Maternal dietary patterns in pregnancy and the association with small-for-gestational-age infants.

Maternal nutritional status before and during pregnancy is important for the growth and development of the fetus. The effects of pre-pregnancy nutrition (estimated by maternal size) are well documented. There is little information in today's Western society on the effect of maternal nutrition during pregnancy on the fetus. The aim of the study was to describe dietary patterns of a cohort of mothers during pregnancy (using principal components analysis with a varimax rotation) and assess the effect of these dietary patterns on the risk of delivering a small-for-gestational-age (SGA) baby. The study was a case-control study investigating factors related to SGA. The population was 1714 subjects in Auckland, New Zealand, born between October 1995 and November 1997, about half of whom were born SGA ( < or = 10th percentile for sex and gestation). Maternal dietary information was collected using FFQ after delivery for the first and last months of pregnancy. Three dietary patterns (traditional, junk and fusion) were defined. Factors associated with these dietary patterns when examined in multivariable analyses included marital status, maternal weight, maternal age and ethnicity. In multivariable analysis, mothers who had higher 'traditional' diet scores in early pregnancy were less likely to deliver a SGA infant (OR = 0.86; 95 % CI 0.75, 0.99). Maternal diet, particularly in early pregnancy, is important for the development of the fetus. Socio-demographic factors tend to be significantly related to dietary patterns, suggesting that extra resources may be necessary for disadvantaged mothers to ensure good nutrition in pregnancy.

Determinants of cognitive ability at 7 years: a longitudinal case-control study of children born small-for-gestational age at term.

The aim of this study was to identify the determinants of children's intelligence at 7 years, including pregnancy, postnatal, demographic factors, and small-for-gestational age (SGA) birth at term. Information was collected at birth (n = 871), 1 year (n = 744), 3.5 years (n = 550), and 7 years (n = 591). Approximately half of the children in this study were born SGA (birthweight

Prevalence and determinants of cytomegalovirus infection in pre-school children.

AIM: The aim of this study is to measure the seroprevalence of cytomegalovirus (CMV) infection in 3.5-year-old children, and identify the determinants of seropositivity. METHODS: A total of 1714 children were enrolled at birth. Approximately half were small for gestational age and half were appropriate for gestational age. Information on the children was collected at birth, 1 year and 3.5 years. At 3.5 years blood was collected and tested for CMV-specific immunoglobulin by an enzyme-linked immunosorbent assay in 530 children. RESULTS: The weighted seroprevalence of CMV was 32.8% (95% confidence interval (CI) 27.4-38.1%). The seroprevalence of CMV varied markedly by ethnicity (European: 26.5% (95% CI 20.9-32.2%); Maori: 68.0% (44.0-92.0%); Pacific: 74.5% (56.3-92.6%); Indian: 50.0% (20.2-79.8%); Chinese: 47.2% (10.8-83.5%); Other: 21.9% (0.0-52.7%); P < 0.001). Socio-economic factors, number of siblings, day care centres attendance, maternal smoking, breastfeeding and other factors examined were not related to CMV seropositivity. CONCLUSIONS: The seroprevalence of CMV in New Zealand pre-school children is similar to that reported from other developed countries. The finding of marked ethnic differences is unexplained by socio-economic factors, or other factors that were examined.

Children born small for gestational age are not at special risk for preschool emotion and behaviour problems.

Despite the wealth of literature examining long term outcomes of preterm low birthweight children, few studies have directly assessed the developmental impact of being born full term but small for gestational age (SGA). We aim to determine whether (i) being SGA increases preschool behavioural problems and (ii) other risk factors operate differently in SGA and appropriate for gestational age (AGA) controls. 550 New Zealand European mothers and their 3.5 year old children participated in this study. All children were born at full term (>37 weeks' gestation) and approximately half were SGA (≤sex specific 10th percentile for gestation) the remainder were AGA controls. Extensive data were collected at the child's birth, 1 year and 3.5 years. Behavioural problems were measured when children were 3.5 years, using the Strengths and Difficulties Questionnaire (SDQ). Multiple regression analyses were used to examine the associations between risk factors and behavioural problems; statistical weighting was used for analyses of the total study group. There was no significant difference in behavioural problems between SGA and AGA groups. In the total sample the significant predictors of behavioural problems included: mothers' school leaving age; smoking during pregnancy; maternal alcohol use during pregnancy; and absence of the father. Predictors of behavioural problems were found to be the same for SGA and AGA groups. These results do not support the view that SGA is a risk for behavioural preschool difficulties or that SGA children are sensitised to risks known to be associated with such difficulties in the preschool years.

