Maternal genotype alters effect of smoking on infant birthweight

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.

Customized birthweight standards for a Spanish population

OBJECTIVE

To analyse the biological factors affecting birthweight and to derive customized birthweight standards for a Spanish population.

METHODS

A retrospective cohort was created with all the singleton pregnancies delivered at term and free of pathology in our Institution. Birthweight was modeled by multiple linear regression from maternal (ethnic origin, maternal height, booking weight, smoking, and parity), and fetal (gender, gestational age) characteristics.

RESULTS

In addition to gestational age and sex, height, booking weight, ethnic origin, parity, and smoking all have significant and independent effects on birthweight. Women from East-Asia, Morocco and South-America had newborns on average 83 g, 74 g and 95 g heavier than White-European Spanish women. The effect of smoking was found to be dose-related.

CONCLUSION

We found the relative effect of the maternal and fetal characteristics to be very similar to that reported in previous studies. We report coefficients for ethnic groups that account for a sizeable proportion of the population composition of several European countries.

Cessation of periodontal care during pregnancy: effect on infant birthweight

The goal of this study was to assess whether interruption of care for chronic periodontitis during pregnancy increased the risk of low-birthweight infants. A population-based case-control study was designed with 793 cases (infants < 2,500 g) and a random sample of 3,172 controls (infants >or= 2,500 g). Generalized estimating equation models were used to relate periodontal treatment history to low birthweight risk and to common risk factors. The results indicate that periodontal care utilization was associated with a 2.35-fold increased odds of self-reported smoking during pregnancy (95% confidence interval: 1.48-3.71), a 2.19-fold increased odds for diabetes (95% confidence interval: 1.21-3.98), a 3.90-fold increased odds for black race (95% confidence interval: 2.31-6.61), and higher maternal age. After adjustment for these factors, interruption of periodontal care during pregnancy did not lead to an increased risk for a low-birthweight infant when compared to women with no history of periodontal care (odds ratio, 0.96; 95% confidence interval, 0.60-1.52). In conclusion, women receiving periodontal care had genetic and environmental characteristics, such as smoking, diabetes and race, that were associated with an increased risk for low-birthweight infants. Periodontal care patterns, in and of themselves, were unrelated to low-birthweight risk.