Ultrasonographic assessment of lower uterine segment thickness and perinatal Outcomes in patients with a previous cesarean history

Objective: The purpose of the study was to establish the validity of the abdominal evaluation of lower uterine segment (LUS) thickness in patients having a previous cesarean section (CS) in predicting uterine rupture, and to evaluate if there is any effect of the number of a previous surgeries on adverse maternal and perinatal outcomes. Materials and methods: A prospective case-control study was carried out between December 2017 and June 2018 in Dr. Zekai Tahir Burak Women’s Health Education and Research Hospital. 555 patients were classified into three groups; Group 1: patients having one previous CS, Group 2: patients having two previous CS, Group 3: patients having more than the two previous CS). Ultrasonographic measurements of the LUS, intraoperative findings and, adverse pregnancy outcomes were assessed. Results: LUS thickness of group 2 was significantly less than the LUS thickness of the other groups (p=0.022). The feeling of pain was significantly more in the patients of group 2, when compared with the other groups (p=0.019). Pregnancy interval was the only parameter that had significant predictivity for adverse pregnancy outcomes for group 1(#CS=2) and group 3 (#CS≥4) (p=0.042, and p=0.021, respectively). In group 2 (#CS=3), age, the thickness of LUS, and thickness of subcutaneous adipose tissue were found to have significantly high predictivity for adverse pregnancy outcomes (p=0.012, p≤0.001, and p=0.007, respectively). Conclusion: Measurement of LUS, in the patients who had previous CS, can be used for risk assessment and management. It is a non-invasive, reliable and, easily applicable method. Standardization of the measurement technique is a necessity.

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Rate of gestational weight gain trajectory is associated with adverse pregnancy outcomes

Public Health Nutrition ◽

10.1017/s1368980020002372 ◽

2020 ◽

Vol 23 (18) ◽

pp. 3304-3314

Author(s):

Heng Yaw Yong ◽

Zalilah Mohd Shariff ◽

Geeta Appannah ◽

Zulida Rejali ◽

Barakatun Nisak Mohd Yusof ◽

...

Keyword(s):

Weight Gain ◽

Pregnancy Outcomes ◽

Caesarean Delivery ◽

Adverse Pregnancy Outcomes ◽

Obese Women ◽

Gestational Weight ◽

Group 3 ◽

Group 2 ◽

Adverse Pregnancy ◽

Group 1

AbstractObjective:To examine the gestational weight gain (GWG) trajectory and its possible association with pregnancy outcomes.Design:GWG trajectories were identified using the latent class growth model. Binary logistic regression was performed to examine the associations between adverse pregnancy outcomes and these trajectories.Setting:Negeri Sembilan, Malaysia.Participants:Two thousand one hundred ninety-three pregnant women.Results:Three GWG trajectories were identified: ‘Group 1 – slow initial GWG but followed by drastic GWG’, ‘Group 2 – maintaining rate of GWG at 0·58 kg/week’ and ‘Group 3 – maintaining rate of GWG at 0·38 kg/week’. Group 1 had higher risk of postpartum weight retention (PWR) (adjusted OR (AOR) 1·02, 95 % CI 1·01, 1·04), caesarean delivery (AOR 1·03, 95 % CI 1·01, 1·04) and having low birth weight (AOR 1·04, 95 % CI 1·02, 1·05) compared with group 3. Group 2 was at higher risk of PWR (AOR 1·18, 95 % CI 1·16, 1·21), preterm delivery (AOR 1·03, 95 % CI 1·01, 1·05) and caesarean delivery (AOR 1·02, 95 % CI 1·01, 1·03), but at lower risk of having small-for-gestational-age infants (AOR 0·97, 95 % CI 0·96, 0·99) compared with group 3. The significant associations between group 1 and PWR were observed among non-overweight/obese women; between group 1 and caesarean delivery among overweight/obese women; group 2 with preterm delivery and caesarean delivery were only found among overweight/obese women.Conclusions:Higher GWG as well as increasing GWG trajectories was associated with higher risk of adverse pregnancy outcomes. Promoting GWG within the recommended range should be emphasised in antenatal care to prevent the risk of adverse pregnancy outcomes.

