Estrogen and -Fetoprotein Levels in Maternal and Umbilical Cord Blood Samples in Relation to Birth Weight

Overview of the etiology of childhood cancer and future directions

PURPOSE OF REVIEW

We provide an overview of the etiology of childhood cancer, the state of the literature, and highlight some opportunities for future research, including technological advancements that could be applied to etiologic studies of childhood cancer to accelerate our understanding.

RECENT FINDINGS

Risk factors of childhood cancer were summarized based on demographics and perinatal factors, environmental risk factors, and genetic risk factors. Overall, demographics and perinatal factors are the most well studied in relation to childhood cancer. While environmental risk factors have been implicated, more work is needed to pinpoint specific exposures, identify window(s) of susceptibility, and understand mechanisms. With genome-wide association studies (GWAS), genetic risk factors of eight childhood cancers have emerged, and opportunities remain to conduct GWAS for other cancer types and determine whether risk variants are inherited or de novo. Technological advancements that can shed light into the susceptibility of childhood cancer include metabolomics, using primary teeth as an exposure matrix, and long-read sequencing.

SUMMARY

The development of childhood cancer remains largely not well understood. Collaboration to increase sample size to conduct analyses by histology and/or molecular subtype and application of novel technologies will accelerate our understanding of childhood cancer.

Associations Between Heavy Metal Exposure from Milk and Steroid Hormones in Mothers

Environmental exposure to heavy metals is ubiquitous. However, its relationship with steroid hormone levels is not well understood, particularly in pregnant women. This study investigated the association between prenatal heavy metal exposure and steroid hormone levels in an e-waste disposal area in China. We analyzed the Cd, Cr, Mn, Pb, Cu, and As concentrations in 102 human milk samples collected 4 weeks after delivery. Multiple regression analysis was used to assess the associations and interactions between heavy metals and steroidal hormones. We found positive associations between Mn and estrone and estriol (estrone: β = 0.713, 95%CI = 0.046, 1.381 and estriol: β = 1.290, 95%CI = 0.494, 2.085) and between Cd and progesterone (β = 0.280; 95%CI = 0.053, 0.506). We observed negative associations between Cr and estrone and estriol (estrone: β = - 0.757, 95%CI = - 1.473, - 0.041 and estriol: β = - 1.354, 95%CI = - 2.209, - 0.499). At last, we found that Pb was negatively associated with estrone (estrone: β = - 0.537, 95%CI = - 1.053, - 0.020). Our results suggest that exposure to heavy metals may affect steroid hormone levels in mothers living in an e-waste recycling area in China.

Organochlorine pesticide residues and urinary arsenic and fluoride levels in mothers and their newborns who are residents of rural areas in Durango State, Mexico

Maternal and prenatal exposure to organochlorine pesticides (OCP), arsenic (As), and fluoride (F-) is a critical public health concern. The present study assessed serum OCP residues and urinary As and F- levels in mother and newborn pairs who are residents of rural areas of Durango State, Mexico, from August 2018 to February 2019. Levels of OCP, As, and F- were measured in serum and urine samples by Gas chromatography - Tandem mass spectrometry (GC - MS/MS), Hydride generation - Atomic fluorescent spectrometry (HG-AFS, and ion-selective electron analysis (ISE), respectively, in 60 binomial mothers - newborns. Dieldrin, endrin aldehyde, and endosulfan-II were significantly higher in newborns than in mothers (p ˂0.05). Meanwhile, no significant differences were observed for As and F- concentrations between mother - newborn pairs. Differences were observed in ∑Dienes and ∑DDTs comparing newborns with normal and low birth weights and a positive relationship in ƩDienes, ƩChlordanes, and ƩDDTs between mother and newborn pairs (p ˂ 0.05). These findings highlight the importance of extensive research regarding the influence of pollution.

The role of prenatal maternal sex steroid hormones in weight and adiposity at birth and growth trajectories during infancy

Objective

Intrauterine factors can impact fetal and child growth and may underlie the developmental origins of childhood obesity. Sex steroid hormone exposure during pregnancy is a plausible target because of the impact on placental vascularization, nutrient transportation, bone growth, adipogenesis, and epigenetic modifications. In this study we assessed maternal sex steroid hormones in each trimester in relation to birthweight, neonatal adiposity, and infant growth trajectories, and evaluate sensitive windows of development.

Methods

Participants from a prospective pregnancy cohort who delivered at term were included in the analysis (n=252). Estrone, estradiol, and estriol, as well as total and free testosterone throughout gestation were assessed using high-performance liquid chromatography and tandem mass spectrometry. Path analyses were used to assess the direct associations of sex steroid hormones in each trimester with birth outcomes and infant growth trajectories (birth to 12 months) adjusting for covariates and considering moderation by sex.

Results

The associations between prenatal sex steroid hormones and fetal/infant growth varied by sex and hormone assessment timing. First trimester estrone were associated with higher birthweight z-scores (β=0.37, 95%CI: 0.02, 0.73) and truncal skinfold thickness (TST) at birth (β=0.94, 95%CI: 0.34, 1.54) in female infants. Third trimester total testosterone was associated with higher TST at birth (β=0.61, 95%CI: 0.02, 1.21) in male infants. First trimester estrone/estradiol and first and third trimesters testosterone were associated with lower probabilities of high stable weight trajectory compared to low stable weight trajectory (Estrone: β=-3.87, 95%CI: -6.59, -1.16; First trimester testosterone: β=-3.53, 95%CI: -6.63, -0.43; Third trimester testosterone: β=-3.67, 95%CI: -6.66, -0.69) during infancy in male infants.

Conclusions

We observed associations between prenatal sex steroid hormone exposure and birthweight, neonatal adiposity and infant growth that were sex and gestational timing dependent. Our findings suggest further investigation on additional mechanisms linking prenatal sex steroid exposure and fetal/postnatal growth is needed.

Fetal growth and pediatric cancer: A pan-cancer analysis in 7000 cases and 37 000 controls

Birth weight is an established risk factor for some pediatric cancers but is dependent on gestational age and sex. Furthermore, it is unclear how associations may differ by infant sex, age at diagnosis, maternal race/ethnicity and maternal nativity status. We examined the association between size for gestation and a spectrum of pediatric cancers registered in the Texas Cancer Registry from 1995 to 2011. We analyzed up to 7547 cases and 37 735 controls. Analyses were conducted using logistic regression. Small-for-gestational age (SGA) and large-for-gestational age (LGA) were significantly associated with several tumors. SGA was associated with hepatic tumors (aOR = 1.76, 95% CI: 1.13, 2.74). Conversely, inverse associations were with Hodgkin lymphoma (aOR = 0.41, 95% CI: 0.19, 0.87) and soft tissue sarcomas (aOR = 0.65, 95% CI: 0.43, 0.97). LGA was associated with acute lymphoblastic leukemia (aOR = 1.37, 95% CI: 1.19, 1.57), Burkitt lymphoma (aOR = 1.90, 95% CI: 1.05, 3.45) and germ cell tumors (aOR = 1.55, 95% CI: 1.08, 2.23). Results did not differ when stratified by infant sex. The association with LGA and leukemia was strongest in those diagnosed 1 to 5 and 6 to 10 years. When stratified by maternal race/ethnicity, the association with LGA and neuroblastoma and renal tumors was strongest in children whose mother identified as non-Hispanic/Latina (H/L) Black. Among H/L women, children of Mexican-born women had a stronger association with LGA and leukemia, CNS tumors, neuroblastoma and renal tumors than children of US-born women (aOR range: 1.61-2.25 vs 1.12-1.27). Size for gestation is associated with several pediatric cancers. Associations may differ by age at diagnosis, maternal race/ethnicity and nativity.

Maternal and fetal outcomes of SLE in pregnancy: a literature review

Systemic Lupus Erythematosus (SLE) is an auto-immune disease in which the immune system assaults its tissues. We aimed to analyse the maternal and foetal outcomes during pregnancy in SLE mothers. A literature search was conducted by two investigators to assess SLE's outcomes on maternal and foetal during pregnancies. We searched PubMed/Medline, Embase, and Google scholar to collect evidence from different research studies, draw the conclusion, and report it. In our investigation, we found out that SLE could cause a spectrum of complications during pregnancy, not only for the mother but also for the foetus. It could affect fertility and cause difficult pregnancies for the couple as well which includes certain complications such as: preterm labour and delivery, high blood pressure (preeclampsia), placental insufficiency, miscarriage or stillbirth, whereas in the foetus SLE can cause mortality, preterm birth, and neonatal lupus (a temporary condition in the baby caused by SLE-related antibodies) and structural abnormalities. The literature suggests that SLE could prove fatal for the foetus and induce many complications in the mother. However, this could be avoided if pregnancy is planned right from the start and proper management is provided to the mother during pregnancy and delivery.p.

