Prenatal and infant exposures and age at menarche

Indications of younger age at menarche in Greek adolescents but with no relation to body mass index

PURPOSE

This study aimed to present recent trends in the pubertal timing of a Greek female sample.

METHODS

Data were collected retrospectively from medical records of healthy females aged 6-18 years who attended a tertiary Adolescent Friendly Health Center over a 5-year period (2016-2020) and included gestational age, birth anthropometrics, and age of thelarche and/or pubarche and/or menarche, along with corresponding anthropometric, hormonal, and biochemical measurements.

RESULTS

Data from 298 girls' medical records were included in the analysis. Median age at menarche, thelarche, and pubarche was 12, 9, and 9 years, respectively. The mean interval between pubertal onset and menarche was 1.99 years. The mean body mass index (BMI) at menarche and thelarche was 20.99 kg/m2 and 18.90 kg/m2, respectively. The mean weight at menarche was 49.6 kg, whereas the mean height difference between thelarche and menarche was 19.17 cm. Among participants, 6.3% had premature menarche, while 24.0% had premature thelarche. Birth weight was moderately correlated with BMI at thelarche/pubarche (rs=0.334, p = 0.005). Birth weight and BMI at thelarche/pubarche were not predictive of premature menarche or premature thelarche. Median (interquartile range, IQR) levels at menarche vs. thelarche were significantly higher for insulin-like growth factor-1 [358.00 (140.50) vs. 176.00 (55.00) ng/ml], follicle stimulation hormone [5.65 (3.14) vs. 3.10 (4.23) mIU/ml], testosterone [25.50 (31.00) vs. 13.00 (21.00) ng/dl], dehydroepiandrosterone sulfate [117.00 (112.50) vs. 46.40 (51.90) µg/dl], and insulin [17.40 (15.05) vs. 8.47 (4.97) µIU/ml].

CONCLUSION

The timing of pubertal stages in the Greek female sample studied followed the recent international downward trends. Younger age at menarche was not related to BMI.

Prenatal, newborn and childhood factors and the timing of puberty in boys and girls

BACKGROUND

Our aim was to determine if prenatal factors, gestational age, birth weight and length, and childhood body mass index (BMI) are associated with the timing of puberty.

METHODS

Our population-based study comprised 4826 girls and 5112 boys born between 1997 and 2002. Multiple linear regression modeled the relationships between the maternal and child predictors and the age at peak height velocity (PHV).

RESULTS

Maternal smoking throughout pregnancy was associated with earlier age at PHV (-1.8 months in girls, 95%CI = -3.2 to -0.3, p = 0.015 and -1.7 months in boys, 95%CI = -3.1 to -0.3, p = 0.016). Older gestational age predicted later age at PHV in boys. One SDS increase in birth weight led to 1.7 months later age at PHV in girls (95%CI = 1.2 to 2.2, p < 0.001) and 0.8 months in boys (95%CI = 0.2 to 1.3, p = 0.005). At the age of 9 years, each increment of BMI by 1 kg/m2 was associated with 1.7 months (95%CI = -1.9 to -1.6, p < 0.001) and 1.3 months (95%CI = -1.4 to -1.1, p < 0.001) earlier age at PHV in girls and boys, respectively.

CONCLUSIONS

Fetal exposure to smoking can potentially exert enduring effects on pubertal timing. Birth weight and childhood nutritional status are significant determinants of pubertal timing in both sexes.

IMPACT

Maternal smoking was associated with earlier timing of puberty and greater birth weight with later timing of puberty in both girls and boys. Most previous studies have focused on girls and used surveys to assess pubertal development, but we studied both sexes and used the same objective measure (age at peak height velocity) for the timing of puberty. Our study increases knowledge especially regarding factors associated with the timing of puberty among boys.

Effects of pharmaceutical and personal care products on pubertal development: Evidence from human and animal studies

Pharmaceutical and personal care products (PPCPs) include a wide range of drugs, personal care products and household chemicals that are produced and used in significant quantities. The safety of PPCPs has become a growing concern in recent decades due to their ubiquitous presence in the environment and potential risks to human health. PPCPs have been detected in various human biological samples, including those from children and adolescents, at concentrations ranging from several ng/L to several thousand μg/L. Epidemiological studies have shown associations between exposure to PPCPs and changes in the timing of puberty in children and adolescents. Animal studies have shown that exposure to PPCPs results in advanced or delayed pubertal onset. Mechanisms by which PPCPs regulate pubertal development include alteration of the hypothalamic kisspeptin and GnRH networks, disruption of steroid hormones, and modulation of metabolic function and epigenetics. Gaps in knowledge and further research needs include the assessment of environmental exposure to pharmaceuticals in children and adolescents, low-dose and long-term effects of exposure to PPCPs, and the modes of action of PPCPs on pubertal development. In summary, this comprehensive review examines the potential effects of exposure to PPCPs on pubertal development based on evidence from human and animal studies.

Maternal Age at Menarche Genes Determines Fetal Growth Restriction Risk

We aimed to explore the potential link of maternal age at menarche (mAAM) gene polymorphisms with risk of the fetal growth restriction (FGR). This case (FGR)-control (FGR free) study included 904 women (273 FGR and 631 control) in the third trimester of gestation examined/treated in the Departments of Obstetrics. For single nucleotide polymorphism (SNP) multiplex genotyping, 50 candidate loci of mAAM were chosen. The relationship of mAAM SNPs and FGR was appreciated by regression procedures (logistic/model-based multifactor dimensionality reduction [MB-MDR]) with subsequent in silico assessment of the assumed functionality pithy of FGR-related loci. Three mAAM-appertain loci were FGR-linked to genes such as KISS1 (rs7538038) (effect allele G-odds ratio (OR)allelic = 0.63/pperm = 0.0003; ORadditive = 0.61/pperm = 0.001; ORdominant = 0.56/pperm = 0.001), NKX2-1 (rs999460) (effect allele A-ORallelic = 1.37/pperm = 0.003; ORadditive = 1.45/pperm = 0.002; ORrecessive = 2.41/pperm = 0.0002), GPRC5B (rs12444979) (effect allele T-ORallelic = 1.67/pperm = 0.0003; ORdominant = 1.59/pperm = 0.011; ORadditive = 1.56/pperm = 0.009). The haplotype ACA FSHB gene (rs555621*rs11031010*rs1782507) was FRG-correlated (OR = 0.71/pperm = 0.05). Ten FGR-implicated interworking models were founded for 13 SNPs (pperm ≤ 0.001). The rs999460 NKX2-1 and rs12444979 GPRC5B interplays significantly influenced the FGR risk (these SNPs were present in 50% of models). FGR-related mAAM-appertain 15 polymorphic variants and 350 linked SNPs were functionally momentous in relation to 39 genes participating in the regulation of hormone levels, the ovulation cycle process, male gonad development and vitamin D metabolism. Thus, this study showed, for the first time, that the mAAM-appertain genes determine FGR risk.

Association of age at menarche with gestational hypertension and preeclampsia: A large prospective cohort in China

This study explored the potential association between age at menarche and the risks of gestational hypertension and preeclampsia in Chinese women. Data were sourced from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. Our study consisted of 209 411 women pre-registered for pregnancy in two provinces in South China. Trained healthcare workers measured blood pressure at registration and recorded other pertinent health information. Using logistic regression, we assessed the correlations between age at menarche and the likelihood of developing gestational hypertension and preeclampsia, considering confounders such as maternal age, body mass index, ethnicity, parity, folic acid supplementation, education level, and occupation. The observed incidences for gestational hypertension and preeclampsia were 9.65% and 2.54%, respectively. The adjusted odds ratios (ORs) for gestational hypertension, based on age at menarche, were as follows: ≤13 years, 1.18 (95% confidence interval: 1.11-1.26); 14 years, 1.09 (1.04-1.15); 15 years, 1.11 (1.06-1.16); 16 years, 1.06 (1.01-1.12); and ≥17 years, 1.00 (reference; P for trend < .001). The correlation between age at menarche and preeclampsia varied across age groups, with the following respective ORs: 1.35 (1.20-1.52), 1.21 (1.09-1.34), 1.27 (1.15-1.39), 1.14 (1.03-1.26), and 1.00 (reference; P for trend < .001). This association appeared to be more pronounced in women with no folic acid supplementation and those with a lower education level. In conclusion, an earlier age at menarche seems to be linked to increased risks of gestational hypertension and preeclampsia.

Utilization of Delivery Services among Mothers in Aluu Community, Ikwerre Local Government Area, Rivers State

Background

Utilization of delivery services is paramount to achieving a safe delivery outcome and preventing maternal mortality/morbidity among mothers. In semi-urban communities, delivery services are provided by both health and non-health facilities and are influenced by either socio-demographic or economic factors. This study aims to evaluate the utilization of delivery services across various places that provide such care and to identify the factors that influence the utilization of delivery services in the Aluu community.

