Publications by authors named "Jonathan W Ramsay"
Background: Poor sperm function is a major cause of infertility. There is no drug therapy to improve sperm function. Semen oxidative stress is a recently identified pathway for sperm damage.
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- Male factor contributes to infertility in about 50% of cases, and evidence suggests that bacteria in the semen, particularly through next-generation sequencing, may affect sperm function, though findings are inconsistent.
- A systematic search included 55 studies with over 51,000 subjects, investigating bacteria in the semen of both fertile and infertile men from 1992 to 2019, utilizing methods like sequencing and PCR.
- Results showed that while the semen microbiome is diverse in both groups, specific bacteria such as Lactobacillus seemed beneficial for sperm quality, whereas Prevotella and Ureaplasma urealyticum negatively affected sperm parameters, with no significant difference found for chlamydia trachomatis.
Background: There are no current pharmacological therapies to improve sperm quality in men with sub-fertility. Reducing the exposure to lifestyle risk factor (LSF) is currently the only intervention for improving sperm quality in men with sub-fertility. No previous study has investigated what proportion of men with sub-fertility are exposed to adverse lifestyle factors.
View Article and Find Full Text PDFDespite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo.
View Article and Find Full Text PDFObjective: To present the first UK data on sperm DNA fragmentation levels in subfertile men and fertile controls, the correlation with semen variables, and to assess the effect on the outcome of intracytoplasmic sperm injection (ICSI).
Patients, Subjects And Methods: In all, 56 subfertile men undergoing ICSI (28 with positive and 28 with a negative outcome for paternity) and 10 control fertile semen donors were recruited. The sperm DNA fragmentation index (DFI) was assessed on raw pre-preparation samples using the sperm chromatin structure assay.
Purpose: To assess the viability of frozen-thawed embryos derived from intracytoplasmic sperm injection (ICSI) in azoospermic men.
Methods: Retrospective analysis of 154 consecutive ICSI cycles using surgically retrieved sperm from azoospermic men and case-control comparison of subsequent frozen transfer cycles with those using embryos generated from ejaculated sperm.
Results: Patient and fresh cycle characteristics were similar in both groups.
Objective: To compare the outcome of intracytoplasmic sperm injection (ICSI) cycles [1] using epididymal and testicular sperm in patients with obstructive azoospermia (OA); [2] using surgically retrieved sperm in patients with OA and nonobstructive azoospermia (NOA); and [3] using fresh and frozen-thawed sperm.
Design: Meta-analysis of published data.
Setting: Assisted conception unit.
Objective: To determine the effects of time since vasectomy and maternal age on intracytoplasmic sperm injection (ICSI) outcome in azoospermic men after vasectomy.
Design: Retrospective analysis.
Setting: Assisted conception unit.
Background: This is the first study to assess the outcome of sperm washing and intrauterine insemination (IUI) cycles in human immunodeficiency virus-positive (HIV(+)) men to determine any predictors of success, as well as evaluating the effect of HIV on sperm parameters.
Methods: Semen characteristics were evaluated in 106 HIV(+) men and a control group of 234 HIV(-) men, and the effect of markers of HIV disease assessed. Age, stimulation regime, sperm parameters, markers of HIV disease and the use of anti-retrovirals were assessed as predictors of the outcome of sperm washing/IUI cycles in the HIV(+) men.
Objective: To present the first reported case of synchronous sperm retrieval followed by sperm washing before an intracytoplasmic sperm injection (ICSI) cycle in an HIV-positive azoospermic man.
Design: Case report.
Setting: Assisted reproduction center.