Vaginal bleeding in pregnancy and adverse clinical outcomes: a systematic review and meta-analysis

Figures & data

Figure 1. The PRISMA flow diagram.

Figure 2. Forest plots of the odds ratio of vaginal bleeding during the first trimester of pregnancy with PROM and 95% confidence interval based on a random effect model in meta-analysis.

Figure 3. Forest plots of the odds ratio of vaginal bleeding during the first trimester of pregnancy with stillbirth and 95% confidence interval based on a random effect model in meta-analysis.

Figure 4. Forest plots of the odds ratio of vaginal bleeding during the first trimester of pregnancy with preeclampsia and 95% confidence interval based on a random effect model in meta-analysis.

Table 1. Associations between vaginal bleeding in the first trimester of pregnancy with clinical outcomes in mother and infant based on random effect meta-analysis.

Variable	Vaginal bleeding in the first trimester of pregnancy
	N*	n^#	OR	CI: 95%	I Squared%
Low birth weight	16	171,855	2.0	1.5−2.6	90.58
Preterm birth	37	1,025,867	1.8	1.6−2.0	89.0
Intrauterine growth retardation	16	112,419	1.2	0.7−1.9	47.1
Preeclampsia	11	410,078	1.5	1.1−1.9	61.4
Abortion	8	72,371	4.3	2.0−9.0	93.0
Stillbirth	13	122,297	2.5	1.2−5.0	98.0
Caesarean delivery	8	12,145	1.0	0.9−1.2	36.5
Premature rupture of membranes	15	92,822	2.3	1.8–3.0	76.4
Placental abruption	11	137,987	2.2	1.4−3.3	95.0
Placental previa	9	847,966	1.9	1.5−2.4	60.0
Apgar score <7	7	18,403	1.6	0.9−2.6	86.0
Hospitalisation in the neonatal intensive care unit	6	19,566	2.4	1.1−4.0	92.8

* Number of studies; ^#number of samples

OR: odds ratio; CI: confidence interval

Figure 5. Funnel chart of the odds ratio in the selected studies.

Figure 6. Meta-regression chart of the odds ratio of preterm birth upon the study year.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its Supplementary materials.