26 research outputs found
Quantile contours and allometric modelling for risk classification of abnormal ratios with an application to asymmetric growth-restriction in preterm infants
We develop an approach to risk classification based on quantile contours and
allometric modelling of multivariate anthropometric measurements. We propose
the definition of allometric direction tangent to the directional quantile
envelope, which divides ratios of measurements into half-spaces. This in turn
provides an operational definition of directional quantile that can be used as
cutoff for risk assessment. We show the application of the proposed approach
using a large dataset from the Vermont Oxford Network containing observations
of birthweight (BW) and head circumference (HC) for more than 150,000 preterm
infants. Our analysis suggests that disproportionately growth-restricted
infants with a larger HC-to-BW ratio are at increased mortality risk as
compared to proportionately growth-restricted infants. The role of maternal
hypertension is also investigated.Comment: 31 pages, 3 figures, 8 table
Maternal serum markers of lipid metabolism in relation to neonatal anthropometry
Objective: The objective of this study is to examine associations between lipids (high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides and lipoprotein (a)) measured on average three time points during pregnancy and neonatal anthropometrics.
Study design: Stored samples from a preeclampsia trial measured as part of a case-control study from five US centers (1992 to 1995) were used. The sample included women without pregnancy complications (n=136) and cases of gestational diabetes (n=93), abnormal glucose tolerance (AGT; n=76), gestational hypertension (n=170) and preeclampsia (n=177). Linear regression and linear mixed-effects models estimated adjusted associations between lipids and birth weight z-score, ponderal index (PI), length and head circumference.
Results: Among women without complications, cross-sectional associations between total cholesterol measured at different gestational ages increased PI 2.23 to 2.55 kg m-3 per-unit increase in cholesterol. HDL was inversely associated with birth length (β\u27s=-2.21 and -2.56 cm). For gestational hypertension, triglycerides were associated with birth weight z-score (β\u27s=0.24 to 0.31). For preeclampsia, HDL was associated with lower birth weight z-scores (β\u27s=-0.49 and -0.82). Women with gestational diabetes or AGT had inconsistent associations. Examining the level changes across pregnancy, each 0.0037 mmol l-1 increase in HDL was associated with decreased birth weight z-score (β=-0.22), length (β=-0.24 cm) and head circumference (β=-0.24 cm), whereas each 0.028 mmol l-1 increase in triglycerides was associated with increased birth weight z-score (β=0.13) and head circumference (β=0.19 cm).
Conclusions: Although associations varied by complications, in general, growth-promoting fuels such as total cholesterol and triglycerides were associated with increased neonatal size, whereas high HDL was associated with smaller size. Maternal HDL that failed to decrease over pregnancy was associated with smaller neonate size
Developmental Origins of Cardiovascular Disease
Although cardiovascular disease has traditionally been viewed as a condition of aging individuals, increasing focus has turned to its developmental origins. Since birthweight has been related to cardiovascular disease risk, research into factors such as gravid conditions that affect fetal growth have grown. Associations between maternal diabetes and childhood obesity from sibling studies suggest a causal role but prospective studies of gestational diabetes remain mixed. Preeclampsia and increased offspring blood pressure has been consistently observed but evidence for other cardiovascular outcomes is lacking. While maternal obesity is associated with childhood obesity, causality remains unclear and paternal obesity should be investigated as an independent risk factor. Environmental chemical exposures in utero, particularly obesogens, are now emerging as another concern, as is conception by infertility treatment. Few studies have investigated subclinical measures of endothelial function or atherosclerosis and more research in these areas may help reveal the underlying pathogenesis
Small for gestational age: Case definition & guidelines for data collection, analysis, and presentation of maternal immunisation safety data
Chorioamnionitis: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data
Chorioamnionitis is a term encompassing a broad spectrum of
disease during pregnancy that is characterized by inflammation
and/or infection of intrauterine structures such as the placenta,
the chorion and amnion. The clinical presentation
of chorioamnionitis can vary based on clinical, microbiologic, and
histologic factors which interact and overlap to varying degrees