Reference Intervals for Urine Sediment Analysis of Healthy Pregnant Women

BACKGROUND

Urine sediment parameters of pregnant women are different from those of non-pregnant women, and it is necessary to establish reference intervals for pregnant women. The aim of this study was to establish reference intervals of white blood cell (WBC), red blood cell (RBC), bacteria (BACT), squamous epithelial cell (EC), small round epithelial cell (SRC), and mucous strands (MUS) for urine sediment test of pregnant women using a UF-1000i analyzer as the detection device. The differences between pregnant women and non-pregnant women in terms of the aforementioned parameters as well as the differences of such parameters in different trimesters of pregnancy were clarified.

METHODS

The experimental subjects were divided into two groups: the experiment group (612 healthy pregnant women) and the control group (582 healthy non-pregnant women). Subjects of both groups are women between the age of 22 and 46. The urine specimens were analyzed using the Sysmex UF-1000i analyzer, followed by manual correction. A statistical analysis was performed by SPSS 22.0. Results were considered significant at p < 0.01.

RESULTS

The pregnancy reference intervals of WBC, RBC, BACT, EC, SRC, and MUS were 0 ~ 30/µL, 0 ~ 23/µL, 0 ~ 698/µL, 0 ~ 28/µL, 0 ~ 8/µL, and 0 ~ 3/µL, respectively. In the experiment group, the concentrations of WBC, BACT, EC, and SRC were significantly higher than those of the control group (p < 0.01), while the concentrations of RBC and MUS were significantly lower than those of the control group (p < 0.01). The inter-trimester differences in terms of the concentrations of WBC, BACT, EC, and SRC were statistically indistinguishable (p > 0.05). However, the concentration of RBC was significantly lower with the increase of trimester of pregnancy (the comparison between the first trimester with the second trimester: p = 0.000 < 0.01; the comparison between the second trimester and the third trimester: p = 0.004 < 0.01). The WBC, BACT, EC, and SRC had moderate intercorrelations (0.569 ~ 0.681, p < 0.01).

CONCLUSIONS

There were significant differences in the aforementioned parameters between the two groups. The intervals of WBC, RBC, BACT, EC, SRC, and MUS for urine sediment analysis of healthy pregnant women using a UF-1000i should be established.

Unhealthy Levels of Phthalates and Bisphenol A in Mexican Pregnant Women with Gestational Diabetes and Its Association to Altered Expression of miRNAs Involved with Metabolic Disease

Several studies indicate that bisphenol A (BPA) and phthalates may have a role in the development of metabolic diseases using different molecular pathways, including epigenetic regulatory mechanisms. However, it is unclear whether exposure to these chemicals modifies serum levels of miRNAs associated with gestational diabetes mellitus (GDM) risk. In the present study, we evaluated the serum levels of miRNAs associated with GDM (miR-9-5p, miR-16-5p, miR-29a-3p and miR-330-3p) and urinary levels of phthalate metabolites (mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), mono-benzyl phthalate (MBzP) and mono(2-ethyl hexyl) phthalate (MEHP)) and bisphenol A in GDM patients and women without GDM during the second trimester of gestation. We observed higher levels of miR-9-5p, miR-29a-3p and miR-330-3p in sera of patients with GDM compared to non-diabetic subjects. Phthalates were detected in 97–100% of urine samples, while BPA only in 40%. Urinary MEHP and BPA concentrations were remarkably higher in both study groups compared to previously reported data. Unadjusted MEHP levels and adjusted BPA levels were higher in non-diabetics than in GDM patients (p = 0.03, p = 0.02). We found positive correlations between adjusted urinary MBzP levels and miR-16-5p expression levels (p < 0.05), adjusted MEHP concentrations and miR-29a-3p expression levels (p < 0.05). We also found negative correlations between unadjusted and adjusted MBP concentrations and miR-29a-3p expression levels (p < 0.0001, p < 0.05), unadjusted MiBP concentrations and miR-29a-3p expression levels (p < 0.01). Urinary MEHP levels reflect a striking exposure to di(2-ethylhexyl) phthalate (DEHP) in pregnant Mexican women. This study highlights the need for a regulatory strategy in the manufacture of several items containing endocrine disruptors in order to avoid involuntary ingestion of these compounds in the Mexican population.

Prenatal arsenic exposure alters the placental expression of multiple epigenetic regulators in a sex-dependent manner

BACKGROUND

Prenatal exposure to arsenic has been linked to a range of adverse health conditions in later life. Such fetal origins of disease are frequently the result of environmental effects on the epigenome, leading to long-term alterations in gene expression. Several studies have demonstrated effects of prenatal arsenic exposure on DNA methylation; however the impact of arsenic on the generation and decoding of post-translational histone modifications (PTHMs) is less well characterized, and has not been studied in the context of prenatal human exposures.

METHODS

In the current study, we examined the effect of exposure to low-to-moderate levels of arsenic in a US birth cohort, on the expression of 138 genes encoding key epigenetic regulators in the fetal portion of the placenta. Our candidate genes included readers, writers and erasers of PTHMs, and chromatin remodelers.

