Objective The objective of this study was to critically examine potential artifacts and biases underlying the use of ‘customised’ standards of birthweight for gestational age (GA).
Design ...Population‐based cohort study.
Setting Sweden.
Population A total of 782 303 singletons ≥28 weeks of gestation born in 1992–2001 to Nordic mothers with complete data on birthweight; GA; and maternal age, parity, height, and pre‐pregnancy weight.
Methods We compared perinatal mortality in four groups of infants based on the following classification of small for gestational age (SGA): non‐SGA based on either population‐based or customised standards (the reference group), SGA based on the population‐based standard only, SGA based on the customised standard only, and SGA according to both standards. We used graphical methods to compare GA‐specific birthweight cutoffs for SGA using the two standards and also used logistic regression to control for differences in GA and maternal pre‐pregnancy body mass index (BMI) in the four groups.
Main outcome measures Perinatal mortality, including stillbirth and neonatal death.
Results Customisation led to a large artifactual increase in the proportion of SGA infants born preterm. Adjustment for differences in GA and maternal BMI markedly reduced the excess risk among infants classified as SGA by customised standards only.
Conclusion The large increase in perinatal mortality risk among infants classified as SGA based on customised standards is largely an artifact due to inclusion of more preterm births.
The efficacy and safety of a selective NK(1) antagonist, L-759274, was investigated in outpatients with diagnosis of major depressive disorder with melancholic features, following evidence obtained ...with the novel compound aprepitant that Substance P (NK(1)) antagonists may provide a unique mechanism of antidepressant activity. A randomized, double-blind placebo-controlled study was carried out. Patients, male or female, aged 18-60, scoring >/=25 points on total of first 17 items of 21-item Hamilton Depression Scale (HAMD), and scoring >/=4 (moderately ill) on Clinical Global Impressions-Severity Scale were randomized to oral L-759274 40 mg daily (n=66) or placebo (n=62) for 6 weeks. For patients receiving L-759274, improvement (mean decrease from baseline) in HAMD-17 total score was 10.7 points, compared with a mean 7.8 point improvement in patients receiving placebo (p<0.009). Mean scores for item 1 of HAMD-17 (depressed mood) also improved to a greater extent in the active group compared with the placebo group (0.3 points, p<0.058). Compared with placebo, mean scores on Clinical Global Impressions-Improvement Scale improved significantly by the end of the trial (p=0.009). L-759274 was generally safe and well-tolerated. The incidence of sexual side effects was on par with that observed in patients receiving placebo, and the incidences of gastrointestinal effects were low. Antidepressant actions have now been observed with two different highly selective NK(1) antagonists (aprepitant and L-759274). NK(1) antagonism is a replicated and generally well-tolerated antidepressant mechanism.
Studies have found associations between low birth weight and increased risks of cardiovascular diseases in adulthood. However, these associations could be due to confounding by genetic or ...socioeconomic factors.
We performed a study on Swedish like-sexed twins with known zygosity who were born from 1926 to 1958. First, to obtain an overall effect of birth weight on risk of hypertension, we performed cohort analyses on all twins (n=16,265). Second, to address genetic and shared environmental confounding, we performed a nested co-twin control analysis within 594 dizygotic and 250 monozygotic twin pairs discordant for hypertension. Birth characteristics, including birth weight, were obtained from original birth records. Information from adulthood was collected from a postal questionnaire in 1973 (body mass index, height, smoking, and alcohol use) and from a telephone interview conducted from 1998 to 2002 (hypertension and socioeconomic status). Hypertension was defined as reporting both high blood pressure and treatment with antihypertensive medication. In the cohort analysis, the adjusted odds ratio for hypertension in relation to a 500-g decrease in birth weight was 1.42 (95% confidence interval, 1.25 to 1.61). In the co-twin control analyses, the corresponding odds ratios were 1.34 (95% confidence interval, 1.07 to 1.69) for dizygotic and 1.74 (95% confidence interval, 1.13 to 2.70) for monozygotic twins.
In the largest twin study on the fetal origins of hypertension, we found that decreased birth weight is associated with increased risk of hypertension independently of genetic factors, shared familial environment, and risk factors for hypertension in adulthood, including body mass index.
