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1.
Reprod Biol Endocrinol ; 22(1): 14, 2024 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-38243286

RESUMEN

BACKGROUND: Erythropoietin (Epo) is a potent vascular growth factor that induces angiogenesis and antiapoptotic signalling. We investigated whether the development of numerous follicles and corpora lutea during in vitro fertilization (IVF) cycle affects circulating Epo levels and further, if Epo could be used as a novel marker for ovarian hyperstimulation syndrome (OHSS). METHODS: 24 women were included in the uncomplicated IVF group and 35 women in the OHSS group. Repeated blood samples from both groups were analysed for Epo, progesterone, blood haemoglobin, and creatinine. Follicular fluid from the IVF group was analysed for Epo and progesterone. Repeated measure analysis was performed for the variables and circulating Epo levels were compared between the IVF group and early OHSS. Furthermore, related growth factors, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1) were analysed from subgroup of women to test for correlation with Epo. RESULTS: During IVF, circulating Epo increased from natural mid-luteal phase to stimulated mid-luteal phase (median 9.5; 95% CI 7.2-13.4 IU/L and 12.5; 10.3-13.4 IU/L; p = 0.003). In cycles resulting in pregnancy, Epo level decreased 14 days after oocyte pick-up (OPU) and remained low thereafter. In cycles not resulting in pregnancy, Epo level increased again 35 days after OPU. Follicle fluid Epo concentration was 1.5 times higher than the serum concentration (median 15.4; 95% CI 10.4-19.2 IU/L vs. 10.2; 8.8-12.7; p = 0.006). There was no difference in circulating Epo concentration between early OHSS and uncomplicated IVF. Circulating Epo did not correlate with VEGF or HIF-1. CONCLUSIONS: Circulating Epo levels fluctuate during IVF cycle. We hypothesise this may suggest Epo's involvement in ovarian physiology and angiogenesis. However, Epo was not a clinical marker for OHSS.


Asunto(s)
Eritropoyetina , Síndrome de Hiperestimulación Ovárica , Embarazo , Femenino , Humanos , Síndrome de Hiperestimulación Ovárica/etiología , Factor A de Crecimiento Endotelial Vascular , Progesterona , Fertilización In Vitro/métodos , Inducción de la Ovulación/efectos adversos
2.
Breast Cancer Res Treat ; 201(3): 425-435, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37491651

RESUMEN

PURPOSE: To analyze serum estradiol (E2) and estrone (E1) during letrozole treatment and their association to Quality of Life (QoL) and side-effects. METHODS: Postmenopausal breast cancer patients starting adjuvant letrozole were eligible. Serum samples were taken at baseline, three, and 12 months. E2 and FSH were measured with routine chemiluminescent immunoassays. E2 and E1 were analyzed after trial completion with a highly sensitive liquid chromatography-tandem mass spectrometry method (LC-MS/MS) with lower limits of quantification (LLOQ) of 5 pmol/L. QoL was measured at baseline and at 12 months with the EORTC QLQ-C30 and QLQ-BR23 and the Women's Health questionnaires, and menopause-related symptoms with the modified Kupperman Index. RESULTS: Of 100 screened patients 90 completed the trial. Baseline mean LC-MS/MS E2 and E1 were 12 pmol/L (range < 5-57) and 66 pmol/L (< 5-226), respectively. E2 levels measured by immunoassay and LC-MS/MS showed no correlation. E2 and E1 were completely suppressed by letrozole except for one occasion (E1 11 pmol/L at 3 months). Pain, side effects of systemic therapy, vasomotor symptoms, joint and muscle aches, and vaginal dryness increased during letrozole treatment. A high baseline E2 was significantly associated with increased aching joints and muscles, but not with the other side effects. CONCLUSIONS: Letrozole supresses E2 and E1 completely below the LLOQ of the LC-MS/MS in postmenopausal women. High pre-treatment E2 levels were associated with more joint and muscle pain during letrozole. Automated immunoassays are unsuitable for E2 monitoring during letrozole therapy due to poor sensitivity.


Asunto(s)
Neoplasias de la Mama , Estrona , Femenino , Humanos , Neoplasias de la Mama/tratamiento farmacológico , Cromatografía Liquida/métodos , Estradiol , Estrógenos/uso terapéutico , Letrozol/uso terapéutico , Posmenopausia , Estudios Prospectivos , Calidad de Vida , Espectrometría de Masas en Tándem/métodos
3.
Fertil Steril ; 120(5): 1033-1041, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37442533

RESUMEN

OBJECTIVE: To investigate whether the risk of major congenital malformations is higher in live-born singletons conceived with intracytoplasmic sperm injection (ICSI) compared with in vitro fertilization (IVF)? DESIGN: Nordic register-based cohort study. SETTING: Cross-linked data from Medical Birth Registers and National ART and Patient Registers in Denmark, Norway and Sweden. Data were included from the year the first child conceived using ICSI was born: Sweden, 1992; Denmark, 1994; and Norway, 1996. Data were included until 2014 for Denmark and 2015 for Norway and Sweden. PATIENT(S): All live-born singletons conceived using fresh ICSI (n = 32,484); fresh IVF (n = 47,178); without medical assistance (n = 4,804,844); and cryo-ICSI (n = 7,200) during the study period. INTERVENTION(S): Different in vitro conception methods, and cryopreservation of embryos. MAIN OUTCOME MEASURE(S): Risk of major congenital malformations on the basis of International Classification of Diseases codes. The European Concerted Action on Congenital Anomalies and Twins was used to differentiate between major and minor malformations. RESULT(S): Among singletons conceived using fresh ICSI, 6.0% had a major malformation, compared with 5.3% of children conceived using fresh IVF; 4.2% of children conceived without medical assistance; and 4.9% of children conceived using cryo-ICSI; adjusted odds ratio (AOR) 1.07 (95% confidence interval [CI] 1.01-1.14) in ICSI vs. IVF; and AOR 1.28 (95% CI, 1.23-1.35) in ICSI vs. no medical assistance; and AOR 1.11 (95% CI, 0.99-1.26) in ICSI fresh vs. cryo-ICSI. When malformations were grouped by different organ systems, children conceived using ICSI had a higher risk of respiratory and chromosomal malformations compared with children conceived using IVF, but there were very few cases in each group. When categorizing children conceived using ICSI according to treatment indication (male factor infertility only vs. other indications), we found a higher risk of hypospadias when ICSI was performed because of male factor infertility only (AOR 1.85 [95% CI 1.03-332]). The indications for ICSI changed over time, as male factor infertility did not remain the primary indication for ICSI throughout the study period. CONCLUSION(S): In this large cohort study, we found the risk of major malformations in live-born singletons to be slightly higher after fresh ICSI compared with fresh IVF. These findings should be considered when choosing the assisted reproductive technology method for couples without male factor infertility.


