Longitudinal analysis of the vaginal microflora in pregnancy suggests that L. crispatus promotes the stability of the normal vaginal microflora and that L. gasseri and/or L. iners are more conducive to the occurrence of abnormal vaginal microflora

Table 1 Overview of microflora patterns for patients who displayed a conversion from normal to abnormal microflora (n = 13)

	Microflora grade on Gram stain
patient number	trimester I	trimester II	trimester III
PB2003/003	Ib	I-like	I-like
PB2003/007	Ib	III	Ia
PB2003/013	Ib	II	Ib
PB2003/018	Ia	Ia	I-like
PB2003/019	Ib	II	II
PB2003/049	Ib	Ib	II
PB2003/084	Ib	II	Ia
PB2003/101	Iab	Ib	II
PB2003/116	Ib	I-like	II
PB2003/130	Ib	I-like	Ib
PB2003/147	Ib	Ib	I-like
PB2003/148	Ib	Ib	II
PB2003/155	Ib	Ib	II

Gram stained vaginal smears were scored according to the criteria previously described by Verhelst et al [7]. Briefly, Gram-stained vaginal smears were categorized as grade I (normal) when only Lactobacillus cell types were present, as grade II (intermediate) when both Lactobacillus and bacterial vaginosis-associated cell types were present, as grade III (bacterial vaginosis) when bacterial vaginosis-associated cell types were abundant in the absence of lactobacilli, as grade IV when only gram-positive cocci were observed, and as grade I-like when irregularly shaped or curved gram-positive rods were predominant [7]. For the purpose of this study, grade I or Lactobacillus-dominated vaginal microflora is designated as 'normal vaginal microflora' and all other grades as 'abnormal vaginal microflora'.

ISSN: 1471-2180