Diabetes and Pregnancy -- Michigan, Missouri, South Carolina, Washington

Pregnant women with preexisting diabetes are at increased risk for adverse pregnancy outcomes. Before the use of insulin, maternal mortality from pregnancies complicated by diabetes mellitus was as high as 40%, and only 50% of pregnancies resulted in live births (1). Newborns often were hypoglycemic and large for gestational age and had increased rates of congenital malformations. Although rates of adverse outcome have decreased dramatically over the past four decades, the prevalence of congenital anomalies in infants born of diabetic mothers still remains well above that for infants of nondiabetic women. Currently, rates of perinatal morbidity and mortality, resulting mainly from poor glycemic control both before conception and during gestation, are approximately three to five times higher than for infants of nondiabetic women (2).

Recently, four states--Michigan, Missouri, South Carolina, and Washington--conducted special studies to evaluate these problems. Their findings follow.

Michigan: Using vital-statistics records for 1975-1976, the Michigan Diabetes Control Program calculated death rates for perinates of diabetic and nondiabetic women (3). For nondiabetic, pregnant women, perinatal mortality was 16.8 per 1,000 live births, and for pregnant women with preexisting diabetes, 63.2/1,000 (rate ratio* = 3.8). The death rate for perinates of nondiabetic women decreased as maternal age increased up to age 30, and, thereafter, the rate increased. Death rates for perinates of diabetic women followed a similar pattern after age 20. Rate ratios peaked for ages 20-24, and then decreased until age 40 and over. Perinatal mortality generally decreased with higher levels of maternal education. Rate ratios were highest for women with high-school education or less (4.5) and lowest for those with education beyond high school (3.0). Race-specific odds ratios were 4.1 for whites and 3.1 for other races. The higher odds ratio for whites reflects a lower perinatal mortality rate for white, nondiabetic women. For 1980, perinatal mortality for the general population was 15.3, and diabetes-specific perinatal mortality was 51.2, yielding an rate ratio of 3.3.

Missouri: The Missouri Diabetes Control Program assessed mortality rates for perinates of diabetic and nondiabetic women for 1972-1982. Total perinatal mortality decreased from 25.4/1,000 live births in 1972 to 16.8/1,000 in 1982. Diabetes-specific perinatal mortality decreased from 227.4 to 38.5 for the same period.

South Carolina: Through a retrospective analysis of vital-statistics records and hospital-discharge data, the South Carolina Diabetes Control Program assessed selected indices of diabetes-related perinatal morbidity and mortality in 1978 (2). Maternal diabetes was observed in 5.9/1,000 deliveries. The overall perinatal mortality rate was 102 deaths/1,000 deliveries by diabetic women, compared with 25/1,000 for infants of nondiabetic women. The rate ratio is approximately 4.0 (whites--2.9; other races--4.5). Perinatal mortality was greatest for races other than white (153/1,000 deliveries). The most frequently reported neonatal morbidities were respiratory distress syndrome (17% of all deliveries), hypoglycemia (13%), infection (6%), and congenital anomalies (6%).

The South Carolina Program also assessed diabetes-associated perinatal mortality for 1980. A total of 397 single-birth deliveries among diabetic women were studied. Twenty-four fetal deaths and six neonatal deaths occurred; the perinatal mortality rate has been provisionally estimated at 76/1,000 deliveries. The perinatal mortality rate for infants of nondiabetic women was 23.4/1,000 in 1980, for an rate ratio of 3.2--nearly 25% less than in 1978. However, this decrease may, in part, reflect better reporting of diabetes in pregnancy (including gestational diabetes), thus neonatal deaths occurred; the perinatal mortality rate has been provisionally estimated at 76/1,000 deliveries. The perinatal mortality rate for infants of nondiabetic women was 23.4/1,000 in 1980, for a rate ratio of 3.2--nearly 25% less than in 1978. However, this decrease may, in part, reflect better reporting of diabetes in pregnancy (including gestational diabetes), thus increasing the denominator and lowering the rate.

Washington: The Diabetes in Pregnancy Study was conducted by the Washington Diabetes Control Program through the University of Washington School of Public Health and Community Medicine. For the years 1979-1980, detailed information from hospital charts of mothers and infants, as well as from vital-records data, was abstracted for approximately 648 preexisting and gestational diabetes-complicated pregnancies and from a control group of 800 pregnant, nondiabetic women. This represents one of the largest population-based studies of its kind ever undertaken.

