Smoking influences male-female birth ratio.Fukuda M, Fukuda K, Shimizu T, et al: Parental periconceptional smoking and male:female ratio of newborn newborn /new·born/ (noo´born?)
1. recently born.
2. newborn infant.
Very recently born.
A neonate. infants. Lancet lancet /lan·cet/ (lan´set) a small, pointed, two-edged surgical knife.
n. 2002; 359:1407-1408
Parental Smoking of more than 20 cigarettes a day may reduce the frequency of conceiving Conceiving may refer to:
The male:female sex ratio of nonsmoking non·smok·ing
1. Not engaging in the smoking of tobacco: nonsmoking passengers.
2. Designated or reserved for nonsmokers: the nonsmoking section of a restaurant. parents was 1.214 (1975:1627), compared to 0.823 (255:310) for two parents who smoked more than 20 cigarettes a day (odds ratio = 0.68, 95% CI = 0.57-0.81, P < .0001). In couples with fathers smoking more than 20 cigarettes a day and mothers who did not smoke, the ratio was 0.984 compared with nonsmoking couples (odds ratio = 0.81, 95% CI = 0.74-0.88, P < .0001). The ratio also appears to decline with maternal smoking, but further research is needed among couples with a nonsmoking father and mother who smokes.