Consequences of smoking and caffeine consumption during pregnancy in women with type 1 diabetes.

OBJECTIVE: To test the hypothesis that, in women with type 1 diabetes, prenatal smoking and caffeine consumption during pregnancy are associated with an increased risk of adverse maternal and perinatal outcomes. METHODS: A secondary analysis of data on pregnant women with type 1 diabetes from an interdisciplinary program of Diabetes in Pregnancy. Women were interviewed monthly, by a trained non-medical member of the research team, using a standardized questionnaire, to ascertain daily smoking habits and caffeine consumption. RESULTS: Smoking and caffeine information were available on 191 pregnancies, 168 progressing beyond 20 weeks of gestation. Early pregnancy smoking (OR 3.3, 95% CI 1.2, 8.7) and caffeine consumption (OR 4.5, 95% CI 1.2, 16.8) were associated with increased risk of spontaneous abortion when controlling for age, years since diagnosis of diabetes, previous spontaneous abortion, nephropathy and retinopathy. Smoking throughout pregnancy was significantly associated with decreased birth weight and prolonged neonatal hospital stay. Smoking throughout pregnancy (OR 0.2, 95% 0.1, 1.0) and caffeine consumption after 20 weeks (OR 0.3, 95% CI 0.1, 1.0) were associated with reduced risk of pre-eclampsia. CONCLUSIONS: Caffeine consumption during early pregnancy, regardless of glycemic control, increases the risk of spontaneous abortion. Smoking throughout pregnancy and caffeine consumption are associated with reduced risk of pre-eclampsia.

A planned randomized clinical trial of treatment for mild gestational diabetes mellitus.

OBJECTIVE: A planned study is described which will determine whether a benefit exists for the treatment of mild carbohydrate intolerance during pregnancy. METHODS: A randomized clinical trial of women with mild gestational diabetes will compare perinatal outcomes in those receiving diet therapy and insulin as required versus those randomized to no specific treatment. RESULTS: The primary outcome of this study will be a composite of neonatal morbidity in the treatment and control groups. CONCLUSIONS: A randomized treatment trial of mild gestational diabetes mellitus will clarify whether identification and treatment of mild gestational diabetes mellitus reduces perinatal morbidity. This information will aid in selecting appropriate thresholds for the treatment of gestational diabetes mellitus.

Occupational fatigue and preterm premature rupture of membranes. National Institute of Child Health and Human Development Maternal-Fetal Medicine, Units Network.

OBJECTIVE: The aim of this study was to prospectively determine the relationship between occupational fatigue and spontaneous preterm delivery segregated into the etiologically distinct categories of spontaneous preterm labor, preterm premature rupture of membranes, and indicated preterm delivery. STUDY DESIGN: A total of 2929 women with singleton pregnancies at 22 to 24 weeks' gestation were enrolled in a multicenter (10 sites) Preterm Prediction Study. Patients reported the number of hours worked per week and answered specific questions designed to determine the following 5 sources of occupational fatigue described by Mamelle et al: posture, work with industrial machines, physical exertion, mental stress, and environmental stress. Fatigue was quantified (0-5 index) according to the number of these sources positively reported. Simple and Mantel-Haenszel chi2 tests were used to test the univariate association and hypothesis of a linear trend between sources of occupational fatigue and spontaneous preterm delivery. Covariables were considered by multivariate logistic regression analysis. Women who did not work outside the home were considered separately from those who worked but did not report any sources of occupational fatigue. RESULTS: Each source of occupational fatigue was independently associated with a significantly increased risk of preterm premature rupture of membranes among nulliparous women but not among multiparous women. The risk of preterm premature rupture of membranes increased (P = .002) with an increasing number of sources of occupational fatigue-not working outside the home, 2.1%; working but not reporting fatigue, 3.7%; working with 1 source of fatigue, 3.2%; working with 2 sources of fatigue, 5.2%; working with 3 sources of fatigue, 5.1%; and working with 4 or 5 sources of fatigue, 7.4%. There was also a significant relationship (P = .01) between preterm premature rupture of membranes and an increasing number of hours worked per week among nulliparous women. Neither spontaneous preterm labor nor indicated preterm delivery was significantly associated with occupational fatigue among either nulliparous or multiparous women. CONCLUSION: The occupational fatigue index of Mamelle et al discriminated a group of nulliparous women at increased risk for preterm premature rupture of membranes. The relationship between preterm premature rupture of membranes and occupational fatigue or hours worked may provide guidelines according to which nulliparous women and their employers can be advised.