Asunto(s)
Infertilidad Masculina , Inyecciones de Esperma Intracitoplasmáticas , Niño , Masculino , Humanos , Inyecciones de Esperma Intracitoplasmáticas/efectos adversos , Estudios de Cohortes , Transferencia de Embrión , Semen , Fertilización In Vitro/efectos adversos
4.
Int J Epidemiol ; 52(2): 403-413, 2023 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-36715050

RESUMEN

BACKGROUND: Within-sibship analyses show lower perinatal mortality after assisted reproductive technology (ART) compared with natural conception (NC), a finding that appears biologically unlikely. We investigated whether this may be attributed to bias from selective fertility and carryover effects. METHODS: Using data from national registries in Denmark (1994-2014), Finland (1990-2014) and Norway and Sweden (1988-2015), we studied 5 722 826 singleton pregnancies, including 119 900 ART-conceived and 37 590 exposure-discordant sibships. Perinatal mortality at the population level and within sibships was compared using multilevel logistic regression with random and fixed intercepts, respectively. We estimated selective fertility as the proportion of primiparous women with and without perinatal loss who had a second delivery, and carryover effects through bidirectional and crosswise associations. RESULTS: Population analysis showed higher perinatal mortality among ART conception compared with NC (odds ratio 1.21, 95% CI 1.13 to 1.30), whereas within-sibship analysis showed the opposite (OR 0.36, 95% CI 0.31 to 0.43). Primiparous women with perinatal loss were more likely to give birth again (selective fertility) and to use ART in this subsequent pregnancy (carryover effects), resulting in strong selection of double-discordant sibships with death of the naturally conceived and survival of the ART-conceived sibling. After controlling for conception method and outcome in the first pregnancy, ART was not consistently associated with perinatal mortality in the second pregnancy. CONCLUSIONS: Whereas population estimates may be biased by residual confounding, within-sibship estimates were biased by selective fertility and carryover effects. It remains unclear whether ART conception contributes to perinatal mortality.


Asunto(s)
Mortalidad Perinatal , Nacimiento Prematuro , Técnicas Reproductivas Asistidas , Femenino , Humanos , Recién Nacido , Embarazo , Fertilidad , Finlandia/epidemiología , Noruega/epidemiología , Resultado del Embarazo/epidemiología , Nacimiento Prematuro/epidemiología , Técnicas Reproductivas Asistidas/estadística & datos numéricos
5.
Fertil Steril ; 119(2): 265-276, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36567207

RESUMEN

OBJECTIVES: To investigate whether risks of stillbirth and neonatal death differ after fresh embryo transfers (fresh-ETs) and frozen embryo transfers (frozen-ETs) compared with singletons conceived without medical assistance. DESIGN: A population-based cohort study. SETTING: Not applicable. PATIENT(S): Data linkage between the nationwide Medical Birth Registries in Denmark (1994-2014), Norway and Sweden (1988-2015), and national quality registries and databases on assisted reproductive technology identified a total of 4,590,853 singletons, including 78,642 conceived by fresh-ET and 18,084 by frozen-ET. INTERVENTION(S): None MAIN OUTCOME MEASURE(S): Stillbirth (fetal death before and during delivery) and neonatal death (live born with death 0-27 days postpartum). RESULT(S): Overall, 17,123 (0.37%) singletons were stillborn and 7,685 (0.17%) died neonatally. Compared with singletons conceived without medical assistance, the odds of stillbirth were similar after fresh-ET and frozen-ET, whereas the odds of neonatal death were high after fresh-ET (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.46-1.95) and frozen-ET (OR, 1.51; 95% CI, 1.08-2.10). Preterm birth (<37 gestational weeks) was more common after fresh-ET (8.0%) and frozen-ET (6.6%) compared with singletons conceived without medical assistance (5.0%), and strongly associated with neonatal mortality across all conception methods. Within gestational age categories, risk of stillbirth and neonatal death was similar for all conception methods, except that singletons from fresh-ET had a higher risk of stillbirth during gestational week 22-27 (OR, 1.85; 95% CI, 1.51-2.26). CONCLUSION(S): Overall, the risk of stillbirth was similar after fresh-ET and frozen-ET compared with singletons conceived without medical assistance, whereas neonatal mortality was high, possibly mediated by the high risk of preterm birth when compared with singletons conceived without medical assistance. Our results gave no clear support for choosing one treatment over the other.


Asunto(s)
Muerte Perinatal , Nacimiento Prematuro , Embarazo , Femenino , Recién Nacido , Humanos , Mortinato/epidemiología , Estudios de Cohortes , Nacimiento Prematuro/epidemiología , Transferencia de Embrión/métodos , Técnicas Reproductivas Asistidas/efectos adversos , Tecnología , Estudios Retrospectivos
6.
Br J Cancer ; 128(5): 825-832, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36550209

RESUMEN

BACKGROUND: There is concern that assisted reproductive technology (ART) may increase ovarian cancer risk, but previous studies are inconclusive. We compared ovarian cancer risk for women who gave birth after ART vs natural conception. METHODS: Through linkage of nationwide registry data, we followed 3,303,880 initially nulliparous women in Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015) and Sweden (1985-2015) from first pregnancy ≥22 weeks to ovarian cancer, emigration, death or end of follow-up (2014/2015). We estimated hazard ratios (HRs), adjusting for age, parity, maternal birth year and country, and for body mass index and smoking in subsamples. RESULTS: Mean age at first birth was 27.7 years. During a mean follow-up of 14.4 person-years, 2683 participants (0.08%) developed ovarian cancer; 135 after ART and 2548 after natural conception only (incidence rates 11.6 and 5.5 per 100,000 person-years, respectively). The risk was higher for women who ever gave birth after ART (HR 1.70, 95% confidence interval 1.42-2.03) compared to natural conception. Associations were stronger for conventional in vitro fertilisation than for intracytoplasmic sperm injection. CONCLUSIONS: Among parous women, ART-conception was associated with a higher risk of ovarian cancer than natural conception. Further studies should decipher whether this is causal or confounded by infertility or other factors.