Association between excessive fetal growth and maternal cancer in Shanghai, China: a large, population-based cohort study

The prevalence of high birth weight or large for gestational age (LGA) infants is increasing, with increasing evidence of pregnancy-related factors that may have long-term impacts on the health of the mother and baby. We aimed to determine the association between excessive fetal growth, specifically LGA and macrosomia, and subsequent maternal cancer by performing a prospective population-based cohort study. The data set was based on the Shanghai Birth Registry and Shanghai Cancer Registry, with medical records from the Shanghai Health Information Network as a supplement. Macrosomia and LGA prevalence was higher in women who developed cancer than in women who did not. Having an LGA child in the first delivery was associated with a subsequently increased risk of maternal cancer (hazard ratio [HR] = 1.08, 95% confidence interval [CI] 1.04-1.11). Additionally, in the last and heaviest deliveries, there were similar associations between LGA births and maternal cancer rates (HR = 1.08, 95% CI 1.04-1.12; HR = 1.08, 95% CI 1.05-1.12, respectively). Furthermore, a substantially increased trend in the risk of maternal cancer was associated with birth weights exceeding 2500 g. Our study supports the association between LGA births and increased risks of maternal cancer, but this risk requires further investigation.

Prenatal Exposure to Bisphenol A: Is There an Association between Bisphenol A in Second Trimester Amniotic Fluid and Fetal Growth?

Background and Objectives: Fetal growth abnormalities increase the risk of negative perinatal and long-term outcomes. Bisphenol A (BPA) is a ubiquitous endocrine-disrupting chemical to which humans may be exposed in a number of ways, such as from the environment, via various consumer products, and through the individual's diet. Since the compound possesses estrogen-mimicking properties and exerts epigenetic and genotoxic effects, it has been associated with harmful effects impacting the entire spectrum of human life, including, vitally, the intrauterine period. We investigated the role of maternal exposure to BPA in abnormal fetal growth velocity, both impaired and excessive. Materials and Methods: Amniotic fluid samples were collected from 35 women who underwent amniocentesis early in the second trimester due to medical reasons. Pregnancies were followed until delivery, and birth weights were recorded. The amniotic fluid samples were subsequently divided into three groups based on fetal birth weight, as follows: AGA (appropriate for gestational age), SGA (small for gestational age), and LGA (large for gestational age). Amniotic fluid BPA levels were determined by gas chromatography coupled with mass spectrometry. Results: BPA was detected in 80% (28/35) of our amniotic fluid samples. Median concentration was 281.495 pg/mL and ranged from 108.82 pg/mL to 1605.36 pg/mL. No significant association was observed between the study groups regarding BPA concentration. A significant positive correlation between amniotic fluid BPA concentration and birth weight centile (r = 0.351, p-value = 0.039) was identified. BPA levels were also inversely associated with gestational age in pregnancies at term (between 37 and 41 weeks) (r = -0.365, p-value = 0.031). Conclusions: Our findings suggest that maternal exposure to BPA during the early second trimester of pregnancy can potentially contribute to increased birthweight percentiles and to decreased gestational age in pregnancies at term.

Pregnancy in lupus: an updated consensus to guide best practice strategies

Background

Systemic lupus erythematosus is a multifaceted chronic relapsing autoimmune disease of unknown etiology. The disease has always been a serious diagnosis in women being a multisystem pathology that is classically encountered during the childbearing age posing serious systemic comorbidities with a potential impact on the functional performance, psychosocial status, and survival. In this article, we review critical issues related to the decision to conceive in female with lupus highlighting the impact of the diagnosis and disease activity status on the mother and the fetus, attempting to suggest a consensus to guide safe decision making for pregnancy with SLE.

Main body

The pleomorphic dysregulated immune nature of lupus in the presence of uncontrolled disease carries a higher risk of complicated pregnancy. Therefore, SLE pregnancies should be well planned and are usually encouraged if the disease is inactive (at least 6 months prior to conception) to ensure immune quiescence towards a safer outcome.

Conclusion

With the proper implementation of preconception counseling strategy, choice of the correct timing of conception, close monitoring of SLE flares with tight control, and the appreciation of the value of multidisciplinary management to best practice most young women with SLE can carry on successful pregnancies with favorable outcome.

Urinary Phthalate Biomarkers during Pregnancy, and Maternal Endocrine Parameters in Association with Anthropometric Parameters of Newborns

Adverse birth outcomes present risk factors resulting in neonatal morbidity and mortality. Sufficient maternal hormonal concentrations are crucial for normal foetal development. Previous studies have shown a relationship between phthalate exposure and maternal hormonal levels during pregnancy. This study aims to investigate if neonatal anthropometric parameters are associated with maternal endocrine parameters during the ≤15th week of gestation and the third trimester of pregnancy concerning phthalate exposure in pregnant women from Nitra, Slovakia. We used high-performance liquid chromatography, tandem mass spectrometry (HPLC-MS/MS), and electro-chemiluminescence immunoassay to quantify urinary concentrations of phthalates and serum concentrations of hormones and sex hormone-binding globulin (SHBG), respectively. We observed a mostly positive correlation between neonatal anthropometric parameters (gestational age, birth length, birth weight, head circumference) and maternal concentration of phthalate metabolites (p ≤ 0.05). The hierarchical multivariate regression results showed a statistically significant association between Apgar score at 5 min after delivery, gestational age, birth weight, head circumference, and maternal endocrine parameters during pregnancy (p ≤ 0.05), adjusted to phthalate metabolites. To the best of our knowledge, our study is the first to indicate that prenatal exposure to phthalates may also affect birth outcomes through interaction with the maternal endocrine system.

Dioxin-like Activity in Pregnant Women and Indices of Fetal Growth: The ACCEPT Birth Cohort

Exposure to lipophilic persistent organic pollutants (lipPOPs) elicits a number of species- and tissue-specific toxic responses, many of which involve the aryl hydrocarbon receptor (AhR). This study aims to measure the combined serum dioxin-like activity of lipPOPs in Greenlandic Inuit pregnant women and the associations with fetal growth indices. The combined dioxin-like activity of serum lipPOPs extracts was determined using the AhR reporter gene bioassay and expressed as pico-gram (pg) TCDD equivalent (TEQ) per gram serum lipid [AhR-TEQ (pg/g lipid)]. Significant AhR-TEQ was found in >87% of serum samples with the median level of 86.2 pg TEQ/g lipid. The AhR-TEQ level positively correlated with the marine food intake biomarker n-3/n-6 polyunsaturated fatty acids ratio, while negatively correlated with body mass index and parity. Women giving birth to infants with low birth weight (<2500 g) and length (<50 cm) had higher AhR-TEQ level compared to those with normal weight and length infants. For previous smokers, we found significant inverse associations between maternal AhR-TEQ level and fetal growth indices. In conclusion, exposure of Greenlandic Inuit pregnant women to dioxin-like compounds through traditional marine food can adversely influence the fetal growth via induced AhR activity. Smoking might have modifying effects.

Shape Detection using Semi-parametric Shape-Restricted Mixed Effects Regression Spline with Applications

Linear models are widely used in the field of epidemiology to model the relationship between placental-fetal hormone and fetal/infant outcome. When researchers suspect curvilinear relationship exists, some nonparametric techniques, including regression splines, smoothing splines and penalized regression splines, can be used to model the relationship (Korevaar et al. 2016; Wu and Zhang 2006). By applying these nonparametric techniques, researchers can relax the linearity assumption and capture scientifically meaningful or appropriate shapes. In this paper, we focus on the regression spline technique and develop a method to help researchers select the most suitable shape to describe their data among increasing, decreasing, convex and concave shapes. Specifically, we develop a mixed effects regression spline to model hormonal data described in this paper. The proposed methodology is general enough to be applied to other similar problems. We illustrate the method using a state-wide prenatal screening program data set.

