B-ultrasound double kidney fuzzy is what problem

The reason why the patient's two B-ultrasound examinations at the hospital at 6 months of pregnancy are blurred and unclear is not that the fetal position is not correct or the fetus is abnormal, because the patient has missed the best time to check the three-dimensional or four-dimensional ultrasound. Therefore, the kidney and heart are unclear. Under normal circumstances, the best time period for three-dimensional and four-dimensional examination should be between 20 weeks and 24 weeks. Pregnant women can go for a reexamination at about 33 weeks to 34 weeks of pregnancy.