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Role of biometric characteristics of the uterine junctional zone in fertility outcomes in patients with adenomyosis

Journal of obstetrics and women s diseases ◽

10.17816/jowd65046 ◽

2021 ◽

Vol 70 (3) ◽

pp. 41-50

Author(s):

Ekaterina K. Orekhova ◽

Olga A. Zhandarova ◽

Igor Yu. Kogan

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Pregnancy Outcomes ◽

Adverse Pregnancy Outcomes ◽

Resonance Imaging ◽

Junctional Zone ◽

History Of ◽

Group 2 ◽

Adverse Pregnancy ◽

Group 1

BACKGROUND: The uterine junctional zone is the inner part of the myometrium. Dysfunction of the zone may underlie the pathogenesis of adenomyosis and its clinical manifestations, while biometric characteristics of the zone are currently considered as promising early diagnostic criteria for this disease. Adenomyosis has traditionally been associated with parity and intrauterine interventions, primarily in older patients. However, modern imaging tools often allow diagnosing the disease in young patients with infertility and an unburdened gynecological history. It is assumed that the detection of changes in the structure and function of the uterine junctional zone in adenomyosis can be the basis for predicting fertility outcomes and complications of pregnancy, as well as for the development of promising therapeutic strategies at the pregravid stage. AIM: The aim of this study was to assess the influence of biometric characteristics of the uterine junctional zone on pregnancy outcomes, depending on the parity and intrauterine interventions in patients with adenomyosis. MATERIALS AND METHODS: This prospective study included 102 patients aged 2239 years old with ultrasound features of adenomyosis who were going to conceive. The patients were divided into two groups: Group 1 (n = 58) consisted of nulliparous patients with no history of previous intrauterine interventions, and Group 2 (n = 44) comprised multipara women with a history of labor and / or intrauterine interventions. Using magnetic resonance imaging, we evaluated minimal, average and maximal junctional zone thicknesses, junctional zone deferential and a ratio of junctional zone thickness to myometrium thickness. Thresholds of biometric characteristics of the uterine junctional zone for adverse pregnancy outcomes were estimated. RESULTS: The frequencies of pregnancy and retrochorial hematoma in patients of Groups 1 and 2 in the first trimester of pregnancy did not differ significantly and amounted to 43.1% and 38.6%, 13.8% and 22.7%, respectively, p 0.05. Adverse pregnancy outcomes were diagnosed in 63.8% of patients in Group 1 and in 68.2% of patients in Group 2, p 0.05. In Group 1, the frequency of retrochorial hematoma depended on the initial junctional zone deferential, as well as on the initial average and maximal junctional zone thicknesses, junctional zone deferentials and ratios of junctional zone thickness to myometrium thickness, which, with an adverse pregnancy outcome, were 1.72.5 times higher than those in patients with a favorable outcome, p 0.05. In Group 2, adverse pregnancy outcomes were recorded with significantly higher values of average and maximal junctional zone thicknesses and junctional zone deferential. ROC curves were constructed using data of logistic regression analysis based on biometric characteristics of the uterine junctional zone to predict spontaneous abortion and infertility in patients with adenomyosis. CONCLUSIONS: Fertility outcomes in patients with adenomyosis depend on a complex of biometric characteristics of the uterine junctional zone as determined by magnetic resonance imaging.

