Ultrasound examination is non-invasive, painless, fast and accurate, and is an important auxiliary examination method for pregnancy examination. It can observe and detect fetal morphology, fetal growth indicators, fetal behavior, fetal appendages (placenta, umbilical cord, amniotic fluid) and fetal hemodynamic changes. With the full liberalization of the second-child policy in my country, the number of elderly parturients continues to increase, and the rate of teratogenesis continues to increase. Obstetric ultrasound has also attracted more and more attention. Many expectant mothers say that among the various examinations, the one who has been waiting the longest and confused the most is ultrasound. Let’s teach you how to read the ultrasound report.
Do at least 5 ultrasound examinations during pregnancy
For expectant mothers, there are at least 5 ultrasound examinations necessary during pregnancy, and each ultrasound examination has the requirements of the gestational period, which should be done on time.
6-8 weeks of pregnancy: Determine the location and number of the fetal sac, exclude ectopic pregnancy and scar pregnancy, determine whether the embryo is alive, and check the gestational week according to the fetal bud nucleus.
11-14 weeks of pregnancy: Check the main NT value (the thickness of the transparent layer of the fetal neck), and check whether there are serious structural deformities.
20 to 24 weeks of pregnancy: screening and diagnosis of fetal malformations.
28 to 32 weeks of pregnancy: the second screening to supplement the missing questions in the first screening.
36 to 40 weeks of pregnancy: mainly observe the fetal position, size, placental maturity, amniotic fluid volume, umbilical cord blood flow, and estimated fetal weight. Provide information for the choice of delivery method and the smooth delivery.
Understand the report
The content on the obstetric ultrasound report form varies with the gestational age. The ultrasound report sheet in the first trimester generally includes embryo sac, germ and heartbeat, and in the middle and late stages it generally includes fetal position, fetal movement, fetal heart, double parietal diameter, femoral length, placenta, amniotic fluid, and umbilical artery S/D ratio. Is it even more confusing to see such a term? Let me pick some to explain.
Gestational sac (GS): For those with regular menstruation, the gestational sac can be seen in the uterine cavity by B ultrasound. The gestational sac is about 2 cm in diameter at 1.5 months of pregnancy, and about 5 cm at 2.5 months. The position of the fetal sac on the fundus, anterior wall, posterior wall, upper and middle of the uterus is normal; the shape is round, oval, and clear as normal; if the fetal sac is irregular, fuzzy, and located in the lower part, pregnant women also When you have abdominal pain or vaginal bleeding, you may have a miscarriage.
Double parietal diameter (BDP): The length of the longest part between the left and right sides of the head, also known as the “large cross diameter of the head”. When CRL (the length from the head to the buttocks of the fetus, also known as “head-buttock length”) cannot be used to determine the expected date of delivery at the initial stage, BPD is often used to predict; after the mid-term, it is often necessary to measure the weight of the fetus. The data. According to the general rule, it is less than 3 cm at 3 months of pregnancy; after 5 months of pregnancy, it basically corresponds to the month of pregnancy, that is to say, BDP is about 7 cm at 28 weeks (7 months) of pregnancy, and 32 weeks (8 Month) is about 8 cm, and so on. After 8 months of pregnancy, an average weekly increase of about 0.2 cm is normal.
Femur length (FL): The length of the fetal femur, also known as “femur length”. Generally around 20 weeks of pregnancy, the development of the fetus is checked by measuring FL.
Amniotic fluid index (AFI), do B overtime, center on the pregnant woman’s umbilical area, divide up, down, left and right 4 regions, add the amniotic fluid depth of the 4 regions to get the amniotic fluid index, the amniotic fluid index in the third trimester is normal The value is 8-18 cm.
The ratio of fetal umbilical artery systolic blood pressure to diastolic blood pressure (S/D): reflects the placental vascular resistance. Under normal circumstances, the S/D ratio decreases as the gestational age increases, and the S/D ratio is less than 3 in near-term pregnancy.
Placental maturity: It is divided into three levels. Level I is the early stage of placental maturation. The echo is uniform, and this change can be seen from 30 to 32 weeks of pregnancy; Level II indicates that the placenta is close to maturity; Level III indicates that the placenta is mature. The closer to term, the more mature the placenta and the more uneven the echo.
Amniotic fluid range: Generally speaking, the amniotic fluid depth is between 3 and 7 cm is normal, more than 7 cm is an increase in amniotic fluid, less than 3 cm is a decrease in amniotic fluid. If the amniotic fluid is too much, it means that the fetus’s neural tube or digestive tract may be abnormal; if the amniotic fluid is too little, it may be a problem with the fetal urinary system.
Fetal movement: It is an important signal used to predict the safety of the fetus in the uterus. The fetal movement is the strongest at 28 to 32 weeks of pregnancy, and the amplitude and frequency of fetal movement gradually decrease after 36 to 38 weeks of pregnancy. If the report says “yes” and “strong” are normal, “no” or “weak” may be that the fetus is sleeping, or it may be abnormal, and it must be combined with other items for comprehensive analysis.