Recurrence of gestational age in sibships: implications for perinatal mortality.

The authors studied the extent to which preterm birth and perinatal mortality are dependent on the gestational ages of previous births within sibships. The study was based on data collected by the Medical Birth Registry of Norway from 1967 to 1995. Newborns were linked to their mothers through Norway's unique personal identification number, yielding 429,554 pairs of mothers and first and second singleton newborns with gestational ages of 22-46 weeks, based on menstrual dates. Siblings' gestational ages were significantly correlated (r = 0.26). The risk of having a preterm second birth was nearly 10 times higher among mothers whose firstborn child had been delivered before 32 weeks' gestation than among mothers whose first child had been born at 40 weeks. However, perinatal mortality in preterm second births was significantly higher among mothers whose first infant had been born at term, compared with mothers whose firstborn child was delivered at 32-37 weeks. Since perinatal mortality among preterm infants is dependent on the gestational age in the mother's previous birth, a common threshold of 37 weeks' gestation for defining preterm birth as a risk factor for perinatal death may not be appropriate for all births to all mothers.     

Prediction of adult height and risk of overweight in females born small-for-gestational-age

The risk of short adult stature in women born small-for-gestational age (SGA) was estimated in this prospective cohort study of 43 872 singleton females, born between 1973 and 1983, who gave birth to a child between 1989 and 1999. The risk of overweight in females born SGA, with and without short adult stature, was also studied. All data on birth characteristics and adult height and weight were obtained from the Swedish Birth Register. SGA-born females were divided into being born short only for gestational age [birth length < -2 standard deviation scores (SDS)], born light for gestational age (birthweight < -2 SDS) or being born both short and light for gestational age. Short adult stature was defined as adult height below -2 SDS. Among females, being born SGA (<-2 SDS in birth length or birthweight) was associated with increased risk of short adult stature, compared with being born appropriate for gestational age. The risk varied substantially within different subgroups of females born SGA: being born short for gestational age was associated with an almost fivefold increased risk [odds ratio (OR) 4.89; 95% confidence interval (CI) 3.70, 6.47] of short adult stature, whereas being born light for gestational age was associated with an almost twofold increased risk [OR 1.95, 95% CI 1.43, 2.65]. Overall, females born SGA did not have increased risk of overweight compared with females with appropriate size at birth. However, among females born short for gestational age, short adult stature was associated with an increased risk of overweight in adulthood [OR 1.77, 95% CI 1.01, 3.12]. In conclusion, among females born SGA, of the birth characteristics, short birth length is associated with the highest increased risk of short adult stature. Spontaneous growth in height to normal adult stature reduced the risk of overweight in females born short for gestational age.     

Outcomes of preterm children according to type of delivery onset: a nationwide population-based study

The objective of the study was to investigate whether spontaneous and iatrogenic preterm births are associated with different paediatric outcomes. A nationwide population-based study comprising 1 010 487 singletons used data from 1991 to 2001 from the Swedish Medical Birth Register and the Swedish Hospital Discharge Register. Intrauterine fetal deaths, unknown type of delivery onset and congenital malformations were excluded. Neonatal, perinatal and long-term neurological outcomes were studied. Spontaneous preterm births were compared with iatrogenic preterm births. Odds ratios (OR) and hazard ratios (HR) for outcome variables were obtained using the Mantel-Haenszel technique and Cox analyses respectively. Adjustments were made for gestational age at birth, maternal age, parity and smoking. The preterm population consisted of 34 215 (73.2%) spontaneous preterm infants and 12 511 (26.8%) iatrogenic preterm infants. Spontaneous preterm infants were at increased risk of cerebral palsy at gestational age 28-31 weeks (HR: 1.86 [95% CI: 1.12, 3.10]), and of sepsis at gestational age 32-33 weeks (HR: 1.58 [95% CI: 1.28, 1.96]). Other outcome variables were associated with iatrogenic preterm birth, especially respiratory and gastrointestinal diagnoses. In conclusion, spontaneous preterm birth and iatrogenic preterm birth are associated with different paediatric outcomes.     

Role of structural birth defects in preterm delivery

The proportion of preterm births associated with structural birth defects has not been adequately quantified. We explored the proportion of preterm infants with structural birth defects diagnosed in the first year of life, as well as the specific phenotypes of birth defects occurring among preterm infants. The data used were from the California Birth Defects Monitoring Program, a population-based registry, as well as data from California vital records corresponding to births and fetal deaths in the period 1984-96. The prevalence of structural birth defects exceeded 8% among deliveries with gestational ages < or = 30 weeks, and prevalence decreased to 2% as gestational age increased to > or = 37 weeks gestation. The decreasing prevalence pattern with increasing gestational age was observed for a variety of anatomically defined birth defect groups suggesting that certain birth defects were not the sole contributors to the elevated prevalences among preterm births. Decreasing prevalence with increasing gestational age was also observed across strata of maternal race/ethnicities, ages, infant's sex and each year studied. These data indicate that structural birth defects may contribute significantly to the proportion of infants who are delivered before 37 weeks gestation.     

