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Objectives There are no direct comparisons of blood glucose values in samples collected with barrier serum tubes (SST™) and NaF/potassium oxalate (NaF/KOx) plasma tubes. Collection of samples in SST™ tubes can offer considerable savings and specimen processing advantages for national level surveys. Design and methods Serum and plasma samples were collected under ‘field conditions’ from a single draw of 3692 individuals participating in the Canadian Health Measures Survey. The samples were analyzed retrospectively using the VITROS GLU Slide method (glucose oxidase-based). Results There was a high rate of hemolysis in the NaF/KOx tubes (86.2%) while hemolysis was infrequently observed with the SST™ tubes (2%). Comparing only blood draws where no hemolysis was observed in both tubes (n = 495; paired t -test) showed no effect of tube type on serum/plasma glucose concentrations. This was also observed when data was restricted to cases when only SST™ samples were not hemolyzed (n = 3546; paired t -test). Conclusions These data show that both collection tubes can be used under survey collection and processing conditions to measure glucose with our assay system with no difference in reported results.

One-carbon metabolism is a network of metabolic pathways, disruption of which has been associated with cancer and other pathological conditions. Biomarkers of these pathways include homocysteine (HCY), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH). A better understanding of the relationships between these biomarkers is needed for their utilization in research. This study investigated the relationships between fasting concentrations of plasma HCY, SAM, SAH and the ratio of SAM:SAH, and serum folate, vitamin B(12) and creatinine in a healthy adult population. A cross-sectional study recruited 678 volunteers; only subjects with complete data (n = 581) were included in this analysis. Correlations were used to examine bivariate relationships among the biomarkers and multivariate linear regression determined independent relationships with HCY, SAM and SAH treated as dependent variables in separate models. Multivariate logistic regression examined determinants of a low SAM:SAH ratio (defined as having a SAM:SAH ratio in the bottom quartile and SAH value in the top quartile). HCY correlated inversely with folate and vitamin B(12) and weakly correlated with SAH and creatinine. Both SAM and SAH correlated with creatinine but were independent of serum folate and vitamin B(12). In multivariate analyses, folate, vitamin B(12), creatinine, sex and age were associated with HCY; age and creatinine were determinants of SAM, and sex and creatinine determinants of SAH. Finally, male sex and increasing creatinine levels were associated with having a low SAM:SAH ratio. Findings suggest that HCY, SAM and SAH are relatively independent parameters and reflect distinct aspects of one-carbon metabolism.

To establish reference intervals for thyroid stimulating hormone (TSH) and free thyroxine (FT4) at 3-6 weeks of age in very low birth weight (VLBW) infants with the Beckman Coulter Unicel DxI 800 by gender, birth weight (BW) and gestational age (GA) subgroups.A 4 year retrospective cohort of 308 VLBW infants (GA=27.9 weeks, BW=992.3g) was studied. All blood samples for TSH and FT4 were analyzed using the modified fTSH2 (TSH) and two-step competitive enzyme immunoassay (FT4). Reference intervals were evaluated according to the most recent Clinical and Laboratory Standards Institute (CLSI) guidelines.The study provides non-parametric 95% reference intervals with associated 90% confidence intervals for FT4 and TSH derived from 308 infants screened at a median of 31 days. The reference intervals for this population are TSH=1.14-11.04 mIU/L and FT4=10.9-21.4 pmol/L. TSH statistically differed according to birth weight (1000 g vs 1000-1499 g) while FT4 differed according to gender and gestational age at time of testing (32 weeks vs ≥ 32 weeks); however, these differences were not clinically significant and a single reference interval for each analyte is reported.The results of this study highlight the importance and complexity of establishing appropriate reference intervals for thyroid function testing for the preterm population.

Smoking has adverse effects on thyroid function in nonpregnant women. For example, a previous study found a small but statistically significant decrease in the concentrations of thyrotropin (TSH) in smokers compared to nonsmokers, and a recent meta-analysis found that the risk of Graves' disease was three-fold greater among smokers than in those who had never smoked; cessation of smoking decreased the risk. However, data on the effects of smoking during pregnancy on maternal and neonatal thyroid function have been conflicting. This prospective cohort study evaluated the effect of smoking on maternal and neonatal thyroid function in 104 healthy women (83 nonsmokers and 21 smokers) undergoing elective cesarean section for term singleton infants during the years 2002-2004. The smoker to nonsmoker ratio (4:1) reflected the general rates of smoking during pregnancy. Mothers who smoked were significantly younger than nonsmokers (median age 29.5 versus 33.0 years, respectively, P ≤.023), and had significantly lighter infants (3250 gm versus 3456 gm, respectively, P ≤.011). Smokers had significantly lower maternal TSH concentrations than nonsmokers (median 1.75 mIU/liter versus 2.15 mIU/liter, respectively, P ≤.007), but there was no difference in free thyroxine (FT4) concentrations (median 9.59 pmol/liter versus 9.56 pmol/liter (P =.755). There was a correlation between the number of cigarettes smoked per day and the maternal TSH concentrations (R = -.427; P ≤.05). Umbilical venous TSH and FT4 concentrations were similar in infants of nonsmokers and smokers (P =.049). This is the first study to show that women who smoke during pregnancy have significantly lower TSH concentrations than nonsmokers.

