Glutathione and glutathione-related enzymes in decidua and placenta of controls and women with pre-eclampsia.

Pre-eclampsia is a major complication of pregnancy with high morbidity and mortality rates. The aetiology is still unclear but impaired detoxification or enhanced levels of reactive (oxygen) metabolites may contribute to the development or maintenance of pre-eclampsia. Glutathione and glutathione-related enzymes, as one of the major detoxificating and free-radical scavenging systems, may play a role in controlling the disease. Seventeen normotensive pregnant women and 24 pre-eclamptic women were investigated prospectively with respect to placental and decidual levels of total glutathione (GSH), glutathione S-transferase activity (GST), selenium-dependent glutathione peroxidase (SeGPX) and total glutathione peroxidase activity (TGPX, both selenium- and non-selenium-dependent GPX). Decidual levels of glutathione and related enzymes were compared with placental levels, and the investigated parameters in pre-eclampsia were compared with those in normotensive pregnancy by the Mann-Whitney U -test. Clinical data were correlated with biochemical parameters by Spearman's correlation test. Glutathione levels were significantly higher in decidua as compared with placenta. Glutathione levels were elevated in pre-eclampsia and HELLP (haemolysis, elevated liver enzymes, low platelets) as compared to normotensive pregnancy for decidua and in the placenta of patients with pre-eclampsia only. Glutathione S-transferase activity was not different between the two groups. In the placenta of patients with pre-eclampsia+HELLP, total glutathione peroxidase activity was elevated versus controls. Selenium-dependent glutathione peroxidase activity was higher in decidua versus placenta and in decidua of pre-eclamptic versus control subjects. Enhanced glutathione concentrations and glutathione peroxidase activities were often found in placenta and decidua in pre-eclampsia, probably as a compensatory mechanism to prevent further damage by peroxides, (oxygen) radicals or other toxins in the placenta or in the feto-placental interface.

Randomized comparison of intranasal and transdermal estradiol.

OBJECTIVE: To compare the efficacy and patient acceptability of intranasal versus transdermal 17 beta-estradiol (E2) delivery systems for postmenopausal symptoms. METHODS: Postmenopausal women were randomly assigned to intranasal 17 beta-E2, 300 microg daily (n = 176) or transdermal 17 beta-E2 (delivering 50 microg/day), two patches per week (n = 185) for 12 weeks, followed by a 4-week period with the alternate treatment. Efficacy was compared between groups using the Kupperman Index and vasomotor symptoms at week 12. Patient acceptability was compared by patient choice of administration route and by questionnaire at week 16. RESULTS: Intranasal and transdermal therapy produced significant reductions in the Kupperman Index and in the occurrence of hot flushes and night sweats at week 12. Alleviation of climacteric symptoms was statistically equivalent in the two treatment groups (P <.001). The difference between groups in the Kupperman Index score of -0.5 +/- 0.9 (95% confidence interval -2.3, 1.3) was within the predetermined interval of equivalence. Both therapies were well tolerated with similar adverse event rates, except for moderate and severe mastalgia which was significantly less frequent with intranasal E2 (7.2%) than with the patch (15.5%, P =.02). Sixty-six percent of patients chose to continue the intranasal therapy and 34% the transdermal therapy (P <.001). Satisfaction was greater with intranasal therapy at week 16 (P <.001). CONCLUSION: Intranasal and transdermal estrogen delivery systems had equivalent efficacy and similar safety profiles. Intranasal therapy was the patients' choice for long-term treatment.

Glutathione S-transferase isoenzymes in decidua and placenta of preeclamptic pregnancies.

OBJECTIVE: To investigate a possible involvement of glutathione S-transferases, major detoxificating enzymes, in the pathophysiology of preeclampsia. METHODS: Levels of glutathione S-transferase isoforms and enzyme activity were assessed in placental and decidual tissues in 22 preeclamptic and 21 normotensive women. Measured values were analyzed statistically using the Mann-Whitney U test for comparison between groups, and the signed-rank test for comparison within groups. RESULTS: Glutathione S-transferase pi is the main glutathione S-transferase isoform in normal placental and decidual tissue. Lower median placental and decidual glutathione S-transferase pi levels were found in preeclamptic women compared with controls: 1268 (range: 524-3925) and 2185 (range: 503-6578), P = .05, for placenta; 1543 (range: 681-2967) and 2169 (range: 893-3929), P = .02, for decidua. The total amount of glutathione S-transferases in control and preeclamptic pregnancies was higher in decidua than in placenta. CONCLUSION: Reduced levels of glutathione S-transferase class pi in preeclampsia might indicate a decreased capacity of the glutathione/glutathione S-transferase detoxification system. A higher total amount of glutathione S-transferases in decidual tissue might point to a more pronounced protective role of decidua compared with placenta.