Asunto(s)
Neoplasias Ováricas , Semen , Embarazo , Masculino , Femenino , Humanos , Adulto , Estudios de Cohortes , Estudios de Seguimiento , Técnicas Reproductivas Asistidas , Sistema de Registros
7.
Hypertension ; 80(2): e6-e16, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36154568

RESUMEN

BACKGROUND: Frozen embryo transfer (frozen-ET) is increasingly common because of improved cryopreservation methods and elective freezing of all embryos. Frozen-ET is associated with higher risk of hypertensive disorders in pregnancy than both natural conception and fresh embryo transfer (fresh-ET), but whether this is attributable to parental factors or treatment is unknown. METHODS: Using the Medical Birth Registries of Denmark (1994-2014), Norway, and Sweden (1988-2015), linked to data from national quality registries and databases on assisted reproduction, we designed a population-based cohort study with within-sibship comparison. We included 4 426 691 naturally conceived, 78 300 fresh-ET, and 18 037 frozen-ET singleton pregnancies, of which 33 209 sibships were conceived using different conception methods. Adjusted odds ratios (aOR) of hypertensive disorders in pregnancy for fresh-ET and frozen-ET versus natural conception with 95% CI were estimated using multilevel logistic regression, where random effects provided conventional population-level estimates and fixed effects gave within-sibship estimates. Main models included adjustment for birth year, maternal age, parity, and country. RESULTS: Risk of hypertensive disorders in pregnancy was higher after frozen-ET compared to natural conception, both at population-level (7.4% versus 4.3%, aOR, 1.74 [95% CI, 1.61-1.89]) and within sibships (aOR, 2.02 [95% CI, 1.72-2.39]). For fresh-ET, risk was similar to natural conception, both at population-level (aOR, 1.02 [95% CI, 0.98-1.07]) and within sibships (aOR, 0.99 [95% CI, 0.89-1.09]). CONCLUSIONS: Frozen-ET was associated with substantially higher risk of hypertensive disorders in pregnancy, even after accounting for shared parental factors within sibships.


Asunto(s)
Hipertensión Inducida en el Embarazo , Embarazo , Femenino , Humanos , Hipertensión Inducida en el Embarazo/epidemiología , Estudios de Cohortes , Transferencia de Embrión/efectos adversos , Transferencia de Embrión/métodos , Fertilización In Vitro/efectos adversos , Fertilización In Vitro/métodos , Reproducción , Estudios Retrospectivos
8.
Acta Obstet Gynecol Scand ; 101(12): 1374-1385, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36210542

RESUMEN

INTRODUCTION: Currently, recurrent pregnancy loss (RPL) examinations focus on the woman, although paternal factors are also involved. Men in couples with RPL have higher sperm DNA fragmentation levels than fertile men, but the effect of sperm DNA damage on couple's later prognosis is unknown. Advanced maternal age and obesity are associated with RPL, but paternal lifestyle factors are less studied. Therefore, we aimed to study the associations of couples' lifestyle factors, causes of RPL, and sperm DNA fragmentation with their prognosis of future live birth. MATERIAL AND METHODS: This descriptive cohort study comprised 506 couples investigated for RPL at Helsinki University Hospital, Finland, between 2007 and 2016, linked with national health and population registers. The primary outcome was couple's live birth after RPL investigations. Data on couple's background factors, including age, body mass index, smoking, and alcohol use, were collected from medical records. Sperm DNA fragmentation index was analyzed from 211 men using the sperm chromatin dispersion test. The associations between background factors, sperm DNA fragmentation, and cumulative probability of live birth over time were analyzed using cross-tabulations and age-adjusted Cox regression. RESULTS: In all, 352 of 506 couples (69.6%) achieved live birth. Maternal age, unexplained RPL, prolonged pregnancy attempts before investigations, paternal obesity, and maternal smoking were associated with prognosis: unadjusted hazard ratio for couple's live birth for women aged 35-39 vs younger than 30 years was 0.63 (95% confidence interval [CI] 0.47-0.84), and for 40 years or older was 0.36 (95% CI 0.22-0.58). Age-adjusted hazard ratio for unexplained vs explained RPL was 1.39 (95% CI 1.12-1.72), for couple's pregnancy attempt at least 4 years vs less than 2 years was 0.50 (95% CI 0.33-0.76), for paternal body mass index at least 30 kg/m2 vs less than 25 kg/m2 was 0.67 (95% CI 0.46-0.98), and for maternal smoking was 0.71 (95% CI 0.51-0.99). Altogether, 96/135 (71.1%) couples with normal (<15%), 38/60 (63.3%) with intermediate (15-30%), and 11/16 (68.8%) with high sperm DNA fragmentation index achieved live birth (p = 0.56). CONCLUSIONS: In couples with RPL, prolonged pregnancy attempts, a cause found in RPL examinations, lifestyle factors, and maternal age are negatively associated with their prognosis of future live birth. Sperm DNA fragmentation was not associated, but the number of men with damaged spermatozoa was small. We suggest that clinicians include women and men in RPL counseling because couple's joint lifestyle seems to determine their later prognosis.


