Patient's question:
Think about it, everyone. On October 7th, I had a prenatal check-up. At that time, I calculated it as 7 weeks based on the start date of my last menstrual period, but the gynecological color Doppler ultrasound report showed that the baby was the size of 8 weeks. Then the doctor told me to come back in 4 or 5 more weeks and to book an early color Doppler ultrasound. Today, I booked a color Doppler ultrasound for November 4th, which is the time I am 11 weeks pregnant. The nurse wanted to book a gynecological color Doppler ultrasound for me, but my colleagues have been doing obstetric color Doppler ultrasounds since they confirmed the pregnancy. The nurse disagreed and said that all appointments for less than 12 weeks of pregnancy are for gynecological color Doppler ultrasounds. Then she booked an obstetric color Doppler ultrasound for November 11th, which is the time I am 12 weeks pregnant. She said the obstetric color Doppler ultrasound includes NT screening. But if I follow the results of the first color Doppler ultrasound, which showed the baby's size, by the time I am 12 weeks pregnant, won't the baby be 13 weeks old then? Will there be errors in the data if I do the obstetric color Doppler ultrasound at that time? I want to ask, based on these dates, which week should I go?Doctor's answer:
NT screening should be performed best between weeks 11 and 14 of pregnancy. Screening before week 14 may not be accurate, as this is the period when fluid accumulates under the baby's neck skin, which can be measured using ultrasound. Therefore, NT screening is conducted earlier than the screening for Down syndrome. NT screening is primarily implemented through ultrasound, with a final measurement value below 3 millimeters considered normal. If the measurement is below 3 millimeters, further screening such as amniocentesis may need to be considered.