Placental chorioamnionitis at term: epidemiology and follow-up in childhood.

The objective was to identify histologic chorioamnionitis ("amnionitis") in the placental disc at term and to investigate associations with demographic, lifestyle, and pregnancy factors and with allergic diseases, atopy, and intelligence quotients in childhood. The setting was a population-based case control study of small-for-gestational age infants at term. One thousand and twelve placentas were assessed histologically for amniocentric inflammation of fetal and/or maternal origin using conservative criteria. Data were collected at birth by maternal interview and from medical records. Follow-up data were obtained from 439 and 418 children at 3.5 and 7 years of age, respectively. Amnionitis was identified in 145 placentas (14.3%), with maternal reaction in 97.2% and fetal reaction in 48.3%. In multivariable analysis any amnionitis was significantly associated with a time from membrane rupture to delivery of 6 to 12 hours, but not with times beyond 12 hours, a duration of total labor exceeding 12 hours, ethnicity (incidences ranging from 8.8% in Indians to 23.5% in Chinese), male infant gender, and anaesthesia during labor, and amnionitis was negatively associated with induction of labor. No associations were found with later allergic disease, atopy, or intelligence quotients. This high incidence of histologic amnionitis at term is similar to historical estimates, despite large reductions in time-related risk factors during labor. Significant ethnic variations contribute to the high incidence and are unexplained, but variation in genetic polymorphisms for susceptibility factors is a possibility. "Silent" histologic amnionitis is a frequent cause of fetal immune activation with potential effects in later life.

Head covering and the risk for SIDS: findings from the New Zealand and German SIDS case-control studies.

OBJECTIVES: The aim of this investigation was to identify risk factors for being found with the head covered in sudden infant death syndrome cases and determine whether head covering was likely to be an agonal event or potentially part of the causal pathway in some cases. By using the data from 2 sudden infant death syndrome case-control studies, consistency of the findings could be assessed. METHODS: Two case-control studies were assessed: (1) the New Zealand Cot Death Study (1987-1990, 393 sudden infant death syndrome cases) and (2) a German SIDS case-control study (1998-2001, 333 sudden infant death syndrome cases). RESULTS: The proportion of sudden infant death syndrome cases in which infants were found with their head covered was 15.6% in the New Zealand study and 28.1% in the German study. Being found with head covering was associated with older infant age. In both studies, being found with head covering was associated with being very sweaty when found. Head covering was also associated with the incidence and severity of thymic petechiae in both studies. Both the position in which the child was placed to sleep and the position in which the child was found were not associated with head covering. CONCLUSIONS: The finding that sudden infant death syndrome cases in which infants were found with their heads covered were often very sweaty suggests that head covering was not an agonal event and that it preceded the death and may have been causally related to the death. Infants who were found with their head covered were older, which probably reflects motor development.

Determinants of developmental delay in infants aged 12 months.