Umbilical cord plasma glutathione S-transferase alpha 1-1 levels as a marker of neonatal hepatocellular integrity.

OBJECTIVE: To investigate possible delivery-related impaired neonatal hepatocellular integrity by assessment of arterial and venous umbilical cord plasma levels of glutathione S-transferase Alpha 1-1. METHODS: Glutathione S-transferase Alpha 1-1 levels were assessed in arterial and venous umbilical cord, and maternal venous plasma samples. The influence of maternal, delivery, and neonatal characteristics on arterial umbilical cord glutathione S-transferase Alpha 1-1 levels was studied, using linear regression analysis after log-transformation. RESULTS: Median (range) arterial umbilical cord glutathione S-transferase Alpha 1-1 plasma levels were higher than venous umbilical cord levels (9.68 [0.64-1125] microg/L and 7.66 [0.78-987.5] microg/L, respectively, P < .005). Median (range) arterial and venous umbilical cord glutathione S-transferase Alpha 1-1 levels were higher than, and did not correlate with, maternal venous plasma levels (8.79 [1.79-183] microg/L and 6.47 [1.58-164.5] microg/L versus 1.47 [0.46-10.4] microg/L, P < .001). Neonates born vaginally demonstrated higher median (range) levels than those delivered by cesarean (13.41 [1.02-1125] microg/L and 5.73 [0.64-172.90] microg/L, respectively, P < .001). Neonates with unfavorable pH (arterial pH under 7.20) demonstrated higher median (range) levels than those with normal pH (arterial pH at least 7.20) (15.15 [0.77-1125] microg/L and 8.82 [0.64-120.90] microg/L, respectively, P < .001). Stepwise multiple linear regression analysis showed that birth weight had the largest influence on arterial umbilical cord glutathione S-transferase Alpha 1-1 levels, followed by arterial base deficit, and route of delivery. CONCLUSION: Arterial umbilical cord glutathione S-transferase Alpha 1-1 plasma levels, being unrelated to maternal venous levels, might give a reliable impression of early neonatal hepatocellular integrity and may become an additional indicator of neonatal condition immediately after birth.

Cigarette smoking and the risk of male factor subfertility: minor association between cotinine in seminal plasma and semen morphology.

OBJECTIVE: To evaluate the impact of cigarette smoking on male factor subfertility and the semen parameters of sperm count, motility, and morphology by questionnaire and determination of the cotinine concentrations in blood and seminal plasma of fertile and subfertile males. DESIGN: Case-control study of 107 fertile and 103 subfertile males who provided a standardized blood and semen specimen and completed a self-administered questionnaire about their smoking habits. SETTING: Outpatient fertility clinic of the University Medical Centre St. Radboud, Nijmegen, The Netherlands. PATIENT(S): One hundred seven fertile and 103 subfertile males. INTERVENTION(S): Vena puncture and semen collection. MAIN OUTCOME MEASURE(S): Blood and seminal plasma cotinine levels in relation to semen parameters. RESULT(S): A higher frequency of cigarette smoking was observed in subfertile males than in fertile males, with an odds ratio of 1.7 (95% confidence interval, 0.9-3.2). The self-reported number of cigarettes smoked per day correlated with the cotinine concentrations in blood and seminal plasma for both groups. A small but statistically significant correlation was found between cotinine concentrations in seminal plasma and the percentage of abnormal sperm morphology, but not for other semen parameters (r(s) = 0.19). CONCLUSION(S): Although the mechanism of the toxicity of cotinine on sperm morphology is not clear, this study indicates only a minor effect of cigarette smoking on male factor subfertility, which is probably due to compounds in cigarette smoke other than nicotine (cotinine).

Mutation frequency of cystic fibrosis transmembrane regulator is not increased in oligozoospermic male candidates for intracytoplasmic sperm injection.