Methodology

A community-based cross-sectional study was conducted in 5 out of 9 villages in the Aluu community. A total of 415 respondents were recruited for the study. The study was carried out between April 2021 and October 2021. A multistage sampling method was used, and data was collected using an interviewer-administered structured questionnaire. The data was analyzed using SPSS version 25. The Chi-square test was used for inferential analysis and a significant level was set at p≤ 0.05 at 95% confidence interval.

Results

Out of 415 respondents, 44.03% were delivered in a healthcare facility while 55.97% were delivered in a non-health care facility. Tribe, religion, educational status, occupation, and Obstetrics and gynecological factors were found to influence the utilization of delivery services.

Conclusion

More than half of women utilized delivery services provided by non-health facilities and there was a significant relationship between tribe, religion, educational status, occupation, and Obstetrics and gynecological factors and the utilization of delivery services in the Aluu community.

Maternal Age at Menarche Gene Polymorphisms Are Associated with Offspring Birth Weight

In this study, the association between maternal age at menarche (AAM)-related polymorphisms and offspring birth weight (BW) was studied. The work was performed on a sample of 716 pregnant women and their newborns. All pregnant women underwent genotyping of 50 SNPs of AAM candidate genes. Regression methods (linear and Model-Based Multifactor Dimensionality Reduction (MB-MDR)) with permutation procedures (the indicator p_perm was calculated) were used to identify the correlation between SNPs and newborn weight (transformed BW values were analyzed) and in silico bioinformatic examination was applied to assess the intended functionality of BW-associated loci. Four AAM-related genetic variants were BW-associated including genes such as POMC (rs7589318) (β_additive = 0.202/p_perm = 0.015), KDM3B (rs757647) (β_recessive = 0.323/p_perm = 0.005), INHBA (rs1079866) (β_additive = 0.110/p_perm = 0.014) and NKX2-1 (rs999460) (β_recessive = -0.176/p_perm = 0.015). Ten BW-significant models of interSNPs interactions (p_perm ≤ 0.001) were identified for 20 polymorphisms. SNPs rs7538038 KISS1, rs713586 RBJ, rs12324955 FTO and rs713586 RBJ-rs12324955 FTO two-locus interaction were included in the largest number of BW-associated models (30% models each). BW-associated AAM-linked 22 SNPs and 350 proxy loci were functionally related to 49 genes relevant to pathways such as the hormone biosynthesis/process and female/male gonad development. In conclusion, maternal AMM-related genes polymorphism is associated with the offspring BW.

Prenatal exposures to isoflavones and neurobehavioral development in children at 2 and 4 years of age: A birth cohort study

Isoflavones (ISOs) are plant-derived estrogen-like compounds, which were already proved with cognition benefits on elderly people. However, studies assessing the associations between prenatal ISOs exposure and children's neurodevelopment are scarce. This study aimed to examine the associations between maternal urinary ISOs concentrations, including genistein (GEN), daidzein (DAD), glycitein (GLY), and metabolite equol (EQU), and children's neurodevelopment, based on a Chinese cohort study. Participants in this study were pregnant women recruited at 12-16 weeks of gestation, and they provided a single spot urine sample for the ISOs assay. Neurodevelopment was measured using the Child Behavior Checklist (CBCL) at 2 and 4 years of age. Negative binomial regression analysis and Generalized Estimating Equation (GEE) were performed to examine the associations between maternal urinary ISOs concentrations and CBCL scores. Associations were observed between moderate levels of prenatal ISOs exposure and decreased risks of childhood neurobehavioral problems, while the highest level of prenatal ISOs exposure was associated with increased risks of neurobehavioral problems among children. The neuroprotective effects were consistently between moderate DAD exposure and specific neurobehavioral problems, across different ages and sexes. For example, compared with the lowest exposure level, the third quartile group was associated with less Anxious/Depressed problems in boys at 2 years of age (RR=0.72 (95%CI: 0.52, 0.99)), girls at 2 years of age (RR=0.70 (95%CI: 0.46, 1.06)), boys at 4 years of age (RR=0.73 (95%CI: 0.55, 0.96)), and girls at 4 years of age (RR=0.95 (95%CI: 0.68, 1.31)).

Oestrogens and progesterone in human milk and their effects on infant health outcomes: A narrative review

Human milk (HM) is a complex biological system that contains a wide range of bioactive components including oestrogens and progesterone. Whilst maternal oestrogens and progesterone concentrations drop rapidly after birth, they remain detectable in HM across lactation. Phytoestrogens and mycoestrogens, which are produced by plants and fungi, are also present in HM and can interact with oestrogen receptors to interfere with normal hormone functions. Despite the potential impact of HM oestrogens and progesterone on the infant, limited research has addressed their impact on the growth and health of breastfed infants. Furthermore, it is important to comprehensively understand the factors that contribute to these hormone levels in HM, in order to establish effective intervention strategies. In this review, we have summarized the concentrations of naturally occurring oestrogens and progesterone in HM from both endogenous and exogenous sources and discussed both maternal factors impacting HM levels and relationships with infant growth.

Short- and Long-Term Outcomes of Preeclampsia in Offspring: Review of the Literature

Preeclampsia is a multisystemic clinical syndrome characterized by the appearance of new-onset hypertension and proteinuria or hypertension and end organ dysfunction even without proteinuria after 20 weeks of pregnancy or postpartum. Residing at the severe end of the spectrum of the hypertensive disorders of pregnancy, preeclampsia occurs in 3 to 8% of pregnancies worldwide and is a major cause of maternal and perinatal morbidity and mortality, accounting for 8-10% of all preterm births. The mechanism whereby preeclampsia increases the risk of the neurodevelopmental, cardiovascular, and metabolic morbidity of the mother's offspring is not well known, but it is possible that the preeclamptic environment induces epigenetic changes that adversely affect developmental plasticity. These developmental changes are crucial for optimal fetal growth and survival but may lead to an increased risk of chronic morbidity in childhood and even later in life. The aim of this review is to summarize both the short- and long-term effects of preeclampsia on offspring based on the current literature.

Racial disparities in uterine fibroids and endometriosis: a systematic review and application of social, structural, and political context

IMPORTANCE

Uterine fibroids and endometriosis are 2 of the leading causes of morbidity among reproductive-aged women. There are significant racial disparities in disease prevalence, incidence, age of onset, and treatment profile in fibroids. The data on endometriosis are less clear.

OBJECTIVE

To conduct a systematic review of racial disparities in prevalence of uterine fibroids and endometriosis in the United States and summarize the literature on these 2 highly prevalent benign gynecologic conditions using a framework that explicitly incorporates and acknowledges the social, structural, and political contexts as a root cause of racial disparities between Black and White women.

EVIDENCE REVIEW

A systematic review regarding racial disparities in prevalence of fibroids and endometriosis was conducted separately. Two separate searches were conducted in PubMed to identify relevant original research manuscripts and prior systematic reviews regarding racial disparities in uterine fibroids and endometriosis using standardized search terms. In addition, we conducted a structured literature search to provide social, structural, and political context of the disparities.

FINDINGS

A systematic review of the literature indicated that the prevalence of uterine fibroids was consistently higher in Black than in White women with the magnitude of the difference varying depending on population and case definition. Prevalence of endometriosis varied considerably depending on the base population and case definition, but was the same or lower among Black vs. White women. As a result of the social, structural, and political context in the United States, Black women disproportionately experience a range of exposures across the life course that may contribute to their increased uterine fibroid incidence, prevalence, and severity of uterine fibroids. However, data suggest no racial difference in the incidence of endometriosis. Nevertheless, Black women with fibroids or endometriosis experience worse clinical and surgical outcomes than their White counterparts.

CONCLUSION AND RELEVANCE

Racial disparities in uterine fibroids and endometriosis can be linked with differential exposures to suspected etiologic agents, lack of adequate access to health care, including highly skilled gynecologic surgeons, and bias and discrimination within the health care system. Eliminating these racial disparities will require solutions that address root causes of health disparities through policy, education and programs to ensure that all patients receive culturally- and structurally-competent care.

Osteoporosis Screening Using Dental Panoramic Radiographs and Age at Menarche

Since early detection of osteoporosis is essential, the development of an efficient and cost-effective screening model would be incredibly beneficial. The aim of this study was to evaluate the diagnostic accuracy of MCW and MCI indices from dental panoramic radiographs in combination with a new variable, age at menarche, for the detection of osteoporosis. The study enrolled 150 Caucasian women (aged 45 to 86) who met the eligibility criteria, had DXA scans of the left hip and lumbar spine (L2 to L4), and were classified as osteoporotic, osteopenic, or normal based on T-score. Two observers evaluated MCW and MCI indexes on panoramic radiographs. There was a statistically significant correlation between the T-score and MCI and MCW. In addition, age at menarche had a statistically significant correlation with T-score (p = 0.006). In conclusion, in the current study, MCW proved to be more effective in detecting osteoporosis when combined with age at menarche. Individuals with MCW less than 3.0 mm and age at menarche later than 14 years old should be referred for DXA since they present high risk of osteoporosis.

