Patients at high risk for low-birth-weight D.
FRANK
JOHN
KALTREIDER,
W.
C.
JOHNSON,
delivery
M.D. M.D.
Baltimore, Maryland A retrospective analysis of 8,839 singleton deliueries war undertaken to determine the relationships of maternal age, maternal hemoglobin concentration, and past obstetric performance to the incidence of low-birth-weight (LBG) delivery. Patients under 19 years of age and patients with hemoglobin values less than 9.0 Gm. per 100 ml. were found to have significantly higher incidences of LBW deliveries. In addition, the incidence of LBW delizjery was found to vary in proportion to the number of previous LBW deliveries and inzlersely with the number of previous term deliveries.
IT IS GENERALLY accepted that premature delivery is the most common obstetric complication associated with perinatal death, accounting for the majority of all such fatalities occurring at this time.” ’ In addition, surviving infants of low birth weight due to prematurity or fetal growth retardation have high incidences of neurologic, intellectual, and emotional deficits39 4 The incidence of prematurity in the United States is generally quoted as being between 7 and 14 per cent. If one assumes an annual birth rate of three million and an incidence of 8.5 per cent prematurity, then approximately 250,000 premature infants are born annually in the United States alone.5 Although this serious complication of pregnancy occurs with alarming frequency, an acceptable cause is identifiable in only 40 per cent of the cases. The maternal complications that most frequently predispose to premature labor are hypertensive cardiovascular disease, abruptio placentae, and placenta previa. In these and other circumstances of maternal and fetal jeopardy, premature delivery may be iatrogenic in that termination of pregnancy is required to protect the lives of the mother and her baby. If one adds multiple pregnancies and
From the Department of Obstetrics Baltimore City Hospitals. Presented
at the Annual Meeting and Gynecologists,
of Obstetricians
congenital anomalies of the fetus to this list, approximately 40 per cent of premature deliveries are accountable. The remaining 60 per cent of premature labors are without apparent explanation.’ In those deliveries characterized by a birth weight below 2,500 grams, premature labor is usually accepted as the most common cause, although fetal growth retardation is said to account for one third.6 The differentiation of these etiologic factors is not always possible, but clearly LBW delivery is a major factor associated with obstetric wastage. For purposes of improved management and clinical investigation, it is desirable to identify those maternity patients who are at high risk. The objectives of this study were to determine the relationship of the following three factors to the incidence of LBW delivery: (1) maternal age, (2) maternal hemoglobin concentration, and (3) past obstetric performance, particularly previous premature delivery.
Methods The obstetric population utilized for this retrospective study was the 8,839 black patients delivered at the University of Maryland between 1955 and 1960. Those patients with multiple pregnancies and those who had had therapeutic terminations of their pregnancies were excluded from the analyses. Maternal age was determined on the basis of information obtained upon the first prenatal visit. For purposes of this study, the hemoglobin concentration assigned to each patient was the lowest value determined antenatally. The past obstetric performance was derived primarily from the history. In an effort to test the cumulative effects of past obstetric events, the
and Gynecology,
of the American
College Las Vegas, Nevada,
1974. Received
for publication
Revised January Accepted January
November
12, 1974.
28, 1975. 28, 1975.
Reprint requests: Dr. John W. C. Johnson, Department Obstetrics and Gynecology, Johns Hopkins Hospital, Baltimore, Maryland 21205.
of
251
252
Kaltreider
Table
and Johnson
I. Maternal Age (yr.)
FRANK
JOHN
KALTREIDER,
W.
C.
JOHNSON,
delivery
M.D. M.D.
Baltimore, Maryland A retrospective analysis of 8,839 singleton deliueries war undertaken to determine the relationships of maternal age, maternal hemoglobin concentration, and past obstetric performance to the incidence of low-birth-weight (LBG) delivery. Patients under 19 years of age and patients with hemoglobin values less than 9.0 Gm. per 100 ml. were found to have significantly higher incidences of LBW deliveries. In addition, the incidence of LBW delizjery was found to vary in proportion to the number of previous LBW deliveries and inzlersely with the number of previous term deliveries.
IT IS GENERALLY accepted that premature delivery is the most common obstetric complication associated with perinatal death, accounting for the majority of all such fatalities occurring at this time.” ’ In addition, surviving infants of low birth weight due to prematurity or fetal growth retardation have high incidences of neurologic, intellectual, and emotional deficits39 4 The incidence of prematurity in the United States is generally quoted as being between 7 and 14 per cent. If one assumes an annual birth rate of three million and an incidence of 8.5 per cent prematurity, then approximately 250,000 premature infants are born annually in the United States alone.5 Although this serious complication of pregnancy occurs with alarming frequency, an acceptable cause is identifiable in only 40 per cent of the cases. The maternal complications that most frequently predispose to premature labor are hypertensive cardiovascular disease, abruptio placentae, and placenta previa. In these and other circumstances of maternal and fetal jeopardy, premature delivery may be iatrogenic in that termination of pregnancy is required to protect the lives of the mother and her baby. If one adds multiple pregnancies and
From the Department of Obstetrics Baltimore City Hospitals. Presented
at the Annual Meeting and Gynecologists,
of Obstetricians
congenital anomalies of the fetus to this list, approximately 40 per cent of premature deliveries are accountable. The remaining 60 per cent of premature labors are without apparent explanation.’ In those deliveries characterized by a birth weight below 2,500 grams, premature labor is usually accepted as the most common cause, although fetal growth retardation is said to account for one third.6 The differentiation of these etiologic factors is not always possible, but clearly LBW delivery is a major factor associated with obstetric wastage. For purposes of improved management and clinical investigation, it is desirable to identify those maternity patients who are at high risk. The objectives of this study were to determine the relationship of the following three factors to the incidence of LBW delivery: (1) maternal age, (2) maternal hemoglobin concentration, and (3) past obstetric performance, particularly previous premature delivery.
Methods The obstetric population utilized for this retrospective study was the 8,839 black patients delivered at the University of Maryland between 1955 and 1960. Those patients with multiple pregnancies and those who had had therapeutic terminations of their pregnancies were excluded from the analyses. Maternal age was determined on the basis of information obtained upon the first prenatal visit. For purposes of this study, the hemoglobin concentration assigned to each patient was the lowest value determined antenatally. The past obstetric performance was derived primarily from the history. In an effort to test the cumulative effects of past obstetric events, the
and Gynecology,
of the American
College Las Vegas, Nevada,
1974. Received
for publication
Revised January Accepted January
November
12, 1974.
28, 1975. 28, 1975.
Reprint requests: Dr. John W. C. Johnson, Department Obstetrics and Gynecology, Johns Hopkins Hospital, Baltimore, Maryland 21205.
of
251
252
Kaltreider
Table
and Johnson
I. Maternal Age (yr.)
