To obtain reliable data on the growth and development of the fetus during pregnancy, a woman undergoes several ultrasound studies, during which biparietal dimensions of the head (BDP) are established. This is the most important indicator that is determined with each bearing. He gives information about the size of the child's head, shows the correspondence of the degree of development of the nervous system to the term of pregnancy.
This study should be carried out in order to confirm the fetal and maternal passage through the birth canals. By the result of BDP choose the most optimal type of delivery. If the BDP head of the fetus for weeks shows that the size of the head at the time of birth will not match the mother's birth canal, designate a planned operation of caesarean section .
Norms of BDP fetus
In order to understand if the biparietal size of the fetus corresponds to the developmental norms, you should familiarize yourself with the FDA table of the fetus for weeks.
This study is carried out for the first time, but the most reliable results can be obtained after 12 weeks, that is, in the second or third trimester. Modern ultrasonic apparatuses are equipped with the necessary tables, including the fetal BPR table, and during the study the doctor or operator selects the type of data and on their basis conducts a study.
If the BDP fetus does not match the deadline, do not immediately worry, in the measurements allowed for certain fluctuations. For example, both the eleventh and thirteenth week of pregnancy, the head's BDP can be equal to 18 mm. The final conclusion, whether the BDP of the fetal head corresponds to your gestation period, should be supplied by the doctor who leads your pregnancy.
The level of fetal development and gestational age can be determined by combining the parameters of the occiputa-frontal size and the biparietal size of the fetal head. This indicator is special in that as the baby grows up inside the mother, the data growth slows down. For example, at the age of 12 weeks, the fruit grows by four millimeters per week, and at thirty-three weeks - by a maximum of 1.3 millimeters.
Variations in the BDP of the fetus from normal
If the BDP of the fetus goes beyond acceptable limits, this may indicate the presence of pathologies in the fetus. But before the diagnosis is made, the doctor carries out additional measurements and only then, based on their results, concludes. Increased BPR may indicate the presence of a brain tumor, a tumor of the bones of the skull, brain hernia, hydrocephalus.
If the size of the head is significantly reduced, this indicates a brain underdevelopment or the absence of some of its structures, such as the cerebellum or one of the two hemispheres. If a decreased BDP is detected in the third trimester, this may indicate the development of the syndrome of intrauterine growth retardation. In this case, prescribe drugs that improve utero-placental blood flow. Such drugs include Kurantil and Actovegin.
In most cases with pathological deviations of the BDP head from the norm, pregnancy is interrupted at any time. An exception is the increase in the size of the head due to the development of hydrocephalus. In this case, the treatment is carried out using antibiotics. And only in rare cases it is necessary to interrupt pregnancy.