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Prediction and management model of preterm birth

Annals of the Russian academy of medical sciences ◽

10.15690/vramn1085 ◽

2019 ◽

Vol 74 (4) ◽

pp. 221-228 ◽

Cited By ~ 1

Author(s):

Yuriy A. Semenov ◽

Valentina F. Dolgushina ◽

Marina G. Moskvicheva ◽

Vasiliy S. Chulkov

Keyword(s):

Preterm Birth ◽

Pregnant Women ◽

Pregnancy Outcomes ◽

Predictive Value ◽

Diagnostic Value ◽

Adverse Pregnancy Outcomes ◽

History Of ◽

Group 2 ◽

Adverse Pregnancy ◽

Group 1

Background: It seems relevant to study the contribution of socio-demographic, somatic and obstetric-gynecological factors in the implementation of preterm birth. Aims: Assessment of the prognostic significance of socio-demographic, obstetric-gynecological and somatic factors in the prediction of preterm birth and associated adverse pregnancy outcomes with subsequent validation of the prognostic model. Materials and methods: Cohort study with a mixed cohort. A retrospective assessment of socio-demographic factors, harmful habits, obstetric and gynecological pathology, somatic diseases, course and outcomes of pregnancy was carried out with the assessment of the status of newborns in 1246 women with subsequent construction of a predictive model of preterm birth and adverse outcomes of pregnancy using Regression with Optimal Scaling and its prospective validation in 100 women. Results: The most significant predictors, that increase the chance of preterm birth and adverse pregnancy outcomes, were history of premature birth, irregular monitoring during pregnancy, history of pelvic inflammatory disease, smoking, obesity, the onset of sexual activity up to 16 years, cardiovascular and endocrine diseases. Intellectual job reduced the chance of preterm birth and adverse pregnancy outcomes This multivariate predictive model has a diagnostic value. The score of risk factors 25 points had a sensitivity of 73%, a specificity of 71%, the area under the ROC curve (AUC) 0.76 (good quality), p0.001. After stratification of high-risk groups by maternal and perinatal pathology the following list of diagnostic and therapeutic measures is introduced and actively implemented in antenatal clinics. To stratificate this model, we prospectively analyze the course and pregnancy outcomes of 100 women divided into 2 groups: group 1 ― 50 women with preterm delivery, group 2 ― 50 women with term delivery. A total score of 25 and above had 44% of women in group 1 and only 10% of women in group 2 (sensitivity 81.4%, specificity 61.6%, positive predictive value 44%, negative predictive value 90%, positive likelihood ratio 2.2 [1.53.0], negative likelihood ratio 0.3 [0.130.68]). Conclusions: We have proposed a model for predicting preterm birth and delivery and perinatal losses using the available characteristics of pregnant women from early pregnancy with moderate indicators of diagnostic value. Further validation of the model in the general population of pregnant women is required.

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Hyaluronan affects extravascular water in lungs of unanesthetized rabbits

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.6.2595 ◽

1989 ◽

Vol 66 (6) ◽

pp. 2595-2599 ◽

Cited By ~ 30

Author(s):

J. Bhattacharya ◽

T. Cruz ◽

S. Bhattacharya ◽

B. A. Bray

Keyword(s):

Body Weight ◽

Water Content ◽

Extravascular Lung Water ◽

Volume Expansion ◽

The Other ◽

Lung Water ◽

Intravenous Saline ◽

Group 3 ◽

Group 2 ◽

Group 1

We have determined whether changes in lung hyaluronan content affect extravascular water in lungs of unanesthetized rabbits. Three groups of experiments were performed. In group 1 (n = 12), no infusions were given; in group 2, nine pairs of rabbits received either intravenous hyaluronidase (750 U.kg-1.min-1) or an equivalent volume of saline; in group 3, nine pairs of rabbits received either hyaluronidase or saline, followed by intravenous saline infusion amounting to 24% of body weight. At the end of each experiment, one lung was analyzed for extravascular lung water by the wet-dry method. Except for group 3, in all animals the other lung was analyzed for hyaluronan content by a method that involved hydrolyzing lung hyaluronan with fungal hyaluronidase to release reducing N-acetyl glucosamine groups, which were quantified. In group 1, lung hyaluronan, which varied from 50 to 159 micrograms/g dry wt (mean 106 +/- 35 micrograms/g dry wt), significantly correlated with variation in extravascular lung water (mean 4.2 +/- 0.3 g/g dry wt). In group 2 rabbits given hyaluronidase, lung hyaluronan was 40% lower and extravascular lung water was 14.6% lower than in paired controls (P less than 0.01). In group 3, volume expansion did not affect lung water, except after hyaluronidase when lung water was 47% higher than paired controls. We conclude that in the lung the content of hyaluronan is one of the determinants of extravascular water content.

