Table 7.

Results from studies identified as high quality which measured communication and language development (n = 6).

Study	n	Exposure	Units	Outcome	Time of Outcome	Estimate	95% CI	p-Value
Barbone et al. (2019)	1272	Hair	ng/g	Bayley-III: Expressive Communication scale	18 months	0.04	−0.06 to 0.13
Barbone et al. (2019)	1086	Hair	ng/g	Bayley-III: Language composite	18 months	0.55	0.05 to 1.05
Barbone et al. (2019)	1075	Hair	ng/g	Bayley-III: Receptive Communication scale	18 months	0.12	0.02 to 0.22
Barbone et al. (2019)	1070	Umbilical cord	ng/g	Bayley-III: Expressive Communication scale	18 months	0.01	−0.09 to 0.11
Barbone et al. (2019)	896	Umbilical cord	ng/g	Bayley-III: Language composite	18 months	0.25	−0.29 to 0.78
Barbone et al. (2019)	887	Umbilical cord	ng/g	Bayley-III: Receptive Communication scale	18 months	0.12	−0.08 to 0.32
Barbone et al. (2019)	727	Whole blood	ng/g	Bayley-III: Expressive Communication scale	18 months	0.13	−0.22 to 0.48
Barbone et al. (2019)	628	Whole blood	ng/g	Bayley-III: Receptive Communication scale	18 months	−0.02	−0.12 to 0.08
Daniels et al. (2004)	1054	Umbilical cord	μg/g	MCDI: Vocabulary Comprehension	15 months	6.1		0.8
Daniels et al. (2004)	1054	Umbilical cord	μg/g	DDST: Language	18 months	0.1		0.9
Hu et al. (2016)	410	Umbilical cord	Ln μg/L	GDS: Language domain	12 months	2.17	−1.88 to 6.21
Hu et al. (2016)	410	Whole blood	Ln μg/L	GDS: Language domain	12 months	1.92	−3.61 to 7.46
Nisevic et al. (2019)	257	Umbilical cord	μg/L	Bayley-III: Language composite	18 months	−0.05		0.74
Oken et al. (2008)	341	Erythrocyte	ng/g	PPVT	36 months	−0.4	−0.8 to −0.1
Valent et al. (2013)	505	Hair	Ln ng/g	Bayley-III: Language composite	18 months	0.85		0.11
Valent et al. (2013)	378	Umbilical cord	Ln ng/g	Bayley-III: Language composite	18 months	0.41		0.46