Time of birth and risk of intrapartum and early neonatal death

BACKGROUND: Previous studies have found that infants born at night and during weekends and holidays have an increased risk of perinatal mortality. However, these associations may be confounded by the distribution of high-risk deliveries according to time of birth. METHODS: We undertook a population-based cohort study of 694,888 singleton births without elective cesarean section in Sweden between 1991 and 1997. We estimated relative risks of intrapartum and early neonatal death according to the hour, day and month of delivery. Estimated risk ratios were adjusted for gestational age, birth weight for gestational age, malformations, induction of labor, breech presentations and year of birth. RESULTS: Infants of high-risk deliveries were more often delivered during daytime (8:00 am to 7:59 pm). Compared with infants born during daytime, infants born at night were at increased risk of early neonatal death (adjusted risk ratio = 1.28; 95% confidence interval = 1.13-1.46), but not intrapartum death (1.05; 0.71-1.54). If this association is causal, 12% of early neonatal deaths can be attributed to the increased risk among nighttime births. There was no association of weekend or holiday births with risks of intrapartum or early neonatal death. CONCLUSIONS: Infants born at night may be at increased risk of early neonatal death.     

Exactness of the birth registry of Barcelona regarding birth weight and weeks of gestation

OBJECTIVE: The aim of the study is to know the accuracy of the variables birth weight and gestational age in the Barcelona Birth Registry. Hospital medical records are used as gold standard. METHODS: A representative sample (n = 1,932) was selected from all the residents born in the city of Barcelona between 1st of May and 31st of December of 1996. The variables birth weight and gestational age were evaluated. Exhaustivity, sensitivity, specificity and predictive value for these variables were calculated. RESULTS: The Registry shows a high exhaustivity for the study variables. The lowest value of sensitivity corresponds to premature births (65.1%) and the lowest value of specificity to term births (63.9%). The predictive value positive was 77.5% for preterm births and 76.7% for term births. CONCLUSIONS: In general, exhaustivity and accuracy of the Barcelona Birth Registry are high, but sensitivity for preterm births in the Registry is lower. However, the corresponding maternal and child health indicators do not vary in an important manner.     

1998～2007年住院分娩活产儿出生体重变化

目的:了解10年住院分娩活产儿出生体重变化。方法:回顾性分析该院1998~2007年住院分娩(孕周≥28周)活产儿出生体重,对出生体重变化及相关因素进行分析。结果:10年活产儿平均出生体重(3 143±496)g,年度间差异无统计学意义(F=1.796 3,P=0.064)。各个月份之间出生体重差异有统计学意义(F=2.425,P=0.005)。男婴、女婴体重差异有统计学意义(t=12.621,P<0.001)。孕周间出生体重差异有统计学意义(F=628.105,P<0.001),孕周与体重呈显著正相关(Pearson系数r=0.578,P<0.001)。不同孕次间出生体重差异有统计学意义(F=10.613,P<0.001)。不同产次的活产儿出生体重的差异有统计学意义(F=8.739,P<0.001)。妊娠胎数与出生体重呈负相关(r=-0.285,P<0.001)。产妇年龄与出生体重呈轻度正相关(r=0.043,P<0.001)。年度间巨大儿构成比的差异无统计学意义(2χ=4.392,P=0.884);低体重儿构成比的差异有统计学意义(2χ=23.229,P=0.006),有上升趋势(2χ=15.111,P<0.001);未足月低体重儿构成比呈上升趋势(2χ=0.207,P=0.649)。结论:各年度活产儿出生体重总体无差异;出生体重与分娩月份、胎儿性别、孕周、胎数及产妇孕产次、年龄有关。10年间巨大儿构成比无增加趋势,低体重儿构成比有逐年增加趋势,其中未足月低体重儿构成比逐年明显增加。     

Children with low birth weight and low gestational age in Oslo, Norway: immigration is not the cause of increasing proportions.

