[Sonographic detection of fetal epiphyseal centers--an additional parameter for determining delivery date]

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Medical Imaging

Context:

• Prenatal diagnosis relies on accurate gestational age estimation.
• Current methods for late-term pregnancy dating have limitations.
• Fetal bone development offers potential markers for gestation.

Purpose:

• To describe a novel ultrasonic method for visualizing prenatal ossification centers.
• To establish average appearance times and growth patterns of specific fetal bones (calcaneus, talus, distal femur, proximal tibia).
• To compare ultrasonic findings with X-ray data and investigate influencing factors.

Summary:

• A new ultrasound technique, inspired by X-ray principles, visualizes ossification centers in fetal tarsal bones and knee joints.
• Average appearance times were determined: calcaneus (24 weeks), talus (26 weeks), distal femur (32 weeks), proximal tibia (37 weeks).
• Growth charts show near-linear increases, with femur epiphysis leveling off after 38 weeks. Fetal weight and length have minimal impact, while sex and maternal factors do not influence timing or size.

Impact:

• This ultrasonic method provides a new tool for assessing fetal development in the third trimester.
• The timing of ossification center appearance and growth can aid in more accurate gestational age determination.
• Understanding bone development variations may help identify specific pregnancy complications.