Table 1

Numbers of male and female infants with IHPS, total number of live births, and yearly incidence of IHPS in Sweden during the years 1987–96

Year	Male infants with IHPS	Female infants with IHPS	All infants with IHPS	Number of live births	Incidence per 1000 births
1987	233	40	273	104 699	2.607
1988	242	58	300	111 086	2.701
1989	234	82	316	114 788	2.753
1990	224	61	285	122 172	2.333
1991	188	49	237	123 142	1.925
1992	195	44	239	122 199	1.956
1993	129	31	160	116 606	1.372
1994	113	24	137	110 570	1.239
1995	110	20	130	101 752	1.278
1996	70	10	80	94 384	0.848
All	1738	419	2157	1 121 398	1.923