Background: According to the Ministry of Health in 2020, the percentage of underweight pregnant women in Indonesia is 9.7%. Underweight is a condition of low body weight for age which is related to height. The condition of being underweight during pregnancy must be addressed immediately because influence fetal development. Insulin is an important factor in pregnant women for fetal development, such as the brain and eyes. Underweight conditions can cause pregnant women to experience insulin resistance since the beginning of pregnancy. This study identified the effect of DHA on changes in insulin in underweight pregnant women at the Made Surabaya Community Health Center.

Methods: This research includes pre-experimental research with one group pre-test post-test using 21 samples of underweight pregnant women who were examined physical, obstetrics, ultrasonography, and venous blood collection procedures were carried out for examination before and after DHA supplementation. Testing was carried out using the paired t-test and Wilcoxon test.

Results: The research results show that there was a significant difference between before and after DHA supplementation was given to underweight pregnant women. The difference is body weight (p=0.001), body mass index (p=0,002), upper arm circumference (p=0.000), body height (p<0.001), and insulin (p<0.001).

Conclusions: The research results showed that there was a significant effect of giving DHA on body weight, body mass index, upper arm circumference, height, and insulin.