Association of Maternal-Neonatal Steroids With Early Pregnancy Endocrine Disrupting Chemicals and Pregnancy Outcomes

CONTEXT

Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.

OBJECTIVE

Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.

DESIGN

Prospective analysis of mother-infant dyads.

SETTING

University hospital.

PARTICIPANTS

121 mother-infant dyads.

MAIN OUTCOME MEASURES

The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.

RESULTS

Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.

CONCLUSIONS

This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome.

Estrogens and development of the rete testis, efferent ductules, epididymis and vas deferens

Estrogen has always been considered the female hormone and testosterone the male hormone. However, estrogen's presence in the testis and deleterious effects of estrogen treatment during development have been known for nearly 90 years, long before estrogen receptors (ESRs) were discovered. Eventually it was learned that testes actually synthesize high levels of estradiol (E2) and sequester high concentrations in the reproductive tract lumen, which seems contradictory to the overwhelming number of studies showing reproductive pathology following exogenous estrogen exposures. For too long, the developmental pathology of estrogen has dominated our thinking, even resulting in the "estrogen hypothesis" as related to the testicular dysgenesis syndrome. However, these early studies and the development of an Esr1 knockout mouse led to a deluge of research into estrogen's potential role in and disruption of development and function of the male reproductive system. What is new is that estrogen action in the male cannot be divorced from that of androgen. This paper presents what is known about components of the estrogen pathway, including its synthesis and target receptors, and the need to achieve a balance between androgen- and estrogen-action in male reproductive tract differentiation and adult functions. The review focuses on what is known regarding development of the male reproductive tract, from the rete testis to the vas deferens, and examines the expression of estrogen receptors and presence of aromatase in the male reproductive system, traces the evidence provided by estrogen-associated knockout and transgenic animal models and discusses the effects of fetal and postnatal exposures to estrogens. Hopefully, there will be enough here to stimulate discussions and new investigations of the androgen:estrogen balance that seems to be essential for development of the male reproductive tract.

Density and proximity to hydraulic fracturing wells and birth outcomes in Northeastern British Columbia, Canada

BACKGROUND

Hydraulic fracturing, a method used in Northeastern British Columbia (Canada) to extract natural gas, can release contaminants with potential deleterious health effects on fetal development. To date, the association between hydraulic fracturing activity and birth outcomes has not been evaluated in this region.

OBJECTIVE

To evaluate the association between the hydraulic fracturing well density/proximity and birth outcomes (birthweight, head circumference, preterm birth and small for gestational age (SGA)).

METHODS

We used birth records from the Fort St John hospital between December 30, 2006 and December 29, 2016 (n = 6333 births). To estimate gestational exposure, we used inverse distance weighting (IDW) to calculate the density/proximity of hydraulic fracturing wells to pregnant women's postal code centroid. For each birth, we calculated three IDWs using 2.5, 5, and 10 km buffer zones around women's postal code centroid. We used linear and logistic regressions to evaluate associations between quartiles of postal code well density/proximity and birth outcomes, controlling for relevant covariates.

RESULTS

No associations were found between postal code well density/proximity and head circumference or SGA. A negative association was found between postal code well density/proximity and birthweight for infants born to women in the 2nd quartile of the 10 km buffer (β [95% confidence interval (CI)]: -47.28 g [-84.30; -10.25]), and in the 2nd (β [95% CI]: -40.87 g [-78.01; -3.73]) and 3rd (β [95% CI]: -42.01 g [-79.15; -4.87]) quartiles of the 5 km buffer. Increased odds of preterm birth were observed among women in the 2nd quartile of the 2.5 km buffer (odds ratio (OR) [95% CI]: 1.60 [1.30; 2.43]).

CONCLUSIONS

This is the first epidemiological study in Northeastern British Columbia evaluating associations between hydraulic fracturing and health outcomes. Our results show inconsistent patterns of association between hydraulic fracturing, preterm birth and reduced birthweight, and effect estimates did not match expected dose-response relationships.

Predictability of Macrosomic Birth based on Maternal Factors and Fetal Aneuploidy Screening Biochemical Markers in Hyperglycemic Mothers

Background: Macrosomic birth weight has been implicated as a significant risk factor for developing various adult metabolic diseases such as diabetes mellitus and coronary heart diseases; it has also been associated with higher incidences of complicated births. This study aimed to examine the predictability of macrosomic births in hyperglycemic pregnant women using maternal clinical characteristics and serum biomarkers of aneuploidy screening performed in the first half of pregnancy. Methods: A retrospective observational study was performed on a cohort of 1,668 pregnant women who 1) had positive outcomes after undergoing 50-g oral glucose challenge test (OGCT) at two university-based hospitals and 2) underwent any one of the following maternal biomarker screening tests for fetal aneuploidy: triple test, quadruple test, and integrated test. Logistic regression-based models for predicting macrosomic births using maternal characteristics and serum biomarkers were developed and evaluated for prediction power. A nomogram, which is a graphical display of the best predictable model, was then generated. Results: The study cohort included 157 macrosomic birth cases defined as birth weight ≥3,820 g, which was equivalent to the top 10 percentile of the modeling cohort. Three primary models solely based on serum biomarkers achieved area under curves (AUCs) of 0.55-0.62. Expanded models, including maternal demographic and clinical factors, demonstrated an improved performance by 25% (AUCs, 0.69-0.73). Conclusion: Our prediction models will help to identify pregnancies with an elevated risk of macrosomic births in hyperglycemic mothers using maternal clinical factors and serum markers from routine antenatal screening tests. Prediction of macrosomic birth at mid-pregnancy may allow customized antenatal care to reduce the risk of macrosomic births.

Perinatal and postnatal exposures and risk of young-onset breast cancer

Background

Perinatal factors have been associated with some adult health outcomes, but have not been well studied in young-onset breast cancer. We aimed to evaluate the association between young-onset breast cancer and perinatal exposures and to explore etiologic heterogeneity in the relationship between associated perinatal factors and estrogen receptor status of the tumor.

Methods

We addressed this in a sister-matched case-control study. Cases were women who had been diagnosed with ductal carcinoma in situ or invasive breast cancer before the age of 50. Each case had a sister control who was free of breast cancer up to the same age at which her case sister developed the disease. The factors considered were self-reported and included the mother’s preeclampsia in that pregnancy, mother’s smoking in that pregnancy, gestational hypertension, prenatal diethylstilbestrol use, and gestational diabetes, as well as low birth weight (less than 5.5 pounds), high birth weight (greater than 8.8 pounds), short gestational length (less than 38 completed weeks), and being breastfed or being fed soy formula.

Results

In conditional logistic regression analyses, high birth weight (odds ratio [OR] = 1.59, 95% confidence interval [CI] 1.07–2.36) and preeclampsia (adjusted OR = 1.92, CI 0.824–4.5162) were positively associated with risk. The association with preeclampsia was stronger when the analysis was restricted to invasive breast cancer (OR = 2.87, CI 1.08–7.59). We also used case-only analyses to assess etiologic heterogeneity for estrogen receptor (ER)-positive versus estrogen receptor-negative cancer. Women who were born to a preeclamptic pregnancy and later developed young-onset breast cancer were at increased odds for the ER-negative type (OR = 2.27; CI 1.05–4.92).

Conclusion

These results suggest that being born to a preeclamptic pregnancy may increase risk for young-onset breast cancer, especially for the ER-negative subtype.

PFOS, PFOA, estrogen homeostasis, and birth size in Chinese infants

Laboratory studies have suggested that perfluoroalkyl substances (PFASs) could affect fetal growth by disrupting estrogen homeostasis, but there are limited data for human. For this, 424 mother-infant pairs were selected from a cohort established in Hebei Province of North China in 2013. Two typical PFASs, perfluorooctyl sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), and three typical estrogens, estrone (E₁), β-estradiol (E₂), and estriol (E₃), were measured in cord serum. After adjusted for important covariates, serum PFOS was positively related to E₁ and E₃, but negatively related to E₂. Serum PFOA was positively related to serum E₁ and negatively related to head circumference at birth. Serum E₂ was negatively related to head circumference, body weight, and body length at birth and serum E₃ was positively related to body weight. Serum E₃ mediated the relationship between serum PFOS and body weight. There were sex-specific differences for the associations between PFOS/PFOA and estrogens/birth size. These findings suggested that exposure to PFASs could affect estrogen homeostasis and fetal growth during pregnancy and that estrogens might mediate the association between exposure to PFASs and fetal growth.