Background: Increased total homocysteine (tHcy) may be associated with placental-mediated adverse pregnancy outcomes, but few prospective studies have measured tHcy before pregnancy outcome. This study was undertaken to determine whether increased tHcy measured in early pregnancy is associated with pregnancy loss, gestational hypertension (GH), preeclampsia, or small for gestational age (SGA) infants. Methods: We conducted a prospective cohort study between 2002 and 2005. We measured tHcy and serum folate in blood samples from pregnant women ( Results: Of the 2119 women included in the study, 103 had a pregnancy loss, 115 had gestational hypertension, 65 had preeclampsia, and 129 had an SGA infant. Subjects with increased tHcy concentrations were at increased risk of pregnancy loss [relative risk (RR) 2.1, 95% CI 1.2–3.6] or preeclampsia (RR 2.7, 95% CI 1.4–5.0) than subjects with lower tHcy concentrations, but increased tHcy concentration was not associated with increased risk of developing GH or having an SGA infant. Conclusion: The finding of high tHcy in early pregnancy as a risk factor for pregnancy loss and preeclampsia is consistent with a hypothesis that increased tHcy results in abnormalities of the placental vasculature.

The Lower North Shore region of the St. Lawrence River is home to a fish-eating population that displays an unusually high body burden of several organochlorines, including polychlorinated biphenyls (PCBs) and dioxin-like compounds (DLCs). We measured biomarkers indicative of liver enzyme induction and investigated the relationship with organochlorine body burden in adult volunteers from this population. We determined plasma concentrations of PCBs and chlorinated pesticides by high-resolution gas chromatography (HRGC) with electron capture detection. DLC concentrations were measured by the dioxin-receptor chemically activated luciferase expression (DR-CALUX) assay and in a subset of participants, by HRGC/high-resolution mass spectrometry. We measured cotinine, d-glucaric acid, and porphyrins in morning urine samples and determined liver CYP1A2 activity in vivo using the caffeine breath test. Neither DLC concentrations as measured by the DR-CALUX nor PCB-153 concentrations, the latter representing total PCB exposure, were correlated with biomarkers of effects. Smoking (morning urinary cotinine concentration) was positively related to CYP1A2 activity as measured by the caffeine breath test (p < 0.01). Liver CYP1A2 activity was in turn negatively correlated with PCB-105:PCB-153 and PCB-118:PCB-153 congener ratios (p < 0.05). Hence, despite the relatively high body burden of PCBs and DLCs in this population, only smoking had a significant correlation with biomarkers of hepatic enzyme induction. Our data are consistent with smoking-induced liver CYP1A2 activity altering heme metabolism and increasing the biotransformation of mono-ortho PCB congeners.

Vascular access thrombosis is the most common and costly complication in hemodialysis patients. The role of thrombophilia in access thrombosis is not established. A case-control study was conducted of 419 hemodialysis patients to determine whether thrombophilia was associated with arteriovenous fistula or graft thrombosis. Participants were enrolled from three in-center and five satellite dialysis units associated with a Canadian academic health science center that provides dialysis services in a catchment area of one million. Patients were tested for factor V Leiden, prothrombin gene mutation, factor XIII genotype, methylenetetrahydrofolate reductase genotype, lupus anticoagulant, anticardiolipin antibody, factor VIII, homocysteine, and lipoprotein (a) concentrations. Overall, 59 (55%) patients with access thrombosis had at least one thrombophilia compared with 122 (39%) patients without access thrombosis (unadjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.23 to 2.98). After controlling for important risk factors, the association between any thrombophilia and access thrombosis remained (adjusted OR, 2.42; 95% CI, 1.47 to 3.99). For each additional thrombophilic disorder, the odds of access thrombosis increased significantly (adjusted OR, 1.87; 95% CI, 1.34 to 2.61). This study suggests that thrombophilia is associated with access thrombosis in dialysis patients. Large, multicenter, prospective cohort studies are needed to confirm the observations from this case-control study.