OBJECTIVE: To examine the frequency of anomalies of the vas deferens and the frequency of mutations of the cystic fibrosis transmembrane regulator (CFTR) gene in male candidates for intracytoplasmic sperm injection (ICSI) who had severe oligoasthenoteratozoospermia. DESIGN: The clinical data for male candidates for ICSI were studied. The three most frequent cystic fibrosis (CF)-causing CFTR mutations in the Dutch population (deltaF508, A455E, and G542X) and the three most frequent CFTR mutations potentially causing congenital bilateral absence of the vas deferens (CBAVD) in the Dutch population (deltaF508, R117H, and IVS8-5T) were analyzed. Delta I507 is also detected by the deltaF508 test. Samples of DNA from patients identified as CFTR mutation carriers were subjected to denaturing gradient gel electrophoresis analysis with use of a two-dimensional electrophoretic technique. SETTING: University-based center for reproductive medicine and clinical genetics. PATIENT(S): Male candidates for ICSI who had oligoasthenoteratozoospermia and no history of operative sterilization and refertilization. Males with a chromosomal aberration or a Y-chromosome microdeletion were excluded. INTERVENTION(S): Semen and blood samples were collected from the patients at their first visit to the clinic. MAIN OUTCOME MEASURE(S): Frequency of anomalies of the vas deferens and frequency of mutations of the CFTR gene in male candidates for ICSI who had oligoasthenoteratozoospermia. RESULT(S): None of the patients had abnormalities of the vas deferens at physical examination. In 4 of the 150 chromosomes (75 patients), a CFTR mutation was found, yielding a CFTR mutation frequency of 2.7% (95% confidence interval, 1.0-6.7%). None of the patients had two CFTR mutations. CONCLUSION(S): The frequency of congenital abnormalities of the vas deferens in patients with oligoasthenoteratozoospermia is low. The frequencies of the CFTR mutations identified in this cohort did not differ significantly from the frequencies found in the normal Dutch population.

Factors influencing the risk of abnormal pregnancy outcome in epileptic women: a multi-centre prospective study.

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 pregnancies of controls. The main outcome measures were abnormal pregnancy outcome: major and minor congenital malformations, ectopic pregnancies, abortions; neonatal headcircumference; birth weight and birth length. Epileptic women had a two-fold risk of having an abnormal pregnancy outcome or an infant with minor malformations compared to healthy controls (odds ratio, with 95% confidence interval, respectively 2.1 (1.1, 4.0) and 2.0 (1.0, 4.0)). A significant correlation between the prevalence of abnormal pregnancy outcome and duration of epilepsy and AED treatment was found (risk increased by 9% (6%, 16%) per annum). No significant effect in terms of the type, the number or the serum level of the AEDs could be established. The head circumference of infants of epileptic mothers was significantly smaller (0.7 (1.2, 0.28 cm) compared to controls. An effect on the outcome of pregnancy of maternal folate supplementation or of folate blood concentrations during the periconceptional period and first trimester of pregnancy could not be determined. The severity of maternal epilepsy and/or AED treatment influences pregnancy outcome.

The impact of calcium, magnesium, zinc, and copper in blood and seminal plasma on semen parameters in men.

To investigate the impact of calcium, magnesium, zinc, and copper in blood and seminal plasma on semen parameters, 107 fertile and 103 subfertile males provided a standardized blood and semen specimen. Total calcium and magnesium concentrations were determined with colorimetric end point assay procedures. Zinc and copper were determined by flame atomic absorption spectrophotometer (AAS). Semen analysis was performed according to World Health Organization guidelines (1992). The concentrations of calcium, magnesium, zinc, and copper in blood and seminal plasma were not different between the subfertile and fertile group. Weak correlations were demonstrated between blood plasma zinc concentrations and sperm count (rs = 0.18), sperm motility (rs = 0.15), and abnormal sperm morphology (rs = 0.13). Zinc and magnesium concentrations in seminal plasma correlated weakly with sperm count (rs = 0.17 and rs = 0.16, respectively), and copper concentrations in blood plasma with motility (rs = 0.25). Strong correlations were found between calcium, magnesium, and zinc in seminal plasma. Although calcium, magnesium, zinc, and copper play an essential role in spermatogenesis and fertility, the determination of these elements in blood and seminal plasma does not discriminate on the basis of fertility in this group of men.

Plasma glutathione S-transferase Pi 1-1 measurements in the study of hemolysis in hypertensive disorders of pregnancy.

