Perinatal Mortality and Congenital Malformations
in Infants Born to Women with Insulin-Dependent Diabetes Mellitus
-- United States, Canada, and Europe, 1940-1988
Women with insulin-dependent diabetes mellitus account for
approximately five per 1000 pregnancies. Because there is no
national surveillance of pregnancies among women with
insulin-dependent diabetes, national trends in the rates of
perinatal mortality (PNM) and congenital malformations associated
with maternal diabetes cannot be monitored.
This report uses data from 225 U.S., Canadian, and European
hospital-based reports* published from 1940 through 1988 of
pregnancies of women with insulin-dependent diabetes to evaluate
the relationship of congenital malformations and PNM in such
pregnancies. These data were compared with published
hospital-based data for all women for the same years. The only
reports included were those that had identified women with
insulin-dependent diabetes and had calculated the PNM rate and/or
the proportion of PNM from congenital malformations for women
with insulin-dependent diabetes.
From 1940 through 1988, in the United States and Canada and in
many European countries, the PNM rate for infants of women with
insulin-dependent diabetes decreased from 250-300 per 1000 births
to 30-50 per 1000. The rates of decline were similar in the
United States and Canada and in Europe (Figure 1). For all
infants, however, the PNM rate did not decrease as much. In the
United States, for example, the overall PNM rate decreased from
about 60 per 1000 in the 1940s to 15 per 1000 in the 1980s.
Progress in the prevention of all causes of PNM has not
proceeded evenly; serious congenital malformations have continued
to be proportionately more frequent among perinatal deaths among
infants of women in both the diabetes and overall groups (Figure
2).
In the United States and Canada and in Europe, the proportion
of perinatal deaths associated with congenital malformations in
the 1950s and 1960s (13%-17%) was almost identical for infants of
women with insulin-dependent diabetes and for infants of all
women. However, although the mortality rate for infants of women
with diabetes declined faster than that for all infants, the
percentage of congenital malformation-associated deaths in the
diabetes group surpassed the percentage of such deaths in the
overall population. For infants of women with diabetes, the
frequency of such deaths increased to greater than 30% in the
1970s and to 45%-50% in the 1980s; in contrast, for infants
overall, it remained less than 30% in the 1970s and 1980s.
Despite the demographic distinctions between the two regions,
incidence rate trends were similar in the United States and
Canada and in Europe (Figure 2).
Reported by: H Kalter, PhD, Children's Hospital Research
Foundation, Dept of Pediatrics, Univ of Cincinnati College of
Medicine, Cincinnati, Ohio. Div of Birth Defects and
Developmental Disabilities, Center for Environmental Health and
Injury Control, CDC.
Editorial Note
Editorial Note: Women with insulin-dependent diabetes are at
increased risk for a variety of adverse pregnancy outcomes such
as stillbirths, obstetric complications, and congenital
malformations. General improvements in prenatal care and in
obstetric management of women with diabetes have led to a
substantial decline in PNM rates among their infants. With these
improvements, however, congenital malformations have emerged as
the most common cause of PNM for infants of women with
insulin-dependent diabetes, accounting for approximately 50% of
all perinatal deaths.
The excess risk for congenital malformations among infants of
mothers with diabetes has been estimated in population-based
studies, such as a recent case-control study conducted by CDC
(1). Although the genesis of congenital malformations among
infants of women with insulin-dependent diabetes is not well
understood, other factors may be involved in addition to glycemic
control (2). Further research on the mechanisms of teratogenesis
associated with diabetes should improve pregnancy outcomes for
women with this form of diabetes.
References
Becerra JE, Khoury MJ, Cordero JF, Erickson JD. Diabetes
mellitus during pregnancy and the risks for specific birth
defects: a population-based case-control study. Pediatrics
1990;85:1-9.
Mills JL, Knopp RH, Simpson JL, et al. Lack of relation of
increased malformation rates in infants of diabetic mothers to
glycemic control during organogenesis. N Engl J Med 1988;
318:671-6.
*References are available on request from CDC's Division of Birth
Defects and Developmental Disabilities, Center for Environmental
Health and Injury Control; telephone (404) 639-4706.
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