By Megan Brooks
NEW YORK (Reuters Health) Jun 15 – Obstetricians can be reassured that repeated cervical exams during active labor won’t increase the risk of maternal infection, say the authors of a report this month in Obstetrics & Gynecology.
In a large retrospective study, they found no significant link between number of cervical examinations and risk of maternal fever (a surrogate marker of infection), even when multiple exams were done after rupture of membranes.
“This is a clinical issue in everyday labor management and these data are reassuring,” Dr. Alison G. Cahill from Washington University in St. Louis, Missouri, and first author on the paper, told Reuters Health.
She noted that some prior studies had suggested that cervical exams may raise the risk of maternal fever, but those did not consider time spent in labor, which is a problem, Dr. Cahill said.
She explained: “If we consider someone who is in labor for two hours and compare them to someone who is in labor for 12 hours, you could imagine that just by virtue of the amount of time they spend in the hospital and in labor they would certainly by definition have fewer or more exams, respectively.”
“When we accounted for the length of labor, there wasn’t a measurable increased risk with number of exams and fever, so it’s probably the length of labor and not the exams themselves that increases risk for febrile morbidity,” Dr. Cahill said.
Dr. Kathleen M. Brennan, an obstetrician at the University of California Los Angeles who was not involved in the study, told Reuters Health the data from this study are “very reassuring, particularly in academic institutions or training hospitals, where patients may have a cervical exam by a more junior physician first, and then a more senior physician may validate the findings with a second cervical exam at the same time point.”
The four-year retrospective cohort study involved all consecutive term singleton deliveries reaching the second stage of labor. Dr. Cahill and colleagues identified women who developed an intrapartum fever and compared them with women who remained afebrile through six hours postpartum. The primary exposure was number of digital cervical examinations. Time-to-event analyses were used to account for length of labor.
Of 2,395 women who were afebrile at admission, 174 (7.2%) developed an intrapartum fever. Women were examined one to 14 times and there was no significant association between increasing number of examinations and risk of fever, the investigators say.
“Even for the 505 women who had more than seven examinations during labor, there was no statistically significant increased risk of fever (hazard ratio 0.9, 95% confidence interval 0.4 – 2.0) compared with those with one to three examinations,” they report.
Subanalyses by labor type and examinations after rupture of membranes also didn’t reveal any significant association between number of cervical examinations and risk of fever.
Dr. Cahill said, “Our data would suggest that it’s not the exams, which is certainly reassuring because our best data from modern obstetrics certainly encourages us to actively manage patients’ labors to optimize outcomes and to do this we really need to be able to examine patients and know how their labor is going.”
Dr. Brennan added, “We are always trying to minimize risk of peripartum infection on labor and delivery. Trying to minimize checks is classically thought to be one way to reduce infection risk. No matter the study findings, I still think we should try to minimize the number of cervical exams a patient has; however, we should not worry about doing an extra cervical exam if it’s necessary to properly manage a patient’s labor.”
“As far as immediate clinical implications, this article is very timely as a new set of interns will be starting residency in the upcoming weeks. This article reassures us that a patient’s health is not compromised by additional cervical exams that more commonly occur as junior residents are learning how to properly evaluate cervical dilation,” Dr. Brennan commented.
Obstet Gynecol 2012;119:1096-1101.
— Megan Brooks0