The aim of this study was to determine which demographic, maternal, obstetric and postnatal variables were associated with achievement of developmental milestones at the age of 12 months in term infants. Mothers and babies were enrolled in the Auckland Birthweight Collaborative Study shortly after birth. All infants were full term (gestation >or= 37 weeks). Approximately half of the sample were small for gestational age (SGA = birthweight 10th percentile). A maternal interview was conducted soon after birth. Phase 2 of the study occurred 12 months later when mothers were sent a postal questionnaire requesting information about the child's health and development during the first year of life using the Denver Prescreening Developmental Questionnaire. Seven hundred and forty-four (85.4%) European mothers returned the postal questionnaire. SGA children were not at increased risk of developmental delay at 12 months of age. In a sample representative of New Zealand European children, after adjustment for the effects of potential confounders, maternal smoking during pregnancy (OR = 2.1 [95% CI 1.1, 4.0]), maternal smoking during the first year of life (OR = 1.9 [95% CI 1.0, 3.8]) and low levels of satisfaction with parenting (OR = 2.4 [95% CI 1.1, 5.2]) were associated with significantly increased risk of developmental delay. In the subgroup of SGA children, maternal smoking during pregnancy (OR = 2.9 [95% CI 1.4, 6.2]), high levels of stress associated with parenting (OR = 2.2 [95% CI 1.2, 4.0]), and low levels of satisfaction with parenting (OR = 4.3 [95% CI 1.3, 13.5]) were significantly associated with developmental delay after adjustment for the effects of potential confounders. In conclusion, maternal and postnatal factors were better predictors of developmental delay than demographic variables.

Risk factors for obesity in 7-year-old European children: the Auckland Birthweight Collaborative Study.

OBJECTIVE: To identify risk factors associated with obesity in primary school children, with a particular focus on those which can be modified. To identify critical periods and growth patterns in the development of childhood obesity. METHODS: 871 New Zealand European children were enrolled in a longitudinal study at birth and data were collected at birth, 1, 3.5 and 7 years of age. Data collected at 7 years included weight, height, bioelectrical impedance analysis (BIA), television viewing time and a 24 h body movement record (actigraphy). The outcome measure was percentage body fat (PBF), which was calculated at 3.5 and 7 years using BIA. Univariate and multiple regression analyses were carried out using PBF as a continuous variable. RESULTS: Multivariable analysis found maternal overweight/obesity, maternal age, female gender, sedentary activity time and hours of television viewing to be independently associated with PBF at 7 years. Growth variables (birth weight, rapid weight gain in infancy, early (1-3.5 years) and middle childhood (3.5-7 years)) were also independently associated with adiposity at 7 years. There was a strong correlation between PBF at 3.5 years and PBF at 7 years. CONCLUSIONS: Many primary school aged children start on the trajectory of obesity in the preschool years, which suggests interventions need to start early. Maternal overweight/obesity, television watching, sedentary activity time and rapid weight gain in infancy, early and middle childhood are risk factors for childhood obesity, and are all potentially modifiable.

Sudden infant death syndrome: risk factors for infants found face down differ from other SIDS cases.

OBJECTIVE: To test the hypothesis that infants with sudden infant death syndrome (SIDS) found face down (FD) would have SIDS risk factors different from those found in other positions (non-face-down position, NFD). STUDY DESIGN: We used the New Zealand Cot Death Study data, a 3-year, nationwide (1987 to 1990), case-control study. Odds ratios (univariate and multivariate) for FD (n = 154) and NFD SIDS (n = 239) were estimated separately, and statistical differences between the two groups were assessed. RESULTS: Of 12 risk factors for SIDS, there were 8 with a statistically significant difference between FD and NFD infants. After adjustment for the potential confounders, younger infant age, Maori ethnicity, low birth weight, prone sleep position, use of a sheepskin, and pillow use were all associated with a greater risk of SIDS in the FD than the NFD group. Sleeping during the nighttime, maternal smoking, and bed-sharing were associated with a risk of SIDS only in the NFD group. Pacifier use was associated with a decreased risk for SIDS only in the NFD group, whereas being found with the head covered was associated with a decreased risk for SIDS for the FD group. CONCLUSIONS: Infants with SIDS in the FD position appear to be a distinct subgroup of SIDS. These differences in risk factors provide clues to mechanisms of death in both SIDS subtypes.

Pulmonary interstitial hemosiderin in infancy: a common consequence of normal labor.