Pre- and perinatal factors and incidence of breast cancer in the Black Women's Health Study

PURPOSE

The purpose of the study was to investigate the association between pre- or perinatal factors and breast cancer risk among African American women.

METHODS

Participants in the Black Women's Health Study, a prospective cohort of 59,000 African American women, reported birth weight, preterm birth, twin or triplet status, maternal age at birth, birth order, and having been breastfed during infancy at various times during follow-up from 1997 to 2015. Numbers of incident cases ranged from 312 for breastfed analyses to 1,583 for twin or triplet analyses. Using multivariable Cox proportional hazards regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between each factor and breast cancer risk overall and by estrogen receptor (ER) status.

RESULTS

Compared to birth weights of 5 lbs. 8 oz.-8 lbs. 13 oz., low (< 5 lbs. 8 oz.) and high (> 8 lbs. 13 oz.) birth weights were associated with increased breast cancer risk; HRs (95% CI) were 1.19 (0.98-1.44) and 1.26 (0.97-1.63), respectively. Associations were similar by ER status. Having been born to a mother aged ≥ 35 years versus < 20 years was associated with risk of ER+ (HR 1.59, 95% CI 1.10-2.29), but not ER- breast cancer. Other perinatal factors were not associated with breast cancer.

CONCLUSION

African American women with a low or high birth weight or born to older mothers may have increased breast cancer risk. Trends towards delayed child birth and higher birth weights, coupled with disproportionately high rates of low birth weight among African Americans, may contribute to increases in breast cancer incidence.

Maternal Acrylamide Intake during Pregnancy and Sex Hormone Levels in Maternal and Umbilical Cord Blood and Birth Size of Offspring

Exposure to acrylamide during pregnancy may disturb pregnancy hormones and the growth of the fetus. The present study aimed to examine the association of maternal acrylamide intake with maternal and cord sex hormone levels during pregnancy and at birth and birth size of offspring. The study subjects were 204 pregnant Japanese women and their newborn girls. Intake of acrylamide was assessed based on 5-day diet records at approximately the 29th week of pregnancy. The concentrations of estradiol, estriol, and testosterone were measured in maternal serum at the 29th weeks of pregnancy and at delivery and umbilical cord blood at delivery. Birth weight, length, and head circumference were measured at the delivery. After controlling for covariates, higher intake of acrylamide was significantly positively associated with higher level of umbilical cord estradiol at the delivery (p for trend = .01), but not with any hormone levels measured in maternal blood. A positive association between acrylamide intake and head circumference was of borderline significance (p for trend = .06). Overall, there were no consistent associations between maternal acrylamide intake and sex hormone levels during pregnancy. However, as this is the first study to examine these associations, additional studies are needed.

Maternal breast cancer risk in relation to birthweight and gestation of her offspring

BACKGROUND

Parity and age at first pregnancy are well-established risk factors for breast cancer, but the effects of other characteristics of pregnancies are uncertain and the literature is inconsistent.

METHODS

In a cohort of 83,451 parous women from the general population of the UK, which collected detailed information on each pregnancy and a wide range of potential confounders, we investigated the associations of length of gestation and birthweight of offspring in a woman's pregnancies with her breast cancer risk, adjusting for a full range of non-reproductive as well as reproductive risk factors unlike in previous large studies.

RESULTS

Gestation of the first-born offspring was significantly inversely related to the risk of pre-menopausal breast cancer (p trend = 0.03; hazard ratio (HR) for 26-31 compared with 40-41 weeks, the baseline group, = 2.38, 95% confidence interval (CI) 1.26-4.49), and was borderline significantly related to risk of breast cancer overall (p trend = 0.05). Risk was significantly raised in mothers of high birthweight first-born (HR for breast cancer overall = 1.53, 95% CI 1.06-2.21 for ≥ 4500 g compared with 3000-3499 g, the baseline group). For gestation and birthweight of most recent birth, there were no clear effects. Analyses without adjustment for confounders (other than age) gave similar results.

CONCLUSIONS

Our data add to evidence that short gestation pregnancies may increase the risk of breast cancer, at least pre-menopausally, perhaps by hormonal stimulation and breast proliferation early in pregnancy without the opportunity for the differentiation that occurs in late pregnancy. High birthweight first pregnancies may increase breast cancer risk, possibly through the association of birthweight with oestrogen and insulin-like growth factor 1 levels.

The association between sex and most childhood cancers is not mediated by birthweight

BACKGROUND

Male sex is associated with an increased risk of childhood cancer as is high birthweight. Given that sex determination precedes birthweight we conducted a mediation analysis to estimate the direct effect of sex in association with childhood cancer tumor type with birthweight as the mediator.

METHODS

Cases (n = 12,632) and controls (n = 64,439) (ages 0-14 years) were identified from population-based cancer and birth registries in Minnesota, New York, and Washington states (1970-2014). An inverse odds weighting (IOW) mediation analysis was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) as the measure of association between sex and cancer.

RESULTS

A significant indirect effect was observed for sex and lymphoid leukemia, mediated by birthweight (indirectOR: 1.03; 95% CI: 1.02-1.04). We observed significant direct effects for male sex and lymphoid leukemia (directOR: 1.16; 95% CI: 1.08-1.25), Hodgkin lymphoma (directOR: 1.48; 95% CI: 1.22-1.81), Burkitt lymphoma (directOR: 5.02; 95% CI: 3.40-7.42), other non-Hodgkin lymphoma (directOR: 1.42; 95% CI: 1.18-1.70), intracranial embryonal tumors (directOR: 1.49; 95% CI: 1.26-1.76), hepatoblastoma (directOR: 1.90; 95% CI: 1.40-2.59), and rhabdomyosarcoma (directOR: 1.47; 95% CI: 1.19-1.81). There were also inverse associations for extracranial GCTs (directOR: 0.41; 95% CI: 0.26-0.63) and thyroid carcinoma (directOR: 0.35; 95% CI: 0.25-0.50).

CONCLUSION

Significant direct effects for sex and numerous childhood cancer types suggests sex-specific factors such as differences in gene expression from the autosomes or the X chromosome, rather than birthweight, may underlie sex differences in tumor risk.

Prenatal low-level phenol exposures and birth outcomes in China

Phenolic compounds are among the endocrine disruptors which are widely used in daily life products. Studies in laboratory animals showed reproductive and developmental effects. In spite of widespread exposure to phenols, only few studies examined their effects on human development. This study was designed to investigate the relationship between antenatal phenol exposure and birth outcomes in a Chinese obstetric population. Four hundred ninety-six mother-infant pairs recruited from the Laizhou Wan prospective birth cohort in northern China between 2010 and 2013 were included in the study. We measured two phenol metabolites in maternal urine at delivery and examined their associations with birth outcomes including birth weight, crown-heel length, head circumference, gestational age, and ponderal index. Median levels of bisphenol A (BPA) and triclosan (TCS) in urine were 1.07 and 0.50μg/g creatinine, respectively. After adjusting for confounders, a 10-fold increase in BPA levels was associated with a 0.63cm [95% confidence interval (CI): 0.25 to 1.01] increase in birth length among boys, but not among girls. No associations were found between TCS levels and any birth outcomes. The positive association of prenatal low-level BPA exposures with anthropometric measures observed among boys, suggests gender differences in the response to antenatal phenol exposure. Given the variability in urinary phenol levels reported during pregnancy, our findings based on levels of the target biomarkers in a single urine sample need to be confirmed in additional studies.

Systemic lupus erythematosus and risk of preterm birth: a systematic review and meta-analysis of observational studies

We performed a meta-analysis to identify the association between systemic lupus erythematosus (SLE) and preterm birth. In this study, we studied the effects of SLE, SLE disease activity, a history of nephritis and active nephritis on preterm birth. Searches were conducted before 20 May 2016 of PubMed, Embase, Medline and Cochrane Library of literature and article reference lists. Eleven observational case-control studies and thirteen cohort studies met the inclusion criteria. The pooled relative risk (RR) for the risk of preterm birth in SLE patients versus controls was 2.05 (95% confidence interval (CI): 1.72-3.32); for active SLE patients versus inactive was 2.98 (95% CI: 2.32-3.83); for SLE patients with a history of lupus nephritis versus those without nephritis it was 1.62 (95% CI: 1.35-1.95); and for SLE patients with active nephritis versus those with quiescent nephritis it was 1.78 (95% CI: 1.17-2.70). In summary, this study identified a significant association in the above results. This association was more significant in active SLE patients versus inactive. With respect to SLE itself, active inflammation (such as disease activity) may be more hazardous for the management of the pregnancy. This suggests that it is essential to control disease activity in order to achieve a better outcome of SLE pregnancy.

