Joint Effect of Maternal Tobacco Smoking and Pregestational Diabetes on Preterm Births and Congenital Anomalies: A Population-Based Study in Northern Italy

Table 1

Demographic characteristics of the study population, according to maternal pregestational diabetes and smoking habits.

	Women with PGD					Women without PGD
	Nonsmoking		Smoking		Total	Nonsmoking		Smoking		Total
		(%)		(%)			(%)		(%)
Age at delivery
<35 years	502	(56.5)	68	(65.4)	570	2469	(58.5)	337	(59.1)	2806
≥35 years	386	(43.5)	36	(34.6)	422	1749	(41.5)	233	(40.9)	1982
Nationality
Italian	465	(52.4)	89	(85.6)	554	3157	(74.8)	511	(89.6)	3668
Other	423	(47.6)	15	(14.4)	438	1061	(25.2)	59	(10.4)	1120
Education
Elementary/middle school	383	(43.1)	42	(40.4)	425	1129	(26.8)	181	(31.8)	1310
High school	360	(40.5)	42	(40.4)	402	1883	(44.6)	288	(50.5)	2171
University	145	(16.3)	20	(19.2)	165	1206	(28.6)	101	(17.7)	1307
Father’s education
Elementary/middle school	423	(47.6)	49	(47.1)	472	1362	(32.3)	236	(41.4)	1598
High school	314	(35.4)	44	(42.3)	358	1734	(41.1)	240	(42.1)	1974
University	110	(12.4)	10	(9.6)	120	903	(21.4)	72	(12.6)	975
Missing	41	(4.6)	1	(1.0)	42	219	(5.2)	22	(3.9)	241
Total	888	(100.0)	104	(100.0)	992	4218	(100.0)	570	(100.0)	4788

PGD = pregestational diabetes.