Interventions to improve fetal heart rate patterns during open myelomeningocele repair

Introduction
To access fetal heart rate (FHR) after multifactorial changes in the performance of open fetal myelomeningocele surgery.

Material and methods
A study with 37 fetuses submitted to intrauterine myelomeningocele repair between the 24th and 27th week of gestation was performed to evaluate FHR at specific periods: pre-anaesthesia, post-anaesthesia, during neurosurgery (early skin manipulation, spinal cord release, and synthesis), and at the end of surgery. Surgery room (SRT) and uterine surface (UST) temperatures were strictly controlled. A plastic cover was used to protect to protect uterine heat loss. We determined the mean ± standard deviation (SD) of FHR of each period, and we used analysis of variance (ANOVA) with repeated measures to assess differences among these periods. Tukey multiple comparation test was used to compare global surgery stages.

Results
The mean FHR in the specific time points were: 138.6, 138.4, 132.8, 127.7, 131.4, and 132.7 bpm, respectively (p < 0.001). In the comparisons between times two by two, the neurosurgery stage presents the lower frequencies, especially during release of the spinal cord, but episodes of bradycardia were no longer found. SRT and UST remained stable during the critical stages of the procedure.

Conclusions
It is known that many are the factors involved in fetal cardiovascular disorders. Possibly, these changes allowed for better haemodynamic control of the fetus, improving the safety of the procedure.