RESULTS

Arsenic exposure was associated with the expression of 27 of the 138 epigenetic genes analyzed. When the cohort was stratified by fetal sex, arsenic exposure was associated with the expression of 40 genes in male fetal placenta, and only 3 non-overlapping genes in female fetal placenta. In particular, we identified an inverse relationship between arsenic exposure and expression of the gene encoding the histone methyltransferase, PRDM6 (p < 0.001). Mutation of PRDM6 has been linked to the congenital heart defect, patent ductus arteriosus.

CONCLUSIONS

Our findings suggest that prenatal arsenic exposure may have sex-specific effects on the fetal epigenome, which could plausibly contribute to its subsequent health impacts.

Prenatal exposure to phthalates and autism spectrum disorder in the MARBLES study

BACKGROUND

Evidence from experimental and observational studies suggests that prenatal phthalate exposures may be associated with autism spectrum disorder (ASD). We examined whether prenatal phthalate exposures were associated with an increased risk of ASD.

METHODS

We quantified 14 metabolites of eight phthalates in 636 multiple maternal urine samples collected during 2nd and 3rd trimesters of pregnancy from 201 mother-child pairs in MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), a high-risk ASD longitudinal cohort. At 3 years old, children were clinically assessed for ASD and classified into three diagnostic categories: ASD (n = 46), non-typical development (Non-TD, n = 55), and typical development (TD, n = 100). We used multinomial logistic regression to evaluate the association of phthalate metabolite concentrations with ASD and Non-TD.

RESULTS

Most associations of phthalate biomarkers with both ASD and Non-TD were null, with the exception that monoethyl phthalate (MEP) was significantly associated with an increased risk of Non-TD (per 2.72-fold relative increase in concentration: Relative risk ratio (RRR) = 1.38; 95% confidence interval (CI): 1.01, 1.90). When stratified by prenatal vitamin use during the first month of pregnancy, among mothers who took vitamins, ASD risk was inversely associated with mono-isobutyl phthalate (MiBP, RRR = 0.44; 95% CI: 0.21, 0.88), mono(3-carboxypropyl) phthalate (MCPP, RRR = 0.41; 95% CI: 0.20, 0.83) and mono-carboxyisooctyl phthalate (MCOP, RRR = 0.49; 95% CI: 0.27, 0.88), but among mothers who did not take prenatal vitamins, Non-TD risk was positively associated with MCPP (RRR = 5.09; 95% CI: 2.05, 12.6), MCOP (RRR = 1.86; 95% CI: 1.01, 3.39), and mono-carboxyisononyl phthalate (MCNP, RRR = 3.67; 95% CI: 1.80, 7.48). When stratified by sex, among boys, MEP, monobenzyl phthalate, MCPP, MCNP, and sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP) were positively associated with Non-TD risk, but associations with ASD were null. Among girls, associations with both ASD and Non-TD were null.

CONCLUSIONS

Our study showed that phthalate exposures in mid- to late pregnancy were not associated with ASD in children from this high-risk ASD cohort. Further studies should be conducted in the general population without high-risk genes to confirm our findings.

Identification of urinary biomarkers for the prediction of gestational diabetes mellitus in early second trimester of young gravidae based on iTRAQ quantitative proteomics

Gestational Diabetes Mellitus (GDM) has brought great harm to maternal and fetus. Up to now, only a few plasma biomarkers for its early diagnosis have been reported; nevertheless, there is no report about identification of urinary biomarkers for prediction of GDM. Thus, it is necessary to correct this deficiency. In our study, urine samples were collected from 889 healthy young gravidae at the early second trimester (15 to 20 weeks), 69 of whom were subsequently diagnosed with GDM at 24 to 28 weeks. iTRAQ (the isobaric tags for relative and absolute quantification) quantitative proteomics was conducted on sixteen GDM (trial group) and an equal number of matched healthy young gravidae (control group). Validation was performed in 40 cases of each group by ELISA. A total of 1,901 proteins were identified in this study, including 119 significantly differential proteins (fold change ≧1.2 or ≦0.83 and p < 0.05). Compared with control group, 83 differential proteins were increased and 36 proteins were decreased in GDM group. The validation for expression of CD59 and IL1RA showed significant difference and the area under the receiver operating characteristic curve was 0.729 and 0.899, respectively (p < 0.05). The two candidate protein biomarkers (CD59 and IL1RA) in urine could be an early, noninvasive diagnostic predictors of young pravidae with GDM, and IL1RA is stronger diagnostic power than CD59.

Iodine status during pregnancy and lactation: a pilot study in the Netherlands

BACKGROUND

Iodine deficiency occurs in West European countries. Iodine is important for brain development of the foetus and infant. The current iodine status of pregnant and lactating Dutch women is unknown.

METHODS

In a pilot study we examined the iodine status of 36 women. From 20 gestational weeks (GW) until 4 weeks postpartum, they ingested 150 μg iodine/day in the form of a multivitamin supplement for pregnant and lactating women. Twenty-four hour urine samples were collected at 20 and 36 GW and at 4 weeks postpartum. A breast milk sample was collected at 4 weeks postpartum. Iodine concentrations were analysed by inductively coupled plasma-mass spectrometry. Cut-off values for the urinary iodine concentration (UIC) for pregnant and lactating women are 150 and 100 μg/l, respectively. Adequate intakes (AI) of iodine for infants aged 0-6 months are 1.1 μmol/l (Institute of Medicine recommendations) or 0.5 μmol/l (Nordic Councilrecommendations).