Prediction of Gestational Diabetes Mellitus by Unconjugated Estriol Levels in Maternal Serum

The aim of this study was to evaluate the association between maternal serum estriol levels, which are routinely measured in the first trimester of pregnancy, and adverse pregnancy outcomes including gestational diabetes. We performed a retrospective chart analysis of women who delivered between July 1, 2007, and December 31, 2009, at Kangnam CHA Medical Center in Seoul, Korea. Only patients with available estriol measurements during their pregnancies and complete follow-up data were included in the study. The effect of estriol on the incidence of adverse pregnancy outcomes was examined using multinomial logistic regression analysis with age and pre-pregnancy body mass index (BMI) as covariates. The total number of subjects was 1,553, the mean age was 32.9 ± 3.7 years, and the mean pre-pregnancy BMI was 21.2 ± 3.0 kg/m². Unconjugated estriol > 95^th percentile of the screened population or unconjugated estriol ≥ 2.0 MoM (Multiple of the Median) was significantly associated with an increased risk for developing gestational diabetes mellitus (GDM), after adjusting for age and pre-pregnancy maternal weight. High levels of unconjugated estriol in the maternal serum during the early second trimester of pregnancy are a useful predictor of GDM development.

Effects of In Utero Exposure to Ethinyl Estradiol on Tamoxifen Resistance and Breast Cancer Recurrence in a Preclinical Model

Background

Responses to endocrine therapies vary among patients with estrogen receptor (ER+) breast cancer. We studied whether in utero exposure to endocrine-disrupting compounds might explain these variations.

Methods

We describe a novel ER+ breast cancer model to study de novo and acquired tamoxifen (TAM) resistance. Pregnant Sprague Dawley rats were exposed to 0 or 0.1 ppm ethinyl estradiol (EE2), and the response of 9,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors to 15 mg/kg TAM, with (n = 17 tumors in the controls and n = 20 tumors in EE2 offspring) or without 1.2 g/kg valproic acid and 5 mg/kg hydralazine (n = 24 tumors in the controls and n = 32 tumors in EE2 offspring) in the female offspring, was assessed. One-sided Chi2 tests were used to calculate P values. Comparisons of differentially expressed genes between mammary tumors in in utero EE2-exposed and control rats, and between anti-estrogen-resistant LCC9 and -sensitive LCC1 human breast cancer cells, were also performed.

Results

In our preclinical model, 54.2% of mammary tumors in the control rats exhibited a complete response to TAM, of which 23.1% acquired resistance with continued anti-estrogen treatment and recurred. Mammary tumors in the EE2 offspring were statistically significantly less likely to respond to TAM (P = .047) and recur (P = .007). In the EE2 offspring, but not in controls, adding valproic acid and hydralazine to TAM prevented recurrence (P < .001). Three downregulated and hypermethylated genes (KLF4, LGALS3, MICB) and one upregulated gene (ETV4) were identified in EE2 tumors and LCC9 breast cancer cells, and valproic acid and hydralazine normalized the altered expression of all four genes.

Conclusions

Resistance to TAM may be preprogrammed by in utero exposure to high estrogen levels and mediated through reversible epigenetic alterations in genes associated with epithelial-mesenchymal transition and tumor immune responses.

Alcohol Intake During Pregnancy and Offspring's Atopic Eczema Risk

BACKGROUND

Although alcohol consumption has been suggested to have an effect on the immune system, it is unknown whether alcohol consumption has a role in developing allergic diseases. We aimed to examine the associations of total alcohol intake during pregnancy with the risks of childhood asthma and atopic eczema in a birth cohort in Japan.

METHODS

Pregnant women were recruited at a maternal clinic from May 2000 to October 2001. The children who were born to these mothers were followed until November 2007. Total alcohol intake, including alcohol as a cooking ingredient, was assessed using 5-day dietary records. Mother reports of physician-diagnosed asthma and atopic eczema were annually obtained from the questionnaires. Asthma assessed by the American Thoracic Society Division of Lung Diseases questionnaire and atopic eczema assessed by International Study of Asthma and Allergies in Childhood questions were also obtained in 2007. A total of 350 children participated in the follow-up survey.

RESULTS

Maternal total alcohol intake during pregnancy was associated with increased risks of atopic eczema before age 3. The positive association with atopic eczema was also observed when it was defined as before age 5. In the high versus the low tertile of maternal total alcohol intake, the estimated hazard ratios (HRs) of child's eczema were 1.90 (95% CI: 0.96 to 3.76) before age 3 and 1.74 (95% CI: 0.93 to 3.24) before age 5, respectively. The estimated HRs of child's asthma before age 3 was 1.61 (95% CI: 0.70 to 3.69) in the high versus the low of maternal total alcohol intake and 2.11 (95% CI: 0.93 to 4.81) among children having drinking mothers versus nondrinking mothers in pregnancy, although maternal alcohol intake during pregnancy was not significantly associated with the risk of asthma before age 5.

CONCLUSIONS

Alcohol consumption during pregnancy might have an effect on developing atopic eczema in offspring.

Fetal growth and subsequent maternal risk of thyroid cancer

Thyroid cancer has peak incidence among women of reproductive age, and growth factors, which have procarcinogenic properties, may play an important etiologic role. However, the association between fetal growth rate during a woman's pregnancy and her subsequent risk of thyroid cancer has not been previously examined. We conducted a national cohort study of 1,837,634 mothers who had a total of 3,588,497 live-births in Sweden in 1973-2008, followed up for thyroid cancer incidence through 2009. There were 2,202 mothers subsequently diagnosed with thyroid cancer in 36.8 million person-years of follow-up. After adjusting for maternal age, height, weight, smoking, and sociodemographic factors, high fetal growth (birth weight standardized for gestational age and sex) was associated with a subsequent increased risk of thyroid cancer in the mother (incidence rate ratio [IRR] per additional 1 standard deviation, 1.05; 95% CI, 1.01-1.09; p = 0.02). Each 1,000 g increase in the infant's birth weight was associated with a 13% increase in the mother's subsequent risk of thyroid cancer (IRR, 1.13; 95% CI, 1.05-1.22; p = 0.001). These findings appeared to involve both papillary and follicular subtypes, and did not vary significantly by the mother's height, weight or smoking status. In this large national cohort study, high fetal growth during a woman's pregnancy was independently associated with a subsequent increased risk of her developing thyroid cancer. If confirmed, these findings suggest an important role of maternal growth factors in the development of thyroid cancer, and potentially may help facilitate the identification of high-risk subgroups of women.

Fetal growth and subsequent maternal risk of colorectal cancer

BACKGROUND

High birth weight has been associated with subsequent increased risk of breast cancer in the infant's mother, possibly related to maternal estrogen and growth factor pathways. However, its association with maternal risk of colorectal cancer, the third most common cancer among women, is unknown.

METHODS

We conducted a national cohort study of 1,838,509 mothers who delivered 3,590,523 babies in Sweden in 1973-2008, followed up for colorectal cancer incidence through 2009.

RESULTS

There were 7,318 mothers diagnosed with colorectal cancer in 36.8 million person-years of follow-up. After adjusting for maternal age, body mass index, diabetes, and other potential confounders, high fetal growth was associated with a subsequent increased risk of colorectal cancer in the mother [incidence rate ratio (IRR) per additional 1 SD relative to mean birth weight for gestational age and sex, 1.05; 95% confidence intervals (CI), 1.03-1.07; P < 0.0001]. Each 1,000 g increase in the infant's birth weight was associated with a 12% increase in the mother's subsequent risk of colorectal cancer (IRR, 1.12; 95% CI, 1.07-1.17; P < 0.0001). Multiple gestation was also independently associated with increased maternal risk of colorectal cancer (IRR for twin or higher order vs. singleton, 1.22; 95% CI, 1.04-1.44; P = 0.02).

