SMOKING DURING PREGNANCY

Cord blood cells and indices: smoking-related differences between the sexes

The values of whole blood cell count, leucocyte differential, and platelet and reticulocyte counts were determined in cord blood of both male (n = 64) and female (n = 75) newborns of 87 non-smoking and 52 smoking mothers. Leucocytes and neutrophils in cord blood from the male newborns of smokers were significantly lower than those in their female counterparts and in male newborns of non-smokers. These results suggest that male newborns are more affected by cigarette exposure than females with regard to some haematological parameters.

Nicotine administration differentially affects gene expression in the maternal and fetal circadian clock

Exposure to nicotine by active and passive cigarette smoke is a common public health problem. Recent studies have demonstrated that human fetuses are also exposed to significant levels of nicotine and that there is a five-fold increase in the incidence of Sudden Infant Death Syndrome among infants born to smoking mothers. We examined the effect of nicotine administration and expression of the immediate early gene c-fos in the maternal and fetal rat brain by in situ hybridization. Nicotine injection (1 mg/kg s.c.) on embryonic day 20 (E20) induced detectable c-fos mRNA in the maternal habenula and hypothalamic paraventricular nucleus whereas, in the fetal brain, c-fos was induced in both these structures and also in the suprachiasmatic nucleus (SCN). Nicotine-induced c-fos expression in the fetal SCN was confirmed by Northern analysis and found to return to near basal levels by 3 h post-injection. These responses were blocked by pre-administration of mecamylamine, indicating that the effect of nicotine is mediated through the cholinergic system. Investigation of the development of this response revealed that nicotine failed to induce c-fos expression in the SCN on E16, caused minimal expression on E18, robust expression on E20 and postnatal day 0 (P0), and no expression on P2 or thereafter. These observations suggest that an alteration in the composition of the nicotinic receptors (nAChR), or the subsequent intracellular responses leading to c-fos expression, occurs in the SCN during the perinatal period. Induction of c-fos mRNA in the SCN by light has been associated with phase-shifts of the circadian system, however, the behavioral consequences of the transient sensitivity of the fetal and neonatal SCN to nicotine administration and the consequences for maternal-fetal entrainment remain to be directly determined.

The adverse effects of tobacco smoking on reproduction and health: a review from the literature

This paper compromises a short literary review of the adverse consequences of tobacco smoking on reproduction, as well as on infant and adult health. Furthermore, attention is drawn to the bad effects of smoking on the nutritional status.

Effects of prenatal nicotine exposure on rat striatal dopaminergic and nicotinic systems

Previously we observed that chronic nicotine-treated adult rats developed locomotor hyperactivity which was mediated by changes in nicotinic and dopaminergic receptors in the striatum. In this study, we further examined if such changes would also occur in pups that were prenatally exposed to nicotine. Fourteen-day-old offspring from dams which were implanted with osmotic minipumps containing nicotine (1.5 mg/kg/day) throughout the entire gestational period were employed in this investigation. Prenatal nicotine treatment lowered the number of male pups born and reduced the postnatal gain in body weight and length of both male and female offspring. Prenatal exposure to nicotine did not alter the motor coordination of the pups. A decrease in the number of striatal dopaminergic receptor binding sites (Bmax) was detected in the male pups, however an increase in the ligand affinity to the receptors (1/KD) had been simultaneously detected. No change in the characteristics of nicotinic receptor binding sites and the levels of dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid was found in the striatal region. The present study indicates that prenatal exposure to nicotine may cause changes in growth and development of the animals. However, in comparison to chronic nicotine-treated adult rats, prenatal exposure to nicotine had only modified the dopaminergic receptor system in the striatal region of male offspring.

The effect of maternal smoking on birth weight and the subsequent health of the child

The effect of maternal smoking during pregnancy on birth weight was studied in 12,068 births, the mothers in 1819 of which were regarded as smokers. The children of the smokers were compared with those of controls of similar age, parity, marital status and place of residence. Maternal smoking reduced birth weight in a dose-related manner. Birth weight was least affected among young, primiparous mothers who smoked only slightly, a difference which was, however, entirely caused by those mothers who stopped smoking for the last 3 mth of pregnancy, and this subgroup showed similar figures for postneonatal mortality and morbidity up to the age of 5 to those of their controls. Postneonatal mortality was higher in the total group of the smokers than among their controls, the primiparous or young mothers not differing in this respect from the others. Morbidity up to the age of 5 was significantly higher (p less than 0.001) among the children of the smokers, the children of the primiparas and young mothers being affected in a similar way to the others. The low birth weight infants of the smokers had a higher mean birth weight and lower perinatal mortality than the low birth weight infants of the controls, but morbidity up to age of 5 and postneonatal mortality were higher among the smokers in respect of both low birth weight infants and others.

Smoking patterns during and before pregnancy: weight, length and head circumference of progeny

This study indicates that tobacco smoking by the mother is associated with a significant reduction of the newborn's size. This effect cannot be explained by either an association of the smoking habit with malformation, premature birth, exaggerated consumption of coffee matrimonial status or paternal smoking, or by a combination of malformation, prematurity and any one of the other factors. The effect is also unrelated to the continuation or discontinuation of smoking during pregnancy. Paternal smoking seems to be associated with a reduced weight in children born to nonsmoking mothers.