Asunto(s)
Aborto Habitual , Embarazo Prolongado , Embarazo , Masculino , Femenino , Humanos , Adulto , Nacimiento Vivo , Estudios de Cohortes , Semen , Aborto Habitual/etiología , Espermatozoides , Pronóstico , Obesidad/epidemiología , Obesidad/complicaciones , ADN
9.
PLoS Med ; 19(9): e1004078, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36048761

RESUMEN

BACKGROUND: The aim was to investigate whether children born after assisted reproduction technology (ART), particularly after frozen-thawed embryo transfer (FET), are at higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. METHODS AND FINDINGS: We performed a registry-based cohort study using data from the 4 Nordic countries: Denmark, Finland, Norway, and Sweden. The study included 7,944,248 children, out of whom 171,774 children were born after use of ART (2.2%) and 7,772,474 children were born after spontaneous conception, representing all children born between the years 1994 to 2014 in Denmark, 1990 to 2014 in Finland, 1984 to 2015 in Norway, and 1985 to 2015 in Sweden. Rates for any cancer and specific cancer groups in children born after each conception method were determined by cross-linking national ART registry data with national cancer and health data registries and population registries. We used Cox proportional hazards models to estimate the risk of any cancer, with age as the time scale. After a mean follow-up of 9.9 and 12.5 years, the incidence rate (IR) of cancer before age 18 years was 19.3/100,000 person-years for children born after ART (329 cases) and 16.7/100,000 person-years for children born after spontaneous conception (16,184 cases). Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96 to 1.21, p = 0.18. Adjustment was performed for sex, plurality, year of birth, country of birth, maternal age at birth, and parity. Children born after FET had a higher risk of cancer (48 cases; IR 30.1/100,000 person-years) compared to both fresh embryo transfer (IR 18.8/100,000 person-years), aHR 1.59, 95% CI 1.15 to 2.20, p = 0.005, and spontaneous conception, aHR 1.65, 95% CI 1.24 to 2.19, p = 0.001. Adjustment either for macrosomia, birth weight, or major birth defects attenuated the association marginally. Higher risks of epithelial tumors and melanoma after any assisted reproductive method and of leukemia after FET were observed. The main limitation of this study is the small number of children with cancer in the FET group. CONCLUSIONS: Children born after FET had a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. The results should be interpreted cautiously based on the small number of children with cancer, but the findings raise concerns considering the increasing use of FET, in particular freeze-all strategies without clear medical indications. TRIAL REGISTRATION: Trial registration number: ISRCTN 11780826.


Asunto(s)
Transferencia de Embrión , Neoplasias , Adolescente , Peso al Nacer , Niño , Estudios de Cohortes , Transferencia de Embrión/efectos adversos , Femenino , Humanos , Recién Nacido , Neoplasias/epidemiología , Neoplasias/etiología , Embarazo , Técnicas Reproductivas Asistidas/efectos adversos , Estudios Retrospectivos
10.
Reprod Biomed Online ; 45(5): 1021-1031, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35934639

RESUMEN

RESEARCH QUESTION: Is the composition of the endometrial or vaginal microbiota associated with recurrent pregnancy loss (RPL)? DESIGN: Endometrial and vaginal samples were collected from 47 women with two or more consecutive pregnancy losses and 39 healthy control women without a history of pregnancy loss, between March 2018 and December 2020 at Helsinki University Hospital, Helsinki, Finland. The compositions of the endometrial and vaginal microbiota, analysed using 16S rRNA gene amplicon sequencing, were compared between the RPL and control women, and between individual vaginal and endometrial samples. The mycobiota composition was analysed using internal transcribed spacer 1 amplicon sequencing for a descriptive summary. The models were adjusted for body mass index, age and parity. False discovery rate-corrected P-values (q-values) were used to define nominal statistical significance at q < 0.05. RESULTS: Lactobacillus crispatus was less abundant in the endometrial samples of women with RPL compared with controls (mean relative abundance 17.2% versus 45.6%, q = 0.04). Gardnerella vaginalis was more abundant in the RPL group than in controls in both endometrial (12.4% versus 5.8%, q < 0.001) and vaginal (8.7% versus 5.7%, q = 0.002) samples. The individual vaginal and endometrial microbial compositions correlated strongly (R = 0.85, P < 0.001). Fungi were detected in 22% of the endometrial and 36% of the vaginal samples. CONCLUSIONS: Dysbiosis of the reproductive tract microbiota is associated with RPL and may represent a novel risk factor for pregnancy losses.


Asunto(s)
Aborto Habitual , Microbiota , Embarazo , Femenino , Humanos , Estudios de Casos y Controles , ARN Ribosómico 16S/genética , Vagina/microbiología
11.
Acta Obstet Gynecol Scand ; 101(7): 779-786, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35546786

RESUMEN

INTRODUCTION: The incidence of ectopic pregnancy is up to four times higher after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) than in spontaneous pregnancies, and the risk of ectopic pregnancy is increased by tubal factor infertility and the transfer of multiple embryos. However, the effect of embryo quality on the probability of ectopic pregnancy has not been investigated until now and it is not clear whether ovarian stimulation parameters affect the incidence of ectopic pregnancy. MATERIAL AND METHODS: An historical cohort study of 15 006 clinical pregnancies (diagnosed by ultrasound at 6-8 gestational weeks) after non-donor IVF/ICSI with fresh embryo transfer (n = 8952) or frozen-thawed embryo transfer (n = 6054). Treatments were performed during 2000-2017 in Finland. A total of 9207 (61.4%) single and 5799 (38.6%) double embryo transfers of no more than one top-quality embryo were evaluated. We analyzed the effects of multiple factors on ectopic pregnancy by logistic regression, including type of cycle (fresh vs frozen embryo transfer), female age, number and quality of embryos transferred, tubal factor infertility and factors of ovarian response to gonadotropin stimulation. RESULTS: Ectopic pregnancy was observed in 2.3% of cycles. There was no significant difference in ectopic pregnancy rate after fresh embryo transfer and frozen embryo transfer (2.2% vs 2.4%, p = 0.3). The ectopic pregnancy rate was lower in cycles with top-quality embryo transfer (1.9%) than of those where only non-top quality embryos were transferred (2.7%, p < 0.0001). Tubal factor infertility was diagnosed more often in ectopic pregnancy than in intrauterine pregnancies (21.2% vs 11.0%, p < 0.0001). Logistic regression revealed lower odds for ectopic pregnancy after a top-quality embryo transfer than after transfer of a non-top quality embryo (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.56-0.92, p = 0.007). Transfer of two vs one embryo (OR 1.35, 95% CI 1.05-1.70, p = 0.02) and tubal factor infertility (OR 2.21, 95% CI 1.68-2.91, p < 0.0001) significantly increased the risk of ectopic pregnancy. CONCLUSIONS: Transfer of non-top quality embryos is associated with a higher rate of ectopic pregnancy. This is particularly important to keep in mind in treatments with only non-top embryos available even in the absence of tubal factor infertility. To minimize the risk of ectopic pregnancy, the number of embryos transferred should be as low as possible.


