What is BDP on ultrasound during pregnancy: description of the indicator, norm, interpretation of the results of the study

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

There is no such woman who would not worry about the state of the fetus inside. The embryo goes through a long way of development from several cells to a full-fledged organism. To track all changes and exclude fetal anomalies, its development is monitored using ultrasound.

With the help of ultrasound, photometry is done, that is, some important indicators are measured. But in this article, we will pay more attention to the biparietal head size of a growing man (BDP). The interpretation of ultrasound - all the data obtained with the help of ultrasound, is given by the doctor. The results on paper are mostly just numbers. It is difficult to understand them without special medical knowledge. You need to have an idea of what screening is. Then it will be clear what information is provided by the ultrasound doctor.

What is BDP on ultrasound during pregnancy

When a woman bears a child, she must undergo an ultrasound 3 times a day.pregnancy. Each time it is necessary to check such basic measurements as BPR, LZR and KTR. What is BDP on ultrasound during pregnancy? Biparietal size is the main indicator that displays the width of the fetal head. According to this indicator, doctors can judge whether or not there is a developmental pathology in the prenatal period. Already in the early stages, doctors are able to detect genetic mutations and malformations due to such parameters as the coccygeal-parietal size of the fetus (KTR), biparietal size (BPR) and fronto-occipital size (LZR).

Biparietal fetal size is measured exactly after the 20th week of pregnancy when the first screening is done. BDP on ultrasound is the size between the two temples. The information received is compared with the data corresponding to your term. All norms are listed in the table. We will review her data, which reflects normal development, later.

BPR weekly norms

Because the baby in the womb develops very quickly, the numbers increase every week. All pregnant women want to know how fast the fetus is developing inside them, if there are any abnormalities.

The size of the fetal head is measured using ultrasound. The other two indicators (BPR and LZR) correlate with those average values that are considered the norm today.

We look at the BDP indicator on ultrasound during pregnancy. The norm is given in millimeters.

The table below shows the measurement norms from 14 to 24 weeks.

Pregnancy term (weeks)	BDP (mm)	Head circumference (mm)
14	22	103
15	27	112
16	32	124
17	36	135
18	40	146
19	44	158
20	47	170
21	50	183
22	54	195
23	57	207
24	59	219

These data are averaged. That is, a deviation of 2 mm in one direction or the other is considered acceptable.

Pregnancy screening at 12 weeks

We looked at what BDP means on ultrasound during pregnancy. This is the distance between the parietal bones of a small head.

An important ultrasound screening is done between 12 and 14 weeks. This study allows you to determine how the baby feels in the womb, how it develops. Ultrasound is done through the skin of the abdomen (transabdominally). By week 12, BDP should be within 21 mm. Also at this time, the diameter of the chest (DHA) is measured. It should be 24 mm, CTE is approximately 51 mm at this time. Another important indicator is the thickness of the collar zone. Its value is a marker of the presence (absence) of Down syndrome. ATTVZ norm should be 0.71 - 2.5 mm.

The doctor also looks at the condition of the uterus, the amount of amniotic fluid, their purity or turbidity.

What deviations can there be

Let's repeat what BDP is on ultrasound during pregnancy. This is a study of the development of the brain. After all, the brain and heart are the most important organs of the child. If they do not develop properly, the child may be born disabled.

When the BDP index does not correspond to normal indicators, the doctor can establish one of the following diagnoses:

• Delayed fetal development. Such a diagnosis is made if all other indicators do not go beyond the permissible limits, and the biparietal size is reduced. This can be observed for two reasons: the size of the brain is less than normal due to its underdevelopment or due to the absence of part of the brain tissue.
• The indicators of LZR and BPR are exceeded, while others are normal. These are indications of hydrocephalus in the fetus. Popularly, this disease is called dropsy.
• Down's syndrome is diagnosed if the collar space is enlarged, heart defects are present and a decrease in the fronto-thalamic distance is diagnosed, and the size of the cerebellum is also less than normal. This is all measured at 23 weeks. In addition to these measurements, it is also necessary to analyze the genome and take the mother's blood for analysis.
• Tumors or cysts in the brain. If BDP has increased due to a tumor, then the mother is recommended to artificially terminate the pregnancy.

If the data obtained from the study is not too optimistic, the doctor prescribes an additional ultrasound. Perhaps there waserror. This is often the case if the period is rather short or the study was performed by an inexperienced doctor.

