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.     

ADA genetic polymorphism and the effect of smoking on neonatal bilirubinemia and developmental parameters

Background

Genetic variability of metabolic enzymes may influence the effect of cigarette smoking on intrauterine development and on early neonatal events.

Aims

To investigate the role of adenosine deaminase genetic polymorphism on the effect of smoking on neonatal bilirubinemia and developmental parameters.

Study design

Analysis of association between adenosine deaminase phenotypes and neonatal developmental parameters. Prospective study of serum bilirubin level in relation to adenosine deaminase phenotype.

Methods

We have studied 360 consecutive newborn infants from the Caucasian population of Rome. Serum bilirubin concentration was determined at birth and every 24 h for the first five days.

Results

Overall maternal smoking is associated with a slight decrease in the incidence of phototherapy (13.4% in non smoking vs 11.7% in smoking mothers) and with a reduction of birth weight (3374 g in non smoking mothers vs 3133 g in smoking mothers). There is a significant interaction between smoke and adenosine deaminase. While in non smoking mothers the incidence of phototherapy in carriers of ADA ?2 allele is higher than in ADA 1 phenotype, in infants from smoking mothers the pattern is reversed and the incidence of phototherapy in carriers of ADA ?2 allele is lower than in infants with ADA 1 phenotype. Other neonatal bilirubin parameters follow a similar pattern of interaction between smoking and ADA. The negative effect of smoke on birth weight is much more evident in infant with ADA 1 phenotype than in those carrying the ADA ?2 allele.

Conclusions

The data suggest that ADA phenotype modifies the effect of smoking on developmental and bilirubin parameters.     

Altered placental development in pregnancies resulting in sudden infant death syndrome (SIDS)

Background

Sudden infant death syndrome (SIDS) is postulated to be a developmental disorder originating during fetal life in utero. Knowledge regarding the intrauterine environment in which SIDS infants develop is, however, inadequate and how the placenta develops prior to a SIDS event has not been studied.

Aim

To investigate the morphological development of the placenta obtained from full-term infants who subsequently succumbed to SIDS.

Study design

To estimate the percentage and total volumes of the chorionic villi and villous trophoblast membrane using stereological techniques.

Subjects

Placentas were obtained retrospectively from normal birthweight (SIDS-NBW n = 18) and small-for-gestational age (SIDS-SGA, n = 14) infants who had succumbed to SIDS, and compared to either control (n = 8) or SGA placentas (n = 7), respectively.

Results

SIDS-NBW placentas displayed evidence of augmented villous growth shown by significantly greater volumes of placental chorionic villi (gas-exchanging (GE) villi) in comparison to controls; this was not observed for SIDS-SGA placentas. However, both SIDS-NBW and SIDS-SGA placentas displayed significantly greater volumes of the cytotrophoblast (CT) (SIDS-NBW only), syncytiotrophoblast (SIDS-SGA only) and syncytial knots (SCT-K) and those displaying apoptotic syncytial nuclei (AP SCT-K). In contrast, SGA placentas displayed significantly reduced volumes of chorionic villi, GE villi and the villous trophoblast indicating a SIDS-specific effect associated with augmented placental growth.

Conclusions

Our findings provide initial evidence that placental abnormality, although not necessarily causative, may precede a subset of SIDS cases supporting the hypothesis that the origins of SIDS begin during fetal life in utero.     

