4. Periodontal treatment versus no treatment ‐ mean gestational age and birth weight.

Mean gestational age (weeks)
	Periodontal treatment			No periodontal treatment
Study ID	Mean	SD	Participants	Mean	SD	Participants
López 2002	39.6	1.2	163	39	2	188
López 2005	39.26	1.5	560	38.9	1.7	283
Newnham 2009	39.1	2.1	538	39.2	2.1	540
Radnai 2009	37.5	1.7	41	36.1	2.8	42
Sadatmansouri 2006	38.5	0.8	15	37.9	1.3	15
Tarannum 2007	33.8	2.8	99	32.7	2.8	89
Mean birth weight (grams)
	Periodontal treatment			No periodontal treatment
Study ID	Mean	SD	Participants	Mean	SD	Participants
López 2002	3501	429	163	3344	598	188
López 2005	3426	477	560	3325	535	283
Michalowicz 2006	3239	586	406	3258	575	403
Newnham 2009	3370.6	613.4	538	3423.4	597.3	540
Offenbacher 2009	3227	612	872	3241	590	866
Radnai 2009	3079	592.3	41	2602.4	668.3	42
Sadatmansouri 2006	3371	394.2	15	3059	389	15
Tarannum 2007	2565.3	331.2	99	2459.6	380.7	89

SD = standard deviation.