Measuring at 23 weeks pregnant

The next ultrasound is usually done at 22-23 weeks. At the 6th month, the baby is already fully formed. At this time, the brain and the entire central nervous system of the fetus are actively developing. Therefore, an ultrasound scan must be done to find out what the biparietal and fronto-occipital size of the skull is at this stage of development in the baby.

What does BPD mean on ultrasound during pregnancy? This information directly speaks about the development of the unborn baby.

At this period, the indicators should be as follows:

• BPR - 52 - 64 mm.
• LZ - 67 - 81 mm.
• Growth at this time is approximately 20-26 cm.

At this time also measured:

• Thigh bone. Its length is 38-42 mm.
• Fetal tibia - 36-42 mm.
• Fibular - 35-42mm.

Brain activity at 23-24 weeks already corresponds to a newborn. They say that the baby is already beginning to dream at this time, smile, and remind his mother of himself with light jerks.

If a baby is born at this time, then such a birth is already classified as a premature birth, not a miscarriage. With the help of medical equipment in the maternity hospital, it is possible to leave him.

Women's he alth status in 2nd and 3rd semesters

In addition to the parameters of the child, with the help of ultrasound, the condition of the amniotic fluid, as well as the blood flow in the umbilical cord in the secondsemester. Mom's he alth is just as important. As you know, both organisms at this time are completely interconnected. The state of the cardiovascular and nervous system of a woman also needs to be examined during pregnancy. In order for the birth to be successful, a woman needs to go to pregnancy courses and gradually engage in physical and breathing exercises. At the 3rd semester, be sure to check the condition of the heart.

Intrauterine growth retardation

GER is basically not obtained by chance. Often, the expectant mother herself is to blame for intrauterine growth retardation. The reasons for the gold reserves can be:

1. Infection. When it occurs, the pathogen is established and treatment is prescribed for the mother. If the infection has already damaged the child's brain, there will be little point in treating it.
2. Oxygen starvation. This is a very dangerous condition for a child. A pregnant woman should walk for 2 hours a day in the fresh air.
3. Fetoplacental insufficiency.

We already know what BDP is on ultrasound during pregnancy. This indicator with developmental delay will be very small - below 18 mm at 14 weeks. In order to prevent such serious deviations, it is advisable to find out about pregnancy in the first weeks in order to follow all the doctor's advice from the very beginning.

Hydrocephalus and microcephaly

With hydrocephalus, the volume of the head is larger than that of the average fetus. And with microcephaly in the unborn child, the head size turns out to be smaller than it should be for a given gestational age.

It doesn't always have to do with mutation or disease. Often the child's parents are short andrelatively small bones of the skull (compared to the majority of the world's population). Then their baby will also be smaller than the average newborn.

BDP at end of pregnancy

Why are measurements taken in the 3rd trimester, if the BPD on ultrasound is completely normal? The fact is that at the end of pregnancy, doctors need to know how much the size of the fetal head corresponds to the mother's genitals. If it is clear that it will be difficult for a woman to give birth on her own due to the large head of the child, then she is advised to have a planned caesarean section.

If everything is foreseen in advance, then the woman will not have any complications during childbirth. However, a caesarean section is an operation that has its own risks, which must also be considered.

Prevention

We explained in detail what BDP means on ultrasound. How to prevent the occurrence of deviations in the development of the embryo? In order for the fetus to develop normally, it needs certain conditions: daily walks in the fresh air and good nutrition of the mother, the measured rhythm of her life, the exclusion of heavy physical exertion and situations that cause nervous tension. A woman also needs a good sleep. If a lady is going to raise a baby alone, it will be very difficult for her. Therefore, doctors insist that the child must be planned. When planning, parents agree in advance on whether a woman will work during gestation, how long she will be engaged in labor activities.

Before conceptionit is important for the expectant mother to undergo an examination. The presence in the blood of infections such as rubella, the herpes virus and toxoplasmosis can lead to the loss of a child. Also, some couples are better off undergoing genetic testing. This is especially important for those parents in whose families there were diseases of a hereditary nature.

Conclusions

We explained what BDP is on ultrasound during pregnancy, what is LZR and KTP. Doctors use these parameters to judge whether the fetal brain is developing correctly.

It is very important for physicians to know the rate of BDP. Ultrasound determines all the necessary indicators. Therefore, even in the womb, it is possible to determine deviations in the development of the fetus and prevent the birth of a terminally ill child.

In some cases, according to the indications of ultrasound, a woman is prescribed treatment, after which repeated measurements of the fetus are made.