Paraben exposure and semen quality of Japanese male partners of subfertile couples.

OBJECTIVES: Possible relationship between semen quality (semen volume, sperm concentration and sperm motility) and parabens exposure was investigated in male partners of couples who visited a gynecology clinic in Tokyo for infertility consultation (n = 42, 36.8 ± 5.4 years). METHODS: Semen parameters were measured according to WHO guideline at the clinic, and urinary methyl- (MP), ethyl- (EP), propyl- (PP) and butyl (BP) paraben concentrations were measured with liquid chromatography-tandem mass spectrometry. RESULTS: Geometric mean urinary concentrations (geometric standard deviation) of the subjects were 48.2 (4.52), 1.88 (4.72), 1.13 (6.75) and 0.184 (11.1) ng/mL for MP, EP, PP and BP, respectively. No significant association was found between semen parameters and urinary paraben concentrations in multiple regression analyses and logistic regression analyses. CONCLUSIONS: Two reasons of the absence of adverse effects on semen quality might be suggested: lower paraben exposure level of the subjects and small sample size. Further investigation of effect of paraben exposure among general male population at environmental levels is warranted.

Urinary inorganic arsenic concentrations and semen quality of male partners of subfertile couples in Tokyo.

Inorganic arsenic (iAs) has been known as a testicular toxicant in experimental rodents. Possible association between iAs exposure and semen quality (semen volume, sperm concentration, and sperm motility) was explored in male partners of couples (n = 42) who visited a gynecology clinic in Tokyo for infertility consultation. Semen parameters were measured according to WHO guideline at the clinic, and urinary iAs and methylarsonic acid (MMA), and dimethylarsinic acid concentrations were determined by liquid chromatography-hydride generation-ICP mass spectrometry. Biological attributes, dietary habits, and exposure levels to other chemicals with known effects on semen parameters were taken into consideration as covariates. Multiple regression analyses and logistic regression analyses did not find iAs exposure as significant contributor to semen parameters. Lower exposure level of subjects (estimated to be 0.5 µg kg(-1) day(-1)) was considered a reason of the absence of adverse effects on semen parameters, which were seen in rodents dosed with 4-7.5 mg kg(-1).

Increased levels of cell-free human placental lactogen mRNA at 28-32 gestational weeks in plasma of pregnant women with placenta previa and invasive placenta.

We compared the levels of cell-free human placental lactogen (hPL) messenger RNA (mRNA) in maternal plasma at 28 to 32 weeks of gestation between women with diagnosis of placenta previa or invasive placenta and women with an uneventful pregnancy. Sensitivity and specificity of hPL mRNA for the prediction of invasive placenta were further explored. Plasma hPL mRNA were quantified by real-time reverse-transcriptase polymerase chain reaction in women with placenta previa (n = 13), invasive placenta (n = 5), and normal pregnancies (n = 92). Median (range) hPL mRNA was significantly higher in women with placenta previa, 782 (10-2301) copies/mL of plasma, and in those with invasive placenta, 615 (522-2102) copies/mL of plasma, when compared to normal pregnancies, 90 (4-4407) copies/mL of plasma, P < .01 and P < .05, respectively. We found a sensitivity of 100% and a specificity of 61.5% for the prediction of invasive placenta among women with placenta previa. In conclusion, expression of hPL mRNA is increased in plasma of women with placenta previa and invasive placenta at 28 to 32 weeks of gestation.

Urinary excretion of parabens in pregnant Japanese women.

Urinary excretion of free and total (free plus conjugated) forms of methyl, ethyl, n-propyl and n-butyl parabens (MP, EP, PP and BP, respectively) and their metabolite p-hydroxybenzoic acid were measured for 111 pregnant Japanese women. Frequent detection of parabens and their metabolite indicated that exposure takes place daily for pregnant Japanese women. The estrogenic potency of PP was 20 times higher than those of the other 3 parabens for the present subjects when both abundance in the urine and the relative estrogenic activity of each compound was considered. Detection of free parabens suggested dermal exposure, probably from their inclusion in personal care products. No statistical association was found between the anogenital index (birth weight-adjusted AGD) of male offspring and the concentrations of any parabens in the urine of the mothers suggesting that the parabens were not apparently estrogenically active at the exposure level of the present subjects.

