Placental weight and placental ratio as predictors of later blood pressure in childhood

Associations of prenatal heavy metals exposure with placental characteristics and birth weight in Hangzhou Birth Cohort: Multi-pollutant models based on elastic net regression

BACKGROUND

The human placenta is vulnerable to environmental pollutants, but the associations between exposure to multiple, correlated metals and placental characteristics have not been studied.

METHODS

The current study population was derived from the Hangzhou Birth Cohort Study. Whole blood and urine samples were collected from mothers during 20-28 gestational week. The concentrations of 11 metals in blood and 11 metals in urine were evaluated by inductively coupled plasma mass spectrometry. The data on placental characteristics and birth weight were retrieved from medical records. The elastic net (ENET) model combined with unpenalized regression model was employed to estimate the relationship between levels of metals and placental characteristics (placental weight, chorionic disc area, chorionic disc eccentricity, placental thickness, placental-fetal birth weight ratio) and birth weight. Mediation analysis was performed to explore the mediated effect of placenta on the association of prenatal metals exposure with birth weight.

RESULTS

Among 512 participants with urine metal levels, the ENET model retained Cadmium (Cd) and Selenium (Se) for placental weight. Further unpenalized regression model including Cd and Se simultaneously showed that one-unite increased natural-logarithm (ln)-transformed urine creatinine corrected (CC) Cd levels was associated with reductions in placental weight of -7.2 g (95% confidence interval (CI): -14.0, -0.4). Among 483 participants with blood metal levels, similarly, blood Cd levels were negatively associated with placental weight (β = -7.5, 95% CI: -17.0, 1.9). Furthermore, mediation analysis demonstrated that urine CC-Cd level was associated with a 21.3 g decrease (95% CI: -42.0, -2.5, p = 0.024) in birth weight through a reduction in placental weight, while blood Cd levels presented a negative association at borderline significance.

CONCLUSION

Our findings suggest a mediation effect of the placenta in the relationship between prenatal Cd exposure and lower birth weight. Additional studies with repeated assessment of exposure and more placental parameters are warranted to confirm this relationship.

The fetal/placental weight ratio is associated with the incidence of atopic dermatitis in female infants during the first 14 months: The Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

Background

Among atopic diseases, atopic dermatitis is the most common allergic disease in children and influences both infantile and parental quality of life.

Objective

The present study investigated the sex-specific relationship between the fetal/placental weight ratio and The incidence of atopic dermatitis in infants during the first 14 months of life.

Methods

Study participants were 922 infants (462 female and 460 male) from singleton pregnancies enrolled in the Hamamatsu Birth Cohort for Mothers and Children (HBC Study) after the exclusion of 298 with missing data on atopic dermatitis. The enrollment of infants with atopic dermatitis was based on a positive response from parents regarding whether a physician had ever diagnosed their child with atopic dermatitis by 14 months of age. The two-sample Wilcoxon rank-sum test or χ² test was adopted for descriptive analyses where appropriate. Unadjusted odds ratios and 95% confidence intervals for the infantile incidence of atopic dermatitis were compared using logistic regression analyses.

Results

Maternal and perinatal factors did not correlate with the incidence of infantile atopic dermatitis. Fetal/placental weight ratio, but not birth or placental weight, correlated with the incidence of atopic dermatitis in female, but not male, infants. A correlation was still observed after adjustments for maternal allergies, gestational age at birth, maternal smoking during pregnancy, and household income at birth (odds ratio: 1.57; 95% confidence interval, 1.05-2.33).

Conclusion

We speculated that the intrauterine fetal environment, represented by a relatively small placenta, programs a predisposition in only female infants to atopic dermatitis during the first 14 months of life.

Changes in maternal hemoglobin during pregnancy and birth outcomes

Background

The relationship between maternal hemoglobin (Hb) levels during pregnancy and birth outcomes has been controversial. Changes in Hb level during pregnancy may have an impact on birth outcomes. This study aimed to investigate whether changes in Hb levels from early to mid- or late pregnancy is associated with birth outcomes.

Methods

Participants were singleton mothers who delivered at the National Center for Child Health and Development between 34 and 41 weeks of gestation in 2010 and 2011 (n = 1,986). Hb levels were measured at three time points: early (<16 weeks), mid- (16–27 weeks), and late (28–36 weeks) pregnancy. Associations between changes in Hb levels from early to mid- or late pregnancy and birth outcomes (birth weight, Z-score of birth weight, placental weight, and placental ratio) were assessed by multiple regression, adjusting for maternal and fetal covariates.

