Table 1.

Crude and adjusted ORs and 95% CIs for congenital anomalies by exposure to TTHM levels (µg/l) during the first trimester of pregnancy

Total trihalomethane exposure (µg/l)	Cases n (%)	Controls n (%)	Crude OR	95% CI	Adjusted OR	95% CI
Heart anomalies
Low (1.3 µg/l)	20 (35.1)	1325 (45.6)	1		1
High (21.9 µg/l)	37 (64.9)	1578 (54.4)	1.55	0.89 to 2.69	1.54*	0.89 to 2.68
Musculoskeletal anomalies
Low (1.3 µg/l)	19 (51.4)	1325 (45.6)	1		1
High (21.9 µg/l)	18 (48.6)	1578 (54.4)	0.80	0.42 to 1.52	0.74†	0.39 to 1.42
Urogenital anomalies
Low (1.3 µg/l)	5 (21.7)	1325 (45.6)	1		1
High (21.9 µg/l)	18 (78.3)	1578 (54.4)	3.02	1.12 to 8.16	3.01‡	1.11 to 8.16

High–Petrasiunai; Low–Other water supply zones.

*Adjusted for: age, body mass index, chronic disease, alcohol consumption and fetus number.

†Adjusted for: body mass index, fetus number, previous premature birth and infant sex.

‡Adjusted for: age, body mass index, chronic disease, previous premature birth and infant sex.