Deposits of hemosiderin are found frequently in the interstitium of the lungs of infants who die suddenly and have been a suggested marker for hypoxia during previous episodes of apnea. We studied the epidemiology of pulmonary interstitial hemosiderin (PIH) in 94 infants with a diagnosis of the sudden infant death syndrome that was established during the New Zealand Cot Death Study. Twenty-seven infants (29%) had widely distributed PIH. Associations were sought between PIH and variables on which information had been obtained from parental interviews or from medical records. Previous suggestions of associations with increasing birth weight and decreasing age at death were confirmed in multivariate analysis (P = 0.0018 and P = 0.03, respectively) and with increasing gestation in univariate analysis (P < 0.0001). PIH was not found in any of the 13 infants delivered by elective cesarean section compared with a 33% incidence in those exposed to labor (P = 0.02). There was no association with previous apnea. We consider that the likely explanation of these findings is that PIH is a residue of interstitial hemorrhage caused by chest compression during labor that occurs particularly in larger infants of greater gestational age and then clears gradually during early infancy.

Pulmonary aspiration of gastric contents and the sudden infant death syndrome.

OBJECTIVE: To determine ante-mortem and post-mortem risk factors for the finding of gastric contents in pulmonary airways (aspiration of gastric contents) at post-mortem examination in the sudden infant death syndrome (SIDS). METHODS: There were 217 post-neonatal deaths in the Auckland region of the New Zealand Cot Death Study. No deaths were certified as due to aspiration of gastric contents. There were 138 SIDS cases. The parents of 110 (80%) of these cases were interviewed. Histological sections from the periphery of the lungs in 99 of the 110 cases were reviewed for evidence of aspiration of gastric contents. A wide range of variables were analysed in SIDS cases with and without aspiration to determine risk factors. RESULTS: Aspiration of gastric contents was identified in 37 (37%) of SIDS cases. Aspiration was of mild-to-moderate degree and in no case was severe and a potential cause of death. Finding infants on their backs at death (P = 0.024) and conducting the post-mortem on the day after the death or subsequently (P = 0.033) were statistically significant variables linked to identification of aspiration. Position placed to sleep, symptoms of gastro-oesophageal reflux and other variables were not related to aspiration. CONCLUSIONS: The only determinants for aspiration of gastric contents identified were agonal or post-mortem events, supporting the contention that aspiration has limited relevance to the mechanism of SIDS.

Placental infarcts, intervillous fibrin plaques, and intervillous thrombi: incidences, cooccurrences, and epidemiological associations.

The incidences, cooccurrences and epidemiological associations at term of the three common focal macroscopic placental lesions, infarcts, intervillous fibrin plaques (IVFP), and intervillous thrombi (IVT) were investigated as part of a population-based case-control study of small-for-gestational age (SGA) infants. Five hundred and nine placentas from women delivering SGA infants (10th percentile or less for gestational age) and 529 placentas from women delivering infants with birthweights appropriate for gestational age were examined using fixed protocols for identification of macroscopic lesions and microscopic diagnoses. One or more of these lesions were found in 280 placentas (28%), including infarcts in 150 (15%), IVFP in 132 (13%), and IVT in 64 (6%). Macroscopic misidentifications, particularly of IVFP as infarcts, emphasize the need for microscopic diagnoses. There were strong associations between the occurrence of any one type of lesion and cooccurrence of either of the other two, and these associations were site-dependent: between central (nonmarginal) infarcts and central IVFP (P = 0.0023); marginal infarcts and marginal IVFP (P < 0.0001); and between IVT (all central) and marginal infarcts (P < 0.0001) and marginal IVFP (P = 0.012). However, a study of associations between the incidences of placentas bearing each of the three lesions and 31 socio-demographic and pregnancy-related factors showed no associations in common. IVFP, an IVFP variant termed "labyrinthine," and IVT did not show any of the independent associations demonstrated between infarcts and SGA, pregnancy-induced hypertension, nonsmoking, age at first pregnancy, and ethnicity. IVFP had no significant associations, and IVT were associated only with male gender. The study has shown that IVFP and IVT do not share the important clinical associations demonstrated for infarcts, but has not identified the pathogenetic factor or factors responsible for the frequent cooccurrence of these lesions. The maternal thrombophilias may have such a role.