Question
At 26 weeks pregnant, the fetus has a biparietal diameter of 6.1 cm, a femur length of 4.1 cm, a humerus length of 3.8 cm, an abdominal circumference of 20.7 cm, and amniotic fluid depth of 4.7 cm. The B-ultrasound report shows the baby is only 24 weeks and 4 days old. Does this indicate that the fetus is overall underdeveloped or just short limbs? Are these values normal? Could it be dwarfism?
Answer
According to your description, the fetus’s various indicators are slightly smaller than the expected gestational age but are still within the normal range. The color Doppler examination indicates that the fetus may be about 10 days smaller than the estimated gestational age calculated from the last menstrual period. If your menstrual cycle is usually inaccurate or if fertilization occurred later than usual, the fetal growth and development indicators may be slightly lower than expected. This situation usually does not require excessive concern, but it is still important to note that if in the color Doppler examination, the size of the fetus’s indicators differs from the actual last menstrual period estimate by more than two weeks, further observation may be necessary.