Introduction:
First, second and third-hand smoke exposure to cigarette smoke during pregnancy is one of the most serious public health problems. According to the World Health Organization (WHO), smoking is a serious chronic disease and the smoker is a patient who needs frequent medical intervention. The aim of this systematic review is to investigate the influence of primary, secondary and tertiary exposure to cigarette smoke on both pregnancy and the fetus.

Methods:
For the systematic review, articles were searched in the Medline online database using keywords ("smoking or tobacco or first hand smoke exposure or second hand smoke exposure or third hand smoke exposure" and "pregnancy or fetus"). The inclusion criteria for the search of the articles were the studies in the Greek and international literature referring to smoking during pregnancy.

Results:
From the literature review 10,928 results of studies were found, 298 were selected for further evaluation and based on the "inclusion-exclusion" criteria 22 studies were selected to be analyzed. The analysis of the studies found that primary, secondary and tertiary exposure to cigarette smoke during pregnancy results in a range of complications in both the fetus and the neonate.

Conclusions:
Smoking cessation at any stage of pregnancy has beneficial benefits for both mother and fetus. Therefore, abstinence from smoking during pregnancy is necessary for the smooth development of the fetus.