RESULTS

The median UICs (percentages below cut-off) were 102 μg/l (83%) at 20 GW, 144 μg/l (56%) at 36 GW and 112 μg/l (40%) at 4 weeks postpartum. The median breast milk iodine concentration was 1.2 μmol/l (range 0.5-3.0); 33% and 0% of the infants had estimated iodine intakes below the IOM-AI and Nordic-AI, respectively.

CONCLUSION

This pilot study suggested a high prevalence of iodine deficiency during pregnancy. Daily supplementation of 150 μg iodine from 20 GW might be insufficient to reach maternal iodine adequacy. The median breast milk iodine concentration seems adequate. Further studies, using a representative sample of the Dutch population, are needed to establish the current Dutch iodine status of pregnant and lactating women.

Trimester-specific phthalate concentrations and glucose levels among women from a fertility clinic

BACKGROUND

Subfertile women are at increased risk of glucose intolerance in pregnancy. Based on epidemiologic studies, exposure to certain phthalates is associated with diabetes, elevated glucose, and increased insulin resistance.

OBJECTIVES

To evaluate the association between urinary phthalate metabolites and pregnancy glucose levels in women seeking medically assisted reproduction.

METHODS

We evaluated 245 women participating in a prospective cohort study based at a large fertility clinic who delivered live births and had data on pregnancy urinary phthalate metabolite concentrations and blood glucose levels. Urinary phthalate metabolite concentrations were from single spot urine samples collected in 1st and 2nd trimesters. Blood glucose data was abstracted from medical records for non-fasting 50-g glucose challenge tests at 24-28 weeks gestation. Multivariable linear regression models were used to evaluate associations between 7 urinary phthalate metabolites in quartiles and mean glucose adjusted for potential confounders.

RESULTS

Eighteen percent of women had glucose levels ≥ 140 mg/dL. Second trimester monoethyl phthalate (MEP) concentrations were positively associated with glucose levels, with adjusted mean (95%CI) glucose levels of 121 mg/dl (114, 128) vs. 109 mg/dL (103, 116) for women in highest and lowest quartiles, respectively. Women in the highest quartile of second trimester mono-isobutyl phthalate (MiBP) concentrations had a mean glucose level 14 mg/dL lower compared to women in the lowest quartile. No other urinary phthalate metabolites were associated with glucose levels.

CONCLUSIONS

MEP and MiBP-metabolites of diethyl phthalate and dibutyl phthalate, respectively-were associated with higher pregnancy glucose in subfertile women-a population at high risk of glucose intolerance in pregnancy.

First and second trimester urinary metabolic profiles and fetal growth restriction: an exploratory nested case-control study within the infant development and environment study

BACKGROUND

Routine prenatal care fails to identify a large proportion of women at risk of fetal growth restriction (FGR). Metabolomics, the comprehensive analysis of low molecular weight molecules (metabolites) in biological samples, can provide new and earlier biomarkers of prenatal health. Recent research has suggested possible predictive first trimester urine metabolites correlating to fetal growth restriction in the third trimester. Our objective in this current study was to examine urinary metabolic profiles in the first and second trimester of pregnancy in relation to third trimester FGR in a US population from a large, multi-center cohort study of healthy pregnant women.

METHODS

We conducted a nested case-control study within The Infant Development and the Environment Study (TIDES), a population-based multi-center pregnancy cohort study. We identified 53 cases of FGR based on the AUDIPOG [Neonatal growth - AUDIPOG [Internet]. [cited 29 Nov 2016]. Available from: http://www.audipog.net/courbes_morpho.php?langue=en ] formula for birthweight percentile considering maternal height, age, and prenatal weight, as well as infant sex, gestational age, and birth rank. Cases were matched to 106 controls based on study site, maternal age (± 2 years), parity, and infant sex. NMR spectroscopy was used to assess concentrations of four urinary metabolites that have been previously associated with FGR (tyrosine, acetate, formate, and trimethylamine) in first and second trimester urine samples. We fit multivariate conditional logistic regression models to estimate the odds of FGR in relation to urinary concentrations of these individual metabolites in the first and second trimesters. Exploratory analyses of custom binned spectroscopy results were run to consider other potentially related metabolites.

RESULTS

We found no significant association between the relative concentrations of each of the four metabolites and odds of FGR. Exploratory analyses did not reveal any significant differences in urinary metabolic profiles. Compared with controls, cases delivered earlier (38.6 vs 39.8, p < 0.001), and had lower birthweights (2527 g vs 3471 g, p < 0.001). Maternal BMI was similar between cases and controls.

CONCLUSIONS

First and second trimester concentrations of urinary metabolites (acetate, formate, trimethylamine and tyrosine) did not predict FGR. This inconsistency with previous studies highlights the need for more rigorous investigation and data collection in this area before metabolomics can be clinically applied to obstetrics.