Endocrine disrupting chemicals in urine of Japanese male partners of subfertile couples: a pilot study on exposure and semen quality.

The concentrations of chemicals with suspected endocrine disrupting effect were measured in urine samples collected from 42 Japanese male partners of couples who had infertility consultation at a gynecology clinic in Tokyo. The urinary analytes included metabolites of 5 phthalate diesters, pyrethroid insecticide (3-phenoxybenzoic acid, 3-PBA) and soy isoflavones (daidzein and equol), and cadmium. The semen parameters (semen volume, concentration and motility) of the male subjects were examined at the clinic as a diagnostic screening. Multiple regression analysis using one of the semen parameters examined as dependent variable and urinary biomarkers with age, body mass index, abstinent period, alcohol drinking, smoking and consumption frequency of selected foods as independent variables. For sperm concentration, urinary mono-n-butyl phthalate was selected as a significant independent variable with positive beta, while urinary daidzein was with negative beta. Consumption frequency of coffee (negative) and fruits (positive) were also significant. For sperm motility, urinary 3-PBA was selected as significant with negative beta as well as detectability of equol and frequency of coffee consumption with negative beta while smoking was with positive beta. This pilot study suggested the pyrethroid exposure level and dietary habit (coffee and soy products) as a significant contributor to poorer semen quality.

Maternal exposure to low-level heavy metals during pregnancy and birth size.

We evaluated the effect of environmental, low-level exposure to heavy metals during pregnancy, as estimated by urine analysis, on birth size of the newborns. Spot urine samples were collected from unexposed 78 pregnant women in Tokyo during 2007 and 2008. The urinary concentrations of beryllium (Be), copper (Cu), arsenic (As), zinc (Zn), selenium (Se), molybdenum (Mo), cadmium (Cd), tin (Sn), antimony (Sb), and lead (Pb) were measured by ICP-MS. The birthweight (BW), length (BL) and head circumference (HC) of the newborns delivered to the subjects were measured and relationship with urinary metal concentration was examined. The geometric mean concentration of urinary Be, Cu, As, Zn, Se, Mo, Cd, Sn, Sb, and Pb were 0.031, 12.8, 393, 76.9, 37.6, 79.0, 0.766, 0.232, < 0.21, 0.483 microg g-creatinine(-1), respectively. The mean birth size of the newborn was close to the national average value in Japan. Stepwise multiple regression analysis using birth size as a dependent variable and urinary metal concentrations and covariates as independent variables extracted urinary Cd with a significant negative standardized partial regression coefficient (beta) for BW along with gestational age and maternal BMI. For HC, Sn was selected with a negative beta. The present study suggested that even a low-level Cd body burden of general population has slight but significant negative effect on BW.

Prenatal exposure to phthalate esters and PAHs and birth outcomes.

The purpose of this study was to investigate the relationship between the levels of prenatal exposure to phthalate ester and PAHs and birth outcomes among 149 Japanese pregnant women. Urinary concentrations of 9 phthalate ester metabolites, mono methyl phthalate (MMP), mono ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono benzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-iso-nonyl phthalate (MINP) and mono-n-octyl phthalate (MnOP) and PAHs metabolite (1-hydroxypyrene, 1-OHP) were analyzed in spot urine samples collected from pregnant women. Correlation analysis and multiple regression analysis were conducted between the concentrations of maternal urinary metabolites and birth outcomes such as birth weight, birth length, head circumference and gestational age. Creatinine-corrected concentration (geometric mean; microg/g cre) was 9.14 (MMP), 9.76 (MEP), 51.6 (MnBP), 5.62 (MBzP), 5.45 (MEHP), 10.6 (MEHHP), 11.3 (MEOHP), 0.031 (MINP), 0.025 (MnOP) and 0.121 (1-OHP). These concentrations are comparable with literature value. The relationships between prenatal exposure to phthalate esters and birth outcomes were not significant. Statistically significant negative correlation was observed between 1-OHP and birth weight, birth length and head circumstances although the correlation was insignificant when only non-smokers were included in multiple regression analysis. In conclusion, we found that prenatal exposure to phthalate esters or PAHs did not affect birth outcomes at the exposure level of the present subjects.

