Yuan-yuan Xu

Maternal vitamin D deficiency during pregnancy elevates the risks of small for gestational age and low birth weight infants in Chinese population.

CONTEXT Vitamin D deficiency is common in pregnant women. Nevertheless, the association between maternal vitamin D status during pregnancy and the risk of having small for gestational age (SGA) and low birth weight (LBW) infants is uncertain. OBJECTIVE The objective of this study was to investigate whether there is a correlation between maternal vitamin D deficiency during pregnancy and the risk of having SGA and LBW infants in a Chinese population. DESIGN AND PARTICIPANTS This was a population-based birth cohort study that recruited 3658 eligible mother-and-singleton-offspring pairs. MAIN OUTCOME MEASURES Serum 25-hydroxyvitamin D was measured by RIA. The rate and relative risk (RR) for SGA and LBW infants were calculated among subjects with vitamin D deficiency and insufficiency during pregnancy. RESULTS There was a positive correlation between maternal serum 25-hydroxyvitamin D level and offspring birth weight (r = 0.477; P < .001). Further analysis showed that 4.98% of neonates were LBW infants among the subjects with vitamin D deficiency (RR, 12.00; 95% confidence interval [CI], 4.37, 33.00) and 1.32% among the subjects with vitamin D insufficiency (RR, 3.18; 95% CI, 1.07, 9.48). After adjustment for confounders, the RR for LBW infants was 12.31 (95% CI, 4.47, 33.89) among subjects with vitamin D deficiency and 3.15 (95% CI, 1.06, 9.39) among subjects with vitamin D insufficiency. Moreover, 16.01% of neonates were SGA infants among subjects with vitamin D deficiency (RR, 5.72; 95% CI, 3.80, 8.59) and 5.59% among subjects with vitamin D insufficiency (RR, 1.99; 95% CI, 1.27, 3.13). After adjustment for confounders, the RR for SGA infants was 6.47 (95% CI, 4.30, 9.75) among subjects with vitamin D deficiency and 2.01 (95% CI, 1.28, 3.16) among subjects with vitamin D insufficiency. CONCLUSION Maternal vitamin D deficiency during pregnancy elevates the risk of SGA and LBW infants in a Chinese population.

Cortisol reactivity, delay discounting and percent body fat in Chinese urban young adolescents.

The purpose of this study is to test the relation of cortisol reactivity, delay discounting and percent body fat (PBF) in adolescents aged 12-13 years (N=87), and evaluate the delay discounting as potential components in models of adolescent obesity. Anthropometry and body composition measurements were assessed in adolescents. The cortisol reactivity to Trier Social Stress Test for Children (TSST-C) and delay discounting were measured. The result showed increased cortisol reactivity and greater delay discounting were associated with higher PBF in girls. Structural equation modeling supported greater delay discounting as a mediator of relations between increased cortisol reactivity and PBF in adolescent girls. The proposed mediation model indicated that cortisol reactivity is linked to PBF through delay discounting, thereby supporting a significant indirect relationship. The direct relationship between increased cortisol reactivity and higher PBF was significant in a model that did not include delay discounting, and was still significant in the mediation model that included delay discounting. This study provides the first evidence that greater delay discounting may partially account for the relationship of hyperactivity of the HPA-axis and higher PBF in girls.

Maternal zinc deficiency during pregnancy elevates the risks of fetal growth restriction: a population-based birth cohort study

We investigated the association between maternal zinc level during pregnancy and the risks of low birth weight (LBW) and small for gestational age (SGA) infants in a large population-based birth cohort study. In this study, 3187 pregnant women were recruited. For serum zinc level, 2940 pregnant women were sufficient (≥56 μg/dL) and 247 deficient (<56 μg/dL). Of interest, 7.3% newborns were with LBW among subjects with low zinc level (RR: 3.48; 95% CI: 2.03, 5.96; P < 0.001). Adjusted RR for LBW was 3.41 (95% CI: 1.97, 5.91; P < 0.001) among subjects with low zinc level. Moreover, 15.0% newborns were with SGA among subjects with low zinc level (RR: 1.98; 95% CI: 1.36, 2.88; P < 0.001). Adjusted RR for SGA was 1.93 (95% CI: 1.32, 2.82; P < 0.001) among subjects with low zinc level. A nested case-control study within above cohort showed that maternal serum zinc level was lower in SGA cases as compared with controls. By contrast, maternal serum C-reactive protein, TNF-α and IL-8 levels were significantly higher in SGA cases than that of controls. Moreover, nuclear NF-κB p65 was significantly up-regulated in placentas of SGA cases as compared with controls. Taken together, maternal zinc deficiency during pregnancy elevates the risks of LBW and SGA infants.