Asunto(s)
Infertilidad , Embarazo Ectópico , Estudios de Cohortes , Transferencia de Embrión/efectos adversos , Femenino , Fertilización In Vitro/efectos adversos , Humanos , Infertilidad/terapia , Embarazo , Índice de Embarazo , Embarazo Ectópico/epidemiología , Embarazo Ectópico/etiología , Estudios Retrospectivos
12.
Fertil Steril ; 117(5): 1026-1037, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35216828

RESUMEN

OBJECTIVE: To assess the risk of neurodevelopmental disorders in singletons born after the use of assisted reproductive technology (ART) compared with singletons born without the use of ART. DESIGN: Nordic register-based study. SETTING: Cross-linked data from Medical Birth Registers and National ART and Patient Registers; liveborn singletons in 1995-2014 in Denmark and Finland, 2005-2015 in Norway, and 1995-2015 in Sweden with follow-up to 2014 (Denmark and Finland) or 2015 (Norway and Sweden). PATIENTS: A total of 5,076,444 singletons: 116,909 (2.3%) born with and 4,959,535 (97.7%) born without the use of ART (non-ART). INTERVENTIONS: In vitro fertilization, intracytoplasmic sperm injection, and fresh and frozen embryo transfer. MAIN OUTCOME MEASURES: The primary outcomes (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes) were learning and motor functioning disorders (F80-F83), autism spectrum disorder (F84), attention-deficit/hyperactivity disorder and conduct disorders (F90-F92), and tic disorders (F95). Crude hazard ratios (HRs) and adjusted hazard ratios (aHRs) with 95% confidence intervals were calculated. RESULTS: Singletons in the ART cohort had a higher adjusted risk of learning and motor functioning disorders (HR, 1.01 [0.96-1.07]; aHR, 1.17 [1.11-1.24]) and a tendency toward a higher risk of autism spectrum disorder (HR, 1.12 [1.04-1.21]; aHR, 1.07 [0.98-1.16]) and attention-deficit/hyperactivity disorder and conduct disorders (HR, 0.82 [0.77-0.86]; aHR, 1.17 [0.99-1.12]) but not of tic disorders (HR, 1.21 [1.06-1.38]; aHR, 1.17 [0.96-1.27]). No differences in risk were found between children born after in vitro fertilization and intracytoplasmic sperm injection or after fresh and frozen embryo transfer. CONCLUSIONS: Our findings of only small differences in neurodevelopment between ART and non-ART singletons are reassuring and in line with previous studies.


Asunto(s)
Trastorno del Espectro Autista , Trastornos de Tic , Niño , Transferencia de Embrión , Femenino , Humanos , Morbilidad , Embarazo , Técnicas Reproductivas Asistidas/efectos adversos
13.
Front Psychol ; 12: 761864, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34925164

RESUMEN

This person-oriented study aimed to identify adolescents' hierarchical attachment profiles with parents and peers, and to analyze associations between the profiles and adolescent psychosocial adjustment. Participants were 449 Finnish 17-19-year-olds reporting their attachments to mother, father, best friend, and romantic partner and details on mental health (internalizing symptoms, inattention/hyperactivity, and anger control problems) and risk-taking behavior (substance use and sexual risk-taking). Attachment was measured with Experiences in Close Relationships - Relationship Structures (ECR-RS); internalizing, inattention/hyperactivity, and anger control problems with Self-Report of Personality - Adolescent (SRP-A) of the Behavior Assessment System for Children, third edition (BASC-3); substance use with the Consumption scale of the Alcohol Use Disorders Identification Test (AUDIT-C) and items from the Finnish School Health Promotion Study; and sexual risk-taking behavior with the Cognitive Appraisal of Risky Events (CARE). Latent profile analysis identified five attachment profiles: "All secure" (39%), "All insecure" (11%), "Parents insecure - Peers secure" (21%), "Parents secure - Friend insecure" (10%), and "Parents secure - Partner insecure" (19%). "All insecure" adolescents showed the highest and "All secure" adolescents the lowest levels of mental health problems and substance use. Further, parental attachment security seemed to specifically prevent substance use and anger control problems, while peer attachment security prevented internalizing problems. Our findings help both understand the organization of attachment hierarchies in adolescence and refine the role of specific attachment relationships in psychosocial adjustment, which can be important for clinical interventions in adolescence.

14.
Front Endocrinol (Lausanne) ; 12: 784195, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34917035

RESUMEN

Objective: In autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) defects in the autoimmune regulator gene lead to impaired immunotolerance. We explored the effects of immunodeficiency and endocrinopathies on gynecologic health in patients with APECED. Design: Cross-sectional cohort study combined with longitudinal follow-up data. Methods: We carried out a gynecologic evaluation, pelvic ultrasound, and laboratory and microbiologic assessment in 19 women with APECED. Retrospective data were collected from previous study visits and hospital records. Results: The study subjects' median age was 42.6 years (range, 16.7-65.5). Sixteen patients (84%) had premature ovarian insufficiency, diagnosed at the median age of 16.5 years; 75% of them used currently either combined contraception or hormonal replacement therapy. In 76% of women, the morphology and size of the uterus were determined normal for age, menopausal status, and current hormonal therapy. Fifteen patients (79%) had primary adrenal insufficiency; three of them used dehydroepiandrosterone substitution. All androgen concentrations were under the detection limit in 11 patients (58%). Genital infections were detected in nine patients (47%); most of them were asymptomatic. Gynecologic C. albicans infection was detected in four patients (21%); one of the strains was resistant to azoles. Five patients (26%) had human papillomavirus infection, three of which were high-risk subtypes. Cervical cell atypia was detected in one patient. No correlation between genital infections and anti-cytokine autoantibodies was found. Conclusions: Ovarian and adrenal insufficiencies manifested with very low androgen levels in over half of the patients. Asymptomatic genital infections, but not cervical cell atypia, were common in female patients with APECED.