Fetal death rates and neonatal mortality among pregnant, diabetic women were assessed (Table 1). Congenital malformations, particularly neural tube defects, were important complications in this cohort. Data were also gathered about the type of maternal diabetes for infants who required ventilatory assistance, were hypoglycemic, had birth-related injuries, or who were either small or large for gestational age (Table 2).

In addition, deliveries were analyzed by type of hospital and type of maternal diabetes, and results indicated that a greater percentage of women with diabetes-complicated pregnancies delivered in tertiary-care hospitals. In addition, as the severity of maternal diabetes increased, the proportions of deliveries in tertiary-care hospitals also increased (Table 3). Although tertiary-care centers often see the most difficult and severe cases (as evidenced by the highest neonatal mortality rate), overall perinatal mortality was lowest in this setting. The high percentage of infants transferred to tertiary-care centers from smaller hospitals may contribute to this higher neonatal mortality rate. Reported by J Eyster, PhD, M Halpern, PhD, Michigan Diabetes Control Program; D Markenson, RD, Missouri Diabetes Control Program, F Wheeler, PhD, C Gollmar, L Deeb, MD, C Murphy, South Carolina Diabetes Control Program; F Connell, MD, I Emanuel, MD, C Vadheim-Roth, W Mitchell, Washington Diabetes Control Program; Div of Diabetes Control, Center for Prevention Svcs, CDC.

Editorial Note

Editorial Note: Although these data may contain cases of gestational diabetes, there has been a clear reduction in perinatal morbidity and mortality in offspring of women with pre-existing diabetes. Three major medical advances have contributed to these improved outcomes--the discovery and use of insulin, comprehensive team care of the pregnant diabetic, and technologic improvements in monitoring fetal health and the effects of maternal insulin. More intensive management of the pregnant diabetic, including early admission, coordinated team approaches utilizing physicians of varying disciplines, normalization of blood-glucose levels both before conception and throughout gestation, and better identification of groups at high risk, has reduced dramatically the rates of maternal/infant mortality associated with pregnancies complicated by diabetes. Preconception counseling regarding the value of strict (80-110 mg/dl) glucose control before conception, as well as throughout pregnancy, helps reduce the number of adverse outcomes in pregnancies complicated by diabetes. Recent evidence suggests that the prevalence of congenital malformations in offspring of diabetic women can be reduced approximately tenfold through preconception counseling coupled with comprehensive team care of the pregnant diabetic (4). Although reductions in adverse outcomes have occurred over the last three decades, perinatal mortality in offspring of diabetic women remains three to five times higher than that for infants of nondiabetic women. More intensive studies aimed at elucidating the major contributors to the high perinatal mortality rate associated with these pregnancies need to be undertaken.

References

1. Freinkel N, Metzger BE, Potter JM. Pregnancy in diabetes. In: Ellenberg M, Rifkin H, eds. Diabetes mellitus--theory and practice, third edition. New Hyde Park, New York: Medical Examination Publishing Company, Inc., 1983:689-714.

2. Wheeler FC, Gollmar CW, Deeb LC. Diabetes and pregnancy in South Carolina: prevalence, perinatal mortality, and neonatal morbidity in 1978. Diabetes Care 1982;5: 561-5.

3. Technical Services Section, Michigan Department of Public Health. Relative risk of perinatal death associated with gestational diabetes and diabetes mellitus, Michigan, 1975-1976. Lansing, Michigan, 1978.

4. Fuhrmann K, Reiher H, Semmler K, Fischer F, Fischer M, Glockner E. Prevention of congenital malformations in infants of insulin-dependent diabetic mothers. Diabetes Care 1983;6:219-23.

Disclaimer   All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

Page converted: 08/05/98

HOME  |  ABOUT MMWR  |  MMWR SEARCH  |  DOWNLOADS  |  RSS |  CONTACT POLICY  |  DISCLAIMER  |  ACCESSIBILITY

Morbidity and Mortality Weekly Report Centers for Disease Control and Prevention 1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A Department of Health and Human Services

This page last reviewed 5/2/01