Periconceptional folic acid supplementation among women attending antenatal clinic in Anhui, China: Data from a population-based cohort study

OBJECTIVES to examine the rate of periconceptional and optimal folic acid supplementation, and to characterise their patterns and determinants among antenatal women in central China. DESIGN data from 4290 women in the Anhui Birth Defects and Child Development Cohort Study recruited between October 2008 and September 2009 were analysed. SETTING seven Maternal and Child Health Centres of two cities (Hefei and Maanshan) in Anhui province of central China. PARTICIPANTS women initiating prenatal care were included and asked to complete a structured questionnaire regarding folic acid supplementation. FINDINGS sixty-eight per cent (2905/4290) of pregnant women reported taking folic acid supplementation periconceptionally (i.e. at some point before or during early pregnancy), and 32.8% (1405/4290) and 65.2% (2797/4290) had taken it before or during early pregnancy, respectively. However, only 16.1% (690/4290) used it optimally (i.e. regularly from four weeks before pregnancy throughout four weeks after pregnancy). Use of periconceptional folic acid was significantly associated with educational level, household income, registered residence, age, gestational age at recruitment, and planning of pregnancy. CONCLUSION optimal folic acid supplementation was relatively low. IMPLICATIONS FOR PRACTICE further efforts are needed to inform the population and promote the use of folic acid supplementation.

Pattern of drug use during the first trimester among Chinese women: data from a population-based cohort study

AimTo describe the pattern of drug use among Chinese women during the first trimester and to examine the impact of maternal diseases on the choice of drugs.MethodThis drug utilisation study of pregnant women was performed using data from the ABCD cohort study. A total of 4,290 women were enrolled in the analysis. Information was collected by self-completion questionnaire combined with the “Maternal health handbook”.ResultsOf the 4,290 women interviewed, 75.9% of women took at least one drug during the first trimester. Users took a mean number of 1.43 drugs. The most frequently used drugs were folic acid (65.2%), vitamins (14.6%), calcium (12.0%), minerals (11.1%), Chinese traditional patent medicine (CTPM; 10.1%) and anti-infectives (6.5%). Among the women having used CTPM, influenza/cold and threatened abortion were the most commonly reported indications. Logistic regression analysis of drug use (excluding nutritional and haematological drugs) shows that CTPM and Western medicine are both associated with the use of drugs for occasional diseases and against threatened abortion. Maternal chronic diseases were not associated with the use of CTPM.ConclusionThis analysis of pregnant women showed that drugs were prescribed to most women, even when nutritional and haematological drugs were excluded. Our data reflect, except for drugs used for chronic diseases, a general reluctance among Chinese women to use Western medicine and resorting to CTPM during pregnancy

Prenatal phthalate exposure and placental size and shape at birth: A birth cohort study

Objective There is concern over the potential placental effects of prenatal phthalate exposure, and the potential adverse effects of prenatal phthalate exposure require further study; however, few data are available in humans. We investigated the associations between phthalate exposure in each trimester and both placental size and shape at birth. Methods We measured the urinary concentrations of phthalate metabolites among 2725 pregnant women in the Ma’anshan Birth Cohort. Before collecting urine samples from each of the three trimesters, the pregnant women were interviewed via questionnaires. Placental information was obtained from hospital records. We estimated the sex‐specific associations between urinary phthalate concentrations in each trimester and both placental size and shape at birth using adjusted multiple regression. A linear mixed model was used for the repeated measures analysis with subject‐specific random intercepts and slopes for gestational age at sample collection to test the effect of phthalate levels on placental size and shape and to estimate the effect sizes. Results Overall, placental breadth increased by 0.148 cm (95% CI: 0.078, 0.218) with each 1 ln‐concentration increase in MBP in the first trimester. The difference between placental length and breadth (length–breadth) decreased by 0.086 cm (95% CI: −0.159, −0.012) and 0.149 cm (95% CI: −0.221, −0.076) with each 1 ln‐concentration increase in MMP and MBP, respectively, in the first trimester. In the second trimester, placental thickness increased by 0.017 cm (95% CI: 0.006, 0.027), 0.020 cm (95% CI: 0.004, 0.036), 0.028 cm (95% CI: 0.007, 0.048), and 0.035 cm (95% CI: 0.018, 0.053) with each 1 ln‐concentration increase in MMP, MBP, MEOHP, and MEHHP, respectively. In the third trimester, placental thickness increased by 0.037 cm (95% CI: 0.019, 0.056) and 0.019 cm (95% CI: 0, 0.037) with each 1 ln‐concentration increase in MBP and MEHP, respectively. Multiple linear regression for each offspring sex indicated that prenatal phthalate exposure increased placental thickness in both the first and second trimesters in males, whereas the corresponding relationship was close to null in females. Linear mixed models (LMMs) yielded similar results. Conclusion Our results suggest the presence of associations between prenatal phthalate exposure and placental size and shape. Exposure to certain phthalates may cause the placenta to become thicker and more circular. Associations appeared stronger for the subsample representing male offspring than those for the subsample representing female offspring. Given the few studies on this topic, additional research is warranted. HighlightsThis study was a prospective cohort study with a large sample size.We evaluated the associations between throughout pregnancy phthalate exposure and placental size and shape.We assessed the urinary concentrations of seven phthalate metabolites among 2725 pregnant women.Prenatal phthalate exposure appeared to effect boys placental growth.