Background: Opinions and recommendations about the optimal duration of exclusive breastfeeding have been strongly divided, but few published studies have provided direct evidence on the relative ...risks and benefits of different breastfeeding durations in recipient infants. Objective: We examined the effects on infant growth and health of 3 compared with 6 mo of exclusive breastfeeding. Design: We conducted an observational cohort study nested within a large randomized trial in Belarus by comparing 2862 infants exclusively breastfed for 3 mo (with continued mixed breastfeeding through greater than 6 mo) with 621 infants who were exclusively breastfed for greater than 6 mo. Regression to the mean, within-cluster correlation, and cluster- and individual-level confounding variables were accounted for by using multilevel regression analyses. Results: From 3 to 6 mo, weight gain was slightly greater in the 3-mo group difference: 29 g/mo (95% CI: 13, 45 g/mo), as was length gain difference: 1.1 mm (0.5, 1.6 mm), but the 6-mo group had a faster length gain from 9 to 12 mo difference: 0.9 mm/mo (0.3, 1.5 mm/mo) and a larger head circumference at 12 mo difference: 0.19 cm (0.07, 0.31 cm). A significant reduction in the incidence density of gastrointestinal infection was observed during the period from 3 to 6 mo in the 6-mo group adjusted incidence density ratio: 0.35 (0.13, 0.96), but no significant differences in risk of respiratory infectious outcomes or atopic eczema were apparent. Conclusions: Exclusive breastfeeding for 6 mo is associated with a lower risk of gastrointestinal infection and no demonstrable adverse health effects in the first year of life.
To determine whether cesarean and operative vaginal deliveries are associated with an increased risk of maternal rehospitalization compared with spontaneous vaginal delivery.
A population-based ...cohort study was conducted by using the Canadian Institute for Health Information's Discharge Abstract Database between 1997/1998 and 2000/2001, which included 900,108 women aged 15-44 years with singleton live births (after excluding several selected obstetric conditions).
A total of 16,404 women (1.8%) were rehospitalized within 60 days after initial discharge. Compared with spontaneous vaginal delivery (rate 1.5%), cesarean delivery was associated with a significantly increased risk of postpartum readmission (rate 2.7%, odds ratio OR 1.9, 95% confidence interval CI 1.8-1.9); ie, there was 1 excess postpartum readmission per 75 cesarean deliveries. Diagnoses associated with significantly increased risks of readmission after cesarean delivery (compared with spontaneous vaginal delivery) included pelvic injury/wounds (rate 0.86% versus 0.06%, OR 13.4, 95% CI 12.0-15.0), obstetric complications (rate 0.23% versus 0.08%, OR 3.0, 95% CI 2.6-3.5), venous disorders and thromboembolism (rate 0.07% versus 0.03%, OR 2.7, 95% CI 2.1-3.4), and major puerperal infection (rate 0.45% versus 0.27%, OR 1.8, 95% CI 1.6-1.9). Women delivered by forceps or vacuum were also at an increased risk of readmission (rates 2.2% and 1.8% versus 1.5%; OR forceps: 1.4, 95% CI 1.3-1.5; OR vacuum: 1.2, 95% CI 1.2-1.3, respectively). Higher readmission rates after operative vaginal delivery were due to pelvic injury/wounds, genitourinary conditions, obstetric complications, postpartum hemorrhage, and major puerperal infection.
Compared with spontaneous vaginal delivery, cesarean delivery, and operative vaginal delivery increase the risk of maternal postpartum readmission.
II-2.
We studied the effects of twins and triplets on perinatal health indicators in the overall population in the 1980s and 1990s in Canada, England and Wales, France, and the United States.
Data were ...derived mostly from live birth registration. We used rates, relative risks, and population attributable risks for twins and triplets separately.
In each country, the increase in multiple births, and the increase in preterm delivery among multiple births, contributed almost equally to the rise in or stabilization of the overall rates of preterm delivery. Twins contributed a much larger proportion of the preterm deliveries and low-birthweight newborns than did triplets.
Twins have a major population-based impact on the trends of perinatal health indicators.
Background Although increased morbidity and mortality associated with pre-term birth and restricted fetal growth have been extensively studied, relatively little is known about variations in health ...outcomes among term births, because they are often assumed to be homogeneous. Methods We examined variations in height, body mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), and intellectual performance by gestational age and fetal ‘growth’ (birth weight for gestational age) among young Swedish men born at term (37–41 weeks of gestation). We also compared the magnitude of associations among 314 642 men from different families and among 72 212 full brothers from 35 215 families to assess whether the associations are explained by familial factors shared by siblings. Results Gestational age in completed weeks was positively associated with height 0.11 cm, 95% confidence interval (CI): 0.09–0.13 and intellectual performance (0.01, 95% CI: 0.00–0.02) and negatively associated with SBP (−0.28 mmHg, 95% CI: −0.33 to −0.24), after controlling for birth weight, maternal age at the men’s birth, parity, family socio-economic position and family structure. The associations with height and SBP were observed also among brothers within families, suggesting that they are not explained by shared family characteristics. However, the positive association between gestational age and intellectual performance was no longer present within families. Birth weight for gestational age (z-score) was positively associated with height, BMI and intellectual performance and negatively associated with SBP. These associations were robust within families. Conclusions Among young men born at term, fetal growth and even gestational age are independently associated with adult size, BP and cognitive ability. The extent to which shared family characteristics explain the associations varies across outcomes.
