Cigarette smoke exposure and development of infants throughout the first year of life: influence of passive smoking and nursing on cotinine levels in breast milk and infant''s urine

The effects of smoke exposure via mothers' milk and/or via passive smoking during the first year of life were investigated in a prospective longitudinal matched-pair study. The somatic and mental development of 69 infants whose mothers smoked more than five cigarettes per day throughout pregnancy and continued smoking after childbirth were compared with 69 children of non-smoking mothers. At birth, mean body weight of neonates from smoking mothers was significantly lower than the weight of neonates from non-smoking mothers. This weight difference between the two groups was no longer significant in infants at 12 months of age. With the methods employed by the authors, neither psychomotor nor mental development was affected by smoke exposure during pregnancy and early infancy. Infections of the lower respiratory tract were more frequent in the children of smoking mothers. These mothers weaned their babies earlier than non-smokers, but the different feeding behaviour did not influence any of the clinical parameters that were investigated in this study. In order to evaluate the extent of smoke exposure, cotinine was measured in children's urine and in breast milk once a month throughout the first year of life. Cotinine in the urine was significantly dependent on feeding behaviour: infants breast fed showed concentrations 10-fold higher than those who were bottle fed. Cotinine excretion in urine of infants from smoking mothers, who were not breast fed (nicotine exposure via passive smoking only) was even higher than that of adult passive smokers. If infants from smoking mothers were breast fed, their urinary cotinine excretion was in the range of adult smokers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence on fetal growth of exposure to tobacco smoke during pregnancy

We analysed the effect of exposure to tobacco smoke during pregnancy on fetal growth parameters in 129 term newborns. Children were classified into four depending on exposure on the basis of a questionnaire completed by the mother. The results confirmed that tobacco smoking reduced weight, length, cranial and thoracic perimeters at birth when exposure was due to either active or passive smoking. Weight deficits of infants whose mothers smoked heavily (458 g) were higher than those whose mothers were exposed to passive smoking (192 g). We conclude that passive smoking is a very important variable and should be taken into account in any study of neonatal growth parameters.     

Effects of heavy maternal smoking on intrauterine growth patterns in sudden infant death victims and surviving infants

Sudden infant death (SID) is associated with both intrauterine growth retardation and maternal smoking during pregnancy. Here, we investigated if the statistical association between maternal smoking and SID is direct or mediated through the well- known growth retarding effects of heavy maternal smoking on the fetoplacental unit. We analysed data from a population-based prospective cohort study (181 cases, total newborn population 227,791 births) within the Westphalian Perinatal Inquiry in Germany between 1990 and 1994. SID victims whose mothers did not smoke had a normal mean birth weight (mean 3415.5 vs 3431.5 g), length (mean 51.46 vs 51.66 cm), and body mass index (BMI) (mean 12.8 vs 12.8 kg/m²) when compared to surviving children. In contrast, SID victims of mothers who smoked heavily (>ten cigarettes per day) had a significantly lower birth weight (2911.21 g vs 3148.34 g), length (48.98 vs 50.39 cm), and BMI (11.8 vs 12.4 kg/m²) when compared to surviving children whose mothers smoked heavily. Stratification for gestational age revealed that these differences are mainly caused by preterm SID infants. Conclusion The statistical association between maternal smoking and SID mainly results from effects of tobacco smoke on the fetoplacental unit which, in later SID victims, appears to be more susceptible to the growth retarding effects of cigarette smoking. Received: 26 May 1997 / Accepted in revised form: 10 September 1997     