Asunto(s)
Enfermedades de los Genitales Femeninos/diagnóstico , Enfermedades de los Genitales Femeninos/epidemiología , Poliendocrinopatías Autoinmunes/diagnóstico , Poliendocrinopatías Autoinmunes/epidemiología , Adolescente , Adulto , Anciano , Autoanticuerpos/sangre , Estudios de Cohortes , Estudios Transversales , Enfermedades del Sistema Endocrino/sangre , Enfermedades del Sistema Endocrino/diagnóstico , Enfermedades del Sistema Endocrino/epidemiología , Femenino , Finlandia/epidemiología , Estudios de Seguimiento , Enfermedades de los Genitales Femeninos/sangre , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Poliendocrinopatías Autoinmunes/sangre , Estudios Retrospectivos
15.
PLoS Med ; 18(9): e1003723, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34491995

RESUMEN

BACKGROUND: Some earlier studies have found indications of significant changes in cardiometabolic risk factors in children born after assisted reproductive technology (ART). Most of these studies are based on small cohorts with high risk of selection bias. In this study, we compared the risk of cardiovascular disease, obesity, and type 2 diabetes between singleton children born after ART and singleton children born after spontaneous conception (SC). METHODS AND FINDINGS: This was a large population-based cohort study of individuals born in Norway, Sweden, Finland, and Denmark between 1984 and 2015. Data were obtained from national ART and medical birth registers and cross-linked with data from national patient registers and other population-based registers in the respective countries. In total, 122,429 children born after ART and 7,574,685 children born after SC were included. Mean (SD) maternal age was 33.9 (4.3) years for ART and 29.7 (5.2) for SC, 67.7% versus 41.8% were primiparous, and 45.2% versus 32.1% had more than 12 years of education. Preterm birth (<37 weeks 0 days) occurred in 7.9% of children born after ART and 4.8% in children born after SC, and 5.7% versus 3.3% had a low birth weight (<2,500 g). Mean (SD) follow-up time was 8.6 (6.2) years for children born after ART and 14.0 (8.6) years for children born after SC. In total, 135 (0.11%), 645 (0.65%), and 18 (0.01%) children born after ART were diagnosed with cardiovascular disease (ischemic heart disease, cardiomyopathy, heart failure, or cerebrovascular disease), obesity or type 2 diabetes, respectively. The corresponding values were 10,702 (0.14%), 30,308 (0.74%), and 2,919 (0.04%) for children born after SC. In the unadjusted analysis, children born after ART had a significantly higher risk of any cardiovascular disease (hazard ratio [HR] 1.24; 95% CI 1.04-1.48; p = 0.02), obesity (HR 1.13; 95% CI 1.05-1.23; p = 0.002), and type 2 diabetes (HR 1.71; 95% CI 1.08-2.73; p = 0.02). After adjustment, there was no significant difference between children born after ART and children born after SC for any cardiovascular disease (adjusted HR [aHR]1.02; 95% CI 0.86-1.22; p = 0.80) or type 2 diabetes (aHR 1.31; 95% CI 0.82-2.09; p = 0.25). For any cardiovascular disease, the 95% CI was reasonably narrow, excluding effects of a substantial magnitude, while the 95% CI for type 2 diabetes was wide, not excluding clinically meaningful effects. For obesity, there was a small but significant increased risk among children born after ART (aHR 1.14; 95% CI 1.06-1.23; p = 0.001). Important limitations of the study were the relatively short follow-up time, the limited number of events for some outcomes, and that the outcome obesity is often not considered as a disease and therefore not caught by registers, likely leading to an underestimation of obesity in both children born after ART and children born after SC. CONCLUSIONS: In this study, we observed no difference in the risk of cardiovascular disease or type 2 diabetes between children born after ART and children born after SC. For obesity, there was a small but significant increased risk for children born after ART. TRIAL REGISTRATION NUMBER: ISRCTN11780826.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Infertilidad/terapia , Obesidad Infantil/epidemiología , Técnicas Reproductivas Asistidas/efectos adversos , Adolescente , Adulto , Factores de Edad , Enfermedades Cardiovasculares/diagnóstico , Niño , Diabetes Mellitus Tipo 2/diagnóstico , Femenino , Humanos , Infertilidad/diagnóstico , Infertilidad/epidemiología , Masculino , Obesidad Infantil/diagnóstico , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Países Escandinavos y Nórdicos/epidemiología , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
16.
Reprod Biomed Online ; 43(4): 719-726, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34493461

RESUMEN

RESEARCH QUESTION: Is the growth of term singletons born after frozen embryo transfer (FET) comparable to those born after fresh embryo transfer and natural conception up to 5 years of age? DESIGN: Observational cohort study in an academic medical centre and municipal child health clinics with repeated measurements carried out by medical professionals. Term singletons born after FET (n = 110) and fresh embryo transfer (n = 181) and their matched natural conception controls (n = 543) born in Oulu, Northern Finland, were included. Mean weights, lengths, heights and head circumferences at the ages of 4, 8 and 18 months and 3 and 5 years were compared. At 3 and 5 years, body mass indices were compared. RESULTS: Childhood growth did not differ between term singletons born after FET, fresh embryo transfer and natural conception, correcting for exact age at measurement and adjusting for maternal body mass index and paternal height. CONCLUSIONS: Similar growth between children born after FET, fresh embryo transfer and natural conception offers reassurance of the safety and feasibility of the steadily increasing use of embryo cryopreservation in assisted reproduction.