CONCLUSION

In this large cohort study, high fetal growth and multiple gestation were independently associated with subsequent higher maternal risk of colorectal cancer. These findings warrant further investigation of maternal growth factor and estrogen pathways in the etiology of colorectal cancer.

IMPACT

If confirmed, our findings may help identify subgroups of women at high risk of colorectal cancer.

Maternal exposure to diethylstilbestrol during pregnancy and increased breast cancer risk in daughters

The idea that susceptibility to breast cancer is determined not only through inherited germline mutations but also by epigenetic changes induced by alterations in hormonal environment during fetal development is gaining increasing support. Using findings obtained in human and animal studies, this review addresses the mechanisms that may explain why daughters of mothers who took synthetic estrogen diethylstilbestrol (DES) during pregnancy have two times higher breast cancer risk than women who were not exposed to it. The mechanisms likely involve epigenetic alterations, such as increased DNA methylation and modifications in histones and microRNA expression. Further, these alterations may target genes that regulate stem cells and prevent differentiation of their daughter cells. Recent findings in a preclinical model suggest that not only are women exposed to DES in utero at an increased risk of developing breast cancer, but this risk may extend to their daughters and granddaughters as well. It is critical, therefore, to determine if the increased risk is driven by epigenetic alterations in genes that increase susceptibility to breast cancer and if these alterations are reversible.

Bone development and mineral homeostasis in the fetus and neonate: roles of the calciotropic and phosphotropic hormones

Mineral and bone metabolism are regulated differently in utero compared with the adult. The fetal kidneys, intestines, and skeleton are not dominant sources of mineral supply for the fetus. Instead, the placenta meets the fetal need for mineral by actively transporting calcium, phosphorus, and magnesium from the maternal circulation. These minerals are maintained in the fetal circulation at higher concentrations than in the mother and normal adult, and such high levels appear necessary for the developing skeleton to accrete a normal amount of mineral by term. Parathyroid hormone (PTH) and calcitriol circulate at low concentrations in the fetal circulation. Fetal bone development and the regulation of serum minerals are critically dependent on PTH and PTH-related protein, but not vitamin D/calcitriol, fibroblast growth factor-23, calcitonin, or the sex steroids. After birth, the serum calcium falls and phosphorus rises before gradually reaching adult values over the subsequent 24-48 h. The intestines are the main source of mineral for the neonate, while the kidneys reabsorb mineral, and bone turnover contributes mineral to the circulation. This switch in the regulation of mineral homeostasis is triggered by loss of the placenta and a postnatal fall in serum calcium, and is followed in sequence by a rise in PTH and then an increase in calcitriol. Intestinal calcium absorption is initially a passive process facilitated by lactose, but later becomes active and calcitriol-dependent. However, calcitriol's role can be bypassed by increasing the calcium content of the diet, or by parenteral administration of calcium.

Persistent organic pollutants exposure during pregnancy, maternal gestational weight gain, and birth outcomes in the mother-child cohort in Crete, Greece (RHEA study)

BACKGROUND

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and pesticides bioaccumulate through the food chain and cross the placenta. POPs are developmental toxicants in animals but the epidemiological evidence on pregnancy outcomes is inconsistent. Maternal gestational weight gain has been recently suggested as a key factor explaining the association between PCBs with lower birth weight.

AIMS

We examined whether in utero exposure to current low levels of different POPs is associated with fetal growth and gestational age in a mother-child cohort in Crete, Greece (Rhea study), and evaluated specifically whether maternal gestational weight gain may affect this association.

METHODS

We included 1117 mothers and their newborns from the Rhea study. Mothers were interviewed and blood samples collected during the first trimester of pregnancy. Information on birth outcomes was retrieved from medical records. Concentrations of several PCBs, other organochlorine compounds (dichlorodiphenyl dichloroethene [DDE], dichlorodiphenyl trichloroethane [DDT] and hexachlorobenzene [HCB]) and one polybrominated diphenyl ether congener (tetra-bromodiphenyl ether [BDE-47]), were determined in maternal serum by triple quadrupole mass spectrometry. Multiple linear regression models were used to investigate the associations of birth weight, gestational age, and head circumference with each compound individually on the log10 scale, and with combined exposures through the development of an exposure score.

RESULTS

In multivariate models, birth weight was negatively associated with increasing levels of HCB (β=-161.1g; 95% CI: -296.6, -25.7) and PCBs (β=-174.1g; 95% CI: -332.4, -15.9); after further adjustment for gestational weight gain these estimates were slightly reduced (β=-154.3g; 95% CI: -300.8, -7.9 for HCB and β=-135.7g; 95% CI: -315.4, 43.9 for PCBs). Furthermore, in stratified analysis, the association between POPs and birth weight was only observed in women with inadequate or excessive gestational weight gain. Small, negative associations were observed with head circumference while no association was observed with gestational age.

CONCLUSIONS

The findings suggest that prenatal exposure to PCBs and HCB impairs fetal growth and adds to the growing literature that demonstrates an association between low-level environmental pollutant exposure and fetal growth. Furthermore our results suggest that the association of POPs, maternal gestational weight gain and birth weight is probably more complex than that previously hypothesized.

Screening preeclamptic cord plasma for proteins associated with decreased breast cancer susceptibility

Preeclampsia, a complication of pregnancy characterized by hypertension and proteinuria, has been found to reduce the subsequent risk for breast cancer in female offspring. As this protective effect could be due to exposure to preeclampsia-specific proteins during intrauterine life, the proteomic profiles of umbilical cord blood plasma between preeclamptic and normotensive pregnancies were compared. Umbilical cord plasma samples, depleted of 14 abundant proteins, were subjected to proteomic analysis using the quantitative method of nanoACQUITY ultra performance liquid chromatography-mass spectrometry with elevated energy mode of acquisition(E) (NanoUPLC-MS(E)). Sixty-nine differentially expressed proteins were identified, of which 15 and 6 proteins were only detected in preeclamptic and normotensive pregnancies, respectively. Additionally, expression of 8 proteins (gelsolin, complement C5, keratin type I cytoskeletal 10, pigment epithelium-derived factor, complement factor B, complement component C7, hemoglobin subunit gamma-2 and alpha-fetoprotein) were up-regulated in preeclampsia with a fold change of ≥2.0 when compared to normotensive pregnancies. The identification of alpha-fetoprotein in preeclamptic umbilical cord blood plasma supported the validity of this screen as alpha-fetoprotein has anti-estrogenic properties and has previously been linked to preeclampsia as well as a reduced breast cancer risk. The findings of this pilot study may provide new insights into the mechanistic link between preeclampsia and potentially reduced breast cancer susceptibility in adult life.

Prenatal exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may influence birth weight among infants in a Swedish cohort with background exposure: a cross-sectional study

BACKGROUND

Prenatal exposure to persistent organic pollutants, e.g. polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) has been suggested to negatively affect birth weight although epidemiological evidence is still inconclusive. We investigated if prenatal exposure to PCBs and PBDEs is related to birth weight in a Swedish population with background exposure.

METHODS

Breast milk was sampled during the third week after delivery from first-time mothers in Uppsala county, Sweden 1996-2010 (POPUP cohort) (N = 413). Samples were analysed for di-ortho PCBs (CB-138, 153, 180) and tetra- to hexa- brominated PBDEs (BDE-47, 99, 100, 153). Simple and multiple linear regression models were used to investigate associations between lipid-adjusted, ln-transformed PCB and PBDE concentrations, and birth weight. Covariates included in the multivariate regression model were PCB and PBDE exposure, maternal age, pre-pregnancy BMI, weight gain during pregnancy, education, smoking, gender of the infant and gestational length. The effect of including fish consumption was also investigated.

RESULTS

In the multivariate model, prenatal exposure to di-ortho PCBs was significantly associated with increased birth weight (β = 137; p = 0.02). The result did not change when gestational length was added to the model. An inverse association between PBDE(4) (sum of BDE-47, -99, -100 and -153) and birth weight was observed in the multivariate model including gestational length (β = -106; p = 0.04). Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders of the association between di-ortho PCBs and birth weight. The associations were not alleviated after adjustment for fish consumption, a major source of PCB and PBDE exposure. The observed associations were stronger for boys than for girls.

