A study reveals that having a high BMI and smoking can lead to longer conception times when trying to have a child.
- According to a new study, the fact of smoking and having a high BMI leads to a greater delay in conception when one wishes to have a child.
- These two characteristics are also associated with the arrival of the first child at a younger age than the others.
- In addition, a high BMI increases the risk of miscarriage and infertility.
If you have baby plans, watch your weight and cigarettes. A study, published in the medical journal BMC Medicine in April 2023, confirms that a high BMI and smoking lengthen the time to conception.
High BMI and smoking linked to longer conception time
To explore the relationship between lifestyle and fertility, the researchers analyzed the records of 84,705 women and 68,002 men from a Norwegian study. Several elements were noted such as alcohol and caffeine consumption, body mass index (BMI), age, health problems or education… In addition, the volunteers answered questionnaires asking for information on previous deliveries, medical history, infertility treatments, time to conception or even mental well-being. In addition, participants were asked to detail their health behavior three and six months before pregnancy. Blood samples were obtained from the intended parents.
First observation of the scientists: in terms of fertility and reproduction, there were no significant differences between men and women, with the exception of the age of the parents at the first birth. It was higher among men.
However, analyzes have mostly shown that a high BMI and smoking are associated with longer conception times. Being overweight is also linked to an increased risk of infertility treatment and miscarriage.
BMI and tobacco: a younger first child too
Moreover, smoking and having a high BMI also seemed to be linked to a younger age at first birth. “Since age at first birth and time of conception are positively correlated, this suggests that mechanisms of reproductive outcomes are distinct from mechanisms affecting fertility”conclude the researchers in their study.
For the team, the arrival of the first child at a younger age in people who smoke or have a high BMI could be explained by the “underlying responsibility for education or attention deficit disorder with or without hyperactivity”. These two elements have already, in fact, been linked to these behaviors.
The researchers add that their work could provide more comprehensive fertility advice.