Objective: To determine the influence of maternal smoking on fetal erythropoietin concentrations in health term pregnancies and test the correlation between cotinine, a biomarker of maternal smoking, and erythropoietin levels in fetuses. Methods: We invited women with healthy term pregnancies to participate in the study, excluding those with conditions previously known to be associated with elevated fetal erythropoietin levels. We recorded demographic data, smoking status, and labor outcome prospectively for each patient. Umbilical venous samples were collected, and serum was stored at −70C to be analyzed later for erythropoietin and cotinine. Umbilical arterial samples were tested for pH and base excess determination. We compared fetal erythropoietin and cotinine between smokers and nonsmokers and examined correlations between erythropoietin and cotinine. Kruskal-Wallis test, t test, median test, and Spearman rank correlation test were used when appropriate. Statistical significance was P Results: We recruited 35 nonsmokers and 26 smokers and analyzed their samples. The two groups were comparable in demographics and birth outcomes, except for birth weights, which were lower in smokers. Fetal erythropoietin concentrations increased significantly with increasing maternal cigarette consumption, ranging from none to more than 15 cigarettes per day ( P = .03). There was positive correlation between fetal erythropoietin and cotinine concentrations ( r = .41; P = .04), suggesting a dose-response relationship. Conclusion: Fetuses of smokers had increased erythropoietin concentrations that correlate positively with fetal cotinine levels; which suggests an increased risk of subacute hypoxia related to degree of maternal cigarette consumption.

The objective of this study was to determine the changes in total plasma homocysteine concentration that occur during normal pregnancy.In this cross-sectional study homocysteine was measured in 155 normal women in the first, second, and third trimesters and in nonpregnant controls. In addition, albumin, serum B12, serum folate, and red blood cell folate concentrations were measured and correlated to homocysteine values.The mean homocysteine concentration (in micromoles per liter) was 5.6 (95% confidence interval 3.9-7.3) at 8-16 weeks' gestation, 4.3 (95% confidence interval 3.5-5.3) at 20-28 weeks' gestation, 5.5 (95% confidence interval 3.3-7.5) at 36-42 weeks' gestation, and 7.9 (95% confidence interval 6.2-9.6) in the nonpregnant control group. Homocysteine was significantly lower in all 3 trimesters of pregnancy compared with nonpregnant controls (P.001). Homocysteine levels were directly correlated with albumin levels, which decreased during pregnancy. Homocysteine concentrations were decreased in subjects taking folic acid supplementation.Serum concentrations of homocysteine decrease during pregnancy. This occurs in association with the physiologic fall in albumin during pregnancy, as well as with folic acid supplementation.

Purpose:Our purpose was to determine whether serum progesterone predicts pregnancy outcome after superovulation. Methods:One hundred twenty-three consecutively pregnant patients were divided into three groups: group I, 55 patients following superovulation for assisted reproductive technologies; group II, 23 patients after correction of oligoovulation; and group III, 45 patients who conceived spontaneously. When β-human chorionic gonadotropin was positive, progesterone was measured on the same serum sample. A serum progesterone level of 45 μm/L was set to differentiate between nonviable pregnancy and ongoing pregnancy. Results:In group I, zero (0%) of 38 ongoing pregnancies and 10 (59%) of 17 nonviable pregnancies were observed with a progesterone level of

To evaluate the analytical and clinical performance of the One Touch II and Advantage glucose meters for use in neonatal specimens.For the laboratory evaluation, a total of 96 umbilical cord whole blood specimens were analyzed on the One Touch II and/or Advantage meters. Samples were centrifuged after analysis on the meters and plasma glucose was determined on the Hitachi 917. For the clinical evaluation, a total of 64 infants had specimens analyzed on each of the meters as well as on the laboratory analyzer.In the laboratory and clinical evaluations, both meters correlated well (r0.9, p0.001) with the plasma values for the Hitachi 917. However, the mean difference between the Advantage and Hitachi 917 was lower than that of the One Touch II in both the laboratory (-0.23 vs -0.64 mmol/L) and the clinical evaluations (-0.08 vs -0.60 mmol/L). 53.1% of One Touch and 26.6% of Advantage results from the clinical study had a discrepancy of0.5 mmol/L from the laboratory value.For neonatal specimens, glucose meters must have good low end precision, sensitivity and accuracy, In this study, the Advantage meter had fewer discordant results and better correlation with the Hitachi 917. Overall, nursing and laboratory staff preferred the performance and characteristics of the Advantage meter.

