Jolanda C. Boxmeer

Low folate in seminal plasma is associated with increased sperm DNA damage

OBJECTIVE To determine associations between vitamin B status, homocysteine (tHcy), semen parameters, and sperm DNA damage. DESIGN Observational study. SETTING A tertiary referral fertility clinic. PATIENT(S) Two hundred fifty-one men of couples undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment, with subgroups of fertile (n = 70) and subfertile men (n = 63) defined according to semen concentration and proven fertility. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) The DNA fragmentation index (DFI) as marker of sperm DNA damage determined using the sperm chromatin structure assay (SCSA), and semen parameters assessed according to World Health Organization criteria; tHcy, folate, cobalamin, and pyridoxine concentrations determined in seminal plasma and blood. RESULT(S) In the total group of fertile and subfertile men, all biomarkers in blood were statistically significantly correlated with those in seminal plasma. No correlation was found between the biomarkers in blood and the semen parameters. In seminal plasma, both tHcy and cobalamin positively correlated with sperm count. Folate, cobalamin, and pyridoxine were inversely correlated with ejaculate volume. In fertile men, seminal plasma folate showed an inverse correlation with the DNA fragmentation index. CONCLUSION(S) Low concentrations of folate in seminal plasma may be detrimental for sperm DNA stability.

IVF outcomes are associated with biomarkers of the homocysteine pathway in monofollicular fluid

BACKGROUND Maternal hyperhomocysteinemia is detrimental for reproduction, but the effects on embryo quality are unknown. The aim of this study was to investigate whether biomarkers of the homocysteine pathway are associated with in vitro fertilization (IVF) outcome. METHODS In a prospective study, we investigated biomarkers of the homocysteine pathway for associations with embryo quality and biochemical pregnancy in women undergoing IVF or intracytoplasmic sperm injection treatment (n = 181). In the treatment cycle, blood and monofollicular fluid samples were collected for determination of folate, cobalamin and total homocysteine (tHcy) concentrations. RESULTS Of all the women in the study, 67% used folic acid supplements. In blood, a significant correlation was established between high cobalamin and better embryo quality [standardized adjusted regression coefficient: -0.17, 95% confidence interval (CI): -0.30, -0.01]. In monofollicular fluid of non-supplemented women, high cobalamin correlated with better embryo quality (estimate: -0.87; 95% CI: -1.68, -0.06), whereas high tHcy resulted in poor embryo quality (estimate: 1.01; 95% CI: 0.08, 1.95). However, in monofollicular fluid of supplemented women, high tHcy correlated with better embryo quality (estimate: -0.58; 95% CI: -1.12, -0.04). In the total group, a 2-fold increase of monofollicular fluid folate corresponded with a 3.3 times higher chance (95% CI: 1.09, 9.71) of achieving pregnancy. CONCLUSIONS An optimal homocysteine pathway in follicular fluid is associated with a better embryo quality and chance of pregnancy.

Sperm Quality Decline Among Men Below 60 Years of Age Undergoing IVF or ICSI Treatment

Because of changes in the society, couples in Western countries are increasingly delaying reproduction. This is accompanied by unhealthy lifestyles that may be detrimental not only to general health but also to reproductive capacity. It is well known that maternal age has detrimental effects on fertility; the paternal influence on this outcome is largely unknown. This study aims to investigate associations between a paternal age below 60 years, lifestyles, and sperm quality. In a periconceptional prospective cohort study we included 227 men undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. Age at sperm collection, lifestyles, cause of subfertility, ethnicity, sperm DNA fragmentation index (DFI; as marker of sperm DNA damage), and sperm parameters were determined. Linear regression analyses showed a positive association between a rising age from 26 to 59 years and DFI (P ≤ .01) and an inverse association with ejaculate volume (P ≤ .05). Inverse associations were determined between DFI and all conventional sperm parameters (all P ≤ .01). There were no associations between smoking, alcohol use, body mass index, and DFI and sperm parameters. Dutch men compared to migrants, however, showed a higher DFI (P ≤ .05) independent of lifestyles. We conclude that the trend of delaying fatherhood in men undergoing IVF or ICSI treatment is detrimental to sperm quality.

Effect of B vitamins and genetics on success of in-vitro fertilisation

P Haggarty and colleagues suggest that high folate status increases the likelihood of twin birth after multiple embryo transfer and that proposals to fortify the diet with folic acid could lead to an increase in the number of twins born after in-vitro fertilisation (IVF). In their study the energy-adjusted median intake of folate was 311 µg per day in study participants and about 87% of them took supplementary folic acid which suggests that the UK is not a folate-deficient area. Kazakhstan on the other hand is a folate-deficient area. The traditional food of the Kazakh people consists mainly of meat such as beef and mutton and the intake of vegetables tends to be deficient especially in rural areas owing to their insufficient distribution. We have screened folate concentrations in the normal Kazakh population and have found that 82% showed low folate concentrations whereas none of an age-matched Japanese population showed low concentrations. (excerpt)