To explore the effects of dietary intervention on dietary behavior, dietary patterns, pregnancy weight gain control and prevention of adverse pregnancy outcome among singleton pregnant women.

From March 2017 to December 2017, a total of 1 000 primiparas with normal singleton pregnancy less than 13 weeks were randomly divided into intervention group and control group with the random number table, 500 cases in each group. Pregnant women of intervention group were received pregnancy diet nutrition health education and individualized nutrition guidance. Pregnant women of control group were treated with routine training on pregnancy nutrition and health care knowledge. The General Information Questionnaire, Nutrition Knowledge, Attitude, Practice (KAP) Questionnaire and the Case Report Form (CRF) were used toinvestigated related information in two groups, such as the population characteristics of sociology, pregnancy outcome, pregnancy complications, the score of KAP questionnaire and pregnancy weight gain. The Food FrequencyQuestionnaire (FFQ) was used to investigate the consumption of foods of pregnant women.

A total of 986 pieces of valid data (494 in intervention group and 492 in control group) were collected in this study. The proportion of pregnant women with normal body mass index (BMI) and pregnancy weight gain in intervention group was higher than that in control group; the incidences of pregnancy complications, cesarean delivery, giant baby and premature baby of intervention group were lower than those of control group with significant differences (P<0.05) . There was no statistical difference in the score of KAP questionnaire of pregnant women between intervention group and control group during first-trimester (P>0.05) . The scores of KAP questionnaire of pregnant women during second-trimester and last trimester in intervention group were significantly higherthan those in control group as well as those during first-trimester (P<0.01) . The consumption frequencies of foods of pregnant women in intervention group during last trimester were higher than those during first-trimester with significant differences (P<0.05) , except for the consumption frequency of "roughage and its products" (P>0.05) .

Pregnancy dietary intervention could help pregnant women to keep normal pregnancy weight gain, improve the level of KAP of pregnancy rational diet, better diet behavior and prevent pregnancy complications as well as adverse pregnancy outcome.

Pregnant women; Pregnancy complication; Pregnancy outcome; Diet intervention; Weight gain