Effects of epidural for pain relief during labor and delivery on fetal heart rate and on newborn well-being
Medical Review (Med. pregled), 2023, 59(2), 40-48.
M. Atanasova1, S. Nashar1, A. Nikolov2
1 Acibadem City Clinic MHAT Tokuda Hospital – Sofia
2 University Hospital “Maichin dom” – Sofia
Abstract. Epidural anesthesia (EA) is the most efficient method of pain reduction during labor and delivery. Objective: The aim of this study was to establish the effects of epidural analgesia for labor on fetal heart rate pattern and on newborn well-being. Material and methods: The study was prospective for a six-year period (2007–2013), included 1489 patients, who met the following criteria: 1) single birth; 2) gestational period > 36 weeks; 3) livebirths; 4.) occipital position of fetus; 5.) active phase of delivery 6.) vaginal delivery. The parturients were divided on two groups, according to method for pain relief – 740 with epidural analgesia and 749 with parenteral opioid with spasmolytic – 50-100 mg Lydol, 40 mg Buscolysin and 25 mg Antiallersin. The condition of fetus was evaluated in all cases by continuous cardiotocograph tracing during the first stage of labor and intermittent auscultation during the second stage. We analyzed and compared the changes of fetal heart rate (FHR) pattern between groups. The condition of newborn was evaluated by neonatologist in all infants by Apgar score on minutes 1 and 5 and umbilical artery blood gases.
Results: There were no significant differences in frequency of changes in cardiotocograph tracing after initiation of EA or application of spasmo-analgetics for pain relief, between groups – 20.29 % (n = 152) in controls, compared with 17.03% (n = 126) in groups with epidural analgesia (p>0.05). The frequencies of different anomalies of FHR were calculated on base only of cardiotocograph tracing with changes in two groups. There were no significant differences in frequency of early, late and variable decelerations between groups – respectively 42.11% (n=64), 3.95% (n=6), 6.58% (n=10) in controls, respectively, compared with 47.62% (n=60), 3.17% (n=4), 5.56% (n=10) in the group with epidural analgesia (p>0.05), respectively. We found differences between the two groups in frequencies of tachycardia, bradycardia and low reactivity and variability. In the control group the frequency of tachycardia and low reactivity and variability was higher than group with epidural analgesia – 21.71% (n=33) in controls and 6.35% (n=8) in the second group. Tachycardia started between 11-21 minutes after intramuscular application of spasmo-analgetics and continued 35-42 minutes. Low reactivity and variability were observed in 23.68% (n=35) in controls, compared with 11.9% (n=15) in the epidural group (p<0.05) that changes start between 35-41 min and continues 52-65 min. The frequency of bradycardia (defined as a fall in FHR below baseline and lasting at least 10 minutes) was higher in the epidural group 34.92% (n=44) and 12.5% (n=19) in controls (p<0.05), respectively. Bradycardia occurred in 6.9 % of parturient women with EA, started between 15–20 min and lasted 12.2 ± 2 min. In 88.63% of cases of fetal bradycardia we established maternal hypotension. Our study showed that there was a significant difference between groups when we compared the need of oxygen therapy during first two hours after delivery of newborn (р<0,05). Oxygen therapy was applied in 8.45% (n=59) of newborn in the group with EA and in 17.55% (n=123) of newborn in the control group (p<0.05). Adaptation periods of all infants took place fluently. Conclusion: EA does not affect the frequency of changes in fetal heart rate patterns. The study established that there were differences in type of changes between groups. The frequency of tachycardia and low reactivity and variability were higher in the control group; the incidence of fetal bradycardia was higher in the epidural group. There were no differences in rate of early, late and variable deceleration between groups. Epidural analgesia for labor and delivery does not affect wellbeing of the newborn. Newborns in the group with EA were in better clinical and metabolic condition and had lower risk for development of respiratory depression compared with the newborns of labor, in which we used Lydol for pain relief.
Key words: fetal heart rate, epidural analgesia, newborn wellbeing, bradycardia, tachycardia, deceleration
Address for correspondence: Maria Atanasova, MD, e-mаil: mgicheva@abv.bg