The impact of maternal smoking on fetal and infant growth

BACKGROUND: Low birth weight is associated with accelerated postnatal growth and adverse adult health outcomes. Maternal smoking is a major risk factor for low birth weight. This study aims to assess: Pre- and postnatal growth associated with maternal smoking compared to other risk factors for low birth weight. The effect of reduction of maternal smoking on growth. SUBJECTS: A cohort (n=269) followed with ultrasound measurements in the third trimester and postnatal anthropometric measurements until 6 months of age. Mothers were interviewed about their smoking habits at 18 and 28 weeks of pregnancy. RESULTS: Maternal smoking was associated with a greater reduction in birth length SDS than other causes of equally reduced birth weight (mean difference: -0.25 SDS, P=0.013). The adjustment of gestational age, based on bi-parietal diameter at an early dating scan, indicated that mothers who reduced smoking carried smaller fetuses than mothers who continued to smoke heavily (mean difference=2.6 days, P=0.012). Birth weights in these two groups were similar (P=0.87). However at 3 months of age, reduced smoking was associated with lower weight (mean difference=-0.38 SDS, P=0.045). CONCLUSIONS: Maternal smoking was associated with a reduction of linear growth, which was more marked than that of other risk factors, and which seemed to occur before the 3rd trimester. The results indicated a beneficial effect of reduction of smoking upon third trimester growth, and that the decision to reduce smoking in mid-pregnancy may be influenced by early fetal size.     

Dietary zinc intake and growth during infancy

Energy, protein, zinc intake, and weight and length were monitored at 3, 6, and 12 months in 50 preterm infants (corrected for gestational age) (mean birthweight, 1,054 +/- 234 g; mean gestation, 29 +/- 2.5 weeks) and 60 full-term infants (mean birthweight, 3,509 +/- 269 g; mean gestation, 40 +/- 1 weeks). Mean energy and protein intake (per kilogram body weight) was higher (p less than 0.05) for the preterm infants at all times and met the recommended levels for preterm infants. No significant differences in zinc intake (per kilogram body weight) between the two groups existed, and at 3 months, mean zinc intake in the preterm group (per kilogram body weight) was below the recommended level for full-term infants. At no time were the growth percentiles of the preterm group equal to those of the full-term group. Multiple regression equations predicting length at 3 months and weight at 12 months for all the infants were significant, the significant variables being length at birth and zinc intake (milligrams per day) at 3 months, and weight at birth and dietary zinc intake (milligrams per day) at 12 months, respectively. Results indicate that zinc intake played a more important role in explaining the length at 3 months and weight at 12 months than did any other variables, including intakes of protein and energy, gestational age, socioeconomic index of the father, midparent height, sex, and age of introduction of solid foods. Results thus support the suggestion that infants, especially those born prematurely, are at risk for inadequate intake of dietary zinc.     

Effects of maternal smoking on fetal growth and nutrition.

Standard anthropometric measurements were made on 320 term neonates to investigate the influence of smoking on fetal growth and nutrition. Maternal height and triceps skinfold thickness were also measured. Of 320 infants, 126 (39%) were born to mothers who smoked. Maternal triceps skinfold thickness was significantly smaller in smoking mothers. A correlation existed between maternal and infant triceps skinfold thickness. Measurements of infant growth, birthweight, occipito-frontal circumference, and crown-to-heel length were significantly smaller in infants of smoking mothers and remained significantly smaller when corrections were made for maternal triceps skinfold thickness, height, and social class. While these data do not exclude a nutritional mechanism for the effect of maternal smoking on the fetus, the major growth-retarding effects remain after corrections for this. This reduction in occipito-frontal circumference in infants of smoking mothers, and the possible significance of this is stressed.     