Impaired Vascular Reactivity in Newborn Infants of Smoking Mothers

ABSTRACT. A transcutaneous PO₂ technique was used to study the influence of cigarette smoking during pregnancy on postocclusive reactive hyperaemia of the skin of newborn infants and their mothers. Forty-seven mothers and their infants were studied on two occasions (24–48 and 96–144 h) after birth. Twenty of the mothers were habitual smokers, 27 were non-smokers. All mothers were healthy and their pregnancies and deliveries were normal. The infants were all healthy throughout their first week of life. The mothers had more marked reactive hyperaemia than their newborn infants ( p <0.001). Infants of smoking mothers had a significantly weaker postischaemic hyperaemic response 24–48 h after birth than infants of nonsmoking mothers ( p <0.01). This difference had disappeared 96–144 h after birth. Smoking mothers also showed a significantly weaker hyperaemic response to ischaemia than the control mothers at the first investigation ( p <0.05). This difference was smaller and not statistically significant at the second recording. A decreased capacity for postocclusive reactive hyperaemia might be particularly harmful in asphyctic infants, but it may also be detrimental for a normal postnatal circulatory adaptation.     

Vascular retinal abnormalities in neonates of mothers who smoked during pregnancy

OBJECTIVE: To investigate whether maternal smoking during pregnancy causes retinal abnormalities in the newborn. STUDY DESIGN: One hundred sixty-two neonates of smoking mothers and 162 matched neonates of nonsmoking mothers (112 appropriate for gestational age [AGA], 30 small for gestational age [SGA], 20 large for gestational age [LGA] in each group) were studied. RESULTS: Retinal arterial narrowing and straightening (RANS) was observed in 52 and 10 eyes of the newborns of smoking and nonsmoking mothers, respectively (P <. 000001) in association with elevated blood pressure in the neonates. The frequency of RANS was more than 3-fold greater in the SGA neonates than in the AGA and LGA neonates of the smoking mothers. Retinal venous dilatation and tortuosity (RVDT) was found in 100 and 36 eyes of neonates of smoking and nonsmoking mothers, respectively (P <.000001). The frequency of RVDT in the SGA neonates of the smoking mothers was 2.5-fold and 4.2-fold greater than in the AGA infants and the LGA infants, respectively. Also, intraretinal hemorrhages were found in 61 and 31 eyes of neonates of smoking and nonsmoking mothers, respectively (P =.0007) in association with elevated hematocrit and RVDT, whereas no intraretinal hemorrhages were found when RANS was present. All retinal abnormalities resolved by 6 months in infants of smoking mothers and by 2 months in infants of nonsmoking mothers. CONCLUSIONS: Maternal smoking during pregnancy causes increased frequency of RANS, RVDT, and intraretinal hemorrhages; but these retinal abnormalities resolve by 6 months of age.     

Impaired vascular reactivity in newborn infants of smoking mothers

A transcutaneous PO2 technique was used to study the influence of cigarette smoking during pregnancy on postocclusive reactive hyperaemia of the skin of newborn infants and their mothers. Forty-seven mothers and their infants were studied on two occasions (24-48 and 96-144 h) after birth. Twenty of the mothers were habitual smokers, 27 were non-smokers. All mothers were healthy and their pregnancies and deliveries were normal. The infants were all healthy throughout their first week of life. The mothers had more marked reactive hyperaemia than their newborn infants (p less than 0.001). Infants of smoking mothers had a significantly weaker postischaemic hyperaemic response 24-48 h after birth than infants of nonsmoking mothers (p less than 0.01). This difference had disappeared 96-144 h after birth. Smoking mothers also showed a significantly weaker hyperaemic response to ischaemia than the control mothers at the first investigation (p less than 0.05). This difference was smaller and not statistically significant at the second recording. A decreased capacity for postocclusive reactive hyperaemia might be particularly harmful in asphyctic infants, but it may also be detrimental for a normal postnatal circulatory adaptation.     

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.     