STUDY OBJECTIVE--To determine the influence of children born to immigrant mothers on the total proportions of low birth weight and preterm deliveries in Oslo and to explain the increases in the proportions of children with low birth weight and low gestational age since 1980-1982. DESIGN--This was a cross sectional study based on Norwegian Medical Birth Registry data and information on mothers' country of birth from the Central Bureau of Statistics. SETTING--Oslo, Norway 1968-91. POPULATION--All births in Oslo between 1968 and 1991 (n = 146 133). MAIN RESULTS--The observed increased proportion of children with low birth weight and low gestational age born after 1980-82 is not the result of an increased proportion of children born to immigrant women. Caesarean section rates have increased dramatically and the higher proportions of children with low birth weight and gestational age may be explained by this. CONCLUSION--Wide use of caesarean section probably results in more children of low birth weight and low gestational age as an iatrogenic effect. The trend in the proportion of children with low birth weight and low gestational age is not correlated to perinatal mortality after 1982. Using proportions of low birth weight and gestational age as indicators of a nation's child health status may therefore be misleading in countries with high rates of caesarean section.     

Risk factors for neonatal seizures: a population-based study, Harris County, Texas, 1992-1994.

Risk factors for neonatal seizures were evaluated in 116,048 infants born between 1992 and 1994 to residents of Harris County, Texas; 207 of these infants were diagnosed with clinical neonatal seizures. Information was obtained from the infant's birth certificate to assess the relation between seizures and birth weight, gender, ethnicity, place of birth, mother's age, method of delivery, parity, and multiple births. These factors were evaluated by univariate and multivariate analysis using logistic regression. For preterm infants, a birth weight of <1,500 g was the strongest risk factor (relative risk (RR) = 9.1, 95% confidence interval (CI): 4.7, 17.5), followed by birth in a private/university hospital (RR = 2.8, 95% CI: 1.5, 5.0) and male gender (RR = 1.8, 95% CI: 1.0, 3.4). For term infants, significant risk factors included birth by cesarean section (RR = 2.2, 95% CI: 1.5, 3.2), small birth weight for gestational age (RR = 1.9, 95% CI: 1.2, 2.9), birth in a private/university hospital (RR = 1.8, 95% CI: 1.1, 3.0), and maternal age of 18-24 compared with 25-29 years (RR = 1.6, 95% CI: 1.1, 2.3). Birth by assisted vaginal delivery and primiparity were marginally significant for term infants. Birth weight is a significant risk factor for neonatal seizures. The role of perinatal complications warrants further evaluation.     

Birth outcomes by birth order and maternal nutritional status

Birth weights were studied of infants born to 432 women who delivered at SSG Hospital and Medical College in Baroda, India, in 1993 to determine whether birth order and maternal age have effects on birth weight independent of social disadvantages, as measured by maternal height, weight, and hemoglobin level. The weight-height product index (WHPI) (kg x cm x 100/45 kg x 150 cm) was used as one of the indicators for maternal nutrition. Mean WHPI was 101.83. Mean maternal weight and height were 46.56 kg and 147.49 cm, respectively. The hemoglobin level stood at 9.5 g/dl. Mean gestational age was 38.02 weeks. Even though the birth weight of newborns of women in the C nutritional status group (i.e., WHPI = 101.83) were significantly smaller than those born to mothers in the next higher nutritional status group (WHPI = 133.49) (2283 vs. 2381 g; Z = 1.99), the proportion of low birth weight ( 2.5 k) infants in the C group was not significantly different from those in the B group (54.54% vs. 53.08%). The proportion of low birth weight newborns was higher in the birth order 1 group than higher birth order groups (61.04% vs. 50.23% for birth order 2-3 and 37.7% for birth order =or 4). Yet, there was no significant difference in mean birth weight by birth order. When comparing birth weights within the same age group, mean birth weight was significantly greater after birth order 1 regardless of maternal age. Among 16.5-34.5 year old mothers, the percentage of low birth weight newborns was much higher in birth order 1 than higher birth orders (60.45% vs. 48.79%; p 0.02). Thus, within the same age group, first order births have a lower birth weight and a higher incidence of low birth weight than higher order births.     

The Impact of Paternal Involvement on Feto-Infant Morbidity Among Whites,Blacks and Hispanics

Few studies have examined paternal involvement in relation to feto-infant health; therefore we aim to assess the impact of absence of the father on birth outcomes among racial-ethnic subgroups. Florida vital statistics records for singleton births occurring between 1998 and 2005 were used for this study. Births to women less than 20 years of age and births outside the gestational age range of 20–44 weeks were excluded. Adjusted and unadjusted odds ratios and 95% confidence intervals were generated to examine the impact of paternal involvement, as defined by presence of paternal information on the birth certificate, on feto-infant morbidity across racial-ethnic sub-populations. There were higher rates of low birth weight, very low birth weight, preterm birth, very preterm birth, and small for gestational age (SGA) among father-absent births. Within each racial-ethnic subgroup, women with absent fathers had higher risks of poor birth outcomes than their counterparts with involved fathers. Black women with absent fathers had the highest risk of low birth weight, very low birth weight, preterm birth, very preterm birth, and SGA. Promoting paternal involvement during the perinatal period may provide a means to decrease the proportion of infants born of very low birth weight or very preterm, thus potentially reducing the black–white disparity in infant mortality.     