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Predicting pregnancy outcomes from homocysteine level: an evidence from a North Indian study

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20201212 ◽

2020 ◽

Vol 9 (4) ◽

pp. 1487

Author(s):

Shaina Chamotra ◽

Kushla Pathania ◽

S. K. Verma ◽

Ankit Chaudhary

Keyword(s):

Pregnancy Outcomes ◽

Homocysteine Level ◽

Perinatal Outcomes ◽

Normal Subjects ◽

Adverse Pregnancy Outcomes ◽

Intrauterine Death ◽

Increased Risk ◽

Causal Pathway ◽

Mother And Child ◽

Adverse Pregnancy

Background: Hypertensive disorders of pregnancy are a major cause of adverse pregnancy outcomes. Though the etiology of spectrum of vascular disorders of pregnancy is still not understood completely, yet abnormally elevated homocysteine level has been implicated in the causal pathway and pathogenesis. Hyperhomocysteinemia has been significantly associated with increased risk of poor maternal and foetal outcomes in terms of PIH, abruption, IUGR, recurrent pregnancy loss, intrauterine death and prematurity.Methods: The present prospective study was conducted among 180 pregnant women (57 exposed and 123 non exposed) in Kamla Nehru State Hospital for Mother and Child, IGMC Shimla, Himachal Pradesh with an objective of determining association of abnormally elevated homocysteine level in pregnancy and adverse pregnancy outcomes. Socio-demographic, clinical, biochemical including homocysteine level, laboratory, ultrasonographic parameters and foeto-maternal outcomes of pregnancy of all the participants were documented.Results: The mean homocysteine level of exposed group (23.26±10.77 µmol/L) was significantly higher than the unexposed group (8.99±2.47 µmol/L). Among hyperhomocysteinemic subjects, 10.5% had abruption, 15.8% had PRES and 8.7% PPH which was significantly higher than normal subjects. Similarly, patients with homocysteinemia had significantly higher proportion (21.3%) of poor Apgar score, more (41.9%) NICU admissions and higher frequency (4.7%) of meconium aspiration syndrome.Conclusions: The present study generates necessary evidence for associating abnormally elevated homocysteine levels with pregnancy related hypertensive ailments and adverse pregnancy outcomes. It further demands the need of robustly designed studies and trials to further explore the phenomenon. Moreover, it emphasizes on a simple and timely intervention like estimating the much-neglected homocysteine levels during pregnancy which can definitely contribute in predicting and preventing adverse perinatal outcomes.

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The Effects of Norepinephrine Infusion on the Circulating Lymphocyte Counts of Post–Open Heart Surgery Patients

Biological Research For Nursing ◽

10.1177/109980040000100305 ◽

2000 ◽

Vol 1 (3) ◽

pp. 199-209

Author(s):

Wanda Zziwambazza ◽

Carrie J. Merkle ◽

Ida M. Moore ◽

Jean Davis

Keyword(s):

