Abstract
Objective This article systematically reviews the literature to establish the normal range
of lactic acid in healthy pregnant women.
Study Design Ovid MEDLINE, Embase.com, and Clinicaltrials.gov were searched to identify studies
that reported maternal lactic acid in healthy pregnant women. Pooled aggregate means
and two standard deviations for each time period were computed using the inverse variance
weighting technique. Analyses were performed separately for 1st, 2nd, and 3rd trimesters,
scheduled cesarean delivery, early labor, active labor, 2nd stage of labor, and delivery.
Results Overall, 22 studies met the inclusion criteria. There were 1,193 patients, and 2,008
observations identified. All time periods had maternal venous lactic acid aggregate
means and two-standard-deviation ranges less than 4 mmol/L. Outside of labor, all
ranges were less than 2 mmol/L. All labor periods had a range higher than 2 mmol/L.
While the pooled ranges were less than 4 mmol/L, many individual studies reported
ranges > 4 mmol/L during labor.
Conclusion This meta-analysis suggests that venous lactic acid levels can be used as a screening
tool in pregnant women just as the test would be used in nonpregnant women, except
that elevations may be seen during labor, especially later in labor when there is
maximal skeletal muscle contraction.
Keywords
pregnancy - lactic acid - reference values - parturition - labor - obstetric - delivery
- obstetric