Perfluorinated compounds in relation to birth weight in the Norwegian Mother and Child Cohort Study

Perfluorooctane sulfonate and perfluorooctanoic acid are perfluorinated compounds (PFCs) widely distributed in the environment. Previous studies of PFCs and birth weight are equivocal. The authors examined this association in the Norwegian Mother and Child Cohort Study (MoBa), using data from 901 women enrolled from 2003 to 2004 and selected for a prior case-based study of PFCs and subfecundity. Maternal plasma samples were obtained around 17 weeks of gestation. Outcomes included birth weight z scores, preterm birth, small for gestational age, and large for gestational age. The adjusted birth weight z scores were slightly lower among infants born to mothers in the highest quartiles of PFCs compared with infants born to mothers in the lowest quartiles: for perfluorooctane sulfonate, β = -0.18 (95% confidence interval: -0.41, 0.05) and, for perfluorooctanoic acid, β = -0.21 (95% confidence interval: -0.45, 0.04). No clear evidence of an association with small for gestational age or large for gestational age was observed. Perfluorooctane sulfonate and perfluorooctanoic acid were each associated with decreased adjusted odds of preterm birth, although the cell counts were small. Whether some of the associations suggested by these findings may be due to a noncausal pharmacokinetic mechanism remains unclear.     

Variation between last-menstrual-period and clinical estimates of gestational age in vital records

An accurate assessment of gestational age is vital to population-based research and surveillance in maternal and infant health. However, the quality of gestational age measurements derived from birth certificates has been in question. Using the 2002 US public-use natality file, the authors examined the agreement between estimates of gestational age based on the last menstrual period (LMP) and clinical estimates in vital records across durations of gestation and US states and explored reasons for disagreement. Agreement between the LMP and the clinical estimate of gestational age varied substantially across gestations and among states. Preterm births were more likely than term births to have disagreement between the two estimates. Maternal age, maternal education, initiation of prenatal care, order of livebirth, and use of ultrasound had significant independent effects on the disagreement between the two measures, regardless of gestational age, but these factors made little difference in the magnitude of gestational age group differences. Information available on birth certificates was not sufficient to understand this disparity. The lowest agreement between the LMP and the clinical estimate was observed among preterm infants born at 28-36 weeks' gestation, who accounted for more than 90% of total preterm births. This finding deserves particular attention and further investigation.     

Moderate alcohol consumption during pregnancy and the risk of low birth weight and preterm birth. The generation R study

PURPOSE: To examine the associations of alcohol consumption in different periods of pregnancy with the risks of low birth weight and preterm birth. METHODS: This study was based on 7141 subjects participating in a population-based prospective cohort study from early pregnancy. Alcohol consumption was assessed in early, mid, and late pregnancy. Birth outcomes were birth weight in grams, low birth weight (<2500 g), small size for gestational age at birth (< -2 standard deviation scores) and preterm birth (gestational age <37 weeks). RESULTS: Overall, alcohol consumption during pregnancy was not associated with adverse birth outcomes. However, dose-response analyses showed tendencies toward adverse effects of average consumption of 1 or more alcoholic drinks per day in early pregnancy on birth weight (difference -129 g [95% confidence interval (CI): -271, 12]), low birth weight (adjusted odds ratio [aOR] 4.81 [95% CI: 1.10, 21.08]), small size for gestational age at birth (aOR 1.45 [95% CI: 0.33, 6.44]) and preterm birth (aOR 2.51 [95% CI: 0.92, 6.81]). Similar effects were found in late pregnancy. CONCLUSION: Average consumption of one or more but not less than one alcoholic drink per day in early or late pregnancy seems to be associated with adverse birth outcomes in the offspring.     