OBJECTIVE: To investigate the value of plasma glutathione S-transferase Pi1-1(GSTP1-1) measurements in the assessment of hemolysis in hypertensive disorders of pregnancy. METHODS: Plasma GSTP1-1 and haptoglobin levels and serum lactate dehydrogenase (LDH) activity were measured in 81 healthy nonpregnant female blood donors between 20 and 40 years of age, 41 women during uncomplicated normotensive pregnancy, 35 women with pregnancy-induced hypertension, 67 women with preeclampsia, and 34 women with the HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome. Levels in hypertensive pregnancies were compared to levels in normotensive pregnancy, and levels in normotensive pregnancy were compared to levels in blood donors by the Mann-Whitney U-test. RESULTS: Median GSTP1-1 and LDH levels were significantly increased (p < 0.01) and haptoglobin significantly decreased (p < 0.01) in preeclampsia and the HELLP syndrome as compared to normotensive pregnancy. Both GSTP1-1 and LDH levels were significantly higher in normotensive pregnant women as compared to nonpregnant women (p < 0.0001). The percentage of preeclamptic patients (26.9%) or patients with the HELLP syndrome (73.5%) with elevated GSTP1-1 levels was lower than those with elevated LDH (38.8% and 100%, respectively) or decreased haptoglobin levels (41.8% and 97%, respectively). CONCLUSIONS: We conclude that plasma GSTP1-1 levels may provide useful information on hemolysis in hypertensive disorders of pregnancy in addition to serum LDH activity and plasma haptoglobin levels and that the degree of hemolysis in hypertensive disorders of pregnancy, especially in the HELLP syndrome, is probably less prominent than generally assumed.

Pregnancy and protein C deficiency.

This report examines a patient with recurrent attacks of thrombo-embolism due to a protein C deficiency. Alterations in the coagulation during pregnancy and the possible consequences of an altered coagulation during pregnancy will be discussed.

A randomized, comparative study of a single oral dose of fluconazole versus a single topical dose of clotrimazole in the treatment of vaginal candidosis among general practitioners and gynaecologists.

OBJECTIVES: To compare efficacy, acceptability and patient preference of a single oral dose of fluconazole with a single intravaginal dose of 500 mg clotrimazole (medication groups) in women with vaginal candidosis visiting gynaecologists or general practitioners (study groups). DESIGN: A comparative, randomized multicenter study. EVENTS: Baseline visit and treatment, short-term follow-up after 1 week and long-term follow-up after 4 weeks. At each visit, symptoms were graded and cultures were obtained. RESULTS: Symptomatic and mycological efficacy did not differ statistical significant in the medication groups or study groups. A complicated history regarding vaginal candidosis was more often found among gynaecologists, yielding poorer results of treatment. Patients preferred oral treatment over intra-vaginal treatment. CONCLUSIONS: No differences were found in the clinical and mycological efficacy of both drugs. Clinical results were related to parameters originating from the patients history, resulting in less favourable results in the study group of gynaecologists.

Neutrophil oxygen radical production in pre-eclampsia with HELLP syndrome.

OBJECTIVE: To determine whether severe pre-eclampsia complicated by hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome alters neutrophil oxygen radical production. MATERIALS AND METHODS: Neutrophils were obtained from 10 healthy non-pregnant, 9 normal pregnant and 9 women with severe pre-eclampsia with concurrently HELLP syndrome. Oxygen radical production was evaluated using luminol-enhanced chemiluminescence and measured by cytochrome C reduction. Furthermore we incubated sera from cases and controls with isolated healthy neutrophils and measured their capacity to generate oxygen radicals. RESULTS: Unstimulated neutrophil oxygen radical production was significantly lower in severe pre-eclamptics compared with healthy non-pregnant and pregnant subjects, whereas phorbol ester-induced oxygen radical production did not differ among categories. Cytochrome C reduction of unstimulated neutrophils showed similar results. Healthy neutrophils incubated with sera from pre-eclamptics enhanced the oxygen radical production significantly more than neutrophils incubated with sera from the healthy subjects. CONCLUSIONS: Severe pre-eclampsia is characterised by decreased unstimulated neutrophil oxygen radical production. This may be the result of an exhausted cellular response due to stimulation by a factor present in the serum of these patients.

Multiple birth prevalence in The Netherlands. Impact of maternal age and assisted reproductive techniques.

