NEW YORK (Reuters Health) – Intrapartum translabial ultrasound (ITU) appears to be an effective way to monitor birth progress in term fetuses in cephalic presentation, researchers reported online November 18th in BJOG.

“Giving birth is a natural process, but sometimes requires urgent medical intervention. We showed that ITU provides objective and reproducible assessment of labor progress by relatively simple means.” Dr. Boris Tutschek told Reuters Health by email

The approach has recently been used to study the progress of labor and to predict vaginal delivery. In fact, “the general principle has even been implemented in a commercial ultrasound system.”

However, Dr. Tutschek of Universitats-Frauenklinik, Bern, Switzerland and colleagues note the correlations of the different parameters during normal term labor haven’t been comprehensively studied.

To do so, the team used ITU to study 50 women with normal singleton pregnancies. Most were in the second stage of normal spontaneous labor.

The managing obstetrician or midwife, who was blinded to the results of the ITU, performed vaginal exams after each ITU exam.

There was good repeatability for ITU “head station,” “angle of descent” and “head direction” — both for individual and different examiners.

Angle of descent and head station were interchangeable, and could be calculated from each other. The head station and head direction changed in a typical pattern along the birth canal and time to delivery correlated with ITU head station.

The researchers note that “digital vaginal examination of head station and head position in labor is operator dependent, and is poorly reproducible. Our data suggest that ITU-measured head station may be more accurate than digital vaginal examination, which cannot quantify subtle differences in head station.”

The researchers call for further studies, but conclude “Our new data may improve our understanding of normal and abnormal labor, enable objective measurement of birth progress, and provide a more scientific basis for assessing labor.”

Moreover, concluded Dr. Tutschek, “Our findings may improve the safety of assisted birth.”

Reference:

A study of progress of labour using intrapartum translabial ultrasound, assessing head station, direction, and angle of descent

BJOG 2010.