OOIR: Observatory of International Research

Papers

(The H4-Index of Human Reproduction Update is 39. The table below lists those papers that are above that threshold based on CrossRef citation counts [max. 250 papers]. The publications cover those that have been published in the past four years, i.e., from 2022-05-01 to 2026-05-01.)

Article	Citations
Maternal and perinatal outcomes in twin pregnancies following assisted reproduction: a systematic review and meta-analysis involving 802 462 pregnancies	560
BMI in children aged 1–18 years conceived after ART with fresh and frozen embryo transfer: a systematic review and meta-analyses	167
Comparison of dietary and physical activity behaviors in women with and without polycystic ovary syndrome: a systematic review and meta-analysis of 39 471 women	143
The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first t	132
Building a human pluripotent stem cell-based gonadal niche: improving in vitro systems with in vivo insigh	116
What do we mean by preconception health and preconception care in research and policy? A systematic review	112
Functional hypothalamic amenorrhoea and polycystic ovarian morphology: a narrative review about an intriguing association	111
Ultrasonographic criteria in the diagnosis of polycystic ovary syndrome: a systematic review and diagnostic meta-analysis	106
The complicated ART of finding consensus on family-building health policy: a comment on the IFFS consensus document	105
Preconception lifestyle interventions for women—a systematic review and meta-analysis of intervention characteristics and behaviour change techniques	101
Total fertilization failure after ICSI: insights into pathophysiology, diagnosis, and management through artificial oocyte activation	101
What is the optimal GnRH antagonist protocol for ovarian stimulation during ART treatment? A systematic review and network meta-analysis	101
Driving factors in treatment decision-making of patients seeking medical assistance for infertility: a systematic review	95
Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries	88
Reproductive ability in survivors of childhood, adolescent, and young adult Hodgkin lymphoma: a review	85
RNA modifications in female reproductive physiology and disease: emerging roles and clinical implications	78
Obstetric, neonatal, and child health outcomes following embryo biopsy for preimplantation genetic testing	78
Reply: Artificial cycle frozen embryo transfer and obstetric adverse outcomes: association or causation?	76
Intrauterine human chorionic gonadotropin administration before embryo transfer (IHABT): an individual participant data meta-analysis of randomized controlled trials	73
What is the expected live birth rate per thawed oocyte?	73
Assessing the influence of preconception diet on female fertility: a systematic scoping review of observational studies	73
Meiotic recombination: insights into its mechanisms and its role in human reproduction with a special focus on non-obstructive azoospermia	72
Correction to: Evaluating interventions and adjuncts to optimize pregnancy outcomes in subfertile women: an overview review	68
Infertility treatment and offspring blood pressure—a systematic review and meta-analysis	63
Administration of growth hormone improves endometrial function in women undergoing in vitro fertilization: a systematic review and meta-analysis	60

COVID-19 in pregnant women: a systematic review and meta-analysis on the risk and prevalence of pregnancy loss	57
Reply. How much evidence is needed to stop calling endometrial scratching ‘controversial’?	55
Endometrial scratching in women undergoing IVF/ICSI: an individual participant data meta-analysis	52
Reply: What is the expected live birth rate per thawed oocyte?	49
Fertility in transgender and gender diverse people: systematic review of the effects of gender-affirming hormones on reproductive organs and fertility	48
Advances in non-hormonal male contraception targeting sperm motility	47
Development and validation of a gonadotropin dose selection model for optimized ovarian stimulation in IVF/ICSI: an individual participant data meta-analysis	46
Molecular insights into sperm head shaping and its role in human male fertility	46
Does the holy grail of the evidence pyramid vindicate the controversial practice of endometrial scratching or is there room for healthy skepticism?	45
Moving toward totipotency: the molecular and cellular features of totipotent and naive pluripotent stem cells	44
Harnessing omics data for drug discovery and development in ovarian aging	43
Prevalence of polycystic ovary syndrome: a global and regional systematic review and meta-analysis	43
Spermatogonia: a unique stem cell orchestrating species-specific transition from pluripotency to sperm production	43
The epigenetic approach of varicocele: a focus on sperm DNA and m6A-RNA methylation	41
Awareness and attitudes toward fertility preservation among healthcare providers: a scoping review of quantitative evidence	39
Bioengineering trends in female reproduction: a systematic review	39
Epitranscriptomic modifications in embryonic development: insights into natural and ART-induced mechanisms and implications	39
Seminal plasma cytokines in fertile versus infertile men: a systematic review and meta-analysis	39