Table 3.

The Prevalence of Placental Malaria, and the Sensitivity and Specificity of an Rapid Diagnostic Test, Polymerase Chain Reaction (PCR) or PCR/Microscopy Undertaken at any Antenatal Contact in Predicting Active Malaria Infection of the Placenta Detected by Histology in Ghanaian Women

Placental Malariaa	Gravidity	Number Tested				Number Positive	Percent Positive by Histology
	All Women	425				122	28.7 (24.6, 33.2)
	Primigravidae	243				76	31.3 (25.7, 37.4)
	Secundigravidae	181				46	25.4 (19.6, 32.3)
		Histology/Diagnostic				Sensitivity % (95% CI)	Specificity % (95% CI)
		+/+	+/−	−/+	−/−
Diagnostic
RDT positive at any ANC contact	All	79	29	196	67	73.1 (63.8, 81.2)	25.5 (20.3, 31.2)
	Primigravidae	55	12	117	28	82.1 (70.8, 90.4)	19.3 (13.2, 26.7)
	Secundigravidae	24	17	78	39	58.5 (42.1, 73.7)	33.3 (24.9, 42.6)
Microscopy positive at any ANC contact	All	65	43	149	112	60.2 (50.3, 69.5)	42.9 (36.8, 49.2)
	Primigravidae	46	21	89	54	68.7 (56.2, 79.4)	37.8 (29.8, 46.2)
	Secundigravidae	19	22	60	57	46.3 (30.7, 62.6)	48.7 (39.4, 58.1)
PCR positive at any ANC contact	All	59	29	152	79	67.0 (56.2, 76.7)	34.2 (28.1, 40.7)
	Primigravidae	40	14	85	37	74.1 (60.3, 85.0)	30.3 (22.3, 39.3)
	Secundigravidae	19	15	67	41	55.9 (37.9, 72.8)	38.0 (28.8, 47.8)
PCR or blood slide positive at any ANC Contact	All	76	27	190	64	73.8 (64.2, 82.0)	25.2 (20.0, 31.0)
	Primigravidae	52	13	109	30	80.0 (68.2, 88.9)	21.6 (15.1, 29.4)
	Secundigravidae	24	14	81	33	63.2 (46.0, 78.2)	28.9 (20.8, 38.2)

1 woman with a placental malaria result had missing data on gravidity.

Abbreviations: ANC, antenatal clinic; CI, confidence interval; PCR, polymerase chain reaction; RDT, rapid diagnostic test.

^a Positivity for placental malaria is defined as the detection of malaria parasites in the placenta on histological examination.