Deciphering the cryptic abbreviations on pregnancy tests
1. CS is the fetal sac. For women with regular menstruation, the gestational sac can be seen in the uterine cavity on B-ultrasound 35 days after menopause. At 1.5 months of pregnancy, the diameter of the gestational sac is approximately 2 cm, and at 2.5 months of pregnancy, the diameter is approximately 5 cm. The position of the fetal sac at the fundus, front wall, back wall, upper part, and middle part of the uterus is normal; it is normal if the shape is round, oval, and clear; if you have abdominal pain or vaginal bleeding, it may be a miscarriage.
2. CR L is the crown-rump distance, which represents the maximum long axis measured parallel to the longitudinal axis of the carcass. It is mainly used to determine the gestational age at 712 weeks of gestation.
3. BPD is the biparietal diameter of the fetal head.
4. FL is the length of the fetal femur.
5. GP is the grade of placenta. Placentas are generally classified into grade 0, grade I, grade II, grade III, and sometimes grade III+.
6. AI is amniotic fluid index. When doing B pause, take the pregnant woman\’s belly button as the center and divide it into four areas: upper, lower, left and right. The amniotic fluid index in the four regions is added up to obtain the amniotic fluid index. The normal value of the amniotic fluid index in the third trimester is 818 cm.
7. S/D is the ratio of fetal umbilical artery systolic blood pressure to diastolic blood pressure, which is related to the fetal blood supply. When the placenta is dysfunctional or the umbilical cord is abnormal, this ratio is abnormal. In a normal pregnancy, fetal S needs increase with increasing gestational age. Decrease, D increases, the ratio decreases, S/D less than 3 indicates recent pregnancy.
8. LOA, ROA, LOP, ROP; LSA, RSA, which are a group of English abbreviations for fetal positions.
Represents the bones on the left or right side of the pelvis, abbreviated as left (L) or right (R);
Indicates the name of the bone. For example, if the top is exposed first, it is the occipital bone, which is O; if the buttocks are exposed first, it is the sacrum, which is S; the chin is exposed first, which is M;
Indicates that bones are located in front of, behind, or across the pelvis. For example, if the top is exposed and the occipital bone is on the left side of the pelvis, facing forward, the fetal position is left occipital anterior (LOA), which is the most common fetal position.
The abbreviations for each fetal position are as follows:
There are six fetal positions in the table above:
Left front (LOA) Left transverse (LOT) Left rear (LOP) Right front (ROA) Right transverse (ROT) Right rear (ROP)
There are six fetal positions for breech presentation:
Left sacral anterior (LSA) Left sacral transverse (LST) Left posterior sacral (LSP) Right sacral anterior (RSA) Right sacral transverse (RST) Right posterior sacral (RSP)
There are six fetal positions on the face:
Left front (LMA) Left transverse (LMT) Left rear (LMP) Right front (RMA) Right transverseToward (RMT) Right rear (RMP)
There are four fetal positions for shoulder presentation:
Front of left shoulder (LScA) Posterior of left shoulder (LScP) Front of right shoulder (RScA) Posterior of right shoulder (RScP)
Normal biparietal diameter and femoral length diameter
Biparietal diameter is commonly used clinically to determine gestational age above 13 weeks of gestation. The size and weight of the fetus can be estimated based on the size of the biparietal diameter in late pregnancy.
Femoral length and biparietal diameter can be used to estimate fetal size and weight. When the sum of the two is greater than 17 centimeters, there is a possibility of macrosomia.
According to general rules, the size of the biparietal diameter after 5 months of pregnancy is basically the same as the month of pregnancy. The time is about 8.0cm and so on. After 8 months of pregnancy, the biparietal diameter increases by about 0.2cm per week on average, which is within the normal range.
Femoral diameter: Femoral diameter is the length of the femur. The difference between the normal value and the biparietal diameter of the corresponding pregnancy month is about 2-3cm. For example, if the biparietal diameter is 9.3cm, the long diameter of the femur should be 7.3cm; if the biparietal diameter is 8.9cm, the long diameter of the femur should be 6.9cm.
What does placental grade mean?
Starting from the third trimester of pregnancy (28 weeks of pregnancy), placental grade will appear on the B-ultrasound report. At this time, the placenta is mostly graded from 0 to I, around 36 weeks the placenta can be graded I to II, and around 40 weeks the placenta can be graded II to III. Generally speaking, a placenta grade II or above indicates that the fetus is mature.
Does a large biparietal diameter (BPD) of the fetal head always indicate macrosomia?
Clinically, we predict fetal weight by measuring uterine height and abdominal circumference, and the reliability is about 70%. The reliability of predicting fetal weight by measuring fetal biparietal diameter length and femoral length diameter via B-ultrasound is also about 70%. The measurement of fetal biparietal diameter is related to the position of the fetal head and the experience of the B-ultrasound doctor. Clinically, we have also found that very few fetal heads are large but not heavy, which may be related to the genetics of the parents.