A prospective statistical study of 48,505 pregnancies indicates no significant relationship between smoking by the mothers and perinatal mortality.
Infants of smoking mothers were smaller at birth, however, and the incidence of prematurity was greater.
Surprisingly, the incidence of preeclampsia was decreased with maternal smoking. But other and frequent complications of pregnancy were increased.
Authors of the two-year Navy study repeatedly emphasized that they were reporting only statistical relationships. They warned against drawing cause-and-effect conclusions about the results.
"A number of factors other than smoking may have influenced these results," said Lt Cdr Paul B. Underwood, MC, USN. "A good example is our finding regarding the effects of paternal smoking.
"In a preliminary report of this material, it appeared that fathers' smoking habits influenced pregnancy outcome, as had been reported by others. However, close observation of the data revealed that an increased number of wives smoked when their husbands also