Heart Surgery ◽

Open Heart Surgery ◽

The Other ◽

Open Heart ◽

Postoperative Infections ◽

Norepinephrine Infusion ◽

Beta Blocking ◽

Group 3 ◽

Group 2 ◽

Group 1

In this retrospective study employing chart reviews, 75 open heart surgery patients (OHSPs) were divided into 3 groups of 25 patients. Group 1 received no intravenous (IV) norepinephrine (NE) after surgery. Group 2 and group 3 received a minimum of 0.028 mcg/kg/min of IV NE for 6-24 h and greater than 24 h, respectively. In the 3 groups, preoperative lymphocyte counts were compared to counts obtained on postoperative days 1 and 2. The results showed lower lymphocyte counts on postoperative day 2 in group 3 subjects, who received NE for 24 h or more, compared to subjects of the other groups who received no NE or 6-24 h of NE (p < 0.05). There was also evidence that preoperative use of beta-blocking agents significantly affected the change in lymphocyte counts from day 1 to day 2 in both groups receiving NE. Furthermore, postoperative infections were more prevalent in group 3 than the other 2 groups (p < 0.05). The lower lymphocyte counts and higher infection rate, however, may be linked to lower postoperative blood pressure and increased number of intensive care unit days in group 3. Further investigation is warranted to elucidate the effects of IV NE administration on the lymphocyte counts of OHSPs and to reduce infections in those receiving NE.

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Maternal Pre-Pregnancy Obesity Combined With Abnormal Glucose Metabolism Further Increases Adverse Pregnancy Outcomes in Chinese Pregnant Women

Frontiers in Endocrinology ◽

10.3389/fendo.2021.754406 ◽

2022 ◽

Vol 12 ◽

Author(s):

Mei-Fang Li ◽

Jiang-Feng Ke ◽

Li Ma ◽

Jun-Wei Wang ◽

Zhi-Hui Zhang ◽

...

Keyword(s):

Glucose Metabolism ◽

Pregnant Women ◽

Pregnancy Outcomes ◽

Perinatal Outcomes ◽

Adverse Pregnancy Outcomes ◽

Control Group ◽

Abnormal Glucose Metabolism ◽

Induced Hypertension ◽

Adverse Perinatal Outcomes ◽

Adverse Pregnancy

AimsOur aim was to evaluate the separate and combined effects of maternal pre-pregnancy obesity and gestational abnormal glucose metabolism (GAGM) on adverse perinatal outcomes.MethodsA total of 2,796 Chinese pregnant women with singleton delivery were studied, including 257 women with pre-pregnancy obesity alone, 604 with GAGM alone, 190 with both two conditions, and 1,745 with neither pre-pregnancy obesity nor GAGM as control group. The prevalence and risks of adverse pregnancy outcomes were compared among the four groups.ResultsCompared with the normal group, pregnant women with maternal pre-pregnancy obesity alone, GAGM alone, and both two conditions faced significantly increased risks of pregnancy-induced hypertension (PIH) (odds ratio (OR) 4.045, [95% confidence interval (CI) 2.286–7.156]; 1.993 [1.171–3.393]; 8.495 [4.982–14.485]), preeclampsia (2.649 [1.224–5.735]; 2.129 [1.128–4.017]; 4.643 [2.217–9.727]), cesarean delivery (1.589 [1.212–2.083]; 1.328 [1.095–1.611]; 2.627 [1.908–3.617]), preterm delivery (1.899 [1.205–2.993]; 1.358 [0.937–1.968]; 2.301 [1.423–3.720]), macrosomia (2.449 [1.517–3.954]; 1.966 [1.356–2.851]; 4.576 [2.895–7.233]), and total adverse maternal outcomes (1.762 [1.331–2.332]; 1.365 [1.122–1.659]; 3.228 [2.272–4.587]) and neonatal outcomes (1.951 [1.361–2.798]; 1.547 [1.170–2.046]; 3.557 [2.471–5.122]). Most importantly, there were no obvious risk differences in adverse pregnancy outcomes between maternal pre-pregnancy obesity and GAGM group except PIH, but pregnant women with both obesity and GAGM exhibited dramatically higher risks of adverse pregnancy outcomes than those with each condition alone.ConclusionsMaternal pre-pregnancy obesity and GAGM were independently associated with increased risks of adverse pregnancy outcomes. The combination of pre-pregnancy obesity and GAGM further worsens adverse pregnancy outcomes compared with each condition alone.