Predictors of urinary flame retardant concentration among pregnant women

BACKGROUND

Organophosphate compounds are commonly used in residential furniture, electronics, and baby products as flame retardants and are also used in other consumer products as plasticizers. Although the levels of exposure biomarkers are generally higher among children and decrease with age, relatively little is known about the individual characteristics associated with higher levels of exposure. Here, we investigate urinary metabolites of several organophosphate flame retardants (PFRs) in a cohort of pregnant women to evaluate patterns of exposure.

METHODS

Pregnant North Carolina women (n=349) provided information on their individual characteristics (e.g. age and body mass index (BMI)) as a part of the Pregnancy Infection and Nutrition Study (2002-2005). Women also provided second trimester urine samples in which six PFR metabolites were measured using mass spectrometry methods.

RESULTS

PFR metabolites were detected in every urine sample, with BDCIPP, DHPH, ip-PPP and BCIPHIPP detected in >80% of samples. Geometric mean concentrations were higher than what has been reported previously for similarly-timed cohorts. Women with higher pre-pregnancy BMI tended to have higher levels of urinary metabolites. For example, those classified as obese at the start of pregnancy had ip-PPP levels that were 1.52 times as high as normal weight range women (95% confidence interval: 1.23, 1.89). Women without previous children also tended to have higher urinary levels of DPHP, but lower levels of ip-PPP. In addition, we saw strong evidence of seasonal trends in metabolite concentrations (e.g. higher DPHP, BDCIPP, and BCIPHIPP in summer, and evidence of increasing ip-PPP between 2002 and 2005).

CONCLUSIONS

Our results indicate ubiquitous exposure to PFRs among NC women in the early 2000s. Additionally, our work suggests that individual characteristics are related to exposure and that temporal variation, both seasonal and annual, may exist.

Urine tests for Down's syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three copies of chromosome 21, or the specific area of chromosome 21 implicated in causing Down's syndrome, rather than two. It is the commonest congenital cause of mental disability and also leads to numerous metabolic and structural problems. It can be life-threatening, or lead to considerable ill health, although some individuals have only mild problems and can lead relatively normal lives. Having a baby with Down's syndrome is likely to have a significant impact on family life. The risk of a Down's syndrome affected pregnancy increases with advancing maternal age.Noninvasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing. Before agreeing to screening tests, parents need to be fully informed about the risks, benefits and possible consequences of such a test. This includes subsequent choices for further tests they may face, and the implications of both false positive and false negative screening tests (i.e. invasive diagnostic testing, and the possibility that a miscarried fetus may be chromosomally normal). The decisions that may be faced by expectant parents inevitably engender a high level of anxiety at all stages of the screening process, and the outcomes of screening can be associated with considerable physical and psychological morbidity. No screening test can predict the severity of problems a person with Down's syndrome will have.

OBJECTIVES

To estimate and compare the accuracy of first and second trimester urine markers for the detection of Down's syndrome.

SEARCH METHODS

We carried out a sensitive and comprehensive literature search of MEDLINE (1980 to 25 August 2011), EMBASE (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), The Database of Abstracts of Reviews of Effectiveness (The Cochrane Library 2011, Issue 7), MEDION (25 August 2011), The Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (25 August 2011), The National Research Register (archived 2007), Health Services Research Projects in Progress database (25 August 2011). We studied reference lists and published review articles.

SELECTION CRITERIA

Studies evaluating tests of maternal urine in women up to 24 weeks of gestation for Down's syndrome, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection.

DATA COLLECTION AND ANALYSIS

We extracted data as test positive or test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria. We used hierarchical summary ROC (receiver operating characteristic) meta-analytical methods to analyse test performance and compare test accuracy. We performed analysis of studies allowing direct comparison between tests. We investigated the impact of maternal age on test performance in subgroup analyses.

MAIN RESULTS

We included 19 studies involving 18,013 pregnancies (including 527 with Down's syndrome). Studies were generally of high quality, although differential verification was common with invasive testing of only high-risk pregnancies. Twenty-four test combinations were evaluated formed from combinations of the following seven different markers with and without maternal age: AFP (alpha-fetoprotein), ITA (invasive trophoblast antigen), ß-core fragment, free ßhCG (beta human chorionic gonadotrophin), total hCG, oestriol, gonadotropin peptide and various marker ratios. The strategies evaluated included three double tests and seven single tests in combination with maternal age, and one triple test, two double tests and 11 single tests without maternal age. Twelve of the 19 studies only evaluated the performance of a single test strategy while the remaining seven evaluated at least two test strategies. Two marker combinations were evaluated in more than four studies; second trimester ß-core fragment (six studies), and second trimester ß-core fragment with maternal age (five studies).In direct test comparisons, for a 5% false positive rate (FPR), the diagnostic accuracy of the double marker second trimester ß-core fragment and oestriol with maternal age test combination was significantly better (ratio of diagnostic odds ratio (RDOR): 2.2 (95% confidence interval (CI) 1.1 to 4.5), P = 0.02) (summary sensitivity of 73% (CI 57 to 85) at a cut-point of 5% FPR) than that of the single marker test strategy of second trimester ß-core fragment and maternal age (summary sensitivity of 56% (CI 45 to 66) at a cut-point of 5% FPR), but was not significantly better (RDOR: 1.5 (0.8 to 2.8), P = 0.21) than that of the second trimester ß-core fragment to oestriol ratio and maternal age test strategy (summary sensitivity of 71% (CI 51 to 86) at a cut-point of 5% FPR).

