Weakly positive antinuclear antibodies in pregnant women suggest the possibility of connective tissue disease and require regular review. Antinuclear antibodies are mainly used in the diagnosis of rheumatoid immune system diseases, and their weak positive results can also be seen in normal people, such as the elderly, most commonly in systemic lupus erythematosus and mixed connective tissue disease. Weakly positive antinuclear antibodies in pregnant women need to be examined for rheumatic immune connective tissue diseases, and cardiac ultrasound, antiphospholipid antibodies, antineutrophil cytoplasmic antibodies, and anti-double-stranded DNA antibodies should be performed to clarify the diagnosis. If a pregnant woman is weakly positive for antinuclear antibodies on several occasions, intervention is generally not necessary as long as she does not have other rheumatologic symptoms and there is no cardiac or other vital organ involvement.