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Evaluation of Mandibular First Molars’ Axial Inclination and Alveolar Morphology in Different Facial Patterns: A CBCT Study

European Journal of Dentistry ◽

10.1055/s-0040-1709932 ◽

2020 ◽

Vol 14 (02) ◽

pp. 250-259 ◽

Cited By ~ 1

Author(s):

Marcos Cezar Ferreira ◽

Karina Maria Salvatore de Freitas ◽

Francyle Simões Herrera-Sanches ◽

Patrícia Bittencourt dos Santos ◽

Daniela Garib ◽

...

Keyword(s):

The Other ◽

Cone Beam ◽

Bone Morphology ◽

Mandibular Molar ◽

Significant Difference ◽

Mandibular Body ◽

Facial Pattern ◽

Group 3 ◽

Group 2 ◽

Group 1

Abstract Objective The purpose of this study was to evaluate and compare the axial inclination of the mandibular first molars and their respective bone morphology among individuals with different facial patterns. Materials and Methods The sample comprised the cone beam computed tomographies (CBCTs) of 58 subjects divided into three groups according to the facial patterns: 18 brachyfacial (Group 1), with a mean age of 21.58 years; 23 mesofacial (Group 2), with a mean age of 19.14 years; and 17 dolichofacial subjects (Group 3), with a mean age of 19.09 years. Eight variables were evaluated on CBCT scans of each subject: buccal and lingual mandibular height, cervical and middle mandibular width, inclination of mandibular body, inclination of the mandibular molar buccal surface, molar width, molar angulation and tooth/bone angle. Intergroup comparisons were performed with one-way analysis of variance followed by Tukey tests. Results Buccal mandibular height presented statistically significant difference in the three facial patterns. Lingual mandibular height and mandibular inclination showed to be statistically and significantly smaller in brachyfacial subjects than in the other two groups. Mandibular width presented a statistically significant difference between brachyfacial and mesofacial groups. Negative correlations could be observed between the facial pattern and the buccal and lingual mandibular heights and inclination of the mandibular body. Conclusion Buccal mandibular height was significantly and progressively larger in brachyfacial, mesofacial, and dolichofacial subjects. Lingual mandibular height was significantly smaller in brachyfacial than in mesofacial and dolichofacial subjects. Mandibular width was significantly thicker in brachyfacial than in mesofacial subjects. Brachyfacial subjects had smaller mandibular inclination than mesofacial and dolichofacial subjects.

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Treatment of ovarian cysts in sows – a field trial

Veterinární Medicína ◽

10.17221/1995-vetmed ◽

2008 ◽

Vol 52 (No. 9) ◽

pp. 413-418 ◽

Cited By ~ 9

Author(s):

S. Cech ◽

R. Dolezel

Keyword(s):

The Other ◽

Ovarian Cysts ◽

Control Group ◽

Initial Examination ◽

Interval Group ◽

Group 4 ◽

Group 3 ◽

Group 5 ◽

Group 2 ◽

Group 1

Different procedures of treatment of large follicular ovarian cysts in 177 sows using GnRH, hCG and PGF2α are evaluated in this study. Ovarian cysts were diagnosed by transcutaneous ultrasonography, which was a part of routine pregnancy diagnosis. No treatment was performed in the control group (Group 1, n = 29); the method of treatment used in the other groups immediately after the diagnosis was intramuscular administration of lecirelin in doses 50 µg (Group 2, n = 28), 100 µg (Group 3, n = 27) and 200 µg divided into 2 equal doses administered at a 12-hour interval (Group 4, n = 25) and of hCG in doses 1 500 IU (Group 5, n = 23), 3 000 IU (Group 6, n = 21), and 250 µg of cloprostenol (Group 7, n = 24). Insemination rate (IR), conception rate (CR) in inseminated sows, pregnancy rate (PR = recovery rate), treatment-insemination interval (TII) and treatment-pregnancy interval (TPI) within 42 days after the initial examination were evaluated. In addition PR in groups of sows divided according to parity (1–3, 4–6 and ≥ 7) were also evaluated. IR and PR were higher in Group 4 (84.0% and 44.0%) and lower in Group 1 (17.2% and 6.9%) in comparison with the other groups (P < 0.001 and P < 0.05). CR, TII and TPI did not differ between the experimental groups. PR were similar in sows with different parity. The study proved a positive response in sows with large follicular ovarian cysts to the treatment consisting of 2 administrations of 100 µg GnRH at a 12-hour interval.