OBJECTIVE: To evaluate the impact of maternal age and use of fertility drugs on multiple birth prevalence from 1970 to 1995 in the Netherlands. STUDY DESIGN: A population-based survey was carried out in which data were collected from the Centraal Bureau voor Statistiek, the Institute of Medical Statistics and from all clinics for in vitro fertilization. RESULTS: In the last two decades, the prevalence of multiple births, especially of twin and triplet births, has increased significantly. Three possible explanations for this phenomenon are: (1) introduction of assisted reproductive techniques in combination with fertility drugs; (2) increasing maternal age; and (3) decreasing fecundity with increasing maternal age, resulting in more fertility treatments. A surplus of 1,366 twins was born in 1995 as compared to 1975. The expected excess of twins was 1,368, of which 104 (7.6%) were a result of the increase in total births in 1995, 583 (42.6%) were due to maternal age > 29 years, and, respectively, 330 (24.1%) and 351 (25.7%) twins were due to in vitro fertilization treatment and intrauterine insemination. CONCLUSION: The delay in achieving pregnancy and the use of fertility-promoting therapies profoundly affect the prevalence of multiple pregnancies in a given country. The general population should be informed of this risk.

Microdeletions of the Y chromosome and intracytoplasmic sperm injection: from gene to clinic.

Intracytoplasmic sperm injection (ICSI) is a successful treatment option for severe male infertility, although the aetiology of the disorder remains unclear in most cases. Recently, microdeletions in the AZF region of the Y chromosome have been detected in men with azoospermia or severe oligozoospermia. In this study we investigated the prevalence of microdeletions in the AZF region of the Y chromosome in a population of men undergoing ICSI, and looked for clinical characteristics of men with and without this deletion. Blood was drawn from 164 men, who were on the waiting list for ICSI treatment: 19 were azoospermic, 111 oligozoospermic and 34 normozoospermic (after previous total fertilization failure). A total of 100 men with proven fertility served as a control. Microdeletions in the AZFc region were present in seven of the 111 oligozoospermic men (6.3%). Compared with oligozoospermic men without microdeletions, men with microdeletions had a lower concentration of follicle stimulating hormone (FSH), a lower number of motile spermatozoa and a lower frequency of abnormal findings at andrological history or examination. No microdeletions were found in the azoospermic, normozoospermic and control groups. In conclusion, microdeletions in the AZFc region are relatively frequently found in men with severe unexplained oligozoospermia. In the ICSI era this finding has an important impact because this form of male infertility is now potentially hereditary. Therefore we recommend DNA screening (and genetic counselling) before ICSI, especially in men with normal FSH, severe oligozoospermia and no abnormal clinical andrological findings.

Glutathione S-transferase alpha levels in epileptic and healthy women preconceptionally and throughout pregnancy.

We studied plasma GSTA1-1 concentrations in preconceptionally recruited epileptic women who received antiepileptic drugs (n = 99) and a control group of healthy women (n = 106). Mean plasma GSTA1-1 concentrations in the control group did not show significant changes preconceptionally and throughout pregnancy. Six weeks postpartum, however, a significant increase in the mean plasma GSTA1-1 concentration (p < 0.001) was found as compared to preconceptional levels and levels during pregnancy. The mean plasma GSTA1-1 concentration in epileptic women was significantly higher in the 4th gestational week compared to those determined in healthy pregnant women (1.68 versus 1.08 microg/l, p < 0.001). Values between the groups in the second and third trimester and postpartum period showed no significant differences.

Liver function following pregnancy complicated by the HELLP syndrome.

Serum levels of aminotransferases, lactate dehydrogenase, gammaglutamyl transferase, alkaline phosphatase, albumin and conjugated bilirubin, measured in 54 women at a median of 31 months (range 3-101) after pregnancies complicated by the HELLP syndrome, were not elevated. Total bilirubin levels, however, were elevated in 20% of these women; this represents a significant difference from the prevalence in 151 women with a previous normal pregnancy (chi2 = 12.23, P < 0.001), or in the normal female population (chi2 = 22.34, P < 0.00001). This raises the possibility that a dysfunction of the bilirubin-conjugating mechanism represents a risk factor for the development of the HELLP syndrome.

Does intracytoplasmic sperm injection lead to a rise in the frequency of microdeletions in the AZFc region of the Y chromosome in future generations?