Maternal smoking and fetal growth of full term infants

Results of investigation into the effects of maternal smoking and other selected independent variables on fetal growth indicated that smoking by gravida was assoicated with reductions in birth weights and crown-heel lengths, but not with ponderal indices of newborn infants. Mothers of single infants were interviewed following delivery and before discharge about the amount of smoking during pregnancy. Infants were weighed and measured at birth, and step-wise multiple regression analyses were used to interpret the data for 4 groups of infants: males born to primiparas, males born to multiparas, females born to primiparas, and females born to multiparas. Results indicate that maternal smoking during pregnancy was associated with reductions in birth weights and crown-heel lengths, but not in ponderal indices of these groups of full-term infants. The effects of smoking on fetal growth did not appear to be related to poor maternal nutrition, and mean weight gains during the last 2 trimesters of pregnancy were not significantly different in smoking and nonsmoking mothers. Conflicting opinions exist concerning whether the reduction in crown-heel lengths are transitory or not; thus further study is recommended.     

Parental smoking and respiratory illness in infancy.

The relationship between parental smoking and respiratory illness in a birth cohort of 1180 one-year-old children was examined. Maternal smoking was associated with an increased incidence of lower respiratory illness but there was no statistically significant association between paternal smoking and lower respiratory illness. While children of mothers who smoked suffered more lower respiratory illnesses, their overall risk of respiratory infection was similar to that for children of nonsmoking mothers. The association between maternal smoking and infantile lower respiratory illness persisted when the child''s social background, perinatal history, and postnatal diet were taken into account. The findings favour the view that prolonged exposure to cigarette smoke predisposes infants to develop lower respiratory symptoms when they contract a respiratory infection.     

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.     

Placental size of small-for-gestational-age infants at term

Placental size was compared between appropriate-for-gestational age (AGA) and small-for-gestational age (SGA) infants born at term. Placental weight, chorionic plate area and villous surface area were significantly reduced in the SGA infants. Although the ratio of placental weight to birth weight was similar in the AGA and SGA infants, the latter had significantly underweight placentas for their head circumference and crown-heel length. The ratios of placental weight to assessed brain weight and villous surface area to assessed brain weight were also significantly reduced in the SGA infants. It is concluded that the study SGA infants had both absolutely and relatively small placentas.     

Hematological parameters and cobalamin status in infants born to smoking mothers

Hematological parameters, serum cobalamin and folate levels, and the concentrations of the functional markers plasma methylmalonic acid and total homocysteine were determined in 173 newborns and 46 infants at 6 weeks to see whether maternal smoking influences the hematological parameters and the vitamin status of the newborn. At birth, there was a strong inverse correlation between the number of cigarettes smoked per day during pregnancy and red blood cell count (r = -0.56, p = 0.001) and hemoglobin level (r = -0.52, p = 0.003) in the newborns. Neonates born to smoking mothers had lower red blood cell counts and lower hemoglobin and serum cobalamin levels as compared with infants born to nonsmoking mothers. At 6 weeks, maternal smoking significantly predicted the methylmalonic acid and total homocysteine levels, suggesting an influence from smoking on the cobalamin function in these infants.     

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.     

Neonatal urinary cotinine correlates with behavioral alterations in newborns prenatally exposed to tobacco smoke

Altered behavior due to prenatal smoke exposure was examined in 25 neonates born from smoking mothers who consumed at least 5 cigarettes/d during the entire gestation. Data were compared with 25 matched neonates born from nonsmoking mothers. Neonatal behavior was evaluated using the Brazelton Neonatal Behavioral Assessment Scale (BNBAS). Antenatal exposure to tobacco smoke at the end of the pregnancy was determined by measurement of urinary cotinine. Newborns from smoking mothers showed significant lower scores in various BNBAS items compared with neonates from nonsmoking mothers. A strong correlation was observed between infant irritability and urinary cotinine in newborns from smoker and nonsmoking mothers and with number of daily smoked cigarettes and maternal nicotine daily intake of infants exposed to active maternal smoking. Linear regression analysis showed that urinary cotinine was the best predictor of infant irritability (r(2) = 0.727). The latter was also associated to the neonate's low level of attention and poor response to inanimate auditory stimuli. Among infants from nonsmoking mothers, paternal smoking significantly correlated with infant urinary cotinine and infant irritability, being also the best predictor of irritability (r(2) = 0.364). Neonatal behavior can be significantly altered in a dose-dependent manner even after modest prenatal exposure to tobacco smoke.     

