Birthweight Difference (birthweight + difference)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Estimating treatment effects in randomized clinical trials with non-compliance: the impact of maternal smoking on birthweight

HEALTH ECONOMICS, Issue 5 2001
Barton H. Hamilton
Abstract This paper assesses the causal impact of late-term (8th month) maternal smoking on birthweight using data from a randomized clinical trial, in which some women were encouraged not to smoke, while others were not. The estimation of treatment effects in this case is made difficult as a result of the presence of non-compliers, women who would not change their smoking status, regardless of the receipt of encouragement. Because these women are not at risk of changing treatment status, treatment effect distributions may be difficult to construct for them. Consequently, the paper focuses on obtaining the distribution of treatment impacts for the sub-set of compliers found in the data. Because compliance status is not observed for all subjects in the sample, a Bayesian finite mixture model is estimated that recovers the treatment effect parameters of interest. The complier average treatment effect implies that smokers give birth to infants weighing 348 g less than those of non-smokers, on average, although the 95% posterior density interval contains zero. The treatment effect is stronger for women who were moderate smokers prior to pregnancy, implying a birthweight difference of 430 g. However, the model predicts that only about 22% of the women in the sample were at risk of changing their smoking behaviour in response to encouragement to quit. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Does birthweight difference predict success/failure of vaginal birth after cesarean section attempts?

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 4 2001
E Paré
No abstract is available for this article. [source]

Selected neonatal outcomes in dizygotic twins after IVF versus non-IVF pregnancies

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2010
B Källén
Please cite this paper as: Källén B, Finnström O, Lindam A, Nilsson E, Nygren K-G, Otterblad Olausson P. Selected neonatal outcomes in dizygotic twins after IVF versus non-IVF pregnancies. BJOG 2010; Objective, To compare neonatal outcome among twins conceived after in vitro fertilisation (IVF) with that of spontaneously conceived twins. Design, Comparison of different-sex (dizygotic) twins born after IVF with non-IVF dizygotic twins. Setting, National health registers in Sweden. Population, All births in Sweden during the period 1982,2007. Methods, We studied gestational duration, lowest birthweight and birthweight difference in the twin pair, presence of one or two twins with a respiratory complication, and with jaundice in one or both twins. Risk estimates were calculated as odds ratios with adjustments for year of birth, maternal age, parity and smoking in pregnancy. Main outcome measures, Gestational duration, birth weight, respiratory complications, jaundice. Results, We studied 1545 pairs of dizygotic twins born after IVF, and 8675 pairs of dizygotic twins where IVF was not known to have occurred. The risk for preterm delivery before 32 weeks of gestation was significantly increased among dizygotic twin pairs born after IVF compared with non-IVF dizygotic twin pairs. No significant difference in low birthweight or birthweight difference within twin pairs was seen. There was an increased occurrence of twin pairs with respiratory problems or jaundice, but only the latter diagnosis occurred in a statistically significant excess. Conclusions, The study confirms recent findings that IVF is associated with an increased risk for some neonatal complications, not only among singletons but also among twins. [source]

Explaining differences in birthweight between ethnic populations.

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2007
The Generation R Study
Objective, To examine whether differences in birthweight of various ethnic groups residing in the Netherlands can be explained by determinants of birthweight. Design, Population-based birth cohort study. Setting, Data of pregnant women and their partners in Rotterdam, the Netherlands. Population, We examined data of 6044 pregnant women with a Dutch, Moroccan, Turkish, Capeverdean, Antillean, Surinamese-Creole, Surinamese-Hindustani and Surinamese-other ethnic background. Methods, Regression analyses were used to assess the impact of biomedical, socio-demographic and lifestyle-related determinants on birthweight differences. Main outcome measure, Birthweight was established immediately after delivery in grams. Results, Compared with mean birthweight of offspring of Dutch women (3485 g, SD 555), the mean birthweight was lower in all non-Dutch populations, except in Moroccans. Differences ranged from an 88-g lower birthweight in offspring of the Turkish women to a 424-g lower birthweight in offspring of Surinamese-Hindustani women. Differences in gestational age, maternal and paternal height largely explained the lower birthweight in the Turkish, Antillean, Surinamese-Creole and Surinamese-other populations. Differences in birthweight between the Dutch and the Capeverdean and Surinamese-Hindustani populations could only partly be explained by the studied determinants. Conclusions, These results confirm significant differences in birthweight between ethnic populations that can only partly be understood from established determinants of birthweight. The part that is understood points to the importance of determinants that cannot easily be modified, such as parental height. Further study is necessary to obtain a fuller understanding. [source]