Results

A smaller reduction in Hb levels from early to mid- or late pregnancy was significantly associated with lower birth weight, Z-score of birth weight, placental weight, and placental ratio. Compared to women with an intermediate reduction from early to late pregnancy, women with the least reduction had a significantly increased risk of delivering low birth weight (LBW) (adjusted odds ratio [aOR], 2.0; 95% confidence interval [CI], 1.3-3.1) and small-for-gestational-age (SGA) (aOR, 1.6; 95% CI, 1.04-2.3) infants, while women with the greatest reduction had a significantly decreased risk of delivering SGA (aOR, 0.38; 95% CI, 0.23-0.65) infants, but an increased risk of high placental ratio (aOR, 1.7; 95% CI, 1.2-2.5).

Conclusions

Hb changes from early to mid- or late pregnancy were inversely associated with birth weight, placental weight, and placental ratio.

Placental morphometry determines the birth weight

BACKGROUND

Placental morphometry determines the foetal development and adulthood disease pattern. Hence, in the present study the influence of placental weight, volume, surface area, and thickness were studied in different groups of birth weight by sex of the newborn.

MATERIAL AND METHODS

Present study was conducted on 164 consecutive singleton deliveries from a teaching hospital of Northern Karnataka, India. Multivariate linear regression models were constructed by maximum likelihood method after checking the linearity. The sensitivity, specificity and predictive values of regression models were computed to exhibit their utility for physicians.

RESULTS

Gestational age exhibited positive relationship with birth weight. Placental parameters showed a positive and significant relationship (p<0.001) with birth weight and higher values in males. The birth weight was estimated by regression models using sex of the newborn and placental morphometry; weight (R(2)=0.474), surface area (R(2)=0.420), and volume (R(2)=0.477) at 95% confidence interval. Low birth weight babies in the study were correctly identified by placental weight, surface area, volume and sex of the newborn. Their sensitivity, specificity and predictive values have been specified.

CONCLUSION

Placental morphometry: weight, surface area, volume and sex of the baby determined the birth weight efficiently to initiate the corrective measures for planning better maternal care and to pacify mothers and their relatives.

Placental morphologic features and chorionic surface vasculature at term are highly correlated with 3-dimensional sonographic measurements at 11 to 14 weeks

OBJECTIVES

The purpose of this study was to examine the potential for 3-dimensional sonographic measurement of the early placenta in predicting ultimate placental morphologic features at delivery.

METHODS

In this prospective cohort study, we collected 3-dimensional sonographic volume sets of placentas at 11 to 14 weeks and then collected the placentas after delivery. The sonographic data were manipulated to obtain various novel measurements of early gross placental morphologic features and the umbilical cord insertion location. The placental weight, chorionic plate area, cord location, and mean chorionic vascular density were obtained from the delivered postpartum placentas. Analyses were performed to identify potential early placental characteristics that were correlated with the ultimate placental morphologic features. The placental weight, cord marginality, and mean chorionic vascular density served as the outcome measures of interest.

RESULTS

Measurements of the early placental volume correlated with the delivered placental weight. An irregular early placental shape, as measured by sonography, was significantly inversely correlated with placental weight (P < .05). The placental morphologic index, a measure of a flatter placenta, was inversely correlated with both the placental weight and chorionic plate area, possibly indicating the importance of placental thickness even in the first trimester before villous arborization. In addition, early sonographic measures of the location of the umbilical cord insertion were significantly correlated with the ultimate marginality of the cord insertion as well as the mean chorionic vascular density (P < .05).

CONCLUSIONS

Many important ultimate placental morphologic features are likely predetermined early in pregnancy. Three-dimensional sonography may play an increasing role in the in utero evaluation of the early placenta.

The association between intrauterine growth restriction in the full-term infant and high blood pressure at age 7 years: results from the Collaborative Perinatal Project

OBJECTIVE

To use neonatal and placental anthropometry as proxy measures of intrauterine growth restriction (IUGR) and to relate these to blood pressure later in childhood.

