Analysis of fetal breathing movements at 30-38 weeks of gestation

Florido, Jesús
Cortés, Elena
Gutiérrez, Marcos
Soto, Victor Manuel
Miranda, María Teresa
Navarrete, Luis

¹Department of Obstetrics and Gynecology, Escuela Universitaria de Ciencias de la Salud and Facultad de Medicina, University of Granada, Granada, Spain
²Obstetrics and Gynecology Service, Hospital General Básico de Baza, Baza, Granada, Spain
³Departament of Physical Education and Sports, Facultad de Ciencias de la Actividad Fisica y del Deporte, University of Granada, Granada, Spain
⁴Departament of Biostatistics, Facultad de Medicina, Universidad de Granada, Granada, Spain

^*Corresponding author: Dr. J. Florido Navío, Escuela Universitaria de Ciencias de la Salud, Universidad de Granada, E-18071 Granada/Spain. Tel.: 958-242873, Fax.: 958-242867, E-mail: [email protected]

Received January 8, 2004. Revised August 17, 2004. Accepted September 30, 2004.

Journal of Perinatal Medicine 33(1):p 38-41, January 2005.

Aims

This study reports the changes in patterns of fetal breathing movements recorded with a photogrammetric method in three successive periods of gestation.

Methods

Respiratory movements were studied in fetuses of 28 healthy women with uncomplicated pregnancies of 30–38 weeks of gestation. Women were divided into three groups according to gestational age of the fetus: 30–32 weeks, 7 fetuses; 33–36 weeks, 9 fetuses; and 37–38 weeks, 12 fetuses. Sonographic images of the fetuses were recorded on videotape, digitized (1 image per 0.12 s) and analyzed with specially developed software.

Results

The proportion of fetuses in each age group for which movements were detectable was similar in all three groups, as was the frequency of movements. Duration of a complete respiratory cycle, the inspiratory phase and the expiratory phase tended to be shorter at 33–36 weeks of gestation than in younger and older fetuses. Fetuses in the 30–32-week group had slower breathing rates than fetuses in the two older groups.

Conclusions

The photogrammetric technique revealed differences in some patterns of fetal breathing movements between weeks 30–32, 33–36 and 37–38 of gestation. The data provide a sound basis for relating changes in fetal breathing movements with physiological and anatomical changes that occur as the respiratory system matures.