Consecuencias del tabaquismo materno (en forma independiente del alcohol) sobre el recién nacido, la placenta y la reactividad de la arteria umbilical a la nicotina

MORALES S; IVELI MF; RIMORINI L; ROLDÁN PALOMO R; ENRIQUE N; SALEMME S; CECOTTI N; GONZALEZ H; REBOLLEDO A; MILESI V

Bariloche

Congreso; XLIV Reunión Anual de la Sociedad Latinoamericana de Investigación Pediátrica; 2006

Sociedad Latinoamericana de Investigación Pediátrica

Introduction: Smoking is one of the risk factors present during pregnancy, and it isassociated with low weight at birth. These alterations are mainly attributed tonicotine and carbon monoxide produced by the cigarette. Objective: To study theconsequences of maternal smoking (independently of ethanol consumption) on thenewborn (NB), the placenta and the contractile response to nicotine of the umbilicalartery (UA) in vitro, having this arteries in vivo an important role in the regulation offetoplacentary circulation. Methods: We worked with two experimental groups:mothers who smoked during pregnancy (S, n=83) and non smoker mothers (NS,n=155). Mothers who consumed ethanol or had any associated comorbility werediscarded from the sample. We performed anthropomorphic measures in the NB andcollected their respective umbilical cords in order to study the in vitro response tonicotine of their UA. Results: maternal smoking exhibited an association with lowweight respect to gestational age: 4% of the NB of the NS group and 16% of the Sgroup presented low weight respect to gestational age (p=0.001 group S vs NS). Theratio placental weight / NB weight was higher in the S group (0.212±0.008 g vs0.186±0.004 g; p<0.05). We observed a positive association between maternalsmoking and a delay in the beginning of breast suction compared to the NS group(children born by cesarean section were excluded). The percentage of NB whichtook more than 2 hours to begin breast suction were of 13% for the NS group(n=118), 46% for a subgroup of S who consumed up to 5 cigarettes/day (n=24,p=0.000 vs NS), and of 67% for a subgroup of S who consumed more than 5cigarettes/day (n=37, p=0.000 vs NS). On the other hand, in UA from either groupwe could not demonstrate contractile effects induced by nicotine concentrationssimilar to those present in a smoker (10-6 M) nor at a concentration 10 times higher.For 10 µM nicotine the values of force expressed in grams force / tissue weight werefor S group: 3.7±1.8 gF/gP (n=19) and for NF: 2.9±4.9 gF/gP (n= 12). Conclusions:we observed a positive association between maternal smoking and a delay in thebeginning of breast suction in the NB, as well as a decrease in their weight respectto gestational age and an increase in the placental weight / NB weight ratio. Arteriesof the NB umbilical cords were not reactive to stimulation with nicotine.