Asunto(s)
Desarrollo Infantil , Criopreservación/estadística & datos numéricos , Transferencia de Embrión/estadística & datos numéricos , Embrión de Mamíferos , Crecimiento , Adulto , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Embarazo , Estudios Retrospectivos
17.
Front Psychol ; 12: 582770, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34149494

RESUMEN

The quality of parenting shapes the development of children's emotion regulation. However, the relative importance of parenting in different developmental stages, indicative of sensitive periods, has rarely been studied. Therefore, we formulated four hypothetical developmental timing models to test the stage-specific effects of mothering and fathering in terms of parental autonomy and intimacy in infancy, middle childhood, and late adolescence on adolescents' emotion regulation. The emotion regulation included reappraisal, suppression, and rumination. We hypothesized that both mothering and fathering in each developmental stage contribute unique effects to adolescents' emotion regulation patterns. The participants were 885 families followed from pregnancy to late adolescence. This preregistered study used data at the children's ages of 1 year, 7 to 8 years, and 18 years. At each measurement point, maternal and paternal autonomy and intimacy were assessed with self- and partner reports using the Subjective Family Picture Test. At the age of 18 years, adolescents' reappraisal and suppression were assessed using the Emotion Regulation Questionnaire and rumination using the Cognitive Emotion Regulation Questionnaire. Stage-specific effects were tested comparing structural equation models. Against our hypotheses, the results showed no effects of mothering or fathering in infancy, middle childhood, or late adolescence on adolescents' emotion regulation patterns. The results were consistent irrespective of both the reporter (i.e., self or partner) and the parental dimension (i.e., autonomy or intimacy). In addition to our main results, there were relatively low agreement between the parents in each other's parenting and descriptive discontinuity of parenting across time (i.e., configural measurement invariance). Overall, we found no support for the stage-specific effects of parent-reported parenting in infancy, middle childhood, or late adolescence on adolescents' emotion regulation. Instead, our findings might reflect the high developmental plasticity of emotion regulation from infancy to late adolescence.

18.
PLoS Med ; 18(6): e1003683, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34170923

RESUMEN

BACKGROUND: Compared to naturally conceived children, adverse perinatal outcomes are more common among children born after assisted reproductive technology with fresh embryo transfer (fresh-ET) or frozen embryo transfer (frozen-ET). However, most previous studies could not adequately control for family confounding factors such as subfertility. We compared birth size and duration of pregnancy among infants born after fresh-ET or frozen-ET versus natural conception, using a within-sibship design to account for confounding by maternal factors. METHODS AND FINDINGS: This registry-based cohort study with nationwide data from Denmark (1994-2014), Norway (1988-2015), and Sweden (1988-2015) consisted of 4,510,790 live-born singletons, 4,414,703 from natural conception, 78,095 from fresh-ET, and 17,990 from frozen-ET. We identified 33,056 offspring sibling groups with the same mother, conceived by at least 2 different conception methods. Outcomes were mean birthweight, small and large for gestational age, mean gestational age, preterm (<37 weeks, versus ≥37), and very preterm birth (<32 weeks, versus ≥32). Singletons born after fresh-ET had lower mean birthweight (-51 g, 95% CI -58 to -45, p < 0.001) and increased odds of small for gestational age (odds ratio [OR] 1.20, 95% CI 1.08 to 1.34, p < 0.001), while those born after frozen-ET had higher mean birthweight (82 g, 95% CI 70 to 94, p < 0.001) and increased odds of large for gestational age (OR 1.84, 95% CI 1.56 to 2.17, p < 0.001), compared to naturally conceived siblings. Conventional population analyses gave similar results. Compared to naturally conceived siblings, mean gestational age was lower after fresh-ET (-1.0 days, 95% CI -1.2 to -0.8, p < 0.001), but not after frozen-ET (0.3 days, 95% CI 0.0 to 0.6, p = 0.028). There were increased odds of preterm birth after fresh-ET (OR 1.27, 95% CI 1.17 to 1.37, p < 0.001), and in most models after frozen-ET, versus naturally conceived siblings, with somewhat stronger associations in population analyses. For very preterm birth, population analyses showed increased odds for both fresh-ET (OR 2.03, 95% CI 1.90 to 2.12, p < 0.001) and frozen-ET (OR 1.66, 95% CI 1.42 to 1.94, p < 0.001) compared with natural conception, but results were notably attenuated within siblings (OR 1.18, 95% CI 1.0 to 1.41, p = 0.059, and OR 0.92, 95% CI 0.67 to 1.27, p = 0.6, for fresh-ET and frozen-ET, respectively). Sensitivity analyses in full siblings, in siblings born within 3-year interval, by birth order, and restricting to single embryo transfers and blastocyst transfers were consistent with the main analyses. Main limitations were high proportions of missing data on maternal body mass index and smoking. CONCLUSIONS: We found that infants conceived by fresh-ET had lower birthweight and increased odds of small for gestational age, and those conceived by frozen-ET had higher birthweight and increased odds of large for gestational age. Conception by either fresh-ET or frozen-ET was associated with increased odds of preterm birth. That these findings were observed within siblings, as well as in conventional multivariable population analyses, reduces the likelihood that they are explained by confounding or selection bias. TRIAL REGISTRATION: ClinicalTrials.gov ISRCTN11780826.