Objectives: To describe temporal trends in fetal “growth” and to examine the roles of sociodemographic, anthropometric, and other determinants. Study design: Hospital-based cohort study of 61,437 ...nonmalformed singleton live births at 22 to 43 weeks' gestational age. Four main measures were examined: (1) birth weight, (2) birth weight-for-gestational-age Z score, (3) small-for-gestational-age (SGA), and (4) large-for-gestational age (LGA), with the latter 3 measures based on a recently developed population-based Canadian reference. Gestational age was based on the last normal menstrual period if confirmed (± 1 week) by early ultrasonogram. Results: The mean birth weight and Z score increased significantly (P <.0001) among infants ≥37 weeks, with a corresponding reduction in % SGA and a rise in % LGA. No consistent trends were seen among births 34 to 36 or ≤33 weeks. When simultaneous changes in maternal prepregnancy body mass index, gestational weight gain, height, cigarette smoking, and other clinical and sociodemographic factors were controlled by using multiple logistic regression, the temporal trends for term infants were no longer evident. Conclusions: Increases in maternal anthropometry, reduced cigarette smoking, and changes in sociodemographic factors have led to an increase in the weight of infants born at or after term. (J Pediatr 2002;141:538-42)
Since the midtwentieth century, stillbirths (late fetal deaths) and early neonatal deaths have often been combined into a single category of “perinatal” deaths. In the past, such a combination was ...justified by the fact that asphyxia was a common cause of death during labor (intrapartum stillbirth) and shortly after birth and by geographic and temporal differences in classification of livebirths versus stillbirths. In more recent years, however, the etiologic determinants have diverged sharply, with many fewer early neonatal deaths caused by asphyxia and relatively many more caused by congenital anomalies. Moreover, the increasingly common stratification of pregnancy outcome measures by gestational age or birth weight leads to the use of an inappropriate denominator (total livebirths plus stillbirths within each gestational age or birth weight category) for denoting risk for the stillbirth component, because all unborn fetuses (including the majority of those not born within the specified gestational age or birth weight range) are at risk of being stillborn in that range. The authors suggest that, whenever possible, stillbirths and early neonatal deaths should be reported separately, with gestational age-specific risks of stillbirth based on all fetuses at risk, and that antepartum and intrapartum stillbirths be reported separately.
Feeding effects on growth during infancy Kramer, Michael S.; Guo, Tong; Platt, Robert W. ...
The Journal of pediatrics,
11/2004, Letnik:
145, Številka:
5
Journal Article
Recenzirano
To examine the effects of formula, other milks, other liquids, cereals, and other solid foods on growth during infancy.
Observational cohort study nested within a large (n=17,046), cluster-randomized ...trial. We compared growth weight-for-age, length-for-age, and weight-for-length z scores (WAZ, LAZ, WLZ) and head circumference (HC) during the intervals 1 to 3, 3 to 6, 6 to 9, and 9 to 12 months, using hierarchical multivariate regression to control for size at the beginning of each interval, maternal education, geographic region, and urban versus rural location.
Mixed BF and formula/other milk were associated with significantly higher (versus breast milk only) LAZ at 1 to 3 months (+0.038 and +0.047, respectively). In the 3- to 6-month interval, mixed BF and formula/other milk led to significantly higher WAZ (+0.125 and +0.139) and LAZ (+0.081 and +0.075), whereas cereal intake was associated with large and highly significant reductions in both measures (−0.293 and −0.240) and in HC (−0.291 cm). Mixed BF and formula/other milk continued to have positive albeit smaller associations with WAZ and LAZ in the 6- to 9-month and 9- to 12-month intervals.
Our results confirm the growth-accelerating effects of formula and other milks (versus breast milk) on weight and length gain throughout infancy, with a dose-response gradient and largest associations observed at 3 to 6 months.
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