Læknablaðið - 15.12.1997, Síða 14

800
LÆKNABLAÐIÐ 1997; 83
Nýgengi meðfæddra hjartagalla hjá
tvíburum fæddum á íslandi 1986-1995
Yrsa B. Löve1), Hróömar Helgason2), Gunnlaugur Sigfússon2'
Löve YB, Helgason H, Sigfússon G
Congenital heart defects in Icelandic twins
Læknablaðið 1997; 83: 800-9
Objective: Several investigations have been publish-
ed on the incidence of congenital heart defects
(CHD), showing the incidence to be 0.8-1.1%. Few
studies have dealt with the incidence of CHD in
twins, but they indicate higher incidence of CHD
among twins compared to singletons. The purpose
of this study was to investigate the incidence of CHD
and the different types of defects among twins born
in Iceland over a 10 year period and compare the
data to the incidence of CHD in the Icelandic pop-
ulation.
Material and methods: Information was obtained on
all twins born alive in Iceland from 1986-1995 at the
Icelandic Statistical Bureau. That list was compared
to a list of all children born in Iceland over the same
period and diagnosed with CHD, thus finding all
twins with diagnosed CHD. The incidence of CHD
for the period of 1986-1990 and 1991-1995 was stud-
ied separately. Causes of death, whether the pa-
tients needed treatment or not, and the results of
treatment were studied. Chi-squared test for statisti-
cal analysis was used when appropriate.
Results: Incidence: Of 1089 liveborn twins 35 had
CHD or 3.21% compared to an incidence rate of
1.0% among singletons, which is a statistically sig-
nificant difference (p<0.001). The incidence was
2.13% in the years 1986-1990 and 3.78% in the years
1991-1995 (p<0.005). Types of defecls: Of 35 twins
with CHD 20 had minor defects (no treatment need-
Frá '’læknadeild Háskóla Islands, 2)Barnaspítala Hringsins.
Fyrirspurnir, bréfaskipti: Hróðmar Helgason, Barnaspítala
Hringsins, Landspítalanum, 101 Reykjavík. Sími: 5601000;
netfang: hrodmar@rsp.is
Lykilorð: meöíæddir hjartagallar, tvíburar, nýgengi.
ed) whereas 15 had major defects. Ventricular septal
defects were the most common defects encountered,
or 40%, atrial septal defects were 20%, patent duc-
tus arteriosus 9%, complex defects 9% and tetra-
logy of Fallot 6%. Other defects were less common.
Sex ratio: The male/female ratio was 0.591, whereas
the ratio in the control population was 1.1. However,
this did not reach statistical difference (p>0.05).
Twin types: Of the twins with CHD 34% were male-
female pairs, 26% were male-male pairs and 40%
were female-female pairs. Age at diagnosis: Thir-
teen patients were diagnosed in the first week of life
and 20 from one week to five months of age. After
six months of age only two patients have been diag-
nosed with CHD. Treatment: Twelve patients have
been operated for CHD, one patient was treated in
an interventional cardiac catheterization and 10 pa-
tients received medical treatment. Mortality: Six
twins died as a consequence of their heart defect
(17%). The mortality rate was significantly higher
among twins with major CHD compared to the con-
trol population (p<0.005).
Conclusion: Congenital heart defects are more com-
mon among twins compared to the control group.
They were also more common in the latter half of
the investigation period. The mortality rate is also
higher among the twins. In 1991 in utero fertilization
was started in Iceland resulting in increased number
of twins and at the same time increase in incidence
of CHD is seen. Further studies are required to
clarify this.
Key words: congenital heart defects, twins, incidence.
Ágrip
Inngangur: Margar rannsóknir hafa verið
gerðar á nýgengi meðfæddra hjartagalla. Þær
benda til þess að nýgengið sé um 0,8-1,1%.
Fáar rannsóknir hafa verið gerðar á nýgengi
meðfæddra hjartagalla meðal tvíbura. Þær
hafa þó gefið til kynna hærra nýgengi hjá tví-
burum. Tilgangur þessarar rannsóknar var að
rannsaka nýgengi og gerðir meðfæddra hjarta-