Asunto(s)
Criopreservación , Transferencia de Embrión , Infertilidad/terapia , Adulto , Peso al Nacer , Transferencia de Embrión/efectos adversos , Femenino , Fertilidad , Fertilización In Vitro , Edad Gestacional , Humanos , Recién Nacido de Bajo Peso , Recien Nacido Prematuro , Recién Nacido Pequeño para la Edad Gestacional , Infertilidad/diagnóstico , Infertilidad/fisiopatología , Nacimiento Vivo , Embarazo , Resultado del Embarazo , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Países Escandinavos y Nórdicos , Resultado del Tratamiento
19.
Hum Reprod ; 36(8): 2358-2370, 2021 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-34051081

RESUMEN

STUDY QUESTION: Are the decreasing multiple birth rates after ART associated with a simultaneous drop in the incidence of cerebral palsy (CP) in ART children over time? SUMMARY ANSWER: The relative odds of CP in ART children have declined in the Nordic countries over the past two decades concurrently with declining multiple birth rates. WHAT IS KNOWN ALREADY: In the Nordic countries, the rate of twin pregnancies after ART has decreased from 30% in the early 1990s to 4-13% in 2014, following the implementation of elective single embryo transfer (SET). Consequently, preterm birth rates have declined substantially in ART pregnancies. However, whether the risk of CP, a known consequence of preterm birth, has decreased correspondingly is still unknown. STUDY DESIGN, SIZE, DURATION: Retrospective register-based cohort study based on data on all singletons, twins, and higher-order multiples born in Denmark (birth year 1994-2010), Finland (1990-2010), and Sweden (1990-2014), corresponding to 111 844 ART children and 4 679 351 spontaneously conceived children. PARTICIPANTS/MATERIAL, SETTING, METHODS: Data were obtained from a large Nordic cohort of children born after ART and spontaneous conception initiated by the Committee of Nordic ART and Safety-CoNARTaS. The CoNARTaS cohort was established by cross-linking national register data using the unique personal identification number, allocated to every citizen in the Nordic countries. Data from the National Medical Birth Registers, where information on maternal, obstetric, and perinatal outcomes is recorded, were cross-linked to data from the National ART- and Patients Registers to obtain information on fertility treatments and CP diagnoses. Relative risks of CP for ART compared to spontaneous conception were estimated as odds ratios from multivariate logistic regression analyses across all birth years, as well as for the following birth year categories: 1990-1993, 1994-1998, 1999-2002, 2003-2006, 2007-2010, and 2011-2014. Analyses were made for all children and for singletons and twins, separately. MAIN RESULTS AND THE ROLE OF CHANCE: The main outcome measure was the relative odds of CP in different time periods for ART versus spontaneously conceived children. CP was diagnosed in 661 ART children and 16 478 spontaneously conceived children born between 1990 and 2014. In 1990-1993, the relative odds of CP were substantially higher in all ART children (adjusted odds ratio (aOR) 2.76 (95% CI 2.03-3.67)) compared with all spontaneously conceived children, while in 2011-2014, it was only moderately higher (aOR 1.39 (95% CI 1.01-1.87)). In singletons, the higher relative odds of CP in ART children diminished over time from 1990 to 1993 (aOR 2.02 (95% CI 1.22-3.14)) to 2003-2006 (aOR 1.18 (95% CI 0.91-1. 49)) and was not significantly increased for birth cohorts 2007-2010 and 2011-2014. For ART twins versus spontaneously conceived twins, the relative odds of CP was not statistically significantly increased throughout the study period. LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study was a shorter follow-up time and younger age at first CP diagnosis for ART children compared with spontaneously conceived children. However, analyses ensuring a minimum of bias from differences in age at CP diagnosis and follow-up time confirmed the results, hence, we do not consider this to cause substantial bias. WIDER IMPLICATIONS OF THE FINDINGS: A SET policy in ART treatments has the potential to reduce the increased risk of cerebral palsy in the ART population due to lower rates of multiple deliveries. At a time with high survival rates of frozen/thawed embryos, this study provides a strong argument against the continued use of multiple embryo transfer in most ART settings. Larger cohort studies including also the number of gestational sacs in early pregnancy will be preferable to show an effect of vanishing twins on the risk of CP in the ART population. STUDY FUNDING/COMPETING INTEREST(S): The study was financed by grants from NordForsk (grant number 71450), Elsass Foundation (19-3-0444), the ALF-agreement (ALFGBG 70940), and The Research Fund of Rigshospitalet, Copenhagen University Hospital. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: ISRCTN11780826.


Asunto(s)
Parálisis Cerebral , Nacimiento Prematuro , Parálisis Cerebral/epidemiología , Niño , Estudios de Cohortes , Femenino , Humanos , Recién Nacido , Embarazo , Embarazo Gemelar , Nacimiento Prematuro/epidemiología , Estudios Retrospectivos
20.
Breast Cancer Res Treat ; 187(3): 769-775, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33710439

RESUMEN

PURPOSE: To analyze whether monitoring serum estradiol (E2) levels using a highly sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) method may identify patients with AI failure with E2 levels below the lower limit of quantification (LLOQ) after schwitching from tamoxifen to letrozole. METHODS: In a prospective study of breast cancer patients switching to letrozole treatment after previous tamoxifen, plasma estrogen levels were measured at baseline and after 3- and 12-months using LC-MS/MS. RESULTS: Forty-six patients were classified postmenopausal and entered into the final analysis. Thirty-nine (85%) patients had three- and 12-month E2 concentrations below the LLOQ (5 pmol/L). In the seven patients classified as AI-failures during letrozole treatment, serum E2-MS level rose above 5 pmol/L at 3 months with a mean E2-MS 77.5 pmol/L or 12 months with a mean E2-MS 21 pmol/L. None of the baseline variables i.e., age at diagnosis, age at study entry, age at menarche, BMI, endometrial thickness, total ovarian volume, baseline FSH, E2-IA, or E2-MS were significantly associated with the risk of AI failure in logistic regression. E2 levels at baseline measured by E2-IA did not significantly correlate to the levels measured by E2-MS. CONCLUSIONS: There is a relatively high risk of inadequate estrogen suppression in patients who switch from tamoxifen treatment to AIs. The use of sensitive and specific assays, such as LC-MS/MS methods, to monitor estrogen levels during AI treatment is essential to minimize the risk of a proceeding inefficient endocrine therapy.


Asunto(s)
Neoplasias de la Mama , Tamoxifeno , Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Quimioterapia Adyuvante , Cromatografía Liquida , Estradiol/uso terapéutico , Femenino , Humanos , Letrozol/uso terapéutico , Nitrilos/uso terapéutico , Estudios Prospectivos , Tamoxifeno/uso terapéutico , Espectrometría de Masas en Tándem
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