Régine P M Steegers-Theunissen

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BACKGROUND The incidence of overweight and obesity in men of reproductive ages is rising, which may affect fertility. Therefore, this study aims to assess the associations between BMI, central adiposity and sperm parameters in men of subfertile couples. METHODS Ejaculate volume (ml), sperm concentration (millions per ml), percentage of progressive motile(More)
Current treatments of subfertile couples are usually empiric, as the true cause of subfertility often remains unknown. Therefore, we outline the role of nutritional and biochemical factors in reproduction and subfertility. A literature search was performed using MEDLINE, Science Direct and bibliographies of published work with both positive and negative(More)
Periconceptional folic acid supplementation may reduce the risk of cleft lip with or without cleft palate (CL(P)). Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene reduce availability of 5-methyltetrahydrofolate, the predominant circulating form of folate. To determine the effect of MTHFR C677T and MTHFR A1298C genotypes and haplotypes(More)
BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available(More)
BACKGROUND An elevated plasma total homocysteine concentration is a risk factor for cardiovascular disease and neural tube defects. A high daily intake of supplemental folic acid is known to decrease total homocysteine concentrations. OBJECTIVE We studied the effect of low-dose folic acid administration (250 or 500 (microgram/d) for 4 wk on plasma total(More)
BACKGROUND Thiols are scavengers of reactive oxygen species (ROS). We aim to investigate associations between thiols in various fluids in (sub)fertile couples and fertility outcome parameters. METHODS In 156 couples undergoing assisted reproduction techniques (ART), we measured the concentrations of glutathione (GSH), cysteine (Cys), homocysteine (Hcy)(More)
An elevated plasma total homocysteine (tHcy) concentration is a risk factor for cardiovascular disease and for having offspring with a neural-tube defect. Folate is a methyl donor in the remethylation of homocysteine into methionine. Although folic acid supplementation decreases tHcy concentrations, effects of folic acid supplementation on plasma methionine(More)
Periconceptional folate supplementation reduces the risk of neural-tube defects. We studied the frequency of the 677C-->T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene in 55 patients with spina bifida and parents of such patients (70 mothers, 60 fathers). 5% of 207 controls were homozygous for the 677C-->T mutation compared with 16%(More)
We studied pregnancy outcome in preconceptionally recruited epileptic and control women in a multi-centre prospective non-intervention study at two university hospitals and three general hospitals. We evaluated 225 singleton pregnancies: 119 pregnancies of epileptic women who received either antiepileptic drugs (AEDs) (n = 99) or not (n = 20), and 106(More)
BACKGROUND Countries worldwide recommend women planning pregnancy to use daily 400 microg of synthetic folic acid in the periconceptional period to prevent birth defects in children. The underlying mechanisms of this preventive effect are not clear, however, epigenetic modulation of growth processes by folic acid is hypothesized. Here, we investigated(More)