CONCLUSIONS

Our results indicate that prenatal exposure to di-ortho PCBs and PBDE(4) may influence birth weight in different directions, i.e. PCB exposure was associated with higher birth weight and PBDE exposure with lower birth weight. Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders that may hide positive association between di-ortho PCB exposure and birth weight if they are not included in the statistical model. We speculate that even small PCB- and PBDE-induced shifts in the distribution of birth weight may influence future public health in populations with background exposure.

Exposures to synthetic estrogens at different times during the life, and their effect on breast cancer risk

Women are using estrogens for many purposes, such as to prevent pregnancy or miscarriage, or to treat menopausal symptoms. Estrogens also have been used to treat breast cancer which seems puzzling, since there is convincing evidence to support a link between high lifetime estrogen exposure and increased breast cancer risk. In this review, we discuss the findings that maternal exposure to the synthetic estrogen diethylstilbestrol during pregnancy increases breast cancer risk in both exposed mothers and their daughters. In addition, we review data regarding the use of estrogens in oral contraceptives and as postmenopausal hormone therapy and discuss the opposing effects on breast cancer risk based upon timing of exposure. We place particular emphasis on studies investigating how maternal estrogenic exposures during pregnancy increase breast cancer risk among daughters. New data suggest that these exposures induce epigenetic modifications in the mammary gland and germ cells, thereby causing an inheritable increase in breast cancer risk for multiple generations.

Predictors of preterm birth in patients with mild systemic lupus erythematosus

OBJECTIVE

While increased disease activity is the best predictor of preterm birth in women with systemic lupus erythematosus (SLE), even women with low disease activity are at increased risk of this complication. Biomarkers that would identify at-risk pregnancies could allow interventions to prevent preterm birth.

METHOD

Measures of SLE activity, inflammation, placental health and renal function between 20 and 28 weeks gestation (mid-gestation) were correlated to preterm birth and gestational age at delivery in a prospective cohort of pregnant women with SLE.

RESULT

Of the 40 pregnancies in 39 women, all with mild-moderate SLE disease, 9 (23.7%) of the 38 live births were delivered preterm. Low C4 was the only marker of SLE activity associated with younger gestational age at delivery. Elevated ferritin and lower oestradiol correlated with younger gestational age at delivery. Renal function remained normal during all pregnancies at mid-gestation and did not correlate with preterm birth. Higher serum uric acid, however, correlated with younger gestational age at delivery.

CONCLUSIONS

In women with SLE with mild-moderate disease activity, ferritin, oestradiol and uric acid levels at mid-gestation may predict preterm birth. These markers may prove to be clinically useful in identifying pregnancies at particularly high risk for adverse outcomes.

Impact of body mass index on breast cancer in accordance with the life-stage of women

A large amount of epidemiological evidence suggests that the impact of body weight on breast cancer risk should be heterogeneous throughout the life-stage of women. At birth, high weight has been positively associated with an increased risk of breast cancer. While, the body mass index (a relative body weight; BMI kg/m²) has been inversely associated with breast cancer risk among pre-menopausal women. The inverse trend had been observed in both Western and Asian population, with a relatively lower percentage of obesity and higher percentage of leanness, suggested that the inverse trend could be explained not only by the protective impact due to obesity, but also by the increased risk of breast cancer due to leanness. Among post-menopausal women, however, an elevated BMI has been positively associated with the development of breast cancer, particularly in the cases of estrogen receptor-positive (ER+) and progesterone receptor-positive (PR+) tumors. Currently, the mechanisms underlying the heterogeneous impacts between BMI on breast cancer risk and the life-stage of women remain poorly understood. We reviewed several proposed biological mechanisms that may contribute to the various impacts of relative body weight on breast cancer risk across life-stage. We also discussed the impact of BMI upon the outcome of endocrine therapy, particularly for aromatase inhibitor, in breast cancer patients. To prevent breast cancer incidence and recurrence, the desirable BMI of women may differ throughout their life-stage. To define the underlying mechanism for the various impacts of BMI in the context of breast cancer across various female life stages, further studies will be required.

Validity and reproducibility of food frequency questionnaire in Japanese children aged 6 years

The aim of the present study was to evaluate the validity and reproducibility of a food frequency questionnaire (FFQ) for use among young Japanese children. Forty-seven mothers of children aged 6 y completed two 3-d diet records and two FFQs over a 6-mo period. The FFQ asked the mothers how often, on average, their children consumed each of the 162 food items listed and what the usual serving size of each item was during the 6 mo prior to the study. Intakes of macro- and micronutrients were estimated by multiplying the frequency by the serving size for each food item. The validity of the FFQ was assessed by comparison of the two 3-d diet records. The reproducibility of the FFQ was based on the first and second FFQ administrations. The validity correlation ranged from 0.05 for α-tocopherol to 0.59 for retinol. The median correlation was 0.40. The reproducibility correlation was higher than 0.50 for all nutrients. For most nutrients, FFQ had acceptable reproducibility, whereas validity showed low to moderate correlations. Our FFQ could reasonably rank individuals according to dietary intake for epidemiologic studies, although the validity of the questionnaire is limited to specific nutrients.

Neonatal DNA methylation patterns associate with gestational age

Risk for adverse neonatal outcome increases with declining gestational age (GA), and changes in DNA methylation may contribute to the relationship between GA and adverse health outcomes in offspring. To test this hypothesis, we evaluated the association between GA and more than 27,000 CpG sites in neonatal DNA extracted from umbilical cord blood from two prospectively-characterized cohorts: (1) a discovery cohort consisting of 259 neonates from women with a history of neuropsychiatric disorders and (2) a replication cohort consisting of 194 neonates of uncomplicated mothers. GA was determined by obstetrician report and maternal last menstrual period. The associations between proportion of DNA methylated and GA were evaluated by fitting a separate linear mixed effects model for each CpG site, adjusting for relevant covariates including neonatal sex, race, parity, birth weight percentile and chip effects. CpG sites in 39 genes were associated with GA (false discovery rate < 0.05) in the discovery cohort. The same CpG sites in 25 of these genes replicated in the replication cohort, with each association replicating in the same direction. Notably, these CpG sites were located in genes previously implicated in labor and delivery (e.g., AVP, OXT, CRHBP and ESR1) or that may influence the risk for adverse health outcomes later in life (e.g., DUOX2, TMEM176A and CASP8). All associations were independent of method of delivery or induction of labor. These results suggest neonatal DNA methylation varies with GA even in term deliveries. The potential contribution of these changes to clinically significant postnatal outcomes warrants further investigation.

Racial variation in umbilical cord blood sex steroid hormones and the insulin-like growth factor axis in African-American and white female neonates

PURPOSE

To evaluate whether there is racial variation in venous umbilical cord blood concentrations of sex steroid hormones and the insulin-like growth factor (IGF) axis between female African-American and white neonates.

METHODS

Maternal and birth characteristics and venous umbilical cord blood samples were collected from 77 African-American and 41 white full-term uncomplicated births at two urban hospitals in 2004 and 2005. Cord blood was measured for testosterone, dehydroespiandrosterone-sulfate, estradiol, and sex steroid hormone-binding globulin (SHBG) by immunoassay. IGF-1, IGF-2, and IGF-binding protein-3 (IGFBP-3) were measured by ELISA. Crude and multivariable-adjusted geometric mean concentrations were computed for the hormones.

RESULTS

African-American neonates weighed less at birth (3,228 g vs. 3,424 g, p < 0.004) than whites. Birth weight was positively correlated with IGF-1, IGFBP-3, and the molar ratio of IGF-1 to IGFBP-3, but inversely correlated with the molar ratio of IGF-2 to IGFBP-3. Adjusted models showed higher testosterone (1.82 ng/ml vs. 1.47 ng/ml, p = 0.006) and the molar ratio of testosterone to SHBG (0.42 vs. 0.30, p = 0.03) in African-American compared to white female neonates. IGF-1, IGF-2, and IGFBP-3 were lower in African-American compared to white female neonates, but only the difference for IGF-2 remained significant (496.5 ng/ml vs. 539.2 ng/ml, p = 0.04).

CONCLUSION

We provide evidence of racial variation in cord blood testosterone and testosterone to SHBG in African-American compared to white female neonates, and higher IGF-2 in white compared to African-American female neonates. Findings suggest plausible explanations for a prenatal influence on subsequent breast cancer risk and mortality. Further work is needed to confirm these observations.