Microdeletions in the AZFc region of the Y chromosome are found in oligo- and azoospermic men. These mutations were genetically lethal before the intracytoplasmic sperm injection (ICSI) era but they can nowadays be transmitted to next generations via ICSI. We have tried to answer the question, 'Does ICSI lead to a significant rise in the frequency of these microdeletions in future generations?', by developing a mathematical model for Y-linked mutations with two variables (fitness and mutation frequency). To illustrate this model we have made estimates according to three imaginary scenarios. Using the assumptions described, the model predicted that the frequency of microdeletions in the AZFc region would increase in each generation until a plateau was reached. The higher the fitness, the higher the plateau and the later the plateau would be reached. Taking realistic estimates for fitness (0.5) and spontaneous mutation frequency (0.0001), the maximum increase in men with microdeletions would be twofold. This maximum would be already reached after five generations. However, if the fitness of these men were improved and approached 1.0, the mechanism of selection would disappear and finally all men would have the deletion in the AZFc region. Because of the assumptions in these scenarios, these estimates have limitations. The model presented shows that the rise in the frequency of men with microdeletions in the AZFc region in future generations would be limited as long as the fitness of these men remained limited.

Single-dose oral fluconazole versus single-dose topical miconazole for the treatment of acute vulvovaginal candidosis.

OBJECTIVES: To compare efficacy, safety and patient preference of a single oral dose of 150 mg fluconazole with a single intravaginal dose of 1200 mg miconazole in vaginal candidosis. To investigate the effect of treatment on Candida colonization of throat and rectum. DESIGN: Double-blind, double-dummy, parallel, randomized trial. Ninety-nine patients with symptomatic and mycologically verified candidosis were given 150 mg fluconazole with an intravaginal dummy, or 1200 mg miconazole with an oral dummy. Patients with an inadequate short-term response were given a second dose. RESULTS: At each visit a patient self assessment and an investigators' global assessment were recorded, and cultures were set up. Adverse events were recorded and laboratory tests were performed. Clinical cure or improvement (investigators' assessment) was obtained in 100% (short-term) and 95% (long term) of the fluconazole group and in 94% and 90%, respectively, of the miconazole group. Patients considered the treatment excellent or good in 81% (short-term) and 88% (long-term) in the fluconazole group and in 84% and 76%, respectively, of the miconazole group. Mycological cure was achieved in 98% (short-term) and 73% (long-term) of the fluconazole group and in 96% and 82% respectively in the miconazole group. The differences in results were not significant. Both treatments significantly reduced the number of positive rectal cultures: neither treatment had a significant effect on throat cultures. Four percent of the patients preferred intravaginal therapy. CONCLUSION: A single dose fluconazole is as safe and effective as a single dose of miconazole.

Longitudinal vitamin and homocysteine levels in normal pregnancy.

Evidence of the impact of maternal nutritional status on pregnancy outcome is increasing. However, reference values for vitamin and homocysteine concentrations in maternal blood during normal pregnancy are scarce, and are lacking for the preconceptional period and early pregnancy. Thus, in a longitudinal study we evaluated vitamin and homocysteine concentrations in 102 nulliparous women with an uneventful singleton pregnancy and normal outcome not using supplements. The physiological changes in vitamin and homocysteine concentrations in blood were determined from the preconceptional period throughout pregnancy until 6 weeks post-partum. The vitamins evaluated comprised retinol, thiamin, riboflavin, pyridoxal 5'-phosphate, folate in serum and erythrocytes, vitamin B12 and alpha-tocopherol. The plasma homocysteine concentration was also measured, considering the essential roles of folate, vitamin B6 and vitamin B12 in homocysteine metabolism. The concentrations of retinol, thiamin, pyridoxal 5'-phosphate serum folate and vitamin B12 decreased during pregnancy. In contrast, the concentrations of riboflavin, alpha-tocopherol, and folate in erythrocytes increased or showed only minor changes. Homocysteine concentrations also remained approximately constant during pregnancy. These observations emphasize the importance of preconceptional and post-partum concentrations of vitamins in the evaluation of pregnancy-induced changes. These data have provided valuable reference values for vitamins and homocysteine before, during and after pregnancy in order to contribute to better diagnosis of maternal deficiencies and to study further the relationship between maternal vitamin status and adverse course and outcome of pregnancy.