Related Experiment Video
Updated: May 5, 2026
State of the Art Cranial Ultrasound Imaging in Neonates
Published on: February 2, 2015
Biparietal diameter at 11 to 13 weeks' gestation in fetuses with holoprosencephaly
Asma Khalil1, Aris Papageorghiou, Amar Bhide
1Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's Hospital Medical School, London, UK.
Insights
First-trimester fetuses with holoprosencephaly show smaller biparietal diameter (BPD). This early BPD measurement can aid in the prenatal diagnosis of holoprosencephaly, improving detection rates.
Area of Science:
- Medical imaging in obstetrics
- Fetal development and anomalies
- Genetics and prenatal diagnostics
Background:
- Holoprosencephaly is often diagnosed later in pregnancy, despite evidence of smaller head size in early gestation.
- Early identification of holoprosencephaly is crucial for timely intervention and management.
Purpose of the Study:
- To evaluate the biparietal diameter (BPD) at 11 to 13 weeks' gestation in fetuses diagnosed with holoprosencephaly.
- To determine if BPD measurements in the first trimester can serve as an early marker for holoprosencephaly.
Main Methods:
- Retrospective analysis of BPD measurements in 34 fetuses with holoprosencephaly and 7775 controls.
- BPD values were adjusted for crown-rump length and maternal factors, expressed as multiples of the median (MoM).
Main Results:
- 32.4% of fetuses with holoprosencephaly had BPD below the 5th centile, and 67.6% were below the 50th centile.
- Significantly smaller BPD MoM values were observed in the holoprosencephaly group compared to controls (p=0.03).
- Increased nuchal translucency and trisomy 13 were common findings in affected fetuses.
Conclusions:
- First-trimester biparietal diameter is reduced in fetuses with holoprosencephaly.
- This finding suggests that BPD measurement in early pregnancy is a valuable tool for the prenatal diagnosis of holoprosencephaly.
Objective:
Studies have suggested that fetuses with holoprosencephaly have smaller head size, demonstrated as early as the first trimester. However, the majority of these cases were diagnosed in the second or third trimesters. The aim of this study was to investigate biparietal diameter (BPD) measured at 11 to 13 weeks' gestation in fetuses with holoprosencephaly.
Methods:
This was a retrospective study in which BPD was measured at 11 to 13 weeks in 34 fetuses with prenatal diagnosis of holoprosencephaly and 7775 unaffected controls. BPD values were converted into multiples of the expected median (MoM) after adjustment for crown-rump length and maternal characteristics.
Results:
The median gestational age at the BPD recording was 12.6 (interquartile range 12.3-13.0) weeks. The nuchal translucency was increased (≥3mm) in 58.8% of the cases. Aneuploidy was confirmed in 73.5% of the cases; the commonest was trisomy 13 (50.0%). BPD values at 11 to 13 weeks were below the 5(th) centile in 32.4% of cases and below the 50(th) centile in 67.6%. BPD MoM values were significantly smaller than in the control group (median: 0.98; interquartile range: 0.90-1.06 vs 1.00; 0.96-1.04 MoM, p = 0.03).
Conclusion:
Fetuses with holoprosencephaly have a smaller BPD in the first trimester. This property may be useful in early diagnosis.