Effects of Prenatal Phthalate Exposure on Thyroid Hormone Concentrations Beginning at The Embryonic Stage

Limited studies have consistently shown an association of phthalates exposure with thyroid hormones (THs) in pregnant women. However, it remains unknown on which specific phthalates can affect THs and whether any effects could differ by gestational age. In the present study, we investigated associations between serum concentrations of phthalate monoesters [monoethyl phthalate (MEP), mono-(n + iso)-butyl phthalate (MBP) and mono(2-ethylhexyl) phthalate (MEHP)] and THs [thyroid-stimulating hormone (TSH), total thyroxine (TT4) and free thyroxine (FT4)] in Chinese pregnant women. 1,397 women were recruited from the China-Anhui Birth Cohort. Maternal serum samples were collected and used to measure phthalate metabolites and THs. Covariate-adjusted linear regression analyses showed that natural log (Ln)-transferred concentrations of MBP and LnMEHP were negatively associated with TT4 (β = −0.277 and –0.461, respectively; p < 0.001). Stratification analyses by gestational weeks showed significant associations of LnMBP and LnMEHP with TT4 in gestational weeks 5 to 8, 9 to 12, and 13 to 20. Our findings suggest an association of serum phthalates with lower TT4. The influence of MBP and MEHP on TT4 concentrations throughout the early pregnancy may begin from the embryonic stage (gestational weeks 5 to 8).

Thyroid autoantibodies in pregnancy are associated with hypertensive disorders of pregnancy: Ma'anshan Birth Cohort Study

Hypertensive disorders of pregnancy (HDP) have been associated with adverse health outcomes for both mothers and children. Previous studies examining associations of maternal thyroid autoantibodies with HDP indicate conflicting results. The objective of this study was to examine associations of maternal thyroid autoantibody positivity in the first and the second trimesters with the risk of HDP.

The impact of isolated maternal hypothyroxinaemia on the incidence of large‐for‐gestational‐age infants: the Ma'anshan Birth Cohort study

The purpose of this study was to investigate whether isolated maternal hypothyroxinaemia (IMH) is associated with risks of small/large‐for‐gestational‐age (SGA/LGA) infants.

Gestational di-(2-ethylhexyl) phthalate exposure causes fetal intrauterine growth restriction through disturbing placental thyroid hormone receptor signaling

Previous study reported that gestational Di-(2-ethylhexyl) phthalate (DEHP) exposure caused fetal intrauterine growth restriction (IUGR). We aimed to investigate the role of placental thyroid hormone receptor (THR) signaling in DEHP-induced IUGR. Dams were treated with DEHP (50 or 200 mg/kg) by gavage daily throughout pregnancy. As expected, gestational DEHP exposure dose-dependently caused fetal IUGR. The mRNA levels of placental Thrα1 and Thrβ1 were reduced and nuclear translocation of placental THRα1 and THRβ1 were suppressed in DEHP-exposed mice even though thyroid hormones in maternal and fetal sera were unaffected. Correspondingly, Vegf, Pgf, Igf1 and Igf2, several THR downstream genes essential for placental angiogenesis, were down-regulated in placenta of DEHP-exposed mice. Histopathology showed that vascular space in the labyrinthine region was shrunken in placenta of DEHP-treated mice. The microvessel density in labyrinthine region was reduced in DEHP-treated mice. A nested case-control study based on MABC suggested that microvessel density was decreased in placenta of SGA cases. Moreover, protein abundance of placental THRα1 and THRβ1 were lower in SGA cases. In conclusion, gestational DEHP exposure increases fetal IUGR incidence through disturbing placental THR signaling. The present study, at least partially, elucidate the underlying mechanism of DEHP-induced fetal IUGR.