Soy-Based Infant Formula Feeding and Uterine Fibroid Development in a Prospective Ultrasound Study of Black/African-American Women

BACKGROUND

Uterine fibroids are highly prevalent, benign tumors. They are the leading indication for hysterectomy, and Black women are disproportionally burdened. Soy-based infant formula contains phytoestrogens, and exposure during sensitive developmental windows may adversely affect the developing uterus; early phytoestrogen treatment in rodent studies led to detrimental uterine effects, including increased fibroid risk in Eker rats. Limited epidemiological studies also have suggested increased fibroid development with soy formula infant feeding.

OBJECTIVE

The goal of this study was to examine the association between soy formula feeding in infancy and fibroid development in adulthood.

METHODS

We evaluated this association among 1,610 Black/African-American women age 23-35 y in the Study of Environment, Lifestyle & Fibroids (SELF). Soy formula feeding data was gathered directly from the participants' mothers (89%). A standardized ultrasound examination was conducted during 4 clinic visits over 5 y to detect fibroids ≥0.5cm in diameter. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between soy formula feeding and incident fibroids adjusted for early-life and adult factors. Fibroid growth was calculated as change in log-volume for fibroids matched at successive visits.

RESULTS

Of 1,121 fibroid-free participants at baseline, 150 (13%) were ever fed soy formula as infants, and 269 (24%) developed incident fibroids. We did not observe an association between ever being fed soy formula and incident fibroid risk (HR=1.08; 95% CI: 0.75, 1.54). However, participants fed soy formula within 2 months of birth and for >6 months (n=53) had an elevated risk of fibroid incidence in comparison with those never fed soy formula (HR=1.56; 95% CI: 0.92, 2.65). Fibroid growth rates did not differ.

DISCUSSION

Adding support to limited human data, this prospective fibroid study found that soy-based formula feeding during infancy was associated with a suggestive increase in risk of ultrasound-identified incident fibroids in adulthood. https://doi.org/10.1289/EHP11089.

Effect of hypertensive disorders of pregnancy on pubertal development in daughters and sons: a systematic review and meta-analysis

Hypertensive disorders of pregnancy (HDP) are a major cause of maternal and offspring morbidity and mortality worldwide. Several studies in recent years have focused on the link between HDP and pubertal development in offspring. The goal of this study was to synthesize the published literature on the effect of HDP on pubertal development in offspring by a systematic review and meta-analysis (PROSPERO 2021: CRD42020148736). A systematic literature search of several databases was conducted through December 2021, focusing on studies reporting pubertal development in offspring of women with and without HDP exposure. Primary outcomes of interest included offspring body mass index (BMI), height, waist and hip circumference, fat mass, pubarche, thelarche, and age at menarche. A total of 21 studies were finally included. Significantly higher values of BMI (SMD: 0.16 [0.11, 0.22]; p < 0.01) and waist circumference (SMD: 0.21 [0.14, 0.29]; p < 0.01) were found in offspring exposed to maternal HDP. In addition, a tendency of the early development of secondary sexual characteristics only in daughters was presented in offspring whose mothers were diagnosed with HDP. The findings imply a possible effect of HDP on pubertal development in offspring, especially for their BMI and waist circumference, which highlights the importance of focusing on adolescent developmental abnormalities in offspring exposed to HDP.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

OBJECTIVES

The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data.

METHODS

The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates.

RESULTS

Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche.

CONCLUSIONS

Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.

Developmental exposure to phytoestrogens found in soy: New findings and clinical implications

Exposure to naturally derived estrogen receptor activators, such as the phytoestrogen genistein, can occur at physiologically relevant concentrations in the human diet. Soy-based infant formulas are of particular concern because infants consuming these products have serum genistein levels almost 20 times greater than those seen in vegetarian adults. Comparable exposures in animal studies have adverse physiologic effects. The timing of exposure is particularly concerning because infants undergo a steroid hormone-sensitive period termed "minipuberty" during which estrogenic chemical exposure may alter normal reproductive tissue patterning and function. The delay between genistein exposure and reproductive outcomes poses a unique challenge to collecting epidemiological data. In 2010, the U.S. National Toxicology Program monograph on the safety of the use of soy formula stated that the use of soy-based infant formula posed minimal concern and emphasized a lack of data from human subjects. Since then, several new human and animal studies have advanced our epidemiological and mechanistic understanding of the risks and benefits of phytoestrogen exposure. Here we aim to identify clinically relevant findings regarding phytoestrogen exposure and female reproductive outcomes from the past 10 years, with a focus on the phytoestrogen genistein, and explore the implications of these findings for soy infant formula recommendations. Research presented in this review will inform clinical practice and dietary recommendations for infants based on evidence from both clinical epidemiology and basic research advances in endocrinology and developmental biology from mechanistic in vitro and animal studies.

Factors Affecting Menstrual Cycle Developmental Trajectory in Adolescents: A Narrative Review

CONTEXT

The time interval between the age at menarche and regulation of menstrual cycles (menstrual cycle developmental trajectory) is considered an indicator of the function of the reproductive system later in life. This study aimed to summarize the factors affecting this trajectory.

EVIDENCE ACQUISITION

A comprehensive literature search in PubMed, Scopus, Google Scholar, and Web of Science was performed to identify studies investigating factors influencing the regularity of the menstrual cycle in adolescents.

RESULTS

The interval between menarche and the onset of the regular menstrual cycle in adolescent girls may vary from several months to several years. Several factors, including genetic, race/ethnicity, intrauterine situation, social factors, geographical factors, lifestyle, and chronic diseases, are considered the predisposing factors for the trajectory.

CONCLUSIONS

Age at menarche and the onset of regular menstrual cycles are directly and indirectly influenced by several genetic, environmental, and lifestyle factors. Understanding these factors may improve our practice in managing irregular menstrual cycles that commonly happen in the first years after menarche.

Could maternal thyroid function during pregnancy affect daughters' age at menarche through child growth? A mediation analysis

Early menarche is associated with adverse health outcomes during adolescence as well as breast and other reproductive cancers later in adulthood. However, the causes of early menarche and the pathways through which they operate are not fully understood. Though maternal thyroid function during pregnancy affects child growth, and rapid childhood growth is associated with a decreased age at menarche, the relationship between prenatal maternal thyroid function and daughters' age at menarche has not been examined. We conducted a mediation analysis in a historical cohort of 260 mother-child pairs to estimate the total and indirect effects of maternal prenatal thyroid function on daughters' age at menarche. No association was observed between thyroid stimulating hormone (TSH) or anti-thyroid peroxidase antibodies (ATPO) and daughters' age at menarche. Using a sample-specific, a-priori cutoff at the 10th percentile, low levels of maternal free thyroxine (FT4) were associated with earlier daughter age at menarche, with a hazard ratio (95 % CI) of 1.70 (1.02, 2.84) comparing the bottom 10th percentile with the top 90th percentile of exposure levels. Higher maternal FT4 was associated with rapid child weight gain from ages 5-9, and rapid child weight gain from ages 5-9 was associated with earlier age at menarche; the estimated indirect effect of this pathway was null. While maternal FT4 is associated with earlier age at menarche in daughters, this is not mediated by rapid weight gain in our study population, suggesting that maternal FT4 is operating through a different pathway.

Early-life exposures and age at thelarche in the Sister Study cohort

BACKGROUND

Early age at breast development (thelarche) has been associated with increased breast cancer risk. Average age at thelarche has declined over time, but there are few established risk factors for early thelarche. We examined associations between pre- and postnatal exposures and age at thelarche in a US cohort of women born between 1928 and 1974.

METHODS

Breast cancer-free women ages 35-74 years who had a sister diagnosed with breast cancer were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported information on early-life exposures and age at thelarche, which we categorized as early (≤ 10 years), average (11-13 years), and late (≥ 14 years). For each exposure, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for early and late thelarche using polytomous logistic regression, adjusted for birth cohort, race/ethnicity and family income level in childhood.

RESULTS

Early thelarche was associated with multiple prenatal exposures: gestational hypertensive disorder (OR = 1.25, 95% CI 1.09-1.43), diethylstilbestrol use (OR = 1.23, 95% CI 1.04-1.45), smoking during pregnancy (OR = 1.20, 95% CI 1.13-1.27), young maternal age (OR 1.30, 95% CI 1.16-1.47 for < 20 vs. 25-29 years), and being firstborn (OR = 1.25, 95% CI 1.17-1.33). Birthweight < 2500 g and soy formula use in infancy were positively associated with both early and late thelarche.

CONCLUSIONS

Associations between pre- and postnatal exposures and age at thelarche suggest that the early-life environment influences breast development and therefore may also affect breast cancer risk by altering the timing of pubertal breast development.