Exposure assessment of phthalate esters in Japanese pregnant women by using urinary metabolite analysis.

OBJECTIVES: Our objectives were (1) to evaluate whether single spot urine is suitable media for longer-term phthalate esters exposure assessment, and (2) to estimate intake level of phthalate esters of Japanese pregnant women using urinary metabolites as an indicator of prenatal exposure level in their offspring. METHODS: We analyzed nine metabolites (MMP, MEP, MnBP, MBzP, MEHP, MEOHP, MEHHP, MINP, MnOP) of seven phthalate esters in spot urine samples from 50 pregnant women by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Using four urine samples collected from each of 12 subjects from 50 pregnant women within 5-12 weeks, we compared intra- and interindividual variation in urinary metabolites by calculation of intraclass correlation coefficient (ICC). We estimated daily intakes of 50 pregnant women from their urinary metabolite concentrations. RESULTS: ICCs for seven phthalate metabolite concentrations in single spot urine samples were: MMP (0.57), MEP (0.47), MnBP (0.69), MBzP (0.28), MEHP (0.51), MEHHP (0.43), and MEOHP (0.41) in 12 pregnant women. Phthalate ester metabolites had high detection rates in 50 subjects. The mean daily intake ranged from 0.01 to 2 mug/kg per day. The daily intake levels in all subjects were lower than corresponding tolerable daily intake (TDI) set by the European Food Safety Authority (EFSA), though maximum value for DnBP of 6.91 mug/kg per day accounted for 70% of TDI value. CONCLUSIONS: Higher ICCs indicated that phthalate metabolite levels in single spot urine could reflect longer-term exposure to the corresponding diesters of subjects. Although the current exposure level was less than TDIs, further studies and exposure monitoring are needed to reveal the toxicity of phthalate esters to sensitive subpopulation.

[Estimation of intake level of di (2-ethyhexyl) phthalate (DEHP) in Japanese pregnant women based on measurement of concentrations of three urinary metabolites].

OBJECTIVES: [corrected] The daily intake level of di (2-ethyhexyl) phthalate (DEHP) of Japanese pregnant women was estimated on the basis of the measurement of the urinary concentrations of three DEHP metabolites. METHODS: Spot urine samples were collected from 42 pregnant women who visited the gynecology division of a hospital for routine health check between June and October, 2003. The urinary concentrations of three DEHP metabolites, namely, mono (2-ethyhexyl) phthalate (MEHP), mono (2-ethy-5-hydroxyhexyl) phthalate (MEHHP), and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) were measured by HPLC/MS/MS. RESULTS: The concentrations of urinary MEHP, MEOHP and MEHHP (n=40) were 3.27-39.5 (median 9.83), 1.51-41.0 (median 10.4) and 4.6-26.6 (median 10.9) microg/g cre, respectively. The ranges of the estimated daily intake of DEHP per body weight based on the MEHP, MEOHP and MEHHP concentrations (n=40) were 3.45-41.6 (median 10.4), 0.66-17.9 (median 4.55) and 1.47-8.57 (median 3.51) microg/kg/day, respectively. The maximum estimated intake level per body weight (41.6 microg/kg/day) reached the Tolerable Daily Intake (TDI) level of 40-140 microg/kg/day set by the Ministry of Health and Welfare (now the Ministry of Health, Labour and Welfare). CONCLUSIONS: The health risk of DEHP exposure of our study subjects was found to be minimum from the viewpoint of the current knowledge of its risk level, although the human health effects of low-level DEHP exposure have to be studied further.