Fatty acids in early human milk after preterm and full-term delivery

BACKGROUND: It has been much debated whether fatty acid composition of human milk differs after preterm as compared to full-term delivery. SUBJECTS AND METHODS: Human milk samples were obtained from mothers of preterm (n = 8, gestational age: 28.0 [4.2] weeks, birthweight: 1,235 [420] g, median [interquartile range]) and full-term (n = 10, gestational age: 38.5 [2.7] weeks, birthweight: 3375 [282] g) infants every day during the first week and thereafter on the 14th, 21st, and 28th day of lactation. Fatty acid composition was measured by high-resolution capillary gas-liquid chromatography. RESULTS: Maternal age and body mass index did not differ, and food frequency questionnaire did not reveal significant differences in diet between the two groups. Fat contents of human milk did not differ between the two groups. Values of linoleic acid (C18:2n-6) and alpha-linolenic acid (C18:3n-3) did not differ throughout the study. Values of the metabolites C18:3n-6 and C20:3n-6 as well as C18:4n-3 and C20:3n-3 were significantly higher after preterm as compared with full-term delivery. Values of arachidonic acid (C20:4n-6; e.g., day 4: 0.82 [0.4] vs. 0.44 [0.28]; day 7: 0.61 [0.25] vs. 0.34 [0.25]; day 21: 0.33 [0.18] vs. 0.44 [0.44]; in weight percent, preterm versus full-term, P < 0.05) and docosahexaenoic acid (C22:6n-3; e.g., day 4: 0.33 [0.23] vs. 0.15 [0.14]; day 7: 0.26 [0.16] vs. 0.13 [0.15]; day 21: 0.11 [0.08] vs. 0.21 [0.17]; P < 0.05) were significantly higher in human milk samples of mothers of preterm as compared with full-term infants. CONCLUSION: In this study, percentage contributions of arachidonic and docosahexaenoic acids as well as the those of the intermediary metabolites of essential fatty acid metabolism were all significantly higher in early human milk samples of mothers giving birth to very low birth weight preterm as compared with full-term infants.     

Is there a relationship between cord blood pregnancy-associated plasma protein-A and birth weight and length?

BACKGROUND: Infants whose mothers had low serum pregnancy-associated plasma protein-A (PAPP-A) in the first trimester were observed to have intrauterine growth retardation. AIM: Suggesting that PAPP-A plays an important role in the availability and activity of insulin-like growth factors (IGFs), which affect growth, we aimed to investigate cord blood PAPP-A levels of infants with different birth lengths and weights. STUDY DESIGN AND OUTCOME MEASURES: The study included 97 full-term, live-birth neonates. After birth, their lengths and weights were measured. Cord blood PAPP-A levels were measured with an ultra sensitive enzyme-linked immunosorbent assay (ELISA). RESULTS: There was a significant negative correlation between cord blood PAPP-A levels and birth weight (r=-0.23; P=0.023) and length (r=-0.24; P=0.016). Using the classification made according to their length, it was found that newborns with short lengths had significantly higher mean PAPP-A levels than neonates with normal and long lengths (P=0.022; P=0.002, respectively), whereas the difference between infants with normal lengths and infants with long lengths was not found to be statistically significant (P>0.05). On the other hand, there was a difference between the mean PAPP-A levels of the neonate groups classified according to weight; however, these differences were not statistically significant (P>0.05). CONCLUSION: We concluded that increased cord blood PAPP-A levels were associated with birth length and weight decreases; however, PAPP-A levels affected birth length more than birth weight.     

Immunogenicity of hepatitis B vaccine in term and preterm infants

Some studies have suggested that decreased seroconversion rates might be found in premature infants with low birthweight (< 2000 g) following administration of hepatitis B vaccine at birth. The aim of the present investigation was to evaluate possible differences in seropositive rates between full-term and preterm infants after primary vaccination, in particular when gestational age or birthweight is very low. Two-thousand and nine neonates born to HBs Ag-negative mothers were vaccinated with 10 μg of recombinant hepatitis B virus (HBV) vaccine, from May 1991 to October 1994. Children with infections, congenital malformations or serious illnesses were excluded. HBV vaccine was administered intramuscularly, on the fourth day of life and again at 1 and 6 months of age. A 1-ml blood sample was drawn from each infant 1 month after the third vaccine dose for determination of the level of anti-HBs antibody. The response to HBV vaccination was evaluated in 241 preterm (gestational age < 38 weeks) infants and 1727 term neonates. No statistical difference was observed in the distribution of anti-HBs antibody level, either between preterm infants (< 38 weeks) and newborns of normal gestational age, or between low birthweight (< 2500 g) and normal weight infants. The results suggest that preterm and low birthweight infants (< 2500 g) respond to HBV vaccine in the same measure as normal-term infants.     