Growth in utero and body mass index at age 5 years in children of smoking and non-smoking mothers

Background

High birth weight is associated with overweight later in life, while tobacco exposure in utero is associated with low birth weight, but with later risk of overweight.

Aims

To examine whether body mass index (BMI) z-scores of children at age 5 are associated with measurements of mid-abdominal diameter (MAD) in utero comparing smoking and non-smoking mothers.

Study Design

Growth in utero was recorded as MAD in mm per days of gestational age (MAD for gestational age) at 17, 25, 33 and 37 weeks of gestation in 561 infants whose mothers participated in a population-based study in Scandinavia (1986-1988).

Outcome Measures

The offspring's BMI z-score at 5 years was used as a dependent variable, and MAD for gestational age as well as birth weight divided by gestational age in days were included as explanatory variables in separate linear regression models. Maternal BMI was considered as a potential confounder.

Results

At 17 and 25 weeks gestation there were no relevant differences in MAD for gestational age between smokers and non-smokers. At 33 and 37 weeks gestation, children of smoking mothers had less increase in MAD than children of non-smoking mothers. In adjusted models, MAD for gestational age in week 33 and 37 was positively associated with BMI z-score at 5 years of age among children of both smoking and non-smoking mothers.

Conclusions

In this study overweight in children exposed to tobacco smoking in utero was apparently not mediated through foetal growth retardation, followed by enhanced fat accretion after birth.     

Rate of mother to child transmission of HIV and factors associated among HIV exposed infants in Oromia Regional State,Ethiopia: Retrospective study

Background

Mother to Child Transmission of HIV (MTCTH) is a major public health challenge in Ethiopia. Monitoring and evaluation of the rate of HIV transmission among infants born to HIV positive mothers is the major indicator to understand the performance of a national HIV control program. However, this is not well documented in Oromia Regional State, Ethiopia.

Insulin and Leptin Levels in Appropriate-for-Gestational-Age Infants of Diabetic Mother

Objective

Intensified management of gestational diabetes mellitus can normalize birth weight. However, it is still unknown whether intrauterine exposure to maternal diabetes is a risk factor for changing hormone levels involved in the development of insulin resistance in these infants. We compared insulin and leptin levels in appropriate for gestational age (AGA) infants of diabetic and non diabetic mothers.

Methods

We performed a cross-sectional study in the department of Neonatology of the Hospital of Gynecology-Pediatrics, in Leon, Mexico. We evaluated 182 full term AGA newborns (86 infants of diabetic and 96 of non-diabetic mothers). A venous blood sample was taken from cord blood immediately after the separation of the placenta and glucose, insulin and leptin levels were measured. In all diabetic mothers HbA1c was also evaluated immediately post-partum.

Findings

Leptin, insulin and insulin resistance index were significantly higher in infants of diabetic mothers. Leptin levels were positive correlated with insulin, parents‘ body mass index and age in the entire group. In infants of diabetic mothers only insulin levels showed a significantly correlation, whereas in those of non-diabetic mothers only mothers‘ age was significantly correlated with leptin levels.

Conclusion

AGA infants of diabetic mothers showed higher leptin, insulin levels and insulin resistance index than those of non-diabetic mothers.     

