What is the standard range for biparietal diameter (BPD)?
May 17, 2022
Source: Cainiu Health
Dr. Chen Zhe
Introduction
At 12 weeks of gestation, the crown-rump length (CRL) is 1.7 cm; at 14 weeks, it is 2.5 cm; at 16 weeks, 3.2 cm; at 18 weeks, 3.9 cm; at 20 weeks, 4.6 cm; at 22 weeks, 5.3 cm; and at 24 weeks, 5.9 cm.
The standard range for fetal biparietal diameter (BPD) varies depending on gestational age. So, what is the standard BPD range?
Standard Biparietal Diameter (BPD) Ranges
At 12 weeks’ gestation, the BPD measures approximately 1.7 cm; at 14 weeks, 2.5 cm; at 16 weeks, 3.2 cm; at 18 weeks, 3.9 cm; at 20 weeks, 4.6 cm; at 22 weeks, 5.3 cm; at 24 weeks, 5.9 cm; at 26 weeks, 6.5 cm; at 30 weeks, 7.6 cm; at 32 weeks, 8.1 cm; at 34 weeks, 8.5 cm; at 36 weeks, 8.9 cm; at 38 weeks, 9.2 cm; and at 40 weeks, 9.4 cm.
The standard BPD value typically becomes relatively stable after 20 weeks’ gestation (i.e., from the fifth month of pregnancy onward), with BPD increasing by roughly 1 cm per month. For example, at 28 weeks (seven months), the fetal BPD is approximately 7 cm; at 32 weeks (eight months), it is about 8 cm.
Prior to labor, healthcare providers routinely measure the fetal biparietal diameter to assess whether fetal development is normal and to determine eligibility for vaginal delivery. Wishing you good health and happiness!