REPRODUCTIVE TOXICOLOGY: Endocrine disruption and reproductive disorders: impacts on sexually dimorphic neuroendocrine pathways

We are all living with hundreds of anthropogenic chemicals in our bodies every day, a situation that threatens the reproductive health of present and future generations. This review focuses on endocrine-disrupting compounds (EDCs), both naturally occurring and man-made, and summarizes how they interfere with the neuroendocrine system to adversely impact pregnancy outcomes, semen quality, age at puberty, and other aspects of human reproductive health. While obvious malformations of the genitals and other reproductive organs are a clear sign of adverse reproductive health outcomes and injury to brain sexual differentiation, the hypothalamic-pituitary-gonadal (HPG) axis can be much more difficult to discern, particularly in humans. It is well-established that, over the course of development, gonadal hormones shape the vertebrate brain such that sex-specific reproductive physiology and behaviors emerge. Decades of work in neuroendocrinology have elucidated many of the discrete and often very short developmental windows across pre- and postnatal development in which this occurs. This has allowed toxicologists to probe how EDC exposures in these critical windows can permanently alter the structure and function of the HPG axis. This review includes a discussion of key EDC principles including how latency between exposure and the emergence of consequential health effects can be long, along with a summary of the most common and less well-understood EDC modes of action. Extensive examples of how EDCs are impacting human reproductive health, and evidence that they have the potential for multi-generational physiological and behavioral effects are also provided.

Biological clock and heredity in pubertal timing: what is new?

Puberty represents a milestone during a person's life and is characterized by several physical and psychological changes which end with the achievement of sexual maturation and of fertility. Puberty onset depends on a series of sophisticated, not completely understood, mechanisms certainly involving Gonadotropin-Releasing Hormone (GnRH) and its effects on pituitary gonadotropins. As recent evidence has demonstrated that pubertal timing deeply affects future adult health life, much efforts have been performed in order to clarify the exact actors involved in the onset and progression of puberty. Genetic factors are undoubtedly essential players in the regulation of pubertal development, accounting for approximately 50-80% of its variability. Mutations in genes such as KISS1, MKRN3 and DLK1 have been associated with central precocious puberty. Interestingly, a possible involvement of epigenetic mechanisms has been proposed as additional element able to affect pubertal phase. Environmental factors have recently attracted much attention. Indeed, an overall decrease in the age of puberty has been observed in the last decades. As genetic factors require long time to exert their effect, other players, such as environmental ones, may be involved. Special focus has been posed on nutritional status, endocrine-disrupting chemicals with non-conclusive results. Pubertal timing deeply affects future life, suggesting the need to clarify mechanisms driving pubertal onset and progression, in order to identify tailored therapeutic strategies and targets.

Hypertensive disorders in pregnancy and timing of pubertal development in daughters and sons

STUDY QUESTION

Do maternal hypertensive disorders affect pubertal development in daughters and sons?

SUMMARY ANSWER

Pubertal development tended to occur earlier in daughters of mothers with 'preeclampsia, eclampsia or HELLP syndrome' (hemolysis, elevated liver enzymes and low blood platelets) or hypertension in pregnancy compared to daughters born of normotensive mothers.

WHAT IS KNOWN ALREADY

The existing literature suggests some or no association between preeclampsia and pubertal development in daughters, but not in sons. None of the previous studies has investigated the possible association between other types of hypertensive disorders (hypertension, eclampsia or HELLP syndrome) and pubertal timing in children.

STUDY DESIGN, SIZE, DURATION

Longitudinal cohort study consisting of 15 819 mother-child pairs with information on maternal hypertensive disorders collected during pregnancy and information on pubertal development collected half-yearly from the age of 11 years and until fully developed or 18 years of age.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants are children from the Puberty Cohort nested within the Danish National Birth Cohort. The exposure was register-based and self-reported information on maternal hypertensive disorders during pregnancy. The outcomes were children's self-reported information on pubertal development, including Tanner stage 1-5 (pubic hair (both daughters and sons) and breast development (daughters) or genital development (sons)), first menstrual bleeding (daughters) or first ejaculation (sons), voice break episode (sons), axillary hair development and acne occurrence (both daughters and sons). The main outcome was mean difference in age at attaining each pubertal milestone and a combined pubertal marker in children of mothers with hypertensive disorders in pregnancy (either hypertension (n = 490), 'preeclampsia, eclampsia or HELLP syndrome' (n = 419) or 'unspecific hypertensive disorders' (n = 334) with unexposed children as reference (n = 14 576)).

MAIN RESULTS AND THE ROLE OF CHANCE

In daughters of mothers with 'preeclampsia, eclampsia or HELLP syndrome', we observed tendencies of earlier pubertal timing (combined marker: -2.0 (95% CI: -3.9; 0.0) months). In daughters of mothers with hypertension, several pubertal milestones tended to occur earlier than in daughters of normotensive mothers; however, all 95% CIs overlapped the null resulting in a combined pubertal marker of -1.0 (95% CI: -3.2; 1.1) months. In sons of mothers with any of the hypertensive disorders, we observed no difference in pubertal timing (combined markers: 'preeclampsia, eclampsia or HELLP syndrome': 0.1 (95% CI: -2.0; 2.1) months; hypertension: -0.6 (95% CI: -2.3; 1.1) months; 'unspecific hypertensive disorders': 0.2 (95% CI: -1.9; 2.2) months).

LIMITATIONS, REASONS FOR CAUTION

The study is subject to non-differential misclassification of self-reported information on maternal hypertensive disorders in pregnancy and current pubertal status; possibly causing bias toward the null.

WIDER IMPLICATIONS OF THE FINDINGS

Hypertensive disorders in pregnancy might accelerate pubertal timing in daughters; however, more studies are needed for causal conclusions.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Faculty of Health at Aarhus University. The authors have no financial relationships or competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Association of the Age at Menarche with Site-Specific Cancer Risks in Pooled Data from Nine Cohorts

The average age at menarche declined in European and U.S. populations during the 19th and 20th centuries. The timing of pubertal events may have broad implications for chronic disease risks in aging women. Here we tested for associations of recalled menarcheal age with risks of 19 cancers in 536,450 women [median age, 60 years (range, 31-39 years)] in nine prospective U.S. and European cohorts that enrolled participants from 1981 to 1998. Cox regression estimated multivariable-adjusted HRs and 95% confidence intervals (CI) for associations of the age at menarche with risk of each cancer in each cohort and random-effects meta-analysis was used to generate summary estimates for each cancer. Over a median 10 years of follow-up, 60,968 women were diagnosed with a first primary incident cancer. Inverse linear associations were observed for seven of 19 cancers studied. Each additional year in the age at menarche was associated with reduced risks of endometrial cancer (HR = 0.91; 95% CI, 0.89-0.94), liver cancer (HR = 0.92; 95% CI, 0.85-0.99), melanoma (HR = 0.95; 95% CI, 0.93-0.98), bladder cancer (HR = 0.96; 95% CI, 0.93-0.99), and cancers of the colon (HR = 0.97; 95% CI, 0.96-0.99), lung (HR = 0.98; 95% CI, 0.96-0.99), and breast (HR = 0.98; 95% CI, 0.93-0.99). All but one of these associations remained statistically significant following adjustment for baseline body mass index. Similarities in the observed associations between menarche and seven cancers suggest shared underlying causes rooted early in life. We propose as a testable hypothesis that early exposure to sex hormones increases mid-life cancer risks by altering functional capacities of stem cells with roles in systemic energy balance and tissue homeostasis. SIGNIFICANCE: Age at menarche is associated with risk for seven cancers in middle-aged women, and understanding the shared underlying causal pathways across these cancers may suggest new avenues for cancer prevention.

Classical toxicity endpoints in female rats are insensitive to the human endocrine disruptors diethylstilbestrol and ketoconazole

Developmental exposure to endocrine disrupting chemicals can have negative consequences for reproductive health in both men and women. Our knowledge about how chemicals can cause adverse health outcomes in females is, however, poorer than our knowledge in males. This is possibly due to lack of sensitive endpoints to evaluate endocrine disruption potential in toxicity studies. To address this shortcoming we carried out rat studies with two well-known human endocrine disruptors, diethylstilbestrol (DES) and ketoconazole (KTZ), and evaluated the sensitivity of a series of endocrine related endpoints. Sprague-Dawley rats were exposed orally from gestational day 7 until postnatal day 22. In a range-finding study, disruption of pregnancy-related endpoints was seen from 0.014 mg/kg bw/day for DES and 14 mg/kg bw/day for KTZ, so doses were adjusted to 0.003; 0.006; and 0.0012 mg/kg bw/day DES and 3; 6; or 12 mg/kg bw/day KTZ in the main study. We observed endocrine disrupting effects on sensitive endpoints in male offspring: both DES and KTZ shortened anogenital distance and increased nipple retention. In female offspring, 0.0012 mg/kg bw/day DES caused slightly longer anogenital distance. We did not see effects on puberty onset when comparing average day of vaginal opening; however, we saw a subtle delay after exposure to both chemicals using a time-curve analysis. No effects on estrous cycle were registered. Our study shows a need for more sensitive test methods to protect the reproductive health of girls and women from harmful chemicals.