Objective To determine the impact of a health system-wide fetal fibronectin (fFN) testing programme on the rates of hospital admission for preterm labour (PTL). Design Multiple baseline time-series design. Setting Canadian province of Ontario. Population A retrospective population-based cohort of antepartum and delivered obstetrical admissions in all Ontario hospitals between 1 April 2002 and 31 March 2010. Methods International Classification of Diseases codes in a health system-wide hospital administrative database were used to identify the study population and define the outcome measure. An aggregate time series of monthly rates of hospital admissions for PTL was analysed using segmented regression models after aligning the fFN test implementation date for each institution. Main outcome measure Rate of obstetrical hospital admission for PTL. Results Estimated rates of hospital admission for PTL following fFN implementation were lower than predicted had pre-implementation trends prevailed. The reduction in the rate was modest, but statistically significant, when estimated at 12 months following fFN implementation (−0.96 hospital admissions for PTL per 100 preterm births; 95% confidence interval [CI], −1.02 to −0.90, P = 0.04). The statistically significant reduction was sustained at 24 and 36 months following implementation. Conclusions Using a robust quasi-experimental study design to overcome confounding as a result of underlying secular trends or concurrent interventions, we found evidence of a small but statistically significant reduction in the health system-level rate of hospital admissions for PTL following implementation of fFN testing in a large Canadian province.

We developed a packed-column chromatographic procedure capable of simultaneous quantitation of methanol, ethanol, isopropanol, acetone, and ethylene glycol. This method was then updated to a rapid, sensitive, wide-bore capillary method. The packed-column system uses direct injection of 1 microL of Na2WO4/H2SO4-deproteinized serum onto a 1.8 m x 2 mm (i.d.) column packed with 80/100 HayeSep R. A linear temperature gradient from 90 to 205 degrees C allows complete elution of all components within 20 min; minimum detection limits are 2 mmol/L. The wide-bore capillary method uses 0.1 microL of sample deproteinized by ultrafiltration, injected onto a 30 m x 0.53 mm (i.d.) 3-microns Rtx-200 (Restek) column. Baseline resolution to a minimum detection limit of 0.1 mmol/L of all compounds is achieved in 5 min with a linear temperature gradient from 40 to 250 degrees C and dual internal standards of n-propanol and 1,2-butanediol.

This prospective cohort study designed to assess the effect of folic acid supplementation in pregnancy on the risk of preeclampsia (PE) took place in Ottawa, ON and Kingston, ON, Canada, from September 1, 2002 to August 31, 2008. Pregnant women, less than 20 weeks gestational age were recruited and delivered in the Ottawa region and the Kingston General Hospital. Demographic characteristics of the study participants and the patterns of supplementation of folic acid were described and occurrence of PE between women with folic acid supplementation during pregnancy and women without were compared. Multiple logistic regression was used in the estimation of the independent effect of supplementation of folic acid. Additional analyses assessing the effect of low RBC and serum folate and dose-response relationship were performed. Analyses were performed in all study participants, and then in high risk and low risk sub-groups, respectively. A total of 7,669 participants were included in the final analysis. Ninety five percent of the study participants were taking folic acid supplementation in early second trimester. The rate of PE was lower in the supplementation group than in the no supplementation group, and the difference was statistically significant in high risk women. Similar patterns of associations were observed in analysis by RBC and serum folate levels and in dose-response analysis. Folic acid supplementation in pregnancy may reduce PE risk in pregnant women, especially in those women with increased risk of developing PE.

Reference intervals were determined for 21 clinical chemistry analytes in umbilical cord arterial and venous blood from healthy term infants. Nonparametric analysis (rank number) was used to determine the central 95% reference interval. No significant differences were observed between male and female infants. Reference intervals for glucose, urea, creatinine, urate, phosphate, calcium, albumin, total protein, cholesterol, triglycerides, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, and magnesium all were significantly different from adult values.

Fibronectin production from amnion and placental tissues was evaluated in pregnant woman smokers and nonsmokers in order to examine if there were alterations of fibronectin metabolism in intrauterine tissues. In both amnion and placental tissues, cycloheximide inhibited the fibronectin output indicating that it was being synthesized. Mean fibronectin output by amnion in pregnant woman smokers was significantly lower than that in pregnant woman nonsmokers. In contrast, in the placenta from pregnant woman smokers, the output was significantly higher than that in pregnant woman nonsmokers. The present observations indicate that smoking alters an important biochemical constituent in amnion and placenta, possible leading to some complications.