STUDY DESIGN

A post hoc analysis of full-term white and black children from the Collaborative Perinatal Project, followed from birth until age 7 years (n = 29,710). Blood pressure above the 90th percentile by gender and race was considered high blood pressure. Anthropometric measures at birth included birth weight, ponderal index (PI, birth weight/birth length(3)), head to chest circumference (HCC) ratio, and placental ratio percentage (PRP, placental weight(*)100/birth weight).

RESULTS

Among anthropometric measures, PI, HCC, and birth weight were not associated with high systolic blood pressure at age 7 years, but PRP was. In multiple logistic regression, high systolic blood pressure and widened pulse pressure were both predicted by increased PRP [odds ratio (OR) 1.03 and 1.04, P < 0.001] but not by birth weight, when adjusted for gender, race, and maternal education. High diastolic blood pressure was weakly predicted by birth weight (OR 1.10, P = 0.05) but not by PRP.

CONCLUSIONS

PRP is associated with an increased risk for high systolic blood pressure and pulse pressure later in childhood, whereas birth weight, PI, and HCC are not. The proportion of placental weight to birth weight is a useful marker of IUGR for studying the developmental origins of adult disease hypothesis.

Maternal protein intake is not associated with infant blood pressure

BACKGROUND

Animal data show that low protein intake in pregnancy programs higher offspring blood pressure, but similar data in humans are limited. We examined the associations of first and second trimester maternal protein intake with offspring blood pressure (BP) at the age of six months.

METHODS

In a prospective US cohort study, called Project Viva, pregnant women completed validated semi-quantitative food-frequency questionnaires (FFQ) to measure gestational protein intake. Among 947 mother-offspring pairs with first trimester dietary data and 910 pairs with second trimester data, we measured systolic blood pressure (SBP) up to five times with an automated device in the offspring at the age of six months. Controlling for blood pressure measurement conditions, maternal and infant characteristics, we examined the effect of energy-adjusted maternal protein intake on infant SBP using multivariable mixed effects models.

RESULTS

Mean daily second trimester maternal protein intake was 17.6% of energy (mean 2111 kcal/day). First trimester nutrient intakes were similar. Mean SBP at age 6 months was 90.0 mm Hg (SD 12.9). Consistent with prior reports, adjusted SBP was 1.94 mm Hg lower [95% confidence interval (CI) -3.45 to -0.42] for each kg increase in birth weight. However, we did not find an association between maternal protein intake and infant SBP. After adjusting for covariates, the effect estimates were 0.14 mm Hg (95% CI 20.12 to 20.40) for a 1% increase in energy from protein during the second trimester, and 20.01 mm Hg (95% CI 20.24 to -0.23) for a 1% increase in energy from protein in the first trimester.

CONCLUSIONS

Variation in maternal total protein intake during pregnancy does not appear to program offspring blood pressure.

Nutritional intake and placental size in gestational diabetic pregnancies--a preliminary observation

A disproportionately large placenta may represent an adaptive response to adverse intrauterine conditions. Both maternal nutritional intake and presence of gestational diabetes (GDM) have been found to affect relative placental growth. As dietary modification is part of the standard management in GDM women, the observed increase in placental size in these women may be partly due to dietary modification. In this study, we set out to examine the relationship between dietary intake and placental size in GDM pregnancies. Food diaries for five consecutive days for 52 women diagnosed with GDM were obtained to assess their nutritional intake in terms of total calories, carbohydrate, protein and fat. Spearman's correlations were calculated for nutritional intake and various factors that may correlate with placental weight. There was a significant inverse relationship (P=0.021) between placental weight and protein intake. No correlations with the other two nutritional components could be demonstrated. Maternal nutritional intake was not correlated with infant birthweight. It is possible that dietary modulations improve GDM pregnancy outcome, not only by improving glycaemic controls but also by affecting placental growth by altering the proportion of protein intake.

Pediatric hypertension 2001

During the past decade, there has been a surge of interest in childhood and adolescent hypertension. The current review summarizes work published during the past year in the following areas: prenatal and early postnatal causes of hypertension; new information on the genetics of childhood hypertension; the relation of obesity, insulin resistance, and diabetes to hypertension; the use of ambulatory blood pressure monitoring to evaluate childhood hypertension; and advances in drug therapy for children with hypertension. The information obtained during the past year has improved our understanding of the pathogenesis, diagnosis, and treatment of childhood hypertension.