Light exposure at night, sleep duration and sex hormone levels in pregnant Japanese women

The association between light exposure at night and sex hormone levels in utero has scarcely reported. We assessed the associations between sleep duration or being awake in the late evening hours, which can be as indicator of light exposure at night, and the maternal and umbilical blood hormone levels during pregnancy and at delivery among Japanese women. The data for 236 women and their newborns who visited a maternal clinic in Gifu, Japan, between May 2000 and October 2001 were analyzed. Maternal blood samples were obtained at approximately the 10th weeks, 29th weeks of gestation, and at delivery. Umbilical cord artery blood was immediately drawn after birth. Information for sleep during pregnancy was obtained by a self-administered questionnaire. The levels of estradiol and testosterone were measured using radioimmunoassay. Maternal serum testosterone level in the 10th week was higher among those who were awake at or after 1:00 a.m. than among those who were asleep at that time (P = 0.032). Maternal estradiol level in the 29th week was inversely associated with sleep duration on weekends (P = 0.043). Umbilical testosterone level at delivery inversely correlated with sleep duration on weekdays (P = 0.030). These associations were somewhat stronger among mothers with female offspring than those with male offspring. These results suggested that exposure to light at night might increase sex hormone levels during pregnancy.

Determinants of maternal sex steroids during the first half of pregnancy

OBJECTIVE

To examine the associations of maternal and child characteristics with early pregnancy maternal concentrations of testosterone, androstenedione, progesterone, 17-hydroxyprogesterone, and estradiol (E2).

METHODS

We analyzed these hormones among 1,343 women with singleton pregnancies who donated serum samples to the Finnish Maternity Cohort from 1986 to 2006 during the first half of pregnancy (median 11 weeks). The associations of maternal and child characteristics with hormone concentrations were investigated by correlation and multivariable regression.

RESULTS

Women older than age 30 years had lower androgen and E2 but higher progesterone concentrations than women younger than that age. Multiparous women had 14% lower testosterone, 11% lower androstenedione and 17-hydroxyprogesterone, 9% lower progesterone, and 16% lower E2 concentrations compared with nulliparous women (all P<.05). Smoking mothers had 11%, 18%, and 8% higher testosterone, androstenedione, and 17-hydroxyprogesterone levels, respectively, but 10% lower progesterone compared with nonsmoking women (all P<.05). E2 concentrations were 9% higher (P<.05) among women with a female fetus compared with those with a male fetus.

CONCLUSION

Parity, smoking, and, to a lesser extent, maternal age and child sex are associated with sex steroid levels during the first half of a singleton pregnancy. The effects of smoking on the maternal hormonal environment and the possible long-term deleterious consequences on the fetus deserve further evaluation.

Birth weight and other prenatal factors and risk of breast cancer in Asian-Americans

Little is known about the role of birth weight and other prenatal factors in the etiology of breast cancer in Asian-Americans. We investigated the relation between birth weight and other prenatal factors and breast cancer risk in a population-based case-control study in Los Angeles County that included 2,259 Asian-American women with incident, histologically confirmed breast cancer and 2,019 control women, who were frequency matched to cases on age, Asian ethnicity, and neighborhood of residence. Breast cancer risk nearly doubled (odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.15-3.39) among those with high (≥ 4000 g) birth weight compared to those with low (<2500 g) birth weight after adjusting for age at menarche, parity, adult body mass index, and other covariates. Risk increased 8% per 500 g increase in birth weight (P trend = 0.10). We observed a significant relationship between birth weight and age at menarche in both cases and controls. Mean birth weight was higher (2948 g) for control women who had early menarche (age ≤ 11 years) compared to those who had menarche late (age ≥ 15 years) (2807 g) (P trend = 0.016); results were similar among case patients (P trend = 0.020). Older maternal age was also a risk factor; risk increased by 6% (95% CI = 1.01-1.12) per 5 years increase in maternal age with adjustment for parity and other risk factors. Our results support the hypothesis that high birth weight and older maternal age at pregnancy may have contributed to the rising breast cancer incidence in Asian-Americans.

Biomonitoring of bisphenol A concentrations in maternal and umbilical cord blood in regard to birth outcomes and adipokine expression: a birth cohort study in Taiwan

BACKGROUND

Bisphenol A (BPA) is a sealant and flux of plastic materials and has been determined to be an endocrine-disrupting chemical. Prenatal exposure to BPA can lead to substantial adverse effects on fetal growth and development. This study was conducted to assess BPA concentration in pregnant women and umbilical cord blood, and to investigate whether maternal BPA exposure affected fetal outcomes including lower birth weight (LBW), smaller size for gestational age (SGA), and high leptin (HLP) and low adiponectin (LAD) secretion.

METHODS

We measured the BPA levels of maternal blood (n = 97) and umbilical cord blood (n = 97) with a high-performance liquid chromatography/UV detector. The protein secretion of leptin and adiponectin were separately determined using enzyme-linked immunosorbent assay. A logistic regression was performed to estimate the effects of maternal exposure to BPA on LBW, SGA, and adverse action of adipokines in newborns.

RESULTS

The geometric means of BPA concentration in maternal blood and fetal cord blood were 2.5 ng/ml and 0.5 ng/ml, respectively. Elevated risks of LBW (OR 2.42, 95% confidence interval (CI) 1.72-3.36), SGA (OR 2.01, 95% CI 1.39-3.01), and adverse action of leptin (OR 1.67, 95% CI 1.12-2.25) and adiponectin (OR 1.25, 95% CI 1.52-3.97) were observed in male neonates in the highest quartile of maternal BPA exposure.

CONCLUSIONS

Elevated prenatal BPA exposure increased the risk of LBW, SGA, and adverse actions of adipokines in neonates, especially in male infants. These results provide further evidence that maternal exposure is correlated with adverse birth outcomes.

Placental characteristics as a proxy measure of serum hormone and protein levels during pregnancy with a male fetus

OBJECTIVE

In utero exposure to steroid hormones may be related to risk of some cancers such as testicular germ cell tumors (TGCT). To determine whether placental characteristics are good surrogate measures of maternal biomarker levels, we evaluated the correlations in mothers of sons at higher (whites, n = 150) and lower (blacks, n = 150) risk of TGCT. Associations with birth weight were also examined.

METHODS

All mothers, participants in the Collaborative Perinatal Project, were primigravidas who gave birth to male singletons. Associations between placental weight and placental thickness and third-trimester biomarker levels were evaluated using linear regression. Partial correlation coefficients for placental characteristics and birth weight were also estimated.

RESULTS

Placental weight was positively correlated with alpha-fetoprotein (AFP), sex hormone-binding globulin (SHBG), testosterone, estradiol and estriol in whites, and AFP and estriol in blacks. Placental thickness was not associated with any biomarker. After adjustment for placental weight, birth weight was not correlated with any biomarker.

CONCLUSIONS

In these data, placental weight was modestly correlated with third-trimester biomarker level; however, it appeared to be a better surrogate for third-trimester biomarker level than birth weight. Placental thickness had limited utility as a surrogate measure for biomarker levels.

A population-based case-control study of fetal growth, gestational age, and maternal breast cancer

Fetal growth or gestational age in a woman's pregnancies may modify pregnancy-related breast cancer risk, yet studies of these exposures are few. The authors conducted a population-based case-control study among parous Michigan women aged ≤50 years using linked Michigan Cancer Registry (1985-2004) and Michigan livebirth records (1978-2004). Breast cancer cases (n = 7,591) were matched 1:4 to controls (n = 28,382) on maternal birth year and race. Using conditional logistic regression, the authors examined the associations of gestational age (in weeks) and fetal growth (defined using birth weight percentiles for gestational age) in first and last births with breast cancer risk. Having a small-for-gestational-age or large-for-gestational-age infant at a maternal first or last birth was not associated with breast cancer risk, but having a small-for-gestational-age infant at a last birth at ≥30 years modestly reduced risk: odds ratio = 0.82 (95% confidence interval: 0.68, 0.98). First delivery at <32 or >41 weeks also modestly reduced risk: odds ratio = 0.80 (95% confidence interval: 0.62, 1.04) or 0.92 (95% confidence interval: 0.85, 0.99), respectively. In the largest case-control study to date, fetal growth was not associated with overall breast cancer risk in women aged ≤50, and there was some evidence for reduced breast cancer risk for early or late gestational age in first births only.