The Role of Fetal, Infant, and Childhood Nutrition in the Timing of Sexual Maturation

Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to central neurotransmitters, hormones, and environmental factors leading to hypothalamic-pituitary-gonadal axis maturation. The connection between hormones and nutrition during critical periods of growth, like fetal life or infancy, is fundamental for metabolic adaptation response and pubertal development control and prediction. Since birth weight is an important indicator of growth estimation during fetal life, restricted prenatal growth, such as intrauterine growth restriction (IUGR) and small for gestational age (SGA), may impact endocrine system, affecting pubertal development. Successively, lactation along with early life optimal nutrition during infancy and childhood may be important in order to set up timing of sexual maturation and provide successful reproduction at a later time. Sexual maturation and healthy growth are also influenced by nutrition requirements and diet composition. Early nutritional surveillance and monitoring of pubertal development is recommended in all children, particularly in those at risk, such as the ones born SGA and/or IUGR, as well as in the case of sudden weight gain during infancy. Adequate macro and micronutrient intake is essential for healthy growth and sexual maturity.

Pubertal timing in boys and girls born to mothers with gestational diabetes mellitus: a systematic review

CONTEXT

The incidence of gestational diabetes mellitus (GDM) has been on the rise, driven by maternal obesity. In parallel, pubertal tempo has increased in the general population, driven by childhood obesity.

OBJECTIVE

To evaluate the available evidence on pubertal timing of boys and girls born to mothers with GDM.

DATA SOURCES

We searched MEDLINE, EMBASE, CINAHL Plus, Cochrane library and grey literature for observational studies up to October 2019.

STUDY SELECTION AND EXTRACTION

Two reviewers independently selected studies, collected data and appraised the studies for risk of bias. Results were tabulated and narratively described as reported in the primary studies.

RESULTS

Seven articles (six for girls and four for boys) were included. Study quality score was mostly moderate (ranging from 4 to 10 out of 11). In girls born to mothers with GDM, estimates suggest earlier timing of pubarche, thelarche and menarche although for each of these outcomes only one study each showed a statistically significant association. In boys, there was some association between maternal GDM and earlier pubarche, but inconsistency in the direction of shift of age at onset of genital and testicular development and first ejaculation. Only a single study analysed growth patterns in children of mothers with GDM, describing a 3-month advancement in the age of attainment of peak height velocity and a slight increase in pubertal tempo.

CONCLUSIONS

Pubertal timing may be influenced by the presence of maternal GDM, though current evidence is sparse and of limited quality. Prospective cohort studies should be conducted, ideally coupled with objective biochemical tests.

Early life factors for endometriosis: a systematic review

BACKGROUND

Despite its high prevalence and health burden, many aspects of endometriosis remain unclear, including risk factors and the underlying biological mechanisms. Exposures during early life, including in utero, are thought to play an important role in the subsequent onset of the condition. To date, however, much of the evidence from studies on early life exposures and diagnosed endometriosis appears mixed and difficult to assess.

OBJECTIVE AND RATIONALE

This study aims to provide a systematic review of the epidemiologic evidence on early life factors associated with the subsequent diagnosis of endometriosis. In utero and early life exposures have previously been linked to a range of adult health outcomes, including infertility.

SEARCH METHODS

A systematic review of case-control, cross-sectional and cohort studies was conducted using the search terms 'endometriosis'[MeSH] AND ('risk factors'[MeSH] OR 'protective factors'[MeSH]) AND ('in utero', 'fetal', 'neonatal, 'perinatal', 'developmental origins', 'early life', 'childhood' OR 'life course') in Embase, PubMed and Scopus databases. The review included articles published in English until 10 June 2018 with original data from studies with diagnosed endometriosis. The quality of primary studies was evaluated using the Newcastle-Ottawa Scale by both authors independently. Due to the degree of inconsistency in the measurements and study methods, a qualitative assessment of findings was undertaken rather than meta-analysis.

OUTCOMES

The search retrieved 70 records without duplicates that contained 20 records on human case-control, cross-sectional or cohort studies, from which 11 papers/studies were selected based on their assessment score. The majority of studies found that women born with low birthweight (<2.5 kg or <5.5 lb) were more likely to be diagnosed with endometriosis. For other early life factors, the evidence is mixed or limited, with further research needed on the association of endometriosis with preterm birth, in utero exposure to diethylstilbestrol and to maternal smoking, passive smoking in early life, and infant formula feeding (compared with breastfeeding).

WIDER IMPLICATIONS

While the weight of evidence points to low birthweight as a risk factor for diagnosis of endometriosis, future research is warranted on this and other key early life exposures where the findings are mixed to provide more robust evidence and for insights on potential causal pathways. Such research, however, needs to address current methodological issues, such as the use of prospective data from large population-based studies, better diagnostic methods to confirm disease free status, more consistent definitions of variables and consideration of potential biological mechanisms to guide the analyses. The improvements will advance the future synthesis of evidence to support clinically relevant risk assessment for a more timely diagnosis and treatment of endometriosis.

Child-related and parental predictors for thelarche in a general population of girls: the PANIC study

BACKGROUND

Obesity has been associated with earlier thelarche, whereas other predictors for it remain unclear.

METHODS

We studied child-related and parental predictors for earlier thelarche in 195 girls aged 6-8 years followed up for 2 years. A physician evaluated breast development by inspection and palpation. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry, diet by food records, and physical activity and sedentary time by body movement and heart rate monitors. Parental education, smoking, and alcohol consumption and household income were assessed by questionnaires. Gestational age, birth weight, and maternal prepregnancy BMI were obtained from hospital registers. Predictors for thelarche were examined using logistic regression analysis adjusted for age and follow-up time.

RESULTS

The incidence of thelarche during 2 years increased by 11% (OR 1.11, CI 1.06-1.17, p < 0.001) for 1 unit increase in baseline BF%. Girls with a smoking parent had a 2.64 (95% CI 1.21-5.77, p = 0.015) times higher incidence of thelarche than other girls. The associations of lower parental education and higher maternal prepregnancy BMI with the higher incidence of thelarche were largely explained by BF%. Other possible predictors were not associated with thelarche.

CONCLUSIONS

Higher BF% and exposure to tobacco smoke are independent predictors for earlier thelarche.

Effect of age at menarche on the mother's weight status two and four years after delivery: a cohort study

We aimed to estimate the effect of age at menarche on the risk of excess body weight in Brazilian women two and four years after delivery. This was a cohort study that used data from adult women of the Predictors of Maternal and Child Excess Body Weight (PREDI) Study obtained at baseline (2012) and at 1^st(2014) and 2^nd(2016) follow-up. A total of 435 women attending a public maternity hospital in Joinville-Brazil were initially included in the study (baseline) and 215 of them continued to participate in the 2^nd follow-up carried out in the homes of the participants. Regression analysis was used to estimate the association between age at menarche (<12; ≥12 years) and excess body weight (≥25 kg/m²) trajectory during the follow-ups. Unadjusted analysis showed that mothers with age at menarche <12 years were 1.29 times (p = .018) more likely to be overweight/obese than those with age at menarche ≥12 years. After adjustment, age at menarche continued to exert an independent effect on the mother's body mass index (RR = 1.23; p = .037) four years after delivery. Strategies designed to attenuate the rising prevalence of maternal overweight and obesity, especially after pregnancy, could help improve the mother's health status in the future.

Association of Early Menarche with Adolescent Health in the Setting of Rapidly Decreasing Age at Menarche

STUDY OBJECTIVE

This study aimed to investigate the association between age at menarche (AAM) and adverse health indicators in adolescent girls.

DESIGN

A retrospective cohort study.

SETTING

Population-based survey data.

PARTICIPANTS

A total of 319,437 female participants aged 12-18 years from the Korea Youth Risk Behaviour Web-based Survey.

INTERVENTIONS AND MAIN OUTCOME MEASURES

We assessed associations between AAM (categorized as ≤10, 11, and ≥12) and health indicators (poor self-rated health, high psychological stress, unhappiness, sexual initiation, and pregnancy). Covariates were individual-level (bodyweight, living with family, parent's education, household wealth, and presence of parents and siblings) and community-level factors (year of birth, single-sex education and level of school, urbanization level of school area, year of survey, and regional deprivation). Odds ratios (ORs) for each adverse health indicator were examined by each AAM group using multivariable regression analyses. For pregnancy, we calculated relative risks (RRs) using a log-binomial regression model.

RESULTS

Age at menarche was <12 in 42% of our study population. Nearly one-half of the girls born in the early 2000s went through menarche before the age of 12 years, whereas only one-third of girls born in the early 1990s went through menarche before the age of 12 years. Girls who experienced menarche at age ≤10 or age 11 years were more likely to show self-rated poor health (AAM ≤ 10: OR, 1.28; 95% confidence intervals [CI], 1.22-1.34; AAM = 11: OR, 1.16; 95% CI, 1.12-1.21), high stress (OR, 1.19; 95% CI, 1.14-1.23, and OR, 1.10; 95% CI, 1.06-1.14), and sexual initiation (OR, 2.21; 95% CI, 2.05-2.38, and OR, 1.32; 95% CI, 1.23-1.41) compared to those with AAM ≥12 years when data were adjusted for all covariates. AAM ≤10 years was associated with consistently higher odds for poor health than AAM ≥12 years. The ORs of sexual initiation increased with earlier AAM. Risk of pregnancy was similar across AAM groups when individual- and community-level covariates were controlled for.