AUTHORS' CONCLUSIONS

Tests involving second trimester ß-core fragment and oestriol with maternal age are significantly more sensitive than the single marker second trimester ß-core fragment and maternal age, however, there were few studies. There is a paucity of evidence available to support the use of urine testing for Down's syndrome screening in clinical practice where alternatives are available.

Bisphenol A and phthalate metabolite urinary concentrations: Daily and across pregnancy variability

Phthalates and bisphenol A (BPA) are high production volume and ubiquitous chemicals that are quickly metabolized in the body. Traditionally, studies have relied on single spot urine analyses to assess exposure; ignoring variability in concentrations throughout a day or over a longer period of time. We compared BPA and phthalate metabolite results from urine samples collected at five different time points. Participants (n=80) were asked to collect all voids in a 24 h period on a weekday and then again on a weekend before 20 weeks of pregnancy. During the second and third trimesters and in the postpartum period, single spot urines were collected. Variability over time in urinary concentrations was assessed using intraclass correlation coefficients (ICCs) and the sensitivity to correctly classify a single sample as high or low versus the geometric mean (GM) of all samples was calculated. We found low reproducibility and sensitivity of BPA and all phthalate metabolites throughout pregnancy and into the postpartum period but much higher reproducibility within a day. Time of day when the urine was collected was a significant predictor of specific gravity adjusted exposure levels. We concluded that, if the interest is in average exposures across pregnancy, maternal/fetal exposure estimation may be more accurate if multiple measurements, collected across the course of the entire pregnancy, rather than a single spot measure, are performed.

A comparison of podocyturia, albuminuria and nephrinuria in predicting the development of preeclampsia: a prospective study

Preeclampsia, a hypertensive multisystem disease that complicates 5–8% of all pregnancy, is a major cause for maternal and fetal mortality and morbidity. The disease is associated with increased spontaneous and evoked preterm birth and remote cardio-renal disorders in the mother and offspring. Thus the ability to predict the disease should lead to earlier care and decreased morbidity. This has led to fervent attempts to identify early predictive biomarkers and research endeavors that have expanded as we learn more regarding possible causes of the disease. As preeclampsia is associated with specific renal pathology including podocyte injury, early urinary podocyte (podocyturia), or the podocyte specific proteinuria nephrin in the urine (nephrinuria), as well as the more easily measured urinary albumin (albuminuria), have all been suggested as predictive markers. We performed a prospective study recruiting 91 pregnant women (78 of whom were high risk) and studied the predictive ability of these three urinary biomarkers. The subjects were recruited between 15–38 weeks of gestation. Fourteen patients, all in the high-risk obstetric group, developed preeclampsia. The levels of podocyturia, nephrinuria, and albuminuria were variably higher in the high-risk pregnant patients who developed preeclampsia. The sensitivities and specificities for podocyturia were 70% and 43%, for albuminuria were 36% and 96%, and for nephrinuria were 57% and 58%, respectively. Also, abnormal nephrinuria (69%) and podocyturia (38%) were detected in low risk women who had uncomplicated gestations; none of these women exhibited albuminuria. In our study, none of the three urinary markers achieved the minimum predictive values required for clinical testing. The lack of excessive albuminuria, however, may indicate a preeclampsia-free gestation. Given a discrepant literature, further studies with larger sample size should be considered.

Urinary metabolites of organophosphate flame retardants and their variability in pregnant women

Organophosphate flame retardants (OPFRs) are commonly added to consumer products to reduce their flammability. Based on levels of OPFRs in indoor environments, human exposure is likely chronic and ubiquitous. Animal studies suggest that exposure to some OPFRs may result in adverse health impacts, particularly for Tris (1,3-dichloropropyl) phosphate (TDCPP); however, human data on the impacts of exposure to OPFRs are lacking. To design human studies, more information is needed on the stability of measured OPFRs in human samples over time. In this study, we sought to assess the degree of temporal variability of urinary TDCPP and triphenyl phosphate (TPP) metabolites throughout pregnancy in a cohort of women from central North Carolina. Eight pregnant women provided multiple urine samples: 3 during the 18th week of pregnancy, 1 during the 28th week, and 1 shortly after the child's birth. Bis (1,3-dichloropropyl) phosphate (BDCPP) and diphenyl phosphate (DPP), the respective metabolites of TDCPP and TPP, were measured in urine samples using liquid chromatography-tandem mass spectrometry. BDCPP and DPP were each detected in 38 of 39 urine samples and were not normally distributed. Geometric mean BDCPP and DPP concentrations were 1.3ng/mL (interquartile range (IQR): 0.8, 2.7ng/mL) and 1.9ng/mL (IQR: 0.9, 3.5ng/mL), respectively. BDCPP and DPP were moderately to strongly reliable over one week (intraclass correlation coefficient (ICC)=0.5; 95% confidence interval (CI): 0.4, 0.7 and ICC=0.7; 95% CI: 0.5, 0.8, respectively), and over the entire pregnancy (ICC=0.5 95% CI: 0.3, 0.7 and ICC=0.6; 95% CI: 0.4, 0.7, respectively). These data suggest that exposures to TDCPP and TPP are widespread and variable for pregnant women, and that a single measure of BDCPP or DPP, taken in the second trimester, likely captures information on the rank order of exposure throughout pregnancy.