Cotinine is a sensitive and specific biochemical marker of exposure to cigarette smoke. We describe a simple solid-phase extraction of cotinine from plasma before quantification by HPLC. Extraction recovery was 97.9% +/- 11.0% for plasma concentrations of 5-400 micrograms/L. Baseline separation of cotinine and caffeine was achieved within 11 min of injection onto a C18 reversed-phase column. The mobile phase was citric acid/dibasic potassium phosphate (30 mmol/L each, pH 6.0) containing 100 mL of acetonitrile per liter. Within-day and day-to-day precision (CV) were 4.7% and 8.4%, respectively. We also describe a modification of the Nicotine Metabolite RIA kit (Diagnostic Products Corp.) for quantifying cotinine in plasma. Recovery of cotinine from supplemented plasma was within 10% of the expected value with this RIA kit. Interassay precision averaged 8.1% for samples in the range 50-400 micrograms/L; intra-assay precision averaged 3.6% at 230 micrograms/L and 8.7% at 53 micrograms/L. Correlation between the two methods was RIA = 1.13 HPLC + 14.8 (n = 128, r = 0.957, P less than 0.001). Both methods are technically simple to perform.

Objective Our objective was to determine if maternal smoking is associated with programming of the fetal hypothalamic–pituitary-adrenal (HPA) axis. Cigarette smoking, which induces a state of hypoxia in the fetus, may promote in utero‘programming’ of the HPA axis. In utero, adaptations to the HPA axis, which become maladaptive later in life, have been hypothesised to contribute to the development of adult cardiovascular disease and metabolic disorders. Design This was a prospective cohort study of term infants. Population and setting The study involved 104 infants born by elective caesarean section, 21 of whom were exposed to in utero tobacco and 83 were nonexposed. Methods Healthy women with healthy pregnancies were recruited if they were undergoing elective caesarean section. Maternal blood was drawn for cortisol and cotinine in the morning, and the umbilical blood was drawn immediately after delivery of the baby. Main outcome measures Umbilical arterial cortisol and adrenocorticotropin hormone (ACTH) levels. Results ACTH levels were significantly elevated in smoke-exposed infants [17 (4–22) pmol/l versus 4 (2–11) pmol/l, respectively, P= 0.005], while cortisol levels were similar [182 (130–240) nmol/l versus 192 (127–265) nmol/l, respectively, P= 0.541]. Conclusions For the first time, it was shown that infants exposed to in utero tobacco smoke have significantly elevated ACTH levels compared with nonexposed infants. The results of this study warrant further exploration of the effect of smoking on the neonatal HPA axis as a potential set up for ‘programming’.

Maternal smoking is associated with adverse perinatal outcomes. Because of concerns of underreporting, investigators routinely perform biochemical testing to confirm smoking status, such as serum cotinine, a major metabolite of nicotine, adding an increased cost to examine compliance. The objectives of this study were to determine the sensitivity and specificity of self-reported smoking with serum cotinine as the gold standard and to determine the correlation between self-reported smoking in cigarettes per day and serum cotinine levels. In this cross-sectional study, we surveyed women during the first trimester of pregnancy on their tobacco exposure. A total of 40 women reported that they were smokers, and 40 were nonsmokers, 1 of whom had quit 5 days prior. The mean (+/-S.D.) serum cotinine value among smokers was 155 (+/-122) ng/l, vs. 1 (+/-6) ng/l in nonsmokers, p

Objective: The objective of this study was to determine whether serum and red blood cell folate levels were decreased in pregnant women who smoke and whether total plasma homocysteine levels were elevated. Study Design: In this cross-sectional study, serum folate, red blood cell folate, and homocysteine were measured in pregnant first- and early second-trimester pregnant women who smoked (case subjects) and pregnant women who did not smoke (control subjects). In addition, vitamin B 12 , albumin, creatinine, cotinine, and hematocrit levels and methylenetetrahydrofolate reductase status were determined and compared between groups. Results: Pregnant women who smoked had significantly lower concentrations of serum folate (22.7 vs 29.4 nmol/L; P =.001) and lower concentrations of red blood cell folate (766 vs 900 nmol/L; P =.038 [not significant]) than pregnant women who did not smoke. Dietary folate intake was not significantly different between pregnant women who smoked and pregnant women who did not smoke. Homocysteine levels were also not significantly different between the groups. For each genotype of methylenetetrahydrofolate reductase, lower levels of serum folate were observed in pregnant women who smoked, with the lowest folate levels seen in homozygous mutant methylenetetrahydrofolate reductase 677TT (18.6 nmol/L in pregnant women who smoked vs 24.2 nmol/L in pregnant women who did not smoke). Conclusion: Both serum folate and red blood cell folate are lower in pregnant women who smoked than in pregnant women who did not smoke, although homocysteine levels are not significantly different. There is an important gene environment interaction between methylenetetrahydrofolate reductase gene activity and tobacco exposure on serum folate levels. Lower levels of serum folate may account for the higher rate of miscarriage, stillbirth, abruptio placentae, and fetal anomalies that are observed in pregnant women who smoke. Pregnant women who smoke may benefit from higher doses of folic acid periconceptionally. (Am J Obstet Gynecol 2002;187:620-5.)