Nicotine in breast milk influences heart rate variability in the infant

AIM: To study the effects of postnatal exposure to nicotine on the regulation of heart rate and blood pressure in infants. SUBJECTS AND METHODS: Thirty-eight mother-infant pairs were studied. Twenty nonsmoking and 18 smoking (2-20 cigarettes per day) mothers were included. All infants were healthy, exclusively breastfed and their postnatal age was 6 weeks. During a home visit infant's urine and mothers' milk were sampled and concentrations of nicotine and cotinine were analyzed. Infants' electrocardiogram (ECG) were recorded, sleep state documented and blood pressure during sleep was measured. Heart rate variability (HRV) was calculated with spectral analysis of R-R intervals. RESULTS: The smoking mothers exposed their infants to nicotine in milk with a median nicotine concentration of 47 (8-192) mug/L. Analysis of infants' urine showed that the nonsmoking group had 0.8 (0-5.2) and the smoke group 60 (17-139) mug cotinine/L (p < 0.01). The frequency domain low-to-high frequency (LF/HF) ratio, was correlated to milk nicotine concentrations in the milk sample, from smoking mothers. HRV decreased, with increasing milk nicotine, ingested by the boys (r =-0.74, p = 0.02) but not the girls (r =-0.13, p = 0.76). The differences of mean arterial pressure between sleep states in the infants, were significantly lower in the smoke group 5.8(6.8) compared to the nonsmoke group 11.5(7.2) mmHg (p = 0.03). CONCLUSIONS: Postnatal exposure to nicotine influences autonomic cardiovascular control in infants.     

Effects of maternal tobacco smoking,sleeping position,and sleep state on arousal in healthy term infants

OBJECTIVES: To investigate whether a history of maternal tobacco smoking affected the maturation of arousal responses and whether sleeping position and infant age alters these relations. DESIGN: Healthy term infants (13 born to mothers who did not smoke and 11 to mothers who smoked during pregnancy) were studied using daytime polysomnography on three occasions: (a) two to three weeks after birth, (b) two to three months after birth, and (c) five to six months after birth. Multiple measurements of arousal threshold in response to air jet stimulation were made in both active sleep (AS) and quiet sleep (QS) when infants slept both prone and supine. RESULTS: Maternal smoking significantly elevated arousal threshold in QS when infants slept supine at 2-3 months of age (p<0.05). Infants of smoking mothers also had fewer spontaneous arousals from QS at 2-3 months in both prone (p<0.05) and supine (p<0.001) sleeping positions. In infants of non-smoking mothers, arousal thresholds were elevated in the prone position in AS at 2-3 months (p<0.01) and QS at 2-3 weeks (p<0.05) and 2-3 months (p<0.001). CONCLUSIONS: Maternal tobacco smoking significantly impairs both stimulus induced and spontaneous arousal from QS when infants sleep in the supine position, at the age when the incidence of sudden infant death syndrome is highest.     

Impact of histological chorioamnionitis, funisitis and clinical chorioamnionitis on neurodevelopmental outcome of preterm infants

Background

The role of chorioamnionitis in neurodevelopment of preterm infants is not fully understood.

Aim

To examine the association between different indicators of intrauterine inflammation (clinical chorioamnionitis, histological chorioamnionitis and funisitis) and neurodevelopmental impairment in very preterm infants.

Methods

Preterm infants with a birth weight of < 1500 g or a gestational age of < 32 weeks were included. Follow-up evaluation up to 2 years of age consisted of neurological examination, neurodevelopmental assessment and visual and audiologic tests. Outcome data were compared between the chorioamnionitis and the control groups, controlling for gestational age, birth weight and Apgar score at 5 min.

Results

One hundred seventy-seven patients comprised the study population (mean gestational age 29 ± 2 weeks, mean birth weight 1167 ± 344 g). Histological chorioamnionitis was present in 49% of placentas, whereas funisitis was observed in 25%. In 57% cases clinical maternal chorioamnionitis was suspected. Follow-up was available for 130 (82%) patients. Infants with funisitis, compared with controls, had a significantly higher incidence of moderate to severe disability (18% vs 5%, OR 4.07; 95% CI 1.10-15.09).

Conclusion

The results of this study suggest that, unlike a broad definition of histological chorioamnionitis including inflammation of maternal or fetal placental tissues, funisitis may entail a higher risk of moderate to severe disability at 2 years of age in preterm infants.