CONCLUSION

Early menarche, defined as <12 years, can be still a useful indicator in adolescent health interventions to identify high-risk groups in the setting of declining AAM.

Early-life factors, in-utero exposures and endometriosis risk: a meta-analysis

This meta-analysis aimed to offer a general picture of the available data on the effects of early-life factors on the risk of developing endometriosis in adult life. An advanced, systematic search of the online medical databases PubMed, EMBASE and CINAHL was limited to full-length manuscripts published in English in peer-reviewed journals up to February 2019. Log of relative risk (RR) was employed to calculate the pooled effect sizes using both fixed and random effects modelling and I-squared tests to assess heterogeneity. Funnel plots were used to investigation publication bias. The meta-analysis was registered in PROSPERO (ID CRD42019138668). Six studies that included a total of 2360 women affected by endometriosis were analysed. The pooled results showed that the risk of developing endometriosis in adult life was significantly increased by being born prematurely (logRR 0.21, 95% CI -0.03 to 0.40), having a low birthweight (logRR 0.35, 95% CI -0.15 to 0.54), being formula-fed (logRR 0.65, 95% CI -0.35 to 0.95) and having been exposed to diethylstilbestrol (DES) in utero (logRR 0.65, 95% CI 0.26 to 1.04. Among intrauterine and early neonatal exposures, prematurity, birthweight, formula feeding and DES were risk factors for the development of endometriosis in adult life.

Postnatal genistein administration selectively abolishes sexual dimorphism in specific hypothalamic dopaminergic system in mice

As demonstrated in previous studies, early postnatal genistein (GEN) administration to mice pups of both sexes, at doses similar to that of infant soy-based formulas, may affect the development of some steroid-sensitive neuronal circuits (i.e. nitrergic and vasopressinergic systems), causing irreversible alterations in adults. Here, we investigated the hypothalamic and mesencephalic dopaminergic system (identified with tyrosine hydroxylase immunohistochemistry). GEN administration (50 mg/kg) to mice of both sexes during the first week of postnatal life specifically affected tyrosine hydroxylase immunohistochemistry in the hypothalamic subpopulation of neurons, abolishing their sexual dimorphism. On the contrary, we did not observe any effects in the mesencephalic groups. Due to the large involvement of dopamine in circuits controlling rodent sexual behavior and food intake, these results clearly indicate that the early postnatal administration of GEN may irreversibly alter the control of reproduction, of energetic metabolism, and other behaviors. These results suggest the need for a careful evaluation of the use of soy products in both human and animal newborns.

Size at birth, infant growth, and age at pubertal development in boys and girls

Purpose

This study investigated whether size at birth and infant growth were associated with age of indicators of pubertal development in boys and girls. We hypothesized that restricted fetal growth and accelerated infant growth lead to earlier pubertal age.

Patients and methods

In total, 15,822 boys and girls answered questionnaires half-yearly with information on pubertal development: age at menarche, first ejaculation, voice break, Tanner stages, axillary hair, and acne. Birth weight and gestational age were used to calculate birth weight Z-scores. Changes in infant weight Z-score from 0 to 5, 5 to 12, and 0 to 12 months were estimated. We estimated the mean monthly difference in timing of puberty between children born small-for-gestational age (SGA) and large-for-gestational age (LGA) with children born appropriate-for-gestational age (AGA) as reference. We further investigated whether increasing infant weight Z-scores were associated with age at attaining indicators of pubertal development.

Results

Girls born SGA reached all pubertal markers at an earlier mean age than girls born AGA, as indicated by mean age differences below zero (eg, age at menarche: -2.3 months, 95% CI: -3.4, -1.2), except for breast development. Girls born LGA reached pubertal markers later than girls born AGA (eg, age at menarche: 1.7 months, 95% CI 0.5, 2.9). Boys born SGA and LGA achieved puberty earlier than boys born AGA, though with CIs crossing zero (eg, age at voice break for SGA: -0.7 months, 95% CI -2.1, 0.7 and for LGA: -0.7 months, 95% CI -2.1, 0.8). A 1-unit increase in weight Z-score from 0 to 12 months was associated with a mean age difference of -1.7 to -0.3 months for pubertal development in both sexes.

Conclusion

Small size at birth and rapid infant growth were associated with early pubertal age, most consistent and pronounced in girls.

Early genistein exposure of California mice and effects on the gut microbiota-brain axis

Human offspring encounter high amounts of phytoestrogens, such as genistein (GEN), through maternal diet and soy-based formulas. Such chemicals can exert estrogenic activity and thereby disrupt neurobehavioral programming. Besides inducing direct host effects, GEN might cause gut dysbiosis and alter gut metabolites. To determine whether exposure to GEN affects these parameters, California mice (Peromyscus californicus) dams were placed 2 weeks prior to breeding and throughout gestation and lactation on a diet supplemented with GEN (250 mg/kg feed weight) or AIN93G phytoestrogen-free control diet (AIN). At weaning, offspring socio-communicative behaviors, gut microbiota and metabolite profiles were assayed. Exposure of offspring to GEN-induced sex-dependent changes in gut microbiota and metabolites. GEN exposed females were less likely to investigate a novel female mouse when tested in a three-chamber social test. When isolated, GEN males and females exhibited increased latency to elicit their first call, suggestive of reduced motivation to communicate with other individuals. Correlation analyses revealed interactions between GEN-induced microbiome, metabolome and socio-communicative behaviors. Comparison of GEN males with AIN males revealed the fraction of calls above 20 kHz was associated with daidzein, α-tocopherol, Flexispira spp. and Odoribacter spp. Results suggest early GEN exposure disrupts normal socio-communicative behaviors in California mice, which are otherwise evident in these social rodents. Such effects may be due to GEN disruptions on neural programming but might also be attributed to GEN-induced microbiota shifts and resultant changes in gut metabolites. Findings indicate cause for concern that perinatal exposure to GEN may detrimentally affect the offspring microbiome-gut-brain axis.

Pubertal development after unintended intrauterine exposure to oral contraceptives: a nationwide cohort study

OBJECTIVE

To study the associations between exposure to oral contraceptives before conception and early in pregnancy and pubertal timing in boys and girls.

DESIGN

Population-based cohort study.

SETTING

Not applicable.

PATIENT(S)

Overall, 15,800 children (70%) born during 2000-2003 into the Danish National Birth Cohort were categorized according to maternal use of combined oral contraceptive pills or progestin-only pills reported around gestational week 17: no exposure (reference), exposure 4 months before conception, and exposure in early pregnancy. Children self-assessed pubertal status using Web-based questionnaires from 11 years and biannually throughout puberty.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adjusted mean age differences (months) for attaining individual pubertal milestones and overall pubertal timing. Proportion mediated by prepubertal body mass index.

RESULT(S)

In boys, intrauterine exposure to oral contraceptives showed a tendency toward slightly earlier mean age for voice break (months, -3.8; 95% confidence interval [CI] -6.5, -1.0) and first ejaculation (months, -2.9; 95% CI -5.9, 0.1) and a mean difference of -1.4 months (95% CI -3.3, 0.4) for overall pubertal timing. Girls with intrauterine exposure tended to have slightly earlier age at menarche (months, -1.9; 95% CI -4.0, 0.3) and Tanner breast stages and had a mean difference of -0.9 months (95% CI -2.7, 1.0) for overall pubertal timing. Exposure before conception was not associated with pubertal timing. Prepubertal body mass index did not play a mediating role.

CONCLUSION(S)

This study shows some evidence that intrauterine exposure to oral contraceptives might slightly affect pubertal timing.

The Sex-Gender Effects in the Road to Tailored Botanicals

Phenols are a wide family of phytochemicals that are characterized by large chemical diversity and are considered to bioactive molecules of foods, beverages, and botanicals. Although they have a multitude of biological actions, their beneficial effects are rarely evidenced in clinical research with high scientific rigor. This may occur due to the presence of numerous confounders, such as the modulation of phenol bioavailability, which can be regulated by microbiota, age, sex-gender. Sex-gender is an important determinant of health and well-being, and has an impact on environmental and occupational risks, access to health care, disease prevalence, and treatment outcomes. In addition, xenobiotic responses may be strongly influenced by sex-gender. This review describes how sex–gender differentially influences the activities of phenols also in some critical periods of women life such as pregnancy and lactation, considering also the sex of fetuses and infants. Thus, sex–gender is a variable that must be carefully considered and should be used to propose directions for future research on the road to tailored medicine and nutrition.

Biochemistry and use of soybean isoflavones in functional food development

Soybeans and their food products exist in the market in various forms, ranging from crude oils and bean meals to nutritious products (e.g. soy milk powers). With the availability of technologies for mass production of soy products and for enrichment of soy components (e.g. phospholipids, saponins, isoflavones, oligosaccharides and edible fiber), the nutritional values of soy products have been enhanced remarkably, offering the potential for functional food development. Among different bioactive components in soybeans, one important component is isoflavones, which have been widely exploited for health implications. While there are studies supporting the health benefits of isoflavones, concerns on adverse effects have been raised in the literature. The objective of this article is to review the recent understanding of the biological activities, adverse effects, and use of isoflavones in functional food development.