Maternal active smoking and newborn body composition

Objective

Maternal smoking during pregnancy is associated with a reduction in birth size but very few studies have collated changes in neonatal anthropometry. Our aims were both to assess body composition differences by anthropometry between new-borns from smoking mothers and those from non-smoking mothers, and to show whether these differences affect proportional body mass distribution.

Methods

Caucasian mothers and their full term singleton new-borns (N = 1216) were selected during 2009. A structured questionnaire was completed regarding obstetric and demographic data, as well as tobacco consumption. Women were categorized, according to their smoking habits, into a non-smoking group (never smoked or stopped smoking prior to pregnancy) and a smoking group (smoked throughout pregnancy).

Results

22.1% of mothers smoked during pregnancy (median: 6 cigarettes/day, range: l–40). Smoking mothers were significantly younger than non-smoking mothers but there were no differences regarding other aspects which could affect infant weight. Infants from non-smoking mothers were heavier, longer, and body circumferences were all larger than those from smoking mothers (p < 0.001), but the Ponderal Index showed no statistical differences. Skinfold thicknesses were significantly lower in new-borns from smoking mothers but these differences were less evident than those from body size. Subcutaneous fat distribution did not show statistical differences between the two groups. After gestational age, to smoke during gestation is the second main determinant of birth weight.

Conclusions

Smoking during pregnancy involves a generalized reduction of most axiological parameters as a result of proportionate fetal growth impairment. In those infants born from mothers who smoked during gestation, neonatal lean body mass appears to be more affected than body fat, and distribution of subcutaneous fat is not different.     

Effects of mother's smoking on their infants' body composition as determined by total body potassium

It has been suggested that the lower birth weight of newborn infants of mothers who smoke is due mainly to a deficit of lean body mass (LBM). We tested this hypothesis by measuring total body potassium, thus deriving the LBM and fat mass, of newborn infants of mothers who smoked (I-SM; n = 32) or did not smoke (I-NSM; n = 46). Mothers who smoked were significantly younger than nonsmoking ones (25.4 and 28.9 yr, respectively) and with less years of education, but were similar in other parameters examined. The 78 infants, all singleton, were studied within 1 to 3 days of birth. The I-SM had significantly reduced birth weight, length, and head circumference but there was no difference in skinfold thickness. We measured total body potassium with a whole-body counter specially made for use with infants. Mean absolute total body potassium was significantly greater in the I-NSM, but the concentration in relation to weight was not different. Assuming 1 kg LBM to contain 52.1 mmol potassium, the mean LBM was 3028 g in the I-NSM and 2739 in the I-SM; mean fat mass was similar in both groups. Multiple regression analysis revealed an independent negative effect of mother's smoking on birth weight and LBM. This unequal reduction in LBM indicates a complex effect of smoking, probably mediated by alterations in protein synthesis and adipocyte metabolism. It may relate to the higher morbidity rates in infants of mothers who smoke.     

A longitudinal study on the effects of maternal smoking and secondhand smoke exposure during pregnancy on neonatal neurobehavior

Maternal smoking during pregnancy is one of the most modifiable causes of morbidity and mortality for both pregnant women and their fetuses. The long-term effects of prenatal exposure to smoke on child behavior and development have been the subject of more extensive research than have the short-term effects. Therefore, the aim of this work is to examine the effects of smoke exposure during pregnancy on neonatal behavior, including in our study a group of mothers exposed to secondhand smoke. The behavior of 282 healthy full-term newborns was assessed using the Neonatal Behavior Assessment Scale (NBAS) at 48-72 h of life. Sixty-two mothers smoked during pregnancy (no mother smoked more than 15 cig/day) and 17 were exposed to secondhand smoke. After adjusting for socio-demographic and obstetric factors, both newborns whose mothers smoked and those whose mothers were exposed to secondhand smoke showed significantly lower scores in the habituation cluster than non-smoking mothers. Exposure to secondhand smoke was also related to lower motor system cluster scores as well as some supplementary items and the newborns of smoking mothers showed significantly lower scores in the state regulation cluster and in some items of the state organization cluster than the newborns of non-smoking mothers. We conclude that active and passive smoking during pregnancy affects several aspects of neurobehavioral development, regardless of socio-demographic, obstetric and pediatric factors.     