To compare the predictive value of serum progesterone in identifying nonviable pregnancy in symptomatic spontaneously pregnant emergency department patients and asymptomatic patients attending an infertility clinic.Retrospective study.Tertiary-care academic health center.One hundred thirty-seven pregnant patients who presented to the emergency department for whom clinical outcomes were available, and 123 consecutive patients who became pregnant during treatment at the infertility clinic.Serum progesterone measurement.The sensitivity, specificity, and predictive value of serum progesterone45 nmol/L in identifying nonviable pregnancies were determined for each of the groups.Sensitivity and specificity of serum progesterone45 nmol/L in predicting nonviable pregnancies were 88.6% and 87.5%, respectively, in spontaneously pregnant patients who presented to the emergency department with pain or bleeding and 58.8% and 100% in infertility patients who had undergone controlled ovarian hyperstimulation for in vitro fertilization or intrauterine insemination. Sensitivity and specificity for all other infertility clinic patients were variable.The predictive value of low serum progesterone in identifying nonviable pregnancies varies with patient populations.

OBJECTIVES: The purpose of this study was to determine whether strict maternal glycemic control for the treatment of gestational diabetes lessened the risk of fetal macrosomia, birth trauma, neonatal hypoglycemia, and operative delivery. The aim of the pilot study was to prepare for a multicenter trial by assessing patient acceptance of the study, by determining realistic accrual rates, and by detecting any major adverse outcomes in the control group that received routine obstetric care. STUDY DESIGN: The study was a prospective randomized controlled trial comparing fetal-neonatal and maternal outcomes in 300 women with gestational diabetes. Women randomized to the treatment arm were managed by strict glycemic control and tertiary level obstetric care, and women in the control arm received routine obstetric care. RESULTS: Three hundred women with gestational diabetes mellitus were studied. There was no difference in maternal age, weight, or length of gestation between groups. The treatment mean birth weight was 3437 ± 575 gm compared with 3544 ± 601 gm in the control group, a difference of 107 gm (not significant). Macrosomia rates were similar. There was no birth trauma in either group. The frequency of neonatal hypoglycemia and other metabolic complications was the same. The mode of delivery also showed similar patterns. The treatment group had significantly lower preprandial and postprandial glucose levels by 32 weeks' gestation, which continued to term. CONCLUSION: This pilot study suggests that intensive treatment of gestational diabetes mellitus may have little effect on birth weight, birth trauma, operative delivery, or neonatal metabolic disorders. It has demonstrated the safety of proceeding to a multicenter trial of sufficient sample size to confirm these findings.(Am J Obstet Gynecol 1997;177:190-5)

This study describes the prevalence of smoking among 3,220 pregnant women. Maternal and umbilical cord cotinine levels were compared with the women's self-reported cigarette consumption, infant birth weight and antepartum and perinatal complications. Of the women who reported themselves as being active smokers (23%), 76% had a partner who smoked, and 38% reported exposure to environmental smoke in the workplace. Only 15% of nonsmokers had a partner who smoked, and 13% reported workplace exposure. The mean number of cigarettes/day was 20.5 (95% CI 19.6-21.4). The relative risk of having a small-for-gestational-age infant was significantly higher in smokers for mothers of both preterm (34-36 wks, RR = 3.38, 95% CI 1.25-9.16) and term babies (> or = 37 wks, RR = 2.04, 95% CI 1.58-2.63). Mean infant birth weight was 207 g lighter in the infants of smokers (p < 0.001) and was inversely correlated to maternal serum cotinine level. Birth weight dropped by 0.99 g for every 1 ug/L increase in cotinine (r = -0.19, p < 0.01).

Objective: To examine the association between parents' report of their child's secondhand smoke exposure and various adjustments of cotinine concentrations in random urine samples. Methods: Urine cotinine and creatinine were measured in 109 six to 11-year-old children from predominantly upper middleclass families. Cotinine values were considered as: (a) unadjusted, (b) as a cotinine/creatinine ratio, (c) as adjusted based on a regression relationship between cotinine and creatinine, and (d) and (e) as a cotinine/creatinine ratio adjusted for age and sex. Results: Little overlap in cotinine values occurred between exposed and nonexposed children, and a dose-response relationship was noted between the parental report and the urine cotinine values (r = 0.67). A modest improvement occurred in the correlation when the cotinine/creatinine ratio was considered. Considering exposure to cigarette smoke outside the home as well as in the household only improved the correlation when the former exposure was heavy. A high degree of concordance exists between the parents' report of exposure and the child's urine cotinine. Conclusions: The value of adjusting this biochemical parameter by various means may be a function of the particular sample being investigated, suggesting no one method is universally appropriate.