Cold ambient temperature in utero and birth outcomes in Uppsala,Sweden, 1915–1929

PurposeAlthough the literature reports adverse birth outcomes following ambient heat, less work focuses on cold. We, moreover, know of no studies of cold that examine stillbirth. We tested the relation between cold ambient temperature during pregnancy in Sweden and four outcomes: stillbirth, preterm, birth weight for gestational age, and birth length. We examined births from 1915 to 1929 in Uppsala, Sweden, which—unlike most societies today—experienced substandard indoor-heating and fewer amenities to provide shelter from cold.MethodsWe retrieved data on almost 14,000 deliveries from the Uppsala Birth Cohort Study. We linked a validated, daily ambient temperature series to all pregnancies and applied Cox proportional hazards (stillbirth and preterm) and linear regression models (birth weight and length). We tested for nonlinearity using quadratic splines.ResultsThe risk of stillbirth rose as ambient temperature during pregnancy fell (hazard ratio for a 1°C decrease in temperature, 1.08; 95% confidence interval, 1.00 to 1.17). Cold extremes adversely affected preterm and birth length, whereas warm extremes increased preterm risk. We observed no relation between cold and birth weight for gestational age.ConclusionIn historical Sweden, cold temperatures during pregnancy increased stillbirth and preterm risk and reduced birth length among live births.     

早产低出生体重儿婴儿期追赶生长情况分析

目的 分析早产低出生体重儿1岁以内的追赶生长特点,研究其追赶生长规律。方法 按照纳入和剔除标准,选择2013年1月-2016年12月在本院儿童保健门诊体检的252名早产低出生体重儿为研究对象。根据1岁时体重、身长Z评分与出生时Z评分之差(△Z)的大小,△Z>0.67定义为婴儿期出现追赶生长;并分析比较不同性别之间追赶生长的差异。结果 纳入252名早产低出生体重儿,其中男婴118名(46.8%),女婴134名(53.2%);早产低出生体重儿婴儿期体重(kg)增长(Z评分为1.41±0.83)、身长(cm)增长(Z评分为0.82±0.76);80.5%在婴儿期出现体重追赶生长,62.7%出现身长追赶生长;不同性别之间的体重和身长的追赶生长情况比较,差异无统计学意义(χ²=1.583、1.082,P>0.05);适于胎龄儿体重追赶生长较小于胎龄儿和大于胎龄儿比例高(χ²=8.552,P=0.014)。结论 大部分早产低出生体重儿在第一年出现追赶生长,积极的营养支持策略和生长发育监测,对早产低出生体重儿的生长发育至关重要。     

NOD样受体介导炎症反应在不同胎龄及出生体重早产儿抗感染免疫中的作用和意义

目的 比较不同胎龄及出生体重早产儿NOD样受体(NOD1和NOD2)和炎症因子IL-6、TNF-α表达的差异,分析早产儿胎龄及出生体重与免疫功能的关系。方法 收集2016年4月-2017年11月苏州大学附属儿童医院新生儿科收治的早产儿外周血标本,分离早产儿外周血单个核细胞,分别加入NOD1激动剂Tri-DAP、NOD2激动剂MDP刺激细胞24 h,测定细胞中NOD1、NOD2的基因水平以及上清液中IL-6、TNF-α的表达水平。结果 胎龄<32周的早产儿NOD1 mRNA及IL-6的表达量明显低于34~36周早产儿(P<0.05);出生体重<1.5 kg的早产儿NOD1 mRNA的表达量明显低于1.5 kg以上的早产儿、NOD2 mRNA以及IL-6的表达明显低于2.0~2.5 kg的早产儿(P<0.05);NOD1 mRNA、NOD2 mRNA的表达量与出生体重呈正相关(r=0.352、0.306,P<0.05),但与胎龄无明显相关性;TNF-α的表达与胎龄和出生体重均呈正相关(r=0.380、0.289,P<0.05)。结论 出生体重越低,早产儿NOD样受体水平越低,介导抗感染免疫也越弱。相比于胎龄,出生体重对早产儿免疫功能影响较大。     

Prematurity as a predictor of childhood asthma among low-income children

PURPOSE: The purpose of this study was to evaluate the association among birth weight, prematurity, and the prevalence of asthma later in childhood and to assess the degree to which this association may differ between black and white children. METHODS: Michigan Medicaid claims data from 2001 through 2003 were analyzed to determine asthma prevalence for 150,204 children between ages 5 and 18 years. Asthma cases were identified using Healthcare Effectiveness Data and Information Set persistent asthma criteria and included children having claims for any of the following services within a calendar year: at least one inpatient or one emergency department (ED) claim with an asthma primary diagnosis; at least four asthma medication-dispensing events; or at least four outpatient visits with an asthma diagnosis, and at least two asthma medication-dispensing events. Birth weight and gestational age from birth certificate data were matched with Medicaid files to determine size-for-gestational-age criteria. RESULTS: Overall, 8.3% of children had persistent asthma; black children had slightly higher asthma prevalence (8.6%) than white children (7.8%; odds ratio [OR]=1.11, 95% confidence interval [CI]: 1.07-1.15). Children born very preterm (相似文献