Association Between Lactate Levels in Vaginal Fluid and Time of Spontaneous Onset of Labor in Suspected Cases of Prelabor Rupture of Membranes

Abstract

Purpose To assess correlation between lactate levels in vaginal fluid and onset of labor in suspected PROM.

Diagnosing onset of labor: a systematic review of definitions in the research literature

“…Of the 62 included studies, 22 (35 %) were from the United States [ 25 – 44 ] and six (10 %) were from Germany [ 12 – 14 , 45 – 48 ]. The remaining studies included four each from Italy [ 49 – 52 ] and Nigeria [ 53 – 56 ], three (5 %) each from Iran [ 57 – 59 ] and Norway [ 60 – 62 ], two each from Israel [ 63 , 64 ] and South Africa [ 65 , 66 ], and one each from Australia [ 67 ], Austria [ 68 ], Bahrain [ 69 ], Canada [ 70 ], France [ 45 ], India [ 71 ], Ireland [ 72 ], Jordan [ 73 ], Korea [ 74 ], Kuwait [ 75 ], New Zealand [ 76 ], Pakistan [ 77 ], Philippines [ 78 ], Saudi Arabia [ 79 ], South Korea [ 80 ], and Sweden [ 81 ]. Most of the included studies ( n = 39, 63 %) were published between 2005–2013 (Fig.…”

“…Most of the included studies ( n = 39, 63 %) were published between 2005–2013 (Fig. 2 ) [ 13 , 14 , 28 , 30 – 34 , 36 , 38 , 39 , 42 – 48 , 50 – 52 , 55 – 59 , 63 , 67 , 69 – 71 , 73 – 77 , 79 – 81 ]. The majority of studies were retrospective cohort studies ( n = 29, 47 %) [ 2 , 25 , 27 , 28 , 30 – 36 , 38 , 40 , 41 , 43 , 44 , 49 – 51 , 55 , 61 , 62 , 65 , 66 , 70 , 72 , 80 , 82 , 83 ], while 29 % were prospective cohort studies ( n = 18) [ 26 , 29 , 37 , 39 , 42 , 46 – 48 , 52 – 54 , 56 , 60 , 67 , 71 , 74 , 79 , 81 ] and 11 % ( n = 7) were randomized controlled trials or cohort [ 57 – 59 , 69 , 75 ...…”

“…In the 62 included studies, we observed four distinct types of labor onset including “active labor”, “latent or early phase labor”, “first stage labor” or simply “labor” without further specification, which we call “unspecified labor”. The majority of studies defined the onset of active phase labor only ( n = 22, 35 %) [ 26 , 27 , 31 , 35 , 41 , 42 , 45 , 50 , 51 , 53 , 56 , 57 , 59 , 61 , 63 , 65 , 66 , 71 , 74 , 77 , 79 , 83 ]. Three studies only defined the latent phase of labor (5 %) [ 40 , 55 , 76 ], while 11 studies only defined onset of the first stage of labor (18 %) (see Table 1 ) [ 32 – 34 , 38 , 47 , 62 , 68 – 70 , 73 , 78 ].…”

“…Studies also varied in their descriptions of the length and frequency of contractions at onset of labor. Twenty-one studies (34 %) included mention of either length or frequency of contractions in their definition of the onset of labor [ 29 , 30 , 32 , 33 , 35 , 49 – 51 , 54 – 56 , 60 – 62 , 66 , 67 , 69 , 71 , 74 , 75 , 83 ]. One study stated that onset of labor in general is also characterized by intact, rather than ruptured, membranes [ 28 ].…”

“…Of the studies that included a definition of the onset of active labor ( n = 33), 27 (82 %) included cervical dilatation in their definition [ 2 , 26 – 29 , 31 , 42 , 45 , 50 , 51 , 53 , 54 , 56 , 57 , 59 , 60 , 63 , 65 – 67 , 71 , 74 , 75 , 77 , 79 – 81 ]. Two (6 %) included ≥2 cm cervical dilation as the measure of labor onset [ 50 , 51 ], ten (30 %) cited 3–4 cm [ 29 , 45 , 53 , 54 , 59 , 65 – 67 , 77 , 79 ], while fourteen (45 %) included ≥4 cm cervical dilation in their definition of active labor onset [ 2 , 26 – 28 , 31 , 42 , 56 , 57 , 60 , 63 , 71 , 74 , 75 , 80 , 81 ]. Two studies (6 %) did not quantify the amount of dilation present at onset of active labor and stated rather that there should be contractions leading to “cervical change” [ 35 , 83 ].…”