**9.2 PPROM**

Preterm prelabor rupture of membrane (PPROM) is defined as 'rupture of the fetal membranes prior to onset of labor in a patient who has a gestational age of less than 37 weeks'. PPROM occurs in approximately 3–5% of all pregnancies and accounts for one-third of all preterm births. PPROM is associated with risks of preterm delivery and with substantially increased risks of perinatal morbidity and mortality.

An accurate diagnosis of PPROM is critical to both long- and short-term health and survival for the baby. The absence of a 'gold standard' for the diagnosis of PPROM has stimulated us to search for a clinically applicable marker of PPROM and a marker to predict onset of preterm labor (Wiberg-Itzel et.al 2009).

We have previously shown that a positive 'LAC test', that is a lactate concentration >4.5 mmol/l in vaginal fluid, is a reliable test for rupture of the membranes in pregnancies of 34 weeks of gestation or more. We have also found a significant association between a positive

Lactate Level in Amniotic Fluid, a New Diagnostic Tool 239

Boylan P et al. (1991). "Effect of active management of labor on the incidence of cesarean

Brooks GA. (1986). "The lactate shuttle during exercise and recovery." Med Sci Sports Exerc

Brooks GA. (2000). "Intra- and extra-cellular lactate shuttles." Med Sci Sports Exerc 32(4):

Brooks GA. (2002). "Lactate shuttle -- between but not within cells?" J Physiol 541(Pt 2): 333-

Challis RG. (1974). "Physiology and pharmacology of PGs in parturition." Popul Rep G (5):

Crone C. (1963). "Does "restricted diffusion" occur in muscle capillaries?" Proc Soc Exp Biol

Fitts RH. (2003). "Effects of regular exercise training on skeletal muscle contractile function."

Fletcher WM & Hopkins FG. (1907). Lactic acid in amphibian muscle. J. Physiol. 275:247

Friedman E. A. (1955), 'Primigravid labor; a graphicostatistical analysis', Obstetrics and

Frigoletto FD et al. (1995). "A clinical trial of active management of labor." N Engl J Med

Hannah ME et al. (1996)."Induction of labor compared with expectant management for

Hartree W & Hill AV. (1921). "The nature of the isometric twitch." J Physiol 55(5-6): 389-

Hermansen L. (1981). "Effect of metabolic changes on force generation in skeletal muscle

Hill AV. (1922). "The maximum work and mechanical efficiency of human muscles, and

Kappy KA et al. (1979). "Premature rupture of the membranes: a conservative approach."

Karlsson J et al. (1975). "Constituents of human muscle in isometric fatigue." J Appl Physiol

Kwast B. E et al (1994), 'World Health Organization partograph in management of labour.

Ladfors L et al. (1996). "A randomised trial of two expectant managements of prelabour

Lavender T et al. (2008), 'Effect of partogram use on outcomes for women in spontaneous labour at term', Cochrane database of systematic reviews, (4), CD005461 Lopez-Zeno JA et al. (1992). "A controlled trial of a program for the active management of

Meyerhof O. (1920). Plügers Arch. Gesamte Physiol. Menschen Tiere. 185;11-32.

World Health Organization Maternal Health and Safe Motherhood Programme',

rupture of the membranes at 34 to 42 weeks." Br J Obstet Gynaecol 103(8): 755-

during maximal exercise." Ciba Found Symp 82: 75-88.

their most economical speed." J Physiol 56(1-2): 19-41.

Am J Obstet Gynecol 134(6): 655-61

Lancet, 343 (8910), 1399-404.

labor." N Engl J Med 326(7): 450-4.

prelabor rupture of the membranes at term. TERM PROM Study Group." N Engl J

section for dystocia in nulliparas." Am J Perinatol 8(6): 373-9.

18(3): 360-8.

790-9.

45-53.

309.

411.

Med 112: 453-5.

333(12): 745-50.

38(2): 208-11.

62.

gynecology, 6 (6), 567-89.

Med 334(16): 1005-10.

Am J Phys Med Rehabil 82(4): 320-31.

4.

LAC test and spontaneous onset of labor within 48 hours in late gestations, that is >34 weeks.

Of the 81 women included in this study, 45 had a gestational age less than 34 weeks at the time of examination. Among these, 11 women (24%) had a lactate concentration of >4.5 mmol/l (positive LAC test), of whom 9 (82%) were in active labor within 48 hours. 'False negatives' (negative LAC test but delivered <48 hours) occurred in 0 of 34 women in this subgroup.

A prediction of spontaneous onset of labor is even more valuable in preterm pregnancies, when antenatal steroids may be administered, and women may be referred to tertiary level of medical care. The publication showed that lactate determination in vaginal fluid seems promising as a tool to predict onset of labor within 48 hours even in women with suspected PPROM. A positive LAC test (>4.5 mmol/l) was more strongly associated with spontaneous onset of labor than visible AF.