Prenatal screening of sialic acid storage disease and confirmation in cultured fibroblasts by LC-MS/MS

Sialic acid storage disease (SASD) is an inborn error resulting from defects in the lysosomal membrane protein sialin. The SASD phenotypical spectrum ranges from a severe presentation, infantile sialic acid storage disease (ISSD) which may present as hydrops fetalis, to a relatively mild form, Salla disease. Screening for SASD is performed by determination of free sialic acid (FSA) in urine or amniotic fluid supernatant (AFS). Subsequent diagnosis of SASD is performed by quantification of FSA in cultured fibroblasts and by mutation analysis of the sialin gene, SLC17A5. We describe simple quantitative procedures to determine FSA as well as conjugated sialic acid in AFS, and FSA in cultured fibroblasts, using isotope dilution ((13)C(3)-sialic acid) and multiple reaction monitoring LC-ESI-MS/MS. The whole procedure can be performed in 2-4 h. Reference values in AFS were 0-8.2 μmol/L for 15-25 weeks of gestation and 3.2-12.0 μmol/L for 26-38 weeks of gestation. In AFS samples from five fetuses affected with ISSD FSA was 23.9-58.9 μmol/L demonstrating that this method is able to discriminate ISSD pregnancies from normal ones. The method was also validated for determination of FSA in fibroblast homogenates. FSA in SASD fibroblasts (ISSD; 20-154 nmol/mg protein, intermediate SASD; 12.9-15.1 nmol/mg, Salla disease; 5.9-7.4 nmol/mg) was clearly elevated compared to normal controls (0.3-2.2 nmol/mg). In conclusion, we report simple quantitative procedures to determine FSA in AFS and cultured fibroblasts improving both prenatal diagnostic efficacy for ISSD as well as confirmatory testing in cultured fibroblasts following initial screening in urine or AFS.

Increased urinary orosomucoid excretion predicts preeclampsia in pregnant women with pregestational type 1 diabetes

AIMS

We evaluated the urinary orosomucoid excretion (UOE) as a biomarker of preeclampsia and preterm delivery in pregnant women with type 1 diabetes.

METHODS

Singleton pregnant women with pregestational type 1 diabetes were included provided one urine sample had been collected before 17 gestational weeks. Serum and urinary orosomucoid were analysed by immunoturbidimetry. Primary outcome measurements were development of preeclampsia (blood pressure>140/90mmHg and proteinuria) and preterm delivery before 37 weeks.

RESULTS

In total 173 women were included. The UOE increased during pregnancy. Preeclampsia developed in 20 women and 65 women delivered preterm. Using logistic regression analysis we found that UOE>1.37mg/l (OR: 6.85 (95% CI: 1.97-23.88; p<0.003)), nulliparity (3.88 (1.10-13.72); p<0.04), systolic blood pressure>120mmHg (4.12 (1.35-12.59); p<0.02) and duration of diabetes>20 years (3.69 (1.18-11.52); p<0.03) independently predicted the development of preeclampsia. Independent predictors of preterm delivery were duration of diabetes and HbA1c>7%. The remaining covariates included in the regression models were BMI, serum creatinine, smoking and microalbuminuria.

CONCLUSIONS

Increased UOE early in pregnancy predicted preeclampsia in women with pregestational type 1 diabetes independently of albuminuria and other known risk factors. No association to preterm delivery was found.

Iodine status among pregnant women in Kuwait

Up to now, little has been known about iodine intake and the prevalence of iodine deficiency (ID), if any, in Kuwait. Urinary iodine excretion (UIE) and changes in thyroid function during pregnancy were thus evaluated.

METHODS

Urinary iodide level was measured in random urine samples collected from 326 pregnant women at different gestational trimesters. Blood samples were drawn for free T4 (FT4) and TSH level determination.

RESULTS

Median UIE levels fall within the normal range during all gestational trimesters i.e. >100 microg/l. However, if the new suggested recommendation for pregnant women <140 microg/l, is applied, median UIE values during trimesters 2 and 3 indicate ID. Mean serum TSH levels increased between trimesters 1 and 3 (p<0.05), whereas serum FT4 decreased between first and second trimesters (p<0.05), and this reduction continued at the third trimester. Furthermore, an increase in TSH levels for subjects with mild and moderate ID (Mi and Mo, respectively) were noticed (p<0.05) during the second trimester. However, FT4 levels dropped in subjects with Mi and Mo ID during the first trimester (p<0.05). In conclusion, these results suggest that 56.8% of pregnant women had median UIE level <145 microg/l, associated with high TSH and low FT4 levels.

CONCLUSION

Data obtained may indicate insufficient iodine intake among pregnant women in Kuwait.