Maternal smoking during pregnancy and possible effects of in utero testosterone: evidence from the 2D:4D finger length ratio

OBJECTIVES: Maternal smoking during pregnancy is linked to high fetal testosterone (FT), and an increased risk in offspring for autism, ADHD, conduct disorder, antisocial behaviour and criminal outcomes. The ratio of the length of the 2nd and 4th fingers (2D:4D) is thought to be negatively related to FT concentration, and is related to autism, hyperactivity, poor social behaviour, and physical aggression. We compare the 2D:4D ratio of children whose mothers smoked during pregnancy with the 2D:4D of children whose mother did not smoke. METHOD: Cross-sectional survey in two primary schools. Questionnaires were distributed to 710 children and 546 were returned. Of these the 2nd and 4th digits of 520 children (259 females and 261 males) were measured. The main outcome measures were 2nd and 4th digit length, smoking history of mother and father. RESULTS: Boys had lower mean 2D:4D than girls and right 2D:4D was lower than left. Among boys, those whose mother's smoked during pregnancy had lower right hand 2D:4D ratio than those whose mother did not smoke. The difference remained significant after the effects of age, height, weight and birth weight were removed. Other household smoking patterns were not associated with male offspring 2D:4D. Female offspring 2D:4D did not differ on the basis of maternal smoking. CONCLUSIONS: Maternal smoking during pregnancy was associated with low right 2D:4D in children, but the effect was restricted to boys. A link between maternal smoking during pregnancy and 2D:4D supports a causal association between FT and such behaviours as hyperactivity and conduct disorder.     

Wheeze associated with prenatal tobacco smoke exposure: a prospective, longitudinal study. ALSPAC Study Team.

AIMS: To determine whether maternal smoking during pregnancy is a risk factor for reported wheeze in early childhood that is independent of postnatal environmental tobacco smoke (ETS) exposure and other known risk factors. METHODS: A total of 8561 mothers and infants completed questions about smoking during pregnancy, ETS exposure, and the mother's recall of wheeze during early childhood. RESULTS: A total of 1869 (21.8%) children had reported wheeze between 18 and 30 months of age, and 3496 (40.8%) had reported wheeze in one or more of the three study periods (birth to 6 months, 6-18 months, 18-30 months). The risk of wheeze between 18 and 30 months of age was higher if the mother smoked during pregnancy. This relation did not show a dose-response effect and became less obvious after adjustment for the effects of other factors. Average daily duration of ETS exposure reported at 6 months of age showed a dose-response effect and conferred a similar risk of reported wheeze. Factors associated with early childhood wheeze had the following adjusted odds ratios: maternal history of asthma 2.03 (1.74 to 2. 37); preterm delivery 1.66 (1.30 to 2.13); male sex 1.42 (1.28 to 1. 59); rented accommodation 1.29 (1.11 to 1.51); and each additional child in household 1.13 (1.04 to 1.24). CONCLUSIONS: Maternal smoking during pregnancy may be a risk factor for reported wheeze during early childhood that is independent of postnatal ETS exposure. For wheeze between 18 and 30 months of age, light smoking during the third trimester of pregnancy appears to confer the same risk as heavier smoking.     

Effects of prenatal methamphetamine exposure on fetal growth and drug withdrawal symptoms in infants born at term

To determine fetal growth and the incidence of withdrawal symptoms in term infants exposed to methamphetamine in utero, we retrospectively identified neonates whose mothers used methamphetamine during pregnancy and matched them to unexposed newborns. Exclusion criteria included multiple and preterm gestations. Although there were no differences in infant growth parameters between the methamphetamine-exposed and methamphetamine-unexposed neonates, methamphetamine exposure throughout gestation was associated with decreased growth relative to infants exposed only for the first two trimesters. In addition, there were significantly more small for gestational age infants in the methamphetamine group compared with the unexposed group. Methamphetamine-exposed infants whose mothers smoked had significantly decreased growth relative to infants exposed to methamphetamine alone. Withdrawal symptoms (as determined by a previously reported scoring system) requiring pharmacologic intervention were observed in 4% of methamphetamine-exposed infants. These preliminary findings indicate that methamphetamine use is associated with growth restriction in infants born at term.     

