It is often said that giving birth to a baby needs to go through layers of examination, and ultrasound examination is one of the important steps. So, how can expectant mothers easily win this "passport"? The ultrasound doctor of Jiujiang Maternal and Child Health Hospital will answer you one by one.

This knowledge of ultrasound screening in early pregnancy

Pregnant mothers should know early.

Q 1

What are the important periods of prenatal ultrasound screening?

The Prenatal Ultrasound Guide recommends three important periods of prenatal ultrasound examination: 1 1- 136 weeks, 22-26 weeks and 28-32 weeks.

1 1- 13 6-week obstetric ultrasound examination is what we call FTS. This gestational age is calculated according to the head and hip length of 45-84 mm measured by the last menstruation or ultrasound.

Q2

What is the significance of early pregnancy screening?

1, prenatal screening can advance the diagnosis of severe fetal structural malformation from the second trimester to the first trimester;

2. For clinical obstetricians, early diagnosis has more time to closely observe the fetus, and then deal with the problematic fetus in advance;

3. For pregnant women, advancing the induced labor time of severely deformed children can reduce the psychological and physical harm to pregnant women and shorten the psychological fear period of pregnant women with a history of fetal abnormalities.

Q3

Which groups are suitable for early pregnancy screening?

Suitable for all pregnant women (high-risk pregnancy, low-risk pregnancy, elderly pregnancy, singleton pregnancy, multiple pregnancy, etc.). ).

Q4

Anyway, ultrasound should be done in the second trimester, so why should ultrasound screening be done in the first trimester?

Carry out the principle of "early detection, early diagnosis and early treatment" in prenatal diagnosis, advance the screening time of fetal malformation, screen abnormal fetuses as early as possible, and have enough time to decide whether to stay or not.

Q5

What does FTS check?

1. Determine whether the fetus is alive;

2. Accurately estimate fetal gestational age;

3. Determine the number of fetuses, and determine the properties of chorion and amniotic membrane in multiple fetuses (this is the best time);

4. Evaluate the gross anatomical structure of the fetus;

5. Assess the risk of fetal chromosomal aneuploidy.

Q6

The fetus is so small in the first trimester, can ultrasound detect abnormalities?

The main organs of the fetus have basically formed before 12 weeks of pregnancy, and more than 80% of the malformations are formed at this stage, so 1 136 weeks of pregnancy is an important period for ultrasound screening of fetal structural abnormalities.

FTS can detect 40% to 70% of serious congenital malformations, such as anencephaly, encephalocele, leafless forebrain anencephaly (holoprosencephaly), lymphocyst, omphalocele, heterotopic heart, giant bridge, single umbilical artery, some limb malformations, and sometimes cleft lip and palate, open spina bifida and so on can be diagnosed.

Q7

What are the ultrasonic evaluation indexes for screening aneuploidy chromosome aberration in early pregnancy?

NT, abnormal blood flow in nasal bone and venous catheter, giant ladder, tricuspid regurgitation, omphalocele, single umbilical artery, etc. These ultrasonic markers have a high incidence in some fetuses with chromosomal abnormalities.

Q8

Do you still need to do FTS after NIPT?

Need! NIPT is a new prenatal screening technique developed rapidly in recent years, and the detection rate of Down syndrome can reach 99.9%. Pregnant women don't need to do an Oscar after NIPT, but they still need to do FTS.

On the surface, the value of FTS in screening Down syndrome may be replaced by NIPT, but NIPT is currently limited to screening three pairs of chromosomal abnormalities (2 1- trisomy, 18- trisomy and 13- trisomy). FTS can not only detect fetal structural abnormalities (with or without chromosomal abnormalities), but also detect some microdeletions and microduplications.

Q9

After FTS, do you still need to do ultrasound screening for fetal structural abnormalities in the second trimester (commonly known as long ovulation period)?

Need! FTS, fetal macrosomia ultrasound and fetal heart ultrasound complement each other and are indispensable.

FTS can diagnose more than 50% fetal abnormalities, but it also has its limitations. Fetal intracranial structures, such as cerebellum and corpus callosum, are not fully developed until 18 weeks after pregnancy, when fetal kidney and sacrococcygeal spine are small, so FTS has limited diagnostic ability for these structures. Fetuses with no abnormalities in FTS should cooperate with subsequent large-scale rejection and fetal echocardiography; Fetuses with abnormal FTS can be followed up by ultrasound at 16 weeks on the basis of gene detection to relieve the anxiety of pregnant women.

I hope expectant mothers have a preliminary understanding of prenatal ultrasound screening in the first trimester, and I also hope that every family has a healthy and lovely baby. Our ultrasound doctor will also strictly follow the ultrasound screening standards and carefully complete the ultrasound examination project!

(Contributed by Jiujiang Maternal and Child Health Hospital)