Assessment of intertrimester and seasonal variations of urinary iodine concentration during pregnancy in an iodine-replete area

OBJECTIVE

To assess intertrimester and seasonal variations in urinary iodine concentration (UIC) among pregnant women.

PATIENTS AND MEASUREMENTS

Pregnant Tehranian women, with no history of thyroid ablation or consumption of thyroid-affecting medication were selected consecutively from November 2004 to November 2006. Morning spot urine samples were collected from each participant during the first, second and third trimesters of pregnancy. Of 466 participants, 298 completed the study in all three trimesters of pregnancy. UIC < 150, 150-250, and > 250 microg/l indicated low, adequate, and high levels, respectively. UIC was measured using a modified Sandell-Kolthoff digestion method.

RESULTS

The pregnant women were aged 25.0 +/- 5.0 (range 16-48) years. Median UIC did not show seasonal fluctuations during pregnancy. However, median (range) UIC was 193 (19-840), 159 (16-640), and 141 (16-400) microg/l in the first, second and third trimesters of pregnancy, respectively (P < 0.0001). Frequency distributions of low, adequate and excessive UIC were 33.2, 31.2 and 35.6% in the first trimester, 46.0, 28.9 and 25.2% in the second trimester, and 53.4, 30.9 and 15.8% in the third trimester of pregnancy, respectively (P < 0.0001). Women with UIC < 150 were more frequently represented in the second vs. the first (P = 0.043; odds ratio 1.49, 95% confidence interval 1.012-2.213) and in the third vs. the first (P = 0.013; odds ratio 1.62, 95% confidence interval 1.108-2.379) trimesters of pregnancy than the 150-250 microg/l group were. UIC decreased throughout pregnancy in all seasons.

CONCLUSIONS

Iranian national salt iodization may prevent seasonal fluctuations of UIC but does not maintain median UIC within adequate and recommended ranges throughout pregnancy. Extra iodine supplementation during pregnancy is recommended.

Cross-trimester marker ratios in prenatal screening for Down syndrome

OBJECTIVE

To examine the performance of Integrated Down syndrome screening (first- and second-trimester measurements integrated into a single screening test) when ratios of the levels of the same serum markers measured in both these trimesters (cross-trimester ratios) are added as new screening markers.

METHODS

Using data from Serum Urine and Ultrasound Screening Study (SURUSS), second-trimester concentrations (in multiples of the median, or MoM) of pregnancy associated plasma protein A (PAPP-A), alphafetoprotein (AFP), unconjugated oestriol (uE(3)), human chorionic gonadotrophin (hCG) (free beta and total), and inhibin-A were divided by the first-trimester concentration to obtain a cross-trimester (CT) ratio for each analyte in 74 Down syndrome and 492 unaffected pregnancies. We identified CT ratios that improved screening performance and then, using Monte Carlo simulations, estimated the efficacy and cost effectiveness of adding them to the Integrated and serum Integrated tests.

RESULTS

All the median CT ratios differed significantly between Down syndrome and unaffected pregnancies. Setting the Integrated test to achieve a 90% detection rate, the false-positive rate (FPR) was 0.7% with CT ratios for PAPP-A, uE(3), inhibin-A, and total hCG compared with 2.2% without CT ratios, a reduction of about two-thirds. Using the serum Integrated test to achieve the same 90% detection rate and the first-trimester measurements made at 11 completed weeks of pregnancy, the corresponding FPRs were 2.4 and 8.1%, a similar proportional reduction. The AFP CT ratio had little effect on screening performance. Using CT ratios did not increase the cost per Down syndrome pregnancy detected.

CONCLUSION

The addition of CT ratios to an Integrated test substantially improves the efficacy and safety of prenatal screening for Down syndrome. It is cost effective and could be usefully introduced into screening programmes.

Status of iodine nutrition in pregnant and lactating women in national capital district, Papua New Guinea

Urinary Iodine excretion is a useful and important indicator of the iodine status of a population. This study attempts to determine the urinary iodine concentration of non-pregnant, pregnant and lactating women, resident in the National Capital District of Papua New Guinea, so as to evaluate their status of iodine nutrition. The study population was made up of 56 non-pregnant, 40 lactating and 212 pregnant women. Of the 212 pregnant women, 14 were in the first, 64 in the second, and 134 in the third Trimester of pregnancy. Casual urine samples were collected and analysed for urinary iodine by Sandell-Kolthoff reaction. The median urinary iodine concentration for the non-pregnant, lactating and pregnant women was 163.0 micro g/L, 134.0 micro g/L and 180.0 micro g/L, respectively. Median urinary iodine for the first, second and third trimesters were 165.0 micro g/L, 221.5 micro g/L and 178.0 micro g/L, respectively. The 20th percentile urinary iodine values were higher than 50 micro g/L for all the groups. This indicates adequate intake of dietary iodine and optimal status of iodine nutrition amongst women in the various groups. Mild to severe status of iodine nutrition was found in 30.4% of non-pregnant, 35.0% of lactating, 22.2% of pregnant women, 28.5% of women in the first, 18.8% in the second, and 23.1% in the third trimester of pregnancy. To achieve optimal iodine nutrition in pregnant and lactating women, an increase in their intake of dietary iodine is recommended.