Laxative abuse, if unrecognized, can lead to unnecessary and costly investigations. The stimulants and chathartics are the most commonly abuse laxatives and have the potential for causing the most long-term damage. We have optimized a solid-phase extraction coupled with high-performance thin-layer chromatography (HPTLC) to provide rapid, simple, and sensitive detection of phenolphthalein, danthron, rhein, aloin, and bisacodyl and its metabolites in urine. Positive screens have revealed laxative abuse in 3 of 42 samples from patients presenting with diarrhea of unknown origin.

Objective The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia. Study Design We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks’ gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis. Results A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 μmol/L), decreased plasma homocysteine (on average 0.39 μmol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75). Conclusion Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.

Objective The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia. Study Design We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks’ gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis. Results A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 μmol/L), decreased plasma homocysteine (on average 0.39 μmol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75). Conclusion Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.

SARAH MCDONALD, ARNE OHLSSON, JOSEPH BEYENE, SHERRY PERKINS, MARK WALKER, McMaster University, Obstetrics and Gynecology, Hamilton, Ontario, Canada, University of Toronto, Pediatrics, Toronto, Ontario, Canada, Hospital for SickChildren, PopulationHealth Sciences, Toronto,Ontario, Canada, University of Ottawa, Biochemistry, Ottawa, Ontario, Canada, University of Ottawa, Obstetrics and Gynecology, Ottawa, Ontario, Canada OBJECTIVE: We sought to determine the relationship between smoking and endocrine disruption of maternal thyroid and adrenal function. STUDY DESIGN: This was a prospective cohort study of 21 smoking and 83 non-smoking mothers. One to four matching was selected to reflect the proportion of smokers in our population and also to increase power. The primary exposure was self-reported cigarette smoking (dichotomous, ‘‘yes’’ or ‘‘no’’). (McDonald, 2005) Healthy women (without endocrine diseases) had fasting, morning blood samples drawn at term from the antecubital vein using standard phlebotomy technique. RESULTS: Baseline characteristics were similar except for maternal age (smokers were significantly younger, 29.4 C 6.0 years versus 32.6 C 4.3 years, respectively, p=0.030) and the household income and education levels were lower in smokers. TSH levels were significantly lower in smokers than nonsmokers (1.8 C0.7 mIU/L versus 2.4 C 1.0 mIU/L, respectively, p=0.012). CONCLUSION: We demonstrated for the first time during pregnancy to our knowledge that smokers have lower TSH levels than non-smokers. This nonpregnant literature supports this, with increased risks of Graves disease in smokers, and of ophthalmopathy in Graves patients who smoke. It has been suggested that the lower TSH levels are due to suppression from glucocorticoids, which are typically elevated in smokers, although the difference was not statistically significant in our population. This study provides further evidence about the detrimental effects of smoking during pregnancy.

The percent recovery of mercury from human hair digest samples, using the peak height cold-vapor atomic adsorption method is 73.0% +/- 10.3%. This value and its reproducibility are raised to 102.2% +/- 6.3% by use of peak area measurements in place of peak height. The so-called matrix effect is thus eliminated, and its origin shown to be in the slower (but still quantitative) release of mercury from biological samples. Although greater reliability is obtained using peak area, this is gained at the cost of analysis time.

The behaviour of mercury(I) ion in the cold-vapour atomic absorption spectrometry under nonreducing conditions is discussed. The signal obtained corresponds to about 35% of total mercury present. Under the same conditions, the same quantity of Hg 2+ is found by dithizone spectrophotometry. Thus the cold-vapour signal is due entirely to disproportionation of mercury(I), which is not inhibited by chloride at mercury concentrations less than 120 μg l −1 . The cold-vapour signal si pH-dependent and at low hydrogen ion concentration, approaches the value expected from complete disproportionation.

