Is it effective for NT to lie down

During NT examination, the fetus lying flat usually affects the accuracy of the results, but it is not completely ineffective. Factors such as fetal posture, gestational week error, device resolution, operator experience, and pregnant woman's position may all affect the measurement. When the fetus is in a prone position, the transparent band behind the neck may be obstructed or the measurement difficulty may increase, leading to data bias. The optimal window period for NT examination is between 11-13 weeks and 6 days of pregnancy. At this time, the fetus is small and has a large space for movement, and some fetuses may temporarily change their posture to obtain effective data. High resolution ultrasound equipment combined with transvaginal ultrasound examination can improve the imaging clarity of lying down fetuses. Experienced ultrasound physicians will try to change the fetal position by gently pressing the pregnant woman's abdomen or adjusting the probe angle. If necessary, it is recommended that the pregnant woman retest after activity. In some special cases, the measurement can still be completed in a prone position, such as when a good sound window is formed between the back of the fetal neck and the amniotic fluid, or when three-dimensional ultrasound multi plane reconstruction technology is used. But if the standard section cannot be obtained continuously, it is necessary to consider scheduled follow-up or comprehensive evaluation combined with serological screening. Eating and emptying the bladder appropriately before a pregnant woman's examination, and choosing a period of active fetal movement to seek medical attention, can help improve the success rate of the examination.

It is recommended that pregnant women maintain a relaxed attitude and avoid fasting or holding urine tests. If the initial NT examination is not satisfactory, a 1-2 day follow-up examination can be recommended by a doctor, or supplemented with non-invasive DNA testing for evaluation. Pay attention to balanced nutrient intake in daily life, avoid stimulating the fetus with intense exercise, and regularly monitor fetal development through prenatal check ups.