Health behaviors in women conceiving by medically assisted reproduction vs natural conception: A cross-sectional study of 23,334 nulliparous women

INTRODUCTION: Women conceiving by medically assisted reproduction (MAR) have a planned pregnancy, easing adherence to preconception recommendations, which they are expected to be highly motivated to comply with. However, little is known about the actual adherence among these women. Thus, we investigate to what extent women conceiving by MAR treatment adhere to recommendations from the Danish Health Authority regarding preconception health behavior and whether the adherence differs from that observed in women conceiving naturally. Secondly, we elucidate differences in health behavior in early pregnancy by mode of conception.

MATERIAL AND METHODS: A cross-sectional study using patient-reported questionnaire data from 23,443 nulliparous women collected in connection with their first-trimester nuchal translucency scan from 2012 to 2022 at Copenhagen University Hospital in Denmark. The women answered an online questionnaire including information on whether they conceived by MAR, which type of treatment, and their health behaviors before and during pregnancy. This included alcohol consumption, smoking, exercise, and intake of dietary supplements. Differences in health behaviors by mode of conception were analyzed using multiple logistic regression with adjustments for age and educational level.

RESULTS: Overall, 91% of women answered the questionnaire. Women who conceived by MAR (15%) had healthier preconception behaviors with significantly higher odds of taking folic acid supplements (adjusted odds ratio [aOR] 11.40, 95% confidence interval [CI]:9.95;13.04), stopping smoking due to planning of pregnancy (aOR 1.72, 95% CI:1.49;1.98), avoiding smoking (aOR 4.67, 95% CI:3.88;5.62), and avoiding alcohol (aOR 2.40 95% CI: 2.19;2.64) compared to women conceiving naturally. Adherence to recommendations among women who conceived by MAR was 30.6% for alcohol avoidance preconceptionally. In early pregnancy, women conceiving by MAR still had significantly healthier behaviors overall, except for exercise, which was lower (aOR 0.86, 95% CI: 0.80; 0.93), with 46.3% meeting the recommended weekly hours of exercise.

CONCLUSIONS: Women conceiving by MAR generally exhibit healthy behaviors with high adherence to recommendations from the Danish Health Authority both preconceptionally and in early pregnancy, though only one third adhered to recommendations on avoiding alcohol preconceptionally, and half of the women adhered to recommendations on exercise in early pregnancy. Overall, women conceiving by MAR had healthier behaviors than women conceiving naturally.