Serum hCG reference intervals for various gestational periods in normal pregnancies were determined using three commercial assays--two standardized against the WHO 2nd IS (Amersham Amerlex-M beta HCG RIA (AMX) and Abbott beta-HCG 15/15 (ABB] and one standardized against the WHO 1 IRP (Hybritech Tandem -E HCG (HYB]. Serial samples from patients with accurately determined gestational periods were analyzed. We correlated these assays to determine the validity of the common practice of interchanging values between assays using the same WHO standard and of converting 1st IRP values to 2nd IS values by a fixed factor. The slope of correlation between the two 2nd IS assays (AMX, ABB) was 1.43, r = 0.960; whereas between the 1 IRP assay (HYB) and the two 2nd IS assays the slopes were 1.67, r = 0.963 and 1.22, r = 0.971 for AMX and ABB, respectively. In a prospective study of 52 patients with normal pregnancies, serum beta-hCG values in 46% of samples taken at 28-35 days gestation fell below the lower limit of the reference curves supplied with the AMX kit. Ninety-two percent of samples were within the newly established intervals. These results indicate that supplier's reference limits may not be accurate; in addition, a common factor should not be used to convert values from one commercial kit to another.

Recent communications from these laboratories (1,2) have reported modified procedures, smaller reaction vessels and reagent volumes, and elimination of the matrix effect, in the Magos method of mercury analysis. With these developments completed, automation of the method (i.e., operator involvement only every 50 or 100 samples) may be considered. Such a development is becoming crucially necessary in view of the increasing number of human hair and blood samples requiring mercury analysis, especially from native populations in Canada (3). This paper reports accomplishment of this objective and describes in detail an apparatus for this purpose. ly, the addition of a water jet for rinsing the apparatus between samples, coupled with a drain at the bottom of the reaction vessel, removed the need for apparatus disassembly. Thirdly, the incorporation of signal integration eliminated the matrix effect (2) and thus, not only removed the need for timeconsuming additional control determinations to measure the extent of this effect, but also greatly simplified the subsequent data processing. Finally, automatic loading of the samples on the one-by-one sample dispenser completely removed the need for an operator from the sample-to-sample routine. Thus, operator control is required only for the initial sample preparation and loading, apparatus (tart-up, and final examination of recorded data. In order to achieve the above, a 10-channel electronic timer was sufficient to control all operations, coupled with solenoid valves to control the reagent addition, sample addition, and rinse cycle. A record-player type arm was required to deliver the sample from the sample tray to the reaction vessel. The details and schematic diagrams of the apparatus are given in the Experimental section. It should be noted that the apparatus is not limited to mercury analysis, but could be readily adapted to other routine analyses, such as fluoride analysis in urine using an ionselective electrode, and creatinine analysis by coupling to a spectrophotometer.

The recent development of techniques in this and other laboratories has allowed the exploration of elemental mercury oxidations by compounds bearing the —O—O—H moiety. The peracid group appears to be a far more effective oxidant of mercury than the peroxide group, and both peracetic acid and m-chloroperbenzoic acid oxidize mercury at the trace level to both mercurous and mercuric forms.

Aqueous solutions containing zero-valent and divalent mercury may be analysed using a double-Magos determination. Results are compared with standard methodology incorporating determinations of divalent mercury, by the dithizone technique, and of total mercury. Excellent correlations of Hg2+ concentrations by the two methods were obtained; the scatter in the comparison of Hg0 determinations was interpreted in terms of the substantial error unavoidably present in the standard methodology. The new method represents a significant improvement.

Both elemental mercury and the mercurous ion give rise to a signal in Cold-Vapor Atomic Absorption Analysis under non-reducing conditions. Distinction between these species based on the greater solubility of the mercurous ion in water is possible, and the potential of this analytical distinction is illustrated with the finding that oxidation of mercury by peracetic acid involves the mercurous state.

Experiments in homogeneous solution confirm previous findings that catalase is an effective oxidant for Hg0 leads to Hg2+. Peroxidase also effects the oxidation, and in both oxidations the co-substrate hydrogen peroxide is not essential for mercury oxidation, although the oxidation is enhanced by the presence of hydrogen peroxide.

Background In 2009 the Ontario Ministry of Health and Long Term Care funded the implementation of province-wide fetal fibronectin testing in Ontario hospitals. This paper reports results from the provincial evaluation that sought to describe the experience of fetal fibronectin testing from the perspective of women with symptoms of preterm labour. Methods A descriptive qualitative design was used, employing semi-structured telephone and face-to-face interviews with women who had fetal fibronectin testing. Results Five hospitals participated in recruiting women for the study and 17 women were interviewed. Women described their experiences of fetal fibronectin testing as an emotional process that moves from expecting, to feeling, to hoping for reassurance; and then to re-defining what is required to feel reassured. Women described feeling anxious while waiting for fetal fibronectin results. When test results were negative, women described feeling a sense of relief that their symptoms would not likely lead to an imminent preterm birth. Women with positive results expressed feeling reassured by the care decisions and quick action taken by the health care team. Conclusion Fetal fibronectin testing was acceptable and beneficial to these women with symptoms of preterm labour. Implications for practice and future research are suggested.