Table 1.

Study characteristics

Study	Method	VD prevalence	Age (normal microbiota)	Age BV	Treatment	Timing of sampling	Country/ethnicity	IVF cycle of sampling
Eskew et al.	16S rRNA	24.0%	18–43 (range) for all included patients		Azithromycin orally, 1 g daily once for both partners on the day of initiation of injectable gonadotropins for controlled ovarian stimulation	At 3 time points: 1. immediately before baseline ultrasound; 2. immediately before egg retrieval; and 3. immediately before embryo transfer	USA/no data	No data on cycle
Ji et al.	Nugent score	40.4%	30.1 (mean)	29.7 (mean)	No	On the day of endometrial transformation	China/no data	Frozen embryo transfer cycles. Some patients participated more than once
Karaer et al.	16S rRNA	44.8%	23–39 (range) for all included patients		No	On the day of embryo transfer	Turkey/no data	No data on cycle
Koort et al.	16S rRNA and Nugent score	26.9%	34.1 (average) for all included patients		No	On follicle puncture day	Estonia/no data	No data on cycle
Vieira-Baptista et al.	Amsel's criteria	17.9%	34.6 (mean) for all included patients		No	Immediately before vaginal disinfection and oocyte retrieval (IVF/ICSI) or IUI	Portugal/no data	No data on cycle
Väinämö et al.	16S rRNA	22.6%	32.9 (mean) for all included patients		No	At the time of fresh embryo transfer and at the eighth gestational week from those women who got pregnant	Finland/no data	No data on cycle
Van den Tweel et al.	16S rRNA	32.3%	37.1 (mean)	38.5 (mean)	No	Vaginal samples taken at oocyte retrieval /at the last ultrasound before the frozen embryo transfer	Netherlands/60% Caucasian	Any cycle
Zeng et al.	Nugent score	19.0%	30.8 (mean)	31.35 (mean)	Women with other bacterial morphologies or BV-positive (Nugent score 7–10) were empirically treated with Ornidazole via vagina for a week. No control after therapy with Ornidazole	Vaginal sample within 2 months before IVF and embryo transfer	China/no data	First cycle

BV, bacterial vaginosis; IVF, in vitro fertilization; VD, vaginal dysbiosis.