Table 1.

Summary of studies providing evidence for bacteria in the human fetoplacental unit in both complicated and uncomplicated pregnancies (✓marks published evidence)

Pregnancy state	Method	Placenta	Amniotic fluid	Fetal membranes	Reference
Normal pregnancy	Microscopy	✓	✓	✓	[26, 37–40]
	Bacterial cultures	✓	✓	✓	[16, 37, 39, 41–50]
	Culture independent methods	✓	✓	✓	[14, 26, 37, 38, 41, 43, 45, 50–62]
Premature rupture of membranes and preterm labor	Microscopy	✓		✓	[41, 61]
	Bacterial cultures	✓	✓		[16, 20, 39, 44, 50, 52, 57, 63–69]
	Culture independent methods	✓	✓	✓	[14, 16, 19, 20, 39, 42, 46, 50, 52, 53, 61, 70]
Intrauterine growth restriction	Bacterial cultures		✓		[71]
	Culture independent methods		✓		[45, 72]
Pre-eclampsia	Bacterial cultures	✓	✓		[46, 72, 73]
	Culture independent methods	✓	✓		[49, 51, 58, 62, 72, 73]