Prenatal exposure to cigarette smoking is associated with a decrease in arousal in infants.

OBJECTIVE: Sudden infant death syndrome has been related to both exposure to prenatal cigarette smoke and impaired arousability from sleep. We evaluated whether healthy infants born to mothers who smoked during pregnancy had higher auditory arousal thresholds than those born to mothers who did not smoke and whether the effects of smoking occurred before birth. STUDY DESIGN: Twenty-six newborns were studied with polygraphic recordings for 1 night: 13 were born to mothers who did not smoke, and 13 were born to mothers who smoked (>9 cigarettes per day). Other infants with a median postnatal age of 12 weeks were also studied, 21 born to nonsmoking mothers and 21 born to smoking mothers. White noise of increasing intensity was administered during rapid eye movement sleep to evaluate arousal and awakening thresholds. RESULTS: More intense auditory stimuli were needed to induce arousals in newborns (P =.002) and infants (P =. 044) of smokers than in infants of nonsmokers. Behavioral awakening occurred significantly less frequently in the newborns of smokers (P =.002) than of nonsmokers. CONCLUSIONS: Newborns and infants born to smoking mothers had higher arousal thresholds to auditory challenges than those born to nonsmoking mothers. The impact of exposure to cigarette smoke occurred before birth.     

Relationship of sudden infant death syndrome to maternal smoking during and after pregnancy.

Sudden infant death syndrome (SIDS) is associated with maternal smoking during pregnancy. However, the relationship between tobacco exposure during infancy and SIDS is unknown. The examination of infants whose mothers smoked only after pregnancy will help determine the relationship between passive cigarette exposure during infancy and SIDS risk. This case-control analysis used data on normal birth weight (> or = 2500 g) infants included in the National Maternal and Infant Health Survey, a nationally representative sample of approximately 10,000 births and 6000 infant deaths. Infants were assigned to one of three exposure groups: maternal smoking during both pregnancy and infancy (combined exposure), maternal smoking only during infancy (passive exposure), and no maternal smoking. SIDS death was determined from death certificate coding. Logistic regression was used to adjust for potentially confounding variables. Infants who died of SIDS were more likely to be exposed to maternal cigarette smoke than were surviving infants. Among black infants the odds ratio was 2.4 for passive exposure and 2.9 for combined exposure. Among white infants the odds ratio was 2.2 for passive exposure and 4.1 for combined exposure. After adjustment for demographic risk factors, the odds ratio for SIDS among normal birth weight infants was approximately 2 for passive exposure and 3 for combined exposure for both races. These data suggest that both intrauterine and passive tobacco exposure are associated with an increased risk of SIDS and are further inducement to encourage smoking cessation among pregnant women and families with children.     

Breast-feeding and environmental tobacco smoke exposure.

BACKGROUND: Exposure to environmental tobacco smoke is associated with adverse effects in infants and children. OBJECTIVE: To explore whether an increase in urinary cotinine fumarate level is caused by ingested nicotine and cotinine in breast-feeding infants. METHODS: We studied newborns at risk for developing asthma and allergies based on a strong family history. We measured urinary cotinine levels in the infants as a measure of environmental tobacco smoke exposure and cotinine levels in the breast milk of breast-feeding mothers. RESULTS: Of 507 infants, urinary cotinine levels during the first 2 weeks of life were significantly increased in infants whose mothers smoked. Breast-fed infants had higher cotinine levels than non-breast-fed infants, but this was statistically significant (P<.05) only if mothers smoked. Urinary cotinine levels were 5 times higher in breast-fed infants whose mothers smoked than in those whose mothers smoked but did not breast-feed. CONCLUSIONS: Mothers should be encouraged to not smoke, and parents must be advised of the potential respiratory and systemic risks of environmental tobacco smoke exposure to their child, including the potential for future addiction to smoking.     