Environmental Mechanisms of Neurodevelopmental Toxicity

PURPOSE OF REVIEW

With the incidence of neurodevelopmental disorders on the rise, it is imperative to identify and understand the mechanisms by which environmental contaminants can impact the developing brain and heighten risk. Here, we report on recent findings regarding novel mechanisms of developmental neurotoxicity and highlight chemicals of concern, beyond traditionally defined neurotoxicants.

RECENT FINDINGS

The perinatal window represents a critical and extremely vulnerable period of time during which chemical insult can alter the morphological and functional trajectory of the developing brain. Numerous chemical classes have been associated with alterations in neurodevelopment including metals, solvents, pesticides, and, more recently, endocrine-disrupting compounds. Although mechanisms of neurotoxicity have traditionally been identified as pathways leading to neuronal cell death, neuropathology, or severe neural injury, recent research highlights alternative mechanisms that result in more subtle but consequential changes in the brain and behavior. These emerging areas of interest include neuroendocrine and immune disruption, as well as indirect toxicity via actions on other organs such as the gut and placenta. Understanding of the myriad ways in which the developing brain is vulnerable to chemical exposures has grown tremendously over the past decade. Further progress and implementation in risk assessment is critical to reducing risk of neurodevelopmental disorders.

Mother's age at delivery and daughters' risk of preeclampsia

BACKGROUND

Some cardiovascular disease risk factors are associated with both risk of preeclampsia and having been born to a younger or older mother. We examined whether mother's age at delivery predicts a primiparous daughter's risk of preeclampsia.

METHODS

The analysis included 39 803 Sister Study participants (designated as "daughters") born between 1930 and 1974. Using log-binomial regression, we estimated relative risks (RR) of preeclampsia in the first pregnancy ending in birth ("primiparous preeclampsia") associated with mother's age at the daughter's birth. Models included: number of older full and maternal half-siblings, income level growing up, daughter's age at delivery, race/ethnicity, and 5-year birth cohort. We examined self-reported relative weight at age 10 (heavier than peers versus not) as a potential effect measure modifier.

RESULTS

Overall, 6.2% of daughters reported preeclampsia. Compared with those who had been born to 20-24-year old mothers, daughters of teenage mothers had a relative risk of 1.20 (95% confidence interval (CI) 1.01, 1.43) and daughters of mothers ≥25 had a ~10% lower risk. Relative weight at age 10 modified the association, with an inverse association between mother's age at delivery and preeclampsia seen only among daughters with low/normal childhood relative weight. In this subset, results were consistent across strata of daughter's age at menarche and age at first birth.

CONCLUSIONS

These findings, based on self-reported data, require replication. Nevertheless, as women increasingly delay childbearing, they provide some reassurance that having been born to an older mother is not, per se, a risk factor for primiparous preeclampsia.

Association between ESR1 polymorphisms and second to fourth digit ratio in school-aged children in the Hokkaido Study

The ratio of the lengths of the 2nd and 4th digits (2D:4D) is considered an index of prenatal exposure to androgen. Indeed, androgen receptors have been linked to digit length, but estrogen receptors are rarely investigated in this context. Thus, we investigated the association between estrogen receptor 1 (ESR1) genetic polymorphisms and 2D:4D in school-aged children. The 2D:4D ratios were determined using Vernier calipers from photocopies of palms provided by 1800 children aged 7 years who were enrolled in an ongoing prospective cohort study in Hokkaido, Japan. The children were genotyped using cord blood collected at birth for single nucleotide polymorphisms in ESR1, specifically PvuII (T > C, dbSNP: rs2234693), XbaI (A > G, dbSNP: rs9340799), and rs2077647 (A > G). The association between ESR1 polymorphisms and 2D:4D was assessed by multiple linear regression adjusted for potential cofounding factors. Boys with the GG genotype at rs9340799 had a significantly lower 2D:4D in the right hand than boys with the AA/AG genotype (-0.96% lower, 95% confidence interval: -1.68 to -0.24). However, this association was detected only in boys born to non-smoking mothers. No significant differences were found between rs9340799 polymorphisms and 2D:4D among girls. There was also no link between 2D:4D and polymorphisms at rs2234693 and rs2077647. These data suggest that rs9340799 polymorphisms in ESR1 may contribute to digit length and 2D:4D.

Maternal Smoking During Pregnancy and Timing of Puberty in Sons and Daughters: A Population-Based Cohort Study

Because early puberty has been linked to diseases later in life, identification of modifiable causes of early puberty is of interest. We explored the possible associations between maternal smoking during pregnancy and pubertal development in sons and daughters. Between 2012 and 2017, 15,819 children from the Danish National Birth Cohort, born during 2000-2003, provided half-yearly information on puberty from the age of 11 years. We estimated adjusted age differences (in months) at attaining various pubertal milestones, including Tanner stages, per 10 daily cigarettes smoked in the first trimester of gestation. In sons, exposure to smoking in utero was associated with earlier genital development (Tanner 2, -1.3 months, 95% confidence interval (CI): -2.5, 0.0; Tanner 5, -3.7 months, 95% CI: -5.3, -2.0), pubic hair development (Tanner 2, -1.8 months, 95% CI: -2.9, -0.6; Tanner 5, -2.9 months, 95% CI: -4.2, -1.7), and voice break (-2.4 months, 95% CI: -3.6, -1.3). In daughters, maternal smoking was associated with earlier breast development (Tanner 2, -3.4 months, 95% CI: -5.3, -1.5; Tanner 5, -4.7 months, 95% CI: -6.5, -2.9), pubic hair development stages 3-5 (Tanner 5, -2.5 months, 95% CI: -4.1, -1.0), and menarche (-3.1 months, 95% CI: -4.0, -2.3). Fetal exposure to tobacco smoke might advance timing of puberty in boys and girls.

Age at menarche and the future risk of gestational diabetes: a systematic review and dose response meta-analysis

Published studies show an inconsistent association between age at menarche and the subsequent risk of developing gestational diabetes mellitus when pregnant. This systematic review and meta-analysis was performed to clarify any trends in this association in published observational population studies. We searched online databases for relevant studies, entered into them up until June 21st 2017. Five eligible studies were found and a pooled random effects dose response meta-analysis of results from these was conducted. This included coverage of 58,133 pregnancies, from which 3,035 women developed gestational diabetes. There was evidence of a non-linear association between age at menarche and gestational diabetes (overall p = 1.4 × 10^-8; p for non-linearity = 2.4 × 10^-4), along with evidence of relatively low heterogeneity (I² = 25.5%). The largest predicted risk of gestational diabetes was associated with having a low age at menarche; the mean (95% confidence interval) risk relative to that associated with menarche at age 13 years being: 9 years 2.0 (1.6, 2.4), 10 years 1.6 (1.4, 1.9), 11 years 1.3 (1.2, 1.4), 12 years 1.1 (1.1, 1.1), 13 years was the reference, 14 years 1.0 (1.0, 1.0), 15 years 1.1 (0.9, 1.2), 16 years 1.1 (0.9, 1.4). There was evidence of potential publication bias, such that the maximal true relative risk of gestational diabetes, associated with an age at menarche of 9 years, may be closer to 1.6 than 2. Nevertheless, the curvilinear relationship between age at menarche and the future risk of gestational diabetes in pregnancy appears robust.

Association of prenatal and childhood environment smoking exposure with puberty timing: a systematic review and meta-analysis

OBJECTIVES

Mothers who smoke during pregnancy or while their children are small were common in some populations. Epidemiological studies have tried to detect the effect of prenatal tobacco smoke (PTS), and childhood environmental tobacco smoke (ETS) on puberty timing have not shown a consensus results. We aimed to examine current evidence and estimate the associations between PTS or/and ETS and puberty timing.

METHODS

Seven databases were searched from inception to May 2017. All the cohort studies examining the associations between PTS and/or ETS and puberty timing were identified. Two reviewers independently screened all studies, evaluated the quality of eligible studies, and extracted the data. The quality assessment of the eligible cohort studies was based on the Newcastle-Ottawa Scale. Risk ratio (RR), standard mean difference (SMD), and 95% confidence intervals (CIs) were calculated and pooled by CMA (Version 2.0, Biostat, Inc., USA).

RESULTS

Compared with controls, girls with PTS and ETS exposure have an earlier age at menarche (SMD - 0.087, 95% CI 0.174 to - 0.000), and similar results were found in both PTS subgroup (SMD - 0.097, 95% CI - 0.192 to - 0.002) and prospective cohort subgroup (SMD - 0.171, 95% CI - 0.253 to - 0.090). And number of boys with early voice break in PTS group was significantly increasing than non-exposed boys (RR 1.34, 95% CI 1.29 to 1.40).

CONCLUSIONS

PTS exposure possibly decrease age of menarche of girls, and studies on boys were urgent needed. Appropriate and comprehensive outcome measures using unified criteria to classify puberty should be reported in future studies.

