Epidural Plus Fever During Labor Put Baby at Risk
By Crystal Phend, Senior Staff Writer, MedPage TodayPublished: January 30, 2012
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
- A temperature spike during labor with epidural analgesia may indicate serious risks for the baby in an otherwise low-risk delivery.
- Point out that the risks of hypotonia, assisted ventilation, low Apgar scores, and early-onset seizures weren’t associated with epidural catheters when fever above 99.5°F didn’t occur.
A temperature spike during labor with epidural analgesia may indicate serious risks for the baby in an otherwise low-risk delivery, researchers found.
Infants whose mother ran a fever over 101°F while receiving an epidural were two- to six-fold more likely to be weak, need ventilation, have low Apgar scores, and experience early-onset seizures, reported Elizabeth A. Greenwell, ScD, and colleagues from various institutions affiliated with Harvard University in Boston. Greenwell is now at the University of Colorado Denver School of Public Health.
The same risks weren’t observed with epidural catheter use when fever above 99.5°F didn’t occur, the group pointed out in the February issue of Pediatrics.
“Although epidural analgesia is generally considered a safe and effective method of pain relief during labor, both randomized trials and observational studies consistently demonstrate an association between epidural and maternal fever during labor,” they noted.
Some evidence suggests epidurals induce an inflammatory response and boost cytokines levels that inflict neurologic damage.
Regardless of the cause of fever, these results from pregnancies not complicated by infection suggest that even a moderately elevated temperature could hurt the baby, perhaps because fetal core temperature runs at least 1°F higher than that measured in the mother, Greenwell’s group explained.
“Although many of the specific outcomes we found associated with elevated maternal temperature may be transient, it is possible that particularly the increase in early-onset neonatal seizures could have implications for longer-term health of the infant,” they acknowledged.
Whether trying to cool down a woman during labor once the fever is detected would reduce risk for the baby isn’t clear, the group cautioned.
They studied outcomes for all women giving birth to their first child at term at Boston’s Brigham and Women’s Hospital in 2000. The patients did not have documented sepsis, meningitis, or major congenital anomaly.
Just 13% of these 3,209 low-risk women opted against an epidural during labor.
Fever of more than 100.4°F developed during labor in 19% of epidural users compared with just 2% of those who went without (P<0.0001).
Lower grade temperatures were also more common with epidural use. Overall, 45% of women who received an epidural had a temperature of at least 99.5°F during admission for delivery compared with 13.2% among women without an epidural.
Undergoing an epidural without developing a temperature didn’t appear to have any affect on infant outcomes measured.
But the higher a woman’s temperature while delivering with an epidural, the higher the risk to the baby. Comparing maternal temperature of 99.5°F or lower to one over 101°F, the results were:
- Transitional hypotonia prevalence rose from 11% to 25% (P<0.001)
- Hypotonia lasting more than a quarter of an hour rose from less than 1% to 3% (P=0.0005)
- Requirement for substantial resuscitation efforts at birth rose from 4.4% to 12.2% (P<0.0001)
- Apgar scores under 7 at one minute after birth rose from 6.4% 13.5% (P<0.0001)
- Apgar scores under 7 at five minutes after birth rose from 0.3% to 2.1% (P=0.0007)
After adjustment for maternal age, baby’s birth weight, duration of labor, and method of delivery, these risks were all significant at a fever of more than 101°F.
A temperature of 99.6° to 100.4°F also significantly predicted more transitional hypotonia and poor Apgar scores at one minute. A temperature of 100.5° to 101°F also predicted poor Apgar scores at one minute along with hypotonia lasting more than 15 minutes.
Only eight infants developed early-onset seizures, but four had been exposed to a maternal temperature over 100.4°F during delivery. Compared with women whose temperature never went over 99.5°F, that represented a 6.5-fold higher risk.
The researchers cautioned that few women in the low-risk population developed a fever in the absence of epidural use, which precluded analysis of whether fever was more dangerous in the setting of an epidural.
Bias from a pediatrician being in the room more frequently when women develop fever during labor likely wasn’t responsible for the difference in outcomes, because the results were similar for women running temperatures of 99.6° to 100.4°F for which pediatricians wouldn’t be called in, the group noted.
Undetected maternal or infant infection was plausible but unlikely to be responsible for the findings either, they added.
The study was supported in part by an award from the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
The researchers reported having no conflicts of interest.