Preterm birth in Sweden: What are the average lengths of hospital stay and the associated inpatient costs?

AIM: To provide estimates of the first-year length of stay and inpatient costs of Swedish infants admitted for neonatal care by week of gestation and by birthweight; and to provide estimates of the length of stay and inpatient costs of delivering mothers during the ante- and postpartum period by week of gestation and birthweight of the infant. METHODS: Population-based registry study covering all live singleton deliveries in Sweden between 1998 and 2001 (n=336 136). First-year hospitalizations of infants admitted for neonatal care 0-6 d after birth (n=24 583) were tracked, as were hospitalizations of mothers for whom the date of admission lay+/-1 mo from the date of delivery. Monetary values were assigned to each hospitalization using the Nord-DRG classification system. RESULTS: On average, preterm infants (GA < 37 wk) had first-year lengths of stay roughly four times as long as full-term infants admitted for neonatal care (30 d vs 8 d, p<0.0001). The average first-year length of stay of the extremely immature infants (GA 22-25 wk) was more than six times as long that of infants born at 34-36 wk (108 d vs 17 d, p<0.0001). Mothers delivering preterm had an average length of stay slightly more than twice as long (p<0.0001) as that of mothers of full-term infants during the ante- and postpartum period. CONCLUSION: The estimated lengths of stay and costs may serve as reference values for a Swedish setting.     

新生儿出生后24小时内凝血功能检测的临床意义分析

目的探讨不同胎龄以及不同体重新生儿凝血功能指标的差异,为判断凝血功能指标的临床意义提供参考。方法2015年1月至2018年12月期间,在解放军总医院第五医学中心新生儿科住院治疗的新生儿中,纳入170例胎龄28~42周、出生8 h内入院的新生儿,其中男性87例,女性83例。按胎龄分为早期早产儿组、晚期早产儿组和足月儿组。按新生儿出生体重分为正常出生体重组、低出生体重组和极低出生体重组。按是否小于胎龄分为早产适于胎龄儿组、早产小于胎龄儿组、足月适于胎龄儿组、足月小于胎龄儿组。于生后24 h内抽取静脉血,检测活化部分凝血活酶时间(activatedpartial thromboplastin time,APTT)、凝血酶原时间(prothrombin time,PT)、纤维蛋白原(fibrinogen,FIB)、凝血酶时间(thrombin,TT)及D-二聚体(D-dimer)。结果早期早产儿组的APTT、PT、D-二聚体水平均高于晚期早产儿组及足月儿组(P值均<0.05),FIB水平低于晚期早产儿组及足月儿组(P值均<0.05);晚期早产儿组的APTT、PT水平均高于足月儿组(P值均<0.05),但两组间D-二聚体、FIB水平比较,差异无统计学意义(P值均>0.05)。极低出生体重组的APTT、PT、D-二聚体水平均高于低出生体重组及正常出生体重组(P值均<0.05),FIB水平低于低出生体重组及正常出生体重组(P值均<0.05);低出生体重组的APTT、PT水平均高于正常出生体重组(P值均<0.05),但两组间D-二聚体、FIB水平比较,差异无统计学意义(P值均>0.05)。早产小于胎龄儿组D-二聚体水平高于早产适于胎龄儿组(P<0.05),其余指标比较差异无统计学意义(P值均>0.05);足月适于胎龄儿与足月小于胎龄儿组的凝血指标比较,差异均无统计学意义(P值均>0.05)。早产儿出血发生率高于足月儿[26.6%(29/109)与8.2%(5/61),χ^2=9.019,P=0.003]。结论新生儿凝血指标有胎龄和体重差异,胎龄越小、体重越低的新生儿凝血功能越不完善。