Prenatal maternal cortisol, fetal activity and growth

Pregnant women (N = 131) were recruited at a prenatal ultrasound clinic between 20 and 28 weeks (M = 24 weeks) gestation. The women were given the CES-D for depression and the State-Trait Anxiety Inventory and were asked to provide a urine sample to be assayed for cortisol, norepinephrine, epinephrine, dopamine, and serotonin. Ultrasound sessions were conducted and coded for fetal activity and estimated fetal weight. Regression analyses were then conducted with fetal activity and fetal weight as outcome variables. Gestational age entered both analyses as the first variable followed by: (1) prenatal cortisol as a significant predictor of fetal activity; and (2) prenatal cortisol as a significant predictor of estimated fetal weight.

Maternal urine beta-core hCG fragment level and small for gestational age neonates

OBJECTIVE

To determine whether second-trimester urine beta-core fragments of hCG predict small for gestational age (SGA) neonates.

METHODS

Spot urine beta-core levels were measured in 733 nonhypertensive women with singleton pregnancies who presented for amniocentesis and had karyotypically normal fetuses. The beta-core level was standardized to urine creatinine and expressed as multiples of the median. The area under a receiver operating characteristics curve was used to determine the screening efficiency of the urine analyte for prediction of small for gestational age (SGA) births. In a subgroup of cases, serum markers (alpha-fetoprotein [AFP], hCG, and unconjugated estriol) were compared using stepwise regression analysis to urine beta-core fragment for SGA prediction.

RESULTS

There were 23 (3.0%) SGA neonates. The mean +/- standard deviation (SD) gestation at urine collection was 16.4 +/- 1.3 weeks and collection to delivery interval was 23.0 +/- 2.2 weeks. Mean beta-core (+/- SD) fragment levels were significantly higher in those who later had SGA infants compared with appropriately grown infants (2982.8 ng/mg creatinine versus 1447.4 ng/mg creatinine, P <.001). Stepwise logistic regression found that urine beta-core fragment and serum AFP were the only significant predictors of SGA, with statistically significant chi(2) values (P <.001 and P =.038, respectively). The urine analyte was significantly superior. Second-trimester urine beta-core fragment had a 78.3% sensitivity and 70% specificity for SGA prediction. Exclusion of preeclamptic cases resulted in a sensitivity of 84.2% and a specificity of 71.2%.

CONCLUSION

Second-trimester elevated maternal urine beta-core fragment of hCG predicted SGA infants, and was superior to other serum analytes in that prediction.

Thyroid hormones and iodine status in Sudanese pregnant women with goitre

Thyroid hormones in relation to iodine status were studied in a group of Sudanese pregnant women with goitre (n = 66). These women were compared with a healthy, non-pregnant control group from the same area (n = 40). Twenty-four-hour urine samples and serum samples were collected during weeks 10-13, 20-24 and 32-39 of pregnancy. The goitrous group had a significantly lower mean urinary iodine concentration (UIC) than the non-pregnant group during weeks 20-24 and 32-39 (P < 0.003 and P < 0.001), respectively. The thyroid-stimulating hormone (TSH) and T3 levels in the pregnant group showed a stable pattern with the progression of pregnancy. TSH values in all the pregnant women were within the reference range. The mean FT4 levels of the goitrous pregnant group, in weeks 20-24 and 32-39 of pregnancy, were significantly lower than that of the non-pregnant control group (P < 0.003 and P < 0.05), respectively. The proportions of the pregnant women with FT4 below the reference range were 31, 50 and 40% in weeks 10-13, 20-24 and 32-39 of pregnancy, respectively. There was no correlation between UIC and TSH, UIC and FT4 and between TSH and FT4 during pregnancy. By virtue of the proportion of subjects falling below and above the reference range, this study indicates that in this particular study area, UIC and FT4 are better indicators of iodine status than TSH.

Calciuria and preeclampsia

Urinary calcium excretion has been reported to be diminished in preeclampsia. The objective of the present study was to determine urinary calcium excretion in pregnant patients with chronic arterial hypertension (CAH) and preeclampsia (PE), and in normotensive patients (N). Forty-four pregnant patients (gestational age, 20-42 weeks; 18 CAH, 17 PE, 9 N) were evaluated for calciuria, proteinuria, plasma uric acid and blood pressure. Patients with PE (82 +/- 15.1 mg/24 h) showed significantly lower calciuria (P < 0.05) than the group with CAH (147 +/- 24.9 mg/24 h) and the N group (317 +/- 86.0 mg/24 h) (P < 0.05, Student t-test). Plasma uric acid was significantly higher in the PE group (6.1 +/- 0.38 mg/dl) than the CAH group (5.0 +/- 0.33 mg/dl; P < 0.05), which also presented higher proteinuria levels, although the difference was not statistically significant. Diastolic and systolic blood pressure did not differ between the PE (164 +/- 105 mmHg) and CAH (164 +/- 107 mmHg) groups. Calciuria was significantly lower in the group with preeclampsia than in the group with chronic arterial hypertension. We conclude that calciuria can be a further factor for identifying preeclampsia.