Fathers’ weight and smoking correlate with low birth weight and preterm birth (China)


A study in China, involving 10,121 participants, has found correlations between, on the one hand, the weight/BMI, smoking and educational level of fathers, and, on the other hand, the incidence of low birth weight (LBW) of their babies, their babies being small for their gestational age (SGA) and preterm birth (PTB).

  • Higher educational level correlates with a smaller chance of LBW and SGA.
  • Higher weight/BMI correlates with a smaller chance of LBW, SGA and PTB.
  • Smoking correlates with a higher chance of PTB .

The researchers do not offer causal conclusions from these correlations. Indeed, they state, “the possible reasons are not clear”. They could originate from genetics, the environment, and/or interactions with maternal factors. The correlation between smoking (at least one cigarette per day for at least one month prior to the birth) and preterm birth was not strong, and passive smoking by the mother could not be controlled for.

The researchers propose more research to understand better the mechanisms for paternal influences on the development of the foetus.


Li J et al (2021), Paternal factors and adverse birth outcomes in Lanzhou, China, BMC Pregnancy & Childbirth 21

Header photo: Stanley Zimney. Creative Commons.