcomes on a subsequent treatment cycle as compared with patients who do not undergo endometria...