[Estimation of intake level of bisphenol A in Japanese pregnant women based on measurement of urinary excretion level of the metabolite].

OBJECTIVE: The daily bisphenol A (BPA) intake level of Japanese pregnant women was surveyed based on the measurement of the urinary excretion level of a BPA metabolite. METHODS: Spot urine samples were collected from 56 pregnant women who visited the gynecology division of a hospital for a routine health check between June and October 2003. The urinary concentrations of the BPA metabolite and creatinine were measured by GC/MS/MS and spectrophotometry, respectively. Daily BPA intake was assumed to be equal to daily excretion. RESULTS: The daily intake of BPA among Japanese pregnant women was estimated to be in the range of < 0.3 to 7.9 microg/day (median < 2.0 microg/day), being consistent with the levels in previous studies for non-pregnant Japanese women. This level was far below the current Acceptable Daily Intake (0.01 mg/kg/day) which was set by the European Commission. The maximum estimated intake per body weight (0.16 microg/kg/day) reached 1/10 of the Lowest Adverse Effect Level of BPA for pregnant mice for a reproductive effect on the offspring (2 microg/kg/day). CONCLUSION: It is desirable to lessen BPA intake from a precautionary viewpoint, particularly in pregnant women.

[Preliminary study on measurement of human fecundity applicability of time to pregnancy with Japanese subjects].

BACKGROUND: Debate has been continuing whether endocrine disrupting chemicals (EDC) in the environment affect human reproduction. We are planning to use time to pregnancy (TTP) as a measure of human fecundity to relate EDC exposure in a future research. TTP is expressed as the number of non-contracepting menstrual cycles or months required for a couple to conceive. An extended TTP might be considered to reflect an injury to reproductive processes. Since this parameter has never been measured in Japan. the present preliminary study aimed at establishing a Japanese version of the TTP questionnaire and determining if TTP could be reliably measured in Japan. METHODS: We prepared a self-administered questionnaire that consisted of questions on TTP, sexual life and dietary habits. Women who visited a gynecology clinic in Tokyo for confirmation of pregnancy during the period October 2000 to March 2001 were the subjects asked to fill in the questionnaire. The results were statistically analyzed by chi-square test, t-test and binorminal logistic model after classifying the subjects into two groups: (a) Group I (TTP < or = 6 months; n = 53) (b) Group II (TTP > 6 months; n = 16) RESULTS: Of the 92 women approached, 69 (75.0%) could report TTP. The distribution of TTP, the mode being around 1-2 months with a positive skew toward longer value, was similar to those reported so far in Western countries. There were statistically significantly more smokers in Group II (smoker 62.5%) than in I (15.6%). Logistic regression analysis indicated prior gravidity and fish and milk consumption, in addition to cigarette smoking, to be related to TTP. CONCLUSIONS: The present preliminary study indicated that TTP surveys are feasible with Japanese based on the high response rate and plausible distribution of reported value. It also indicated that TTP was related to cigarette smoking, gravidity and dietary habits, again consistent with previous studies.

Immunological and endocrinological studies on lymphocyte subpopulation and medical treatment for infertility in patients with endometriosis.

We investigated the relationship between interleukin-6 (IL-6) levels and subset profiles of T lymphocyte (T-cell) and macrophage in peritoneal fluid (PF) with or without endometriosis (EM). IL-6 levels in PF with EM were significantly higher than those without EM. IL-6 producing cells with EM were analyzed in each activated mature T-cell (CD3+CD69+) and macrophage (CD14+) were 0.5 and 3.5%, respectively, whereas it was mostly negative in those without EM. Cytotoxic T-cell (CD8+CD11b-) profiles in PF with EM were also quiet different from those without EM. Cellular immunity in the peripheral blood did not change during the course of IVF-ET cycles, although plasma levels of ovarian steroid hormones significantly increased comparing with that in normal ovarian cycles. Cytotoxic T-cell type 1 (Tc1) profiles might be useful predictive values in the pregnancy outcome for infertile patients with EM.