Maternal diabetes mellitus and timing of pubertal development in daughters and sons: a nationwide cohort study

OBJECTIVE

To study the association between maternal diabetes and timing of pubertal development in daughters and sons.

DESIGN

Prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 15,822 mother-child pairs included in the Danish National Birth Cohort and the Puberty Cohort with prospectively collected, register-based and self-reported information on maternal diabetes and self-reported information on pubertal development.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adjusted mean monthly difference in age at attaining pubertal milestones in children born of mothers with diabetes compared with children born of mothers without diabetes.

RESULT(S)

A total of 502 children were born of mothers with diabetes during pregnancy. In daughters exposed to gestational diabetes mellitus, we observed advanced onset in all pubertal milestones. The associations were statistically significant with regard to pubic hair Tanner stage 2 (-4.8 months) (95% confidence interval [CI] -7.7, -2.0), pubic hair Tanner stage 3 (-2.2 months) (95 % CI -4.4, 0.0), pubic hair Tanner stage 5 (-6.0 months) (95% CI -10.8, -1.2), and menarche (-2.5 months) (95 % CI -4.9, 0.0). We observed no tendencies between maternal type 1 or type 2 diabetes mellitus and pubertal development in daughters. We observed no associations between maternal diabetes and pubertal development in sons.

CONCLUSION(S)

Our findings suggest that gestational diabetes mellitus may accelerate the pubertal development in daughters. Our results did not support an association between type 1 or type 2 diabetes mellitus and daughters' pubertal development, as well as between any type of maternal diabetes and sons' pubertal development.

A Longitudinal Study of Estrogen-Responsive Tissues and Hormone Concentrations in Infants Fed Soy Formula

PURPOSE

Chemicals with hormonelike activity, such as estrogenic isoflavones, may perturb human development. Infants exclusively fed soy-based formula are highly exposed to isoflavones, but their physiologic responses remain uncharacterized. Estrogen-responsive postnatal development was compared in infants exclusively fed soy formula, cow-milk formula, and breast milk.

METHODS

We enrolled 410 infants born in Philadelphia-area hospitals between 2010 and 2014; 283 were exclusively fed soy formula (n = 102), cow-milk formula (n = 111), or breast milk (n = 70) throughout the study (birth to 28 or 36 weeks for boys and girls, respectively). We repeatedly measured maturation index (MI) in vaginal and urethral epithelial cells using standard cytological methods, uterine volume and breast-bud diameter using ultrasound, and serum estradiol and follicle-stimulating hormone levels. We estimated MI, organ-growth, and hormone trajectories by diet using mixed-effects regression splines.

RESULTS

Maternal demographics did not differ between cow-milk-fed and soy-fed infants but did differ between formula-fed and breastfed infants. Vaginal-cell MI trended higher (P = 0.01) and uterine volume decreased more slowly (P = 0.01) in soy-fed girls compared with cow-milk-fed girls; however, their trajectories of breast-bud diameter and hormone concentrations did not differ. We observed no significant differences between boys fed cow-milk vs soy formula; estradiol was not detectable. Breastfed infants differed from soy-formula-fed infants in vaginal-cell MI, uterine volume, and girls' estradiol and boys' breast-bud diameter trajectories.

CONCLUSIONS

Relative to girls fed cow-milk formula, those fed soy formula demonstrated tissue- and organ-level developmental trajectories consistent with response to exogenous estrogen exposure. Studies are needed to further evaluate the effects of soy on child development.

Prenatal Dexamethasone Exposure Induced Ovarian Developmental Toxicity and Transgenerational Effect in Rat Offspring

Prenatal dexamethasone exposure (PDE) induces multiorgan developmental toxicities in offspring. Here we verified the transgenerational inheritance effect of ovarian developmental toxicity by PDE and explored its intrauterine programming mechanism. Pregnant rats subcutaneously received 0.2 mg/kg/d dexamethasone from gestational day (GD) 9 to GD20. A subgroup was euthanized for fetuses on GD20, and the other group went on to spontaneous labor to produce F1 offspring. The adult F1 females were mated with normal males to produce the F2 and F3 generations. The PDE fetal rats exhibited ovarian mitochondrial structural abnormalities, decreased serum estradiol (E2) levels, and lower expression levels of ovarian steroidogenic factor 1 (SF1), steroidal synthetases, and insulinlike growth factor 1 (IGF1). On postnatal week (PW) 6 and PW12, the PDE F1 offspring showed altered reproductive behavior and ovarian morphology. The serum E2 level and ovarian expression of SF1, steroidal synthetases, and IGF1 were also decreased. The adult F3 offspring showed alterations in reproductive phenotype and ovarian IGF1, SF1, and steroidal synthetase expression similar to those of F1. PDE induces ovarian developmental toxicity and transgenerational inheritance effects. The mechanism by which this toxicity occurs may be related to PDE-induced low-functional programming of fetal ovarian IGF1/SF1 and steroidal synthetases.

Communicating with Daughters About Familial Risk of Breast Cancer: Individual, Family, and Provider Influences on Women's Knowledge of Cancer Risk

INTRODUCTION

Women facing complex and uncertain situations such as cancer in their families may seek information from a variety of sources to gain knowledge about cancer risk and reduce uncertainty. We describe and assess the relative importance of information sources about familial breast cancer at the individual, family, and healthcare provider levels influencing women's reporting they had enough information to speak with daughters about breast cancer. This outcome we refer to as being informed about breast cancer.

MATERIALS AND METHODS

Sister Study participants, a cohort of women with a family history of breast cancer, were surveyed on family cancer history, family communication, social support, and interactions with healthcare providers (n = 11,766). Adjusted percentages and 95% confidence intervals for being informed about breast cancer versus not being informed were computed for individual-, family-, and provider-level characteristics in three steps using multivariate logistic regression models.

RESULTS

We found 65% of women reported being informed about breast cancer while 35% did not. Having a trusted person with whom to discuss cancer concerns, having a lower versus higher perceived risk of breast cancer, having undergone genetic counseling, and being satisfied with physician discussions about breast cancer in their families were predictors of being informed about breast cancer.

CONCLUSIONS

Although acquiring objective risk information, such as through genetic counseling, may contribute to a basic level of understanding, communication with providers and within other trusted relationships appears to be an essential component in women's reporting they had all the information they need to talk with their daughters about breast cancer.

Preterm birth and the timing of puberty: a systematic review

BACKGROUND

An estimated 11% of births occur preterm, and survival is improving. Early studies suggested an association between preterm birth and earlier puberty. Given the adverse outcomes associated with early puberty this could have significant public health implications. The objective of this review was to assess the timing of puberty after preterm birth.

METHODS

Pubmed, Embase, Popline, Global Health and Global Health Library were searched using terms relating to "premature birth", "menarche", "puberty" and "follow up studies". Inclusion criteria were a population consisting of pubertal or post-pubertal adolescents and adults; studies which defined preterm delivery in participants and compared outcomes to those after term delivery; and a quantitative assessment of pubertal onset. Assessment of risk of bias was conducted using principles from the Critical Appraisal Study Process.

RESULTS

Our search identified 1051 studies, of which 16 met the inclusion criteria. In females, 8 studies found no association between preterm birth and the timing of menarche. Five studies found earlier onset in preterm infants, 1 found later onset, and 1 showed both earlier and later menarche, depending on birth weight. The range of effect of studies showing earlier menarche was - 0.94 to -0.07 years in the preterm group, with a median of - 0.3 years. In males, 2 studies showed earlier onset of puberty in the preterm group, 5 showed no difference, and 1 showed later onset. Most studies did not present outcomes in the form of a mean with standard deviation, precluding a meta-analysis. There was insufficient data to address potential confounding factors.

CONCLUSIONS

The published evidence does not suggest that being born preterm leads to a significant acceleration in the onset of puberty. This should prove reassuring for public health purposes, and for clinicians counseling parents of infants born preterm.

Birth weight, early life weight gain and age at menarche: a systematic review of longitudinal studies

BACKGROUND AND OBJECTIVE

Adiposity in pre- and postnatal life may influence menarcheal age. Existing evidence is primarily cross-sectional, failing to address temporality, for which the role of adiposity in early life remains unclear. The current study sought to systematically review longitudinal studies evaluating the associations between birth weight and infant/childhood weight status/weight gain in relation to menarcheal age.

METHODS

PubMed, EMBASE, Web of Science, Global Health (Ovid) and CINAHL were systematically searched. Selected studies were limited to English-language articles presenting multi-variable analyses. Seventeen studies reporting risk estimates for birth weight (n = 3), infant/childhood weight gain/weight status (n = 4) or both (n = 10), in relation to menarcheal age were included.

RESULTS

Lower vs. higher birth weight was associated with earlier menarche in nine studies and later menarche in one study, while three studies reported a null association. Greater BMI or weight gain over time and greater childhood weight were significantly associated with earlier menarche in nine of nine and six of seven studies, respectively.

CONCLUSIONS

Studies suggested that lower birth weight and higher body weight and weight gain in infancy and childhood may increase the risk of early menarche. The pre- and postnatal period may thus be an opportune time for weight control interventions to prevent early menarche, and its subsequent consequences.