Abstract:

Objective To evaluate the interaction between adherence to the Mediterranean diet （MD） and pre-pregnancy BMI， as well as the modifying effect of physical activity during pregnancy， on the risk of pregnancy complications. Methods A total of 568 pregnant women were randomly selected from Urumqi Maternal and Child Health Hospital and Urumqi Youai Hospital between January 2025 and January 2026. Dietary intake during pregnancy was assessed using a 14-point Mediterranean Diet Adherence Score （MEDAS）. Logistic regression models were used to analyze the independent effects and interactions of MD adherence with pre-pregnancy BMI， as well as the modifying role of exercise during pregnancy， on pregnancy complications. Results The average age of the subjects was （30.39 ± 4.046） years， and 192 cases of pregnancy complications occurred. Among them，83（14.61%） had gestational diabetes（GDM）， 63（11.09%） had gestational hypertension（HDP），28（4.93%） had anemia，26（4.58%） had too much or too little amniotic fluid， 20 （3.52%） had thyroid abnormalities， and 10（1.76%） had placental abnormalities. Logistic regression showed that after adjusting for confounding factors， highly adherence MD was a protective factor for overall disease during pregnancy （OR = 0.912， 95%CI： 0.838 - 0.991， P = 0.030）， HDP（OR = 0.770， 95%CI： 0.675 - 0.879， P < 0.001）， and GDM （OR = 0.882， 95%CI： 0.789 - 0.985， P = 0.027）. Stratified display suggests that this protective effect is more significant in the exercise pregnant population. Pre pregnancy overweight and obesity are risk factors for HDP （OR = 3.256，95%CI： 1.683 - 6.299， P < 0.001； OR = 12.095， 95% CI： 5.288 - 27.663， P < 0.001） and GDM （OR = 2.499， 95%CI： 1.409 - 4.430， P = 0.002； OR = 9.035， 95%CI： 4.097 - 19.923， P < 0.001）， with a more significant increase in risk in the non exercise group. Interaction analysis showed a significant interaction between pre pregnancy BMI and MD compliance， with overweight （total disease OR = 0.773， P = 0.022）；HDP OR = 0.707，P = 0.040）、Obese pregnant women （total disease OR = 0.500， P = 0.006）；HDP OR = 0.457，P = 0.009；GDM OR = 0.565， P = 0.017） MD has a stronger protective effect. After exercise stratification， the combination of high compliance MD diet with exercise during pregnancy is a protective factor for HDP in pre pregnancy overweight population （OR = 0.484， 95%CI： 0.264 - 0.887， P < 0.05）. Conclusion Improving adherence to the Mediterranean diet， maintaining a normal pre-pregnancy BMI， and engaging in regular physical activity during pregnancy can effectively reduce the risk of pregnancy complications such as HDP and GDM.

Key words: mediterranean diet pattern, pre-pregnancy BMI, exercise during pregnancy, complications during pregnancy