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P–194 Impact of cryopreservation duration on pregnancy outcomes of vitrified-warmed blastocysts transfer using an open-device system

Human Reproduction ◽

10.1093/humrep/deab130.193 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Q Zheng ◽

H Zhang ◽

S Xu ◽

F Xu ◽

F Xiong ◽

...

Keyword(s):

Pregnancy Outcomes ◽

Clinical Pregnancy ◽

Miscarriage Rate ◽

Storage Duration ◽

Group 4 ◽

Group 3 ◽

Group 5 ◽

Group 2 ◽

Group 1

Abstract Study question Is there a negative effect of long-term cryopreservation upon pregnancy outcomes after transfer of vitrified-warmed blastocysts stored in an open-device system? Summary answer Prolonged cryopreservation of vitrified blastocysts up to 24 months increased the incidences of clinical pregnancy, ongoing pregnancy, and live birth, while decreased early miscarriage rate. What is known already Vitrification is adopted as the dominant approach for cryopreservation of human oocytes and embryos. However, little is known about the potential effect of prolonged storage after vitrification on the genomic integrity and metabolism of embryos. Several studies have sought to decipher the effect of cryopreservation duration on IVF pregnancy outcomes, but few were confined to vitrification and the results were inconsistent. Study design, size, duration This retrospective study included 6722 patients undergoing their first vitrified-warmed blastocyst transfer (VBT) cycles from January 2015 to June 2019 in a single fertility center in South China. The study was approved by the hospital’s Ethics Committee. Participants/materials, setting, methods A total of 6722 eligible patients were divided into five groups according to the storage duration after vitrification: Group I: 0–3 months; Group II: 3–6 months; Group III: 6–12 months; Group IV: 12–24 months; Group V: 24–36 months. The IVF pregnancy outcomes were compared between groups. Multivariate logistic regression was conducted to evaluate the independent effect of storage duration on pregnancy outcomes. Main results and the role of chance The odds of clinical pregnancy outcomes were similar from Group 1 to 4. However, the chance of clinical pregnancy (Group 1 as reference; Group 2: adjusted odds ratio (aOR)= 1.04, 95% CI 0.93–1.17; Group 3: aOR = 1.02, 95% CI 0.84–1.25; Group 4: aOR = 0.93, 95% CI 0.66–1.31; Group 5: aOR = 0.54, 95% CI 0.38–0.76) , ongoing pregnancy (Group 2: aOR=0.99, 95% CI 0.89–1.11; Group 3: aOR = 0.94, 95% CI 0.77–1.14; Group 4: aOR = 0.87, 95% CI 0.62–1.22; Group 5: aOR = 0.41, 95% CI 0.29–0.60), and live birth rate (Group 2: aOR=1.00, 95% CI 0.89–1.12; Group 3: aOR = 0.98, 95% CI 0.81–1.19; Group 4: aOR = 0.91, 95% CI 0.65–1.27; Group 5: aOR = 0.46, 95% CI 0.32–0.66) significantly decreased, while the early miscarriage rate (Group 2: aOR=1.11, 95% CI 0.92–1.35; Group 3: aOR =1.25, 95% CI 0.92–1.70; Group 4: aOR = 1.33, 95% CI 0.77–2.31; Group 5: aOR = 2.42, 95% CI 1.36–4.31) significantly increased as the storage duration increased up to 24–36 months. Limitations, reasons for caution The primary limitation of this study was its retrospective nature. Besides, as all these data come from a single IVF treatment center, the results should be confirmed by a larger multicenter study. Wider implications of the findings: Our study provides more evidence about the negative impact of long-term storage of vitrified embryos on the clinical outcome. Clinicians should adapt FET strategies based on the embryo storage duration. Trial registration number Not applicable

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