News | High BMI and Smoking Both Linked to Longer Time to Pregnancy
A BMC Medicine study assessed lifestyle effects on fertility and reproductive outcomes. High BMI and smoking were associated with longer time to pregnancy and younger age at first birth.
Background
Smoking, heavy alcohol use, high caffeine intake, and obesity are associated with infertility. Smoking and alcohol reduce semen quality and raise miscarriage risk; obesity lengthens time to pregnancy. Observational advice may be affected by diet, sleep, and activity.
The study used Mendelian randomization (MR) to examine possible causal relationships.
Study Design
Data came from 84,705 participants in the Norwegian Mother, Father and Child Cohort Study (MoBa), including 68,002 women. Models assessed smoking, alcohol, caffeine, and BMI against time to pregnancy, infertility treatment, miscarriage, age at first birth, and number of children.
Analyses controlled for birth year, education, and ADHD traits and used UK Biobank data for multivariable MR validation.
Results
BMI and fertility
Higher BMI was linked to longer time to pregnancy, more infertility treatment and miscarriage, and younger age at first birth.
Smoking
Smoking was linked to longer time to pregnancy in women, fewer children, and younger age at first birth.
Alcohol and caffeine
Frequent alcohol use was linked to fewer children and later first birth but less infertility treatment. High caffeine intake was linked to younger paternal age at first birth.
Other findings
Later first birth was associated with fewer children, longer time to pregnancy, miscarriage, and infertility treatment.
Significance
Using several statistical methods, the study highlighted multiple genetic and lifestyle links. Smoking cessation and weight management may support fertility.
The findings may inform fertility guidance and show potential roles for education and ADHD traits.
News | High BMI and Smoking Both Linked to Longer Time to Pregnancy
News | High BMI and Smoking Both Linked to Longer Time to Pregnancy
A BMC Medicine study assessed lifestyle effects on fertility and reproductive outcomes. High BMI and smoking were associated with longer time to pregnancy and younger age at first birth.
Background
Smoking, heavy alcohol use, high caffeine intake, and obesity are associated with infertility. Smoking and alcohol reduce semen quality and raise miscarriage risk; obesity lengthens time to pregnancy. Observational advice may be affected by diet, sleep, and activity.
The study used Mendelian randomization (MR) to examine possible causal relationships.
Study Design
Data came from 84,705 participants in the Norwegian Mother, Father and Child Cohort Study (MoBa), including 68,002 women. Models assessed smoking, alcohol, caffeine, and BMI against time to pregnancy, infertility treatment, miscarriage, age at first birth, and number of children.
Analyses controlled for birth year, education, and ADHD traits and used UK Biobank data for multivariable MR validation.
Results
BMI and fertility
Higher BMI was linked to longer time to pregnancy, more infertility treatment and miscarriage, and younger age at first birth.
Smoking
Smoking was linked to longer time to pregnancy in women, fewer children, and younger age at first birth.
Alcohol and caffeine
Frequent alcohol use was linked to fewer children and later first birth but less infertility treatment. High caffeine intake was linked to younger paternal age at first birth.
Other findings
Later first birth was associated with fewer children, longer time to pregnancy, miscarriage, and infertility treatment.
Significance
Using several statistical methods, the study highlighted multiple genetic and lifestyle links. Smoking cessation and weight management may support fertility.
The findings may inform fertility guidance and show potential roles for education and ADHD traits.
Source:
Collected online