The Preterm Prediction Study: association between cervical interleukin 6 concentration and spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: The aim of this study was to determine the interrelationship between cervical concentration of interleukin 6 and detection of fetal fibronectin and other risk factors for spontaneous preterm birth. STUDY DESIGN: All patients with spontaneous preterm birth at <35 weeks' gestation (case patients; n = 125) and subjects matched for race, parity, and center delivered at > or = 37 weeks' gestation (n = 125; control subjects) were selected from women enrolled in the National Institute of Child Health and Human Development's Preterm Prediction Study. Interleukin 6 concentrations were determined by enzyme-linked immunosorbent assay in cervical swabs obtained at 22 weeks' to 24 weeks 6 days' gestation. Cutoffs to define an elevated interleukin 6 concentration included the 90th and 95th percentiles for control subjects (>305 and >538 pg/mL, respectively). RESULTS: The mean (+/-SD) interleukin 6 concentration was significantly higher in case patients than in control subjects (212 +/- 339 vs 111 +/- 186 pg/mL; P = .008). With either cutoff value elevated interleukin 6 concentration was significantly associated with spontaneous preterm birth (90th percentile, 20% vs 9.6%; P = .02; 95th percentile, 12% vs 4.8%; P = .04). Cervical interleukin 6 levels were highest within 4 weeks of delivery, and the trend continued until term. Elevated interleukin 6 concentration was not significantly associated with bacterial vaginosis, maternal body mass index <19.8 kg/m2, or a short cervix (< or = 25 mm), but it was significantly associated with a positive cervicovaginal fetal fibronectin test result (90th percentile, odds ratio, 5.5; 95% confidence interval, 2.6-11.9; 95th percentile, odds ratio, 5.3, 95% confidence interval, 2.1-12.9). The mean interleukin 6 concentration among women with a positive fibronectin test result was 373 +/- 406 pg/mL; that among women with a negative fetal fibronectin test result was 130 +/- 239 pg/mL (P = .001). In a regression analysis that adjusted for risk factors significantly associated with spontaneous preterm birth in this population (positive fetal fibronectin test result, body mass index <19.8 kg/m2, vaginal bleeding in the first or second trimester, previous spontaneous preterm birth, and short cervix) elevated cervical interleukin 6 concentration was not independently associated with spontaneous preterm birth (odds ratio, 1.8; 95% confidence interval, 0.8-4.3). CONCLUSIONS: At 24 weeks' gestation cervical interleukin 6 concentration in women who subsequently had a spontaneous preterm birth at <35 weeks' gestation was significantly elevated relative to those who were delivered at term. The association was particularly strong within 4 weeks of testing. A positive fetal fibronectin test result was strongly associated with elevated cervical interleukin 6 concentration, but bacterial vaginosis was not.

Preterm prediction study: is socioeconomic status a risk factor for bacterial vaginosis in Black or in White women?

Bacterial vaginosis (BV), an important risk factor for preterm birth, is a more common infection in Black compared with White pregnant women. Because Black women in the United States are more likely to have lower measures of socioeconomic status (SES), this study examined the hypothesis that BV is associated with low SES. The project evaluated data from the Preterm Prediction Study of 2,929 women prospectively followed during their pregnancies. The women, who were screened for BV at 24 and 28 weeks of gestation, underwent a structured interview to evaluate demographic factors, SES, home and work environment, drug or alcohol use, and prior medical history. Black women in the study had many measures of lower SES compared with the White women, and reported less use of tobacco, alcohol and drugs. In neither the Black nor White women was an association found between BV and measures of SES (with the sole exception of "absence of a home telephone"). Most measures of SES do not explain the difference in rates of BV in Black and in White pregnant women.

The preterm prediction study: failure of midtrimester cervical sialidase level elevation to predict subsequent spontaneous preterm birth.

OBJECTIVE: Our objective was to determine any associations among midtrimester cervical fluid sialidase activity, bacterial vaginosis, and subsequent spontaneous preterm birth. STUDY DESIGN: In this nested case-control study all patients (n = 126) with spontaneous preterm birth at <35 weeks' gestation and selected control subjects delivered at >/=37 weeks' gestation (n = 126, matched for race, parity, and center) were derived from women enrolled in the multicenter National Institute of Child Health and Human Development Preterm Prediction Study. Sialidase activity and presence of bacterial vaginosis according to Gram stain were determined in cervical swabs and vaginal smears, respectively, obtained at 22 weeks' to 24 weeks 6 days' gestation. RESULTS: The mean +/- SD sialidase activities were similar in case patients and control subjects (0.64 +/- 1.60 vs 0.41 +/- 0.94 nmol. mL-1. min-1, P =.21). Neither sialidase activity above the 90th percentile (10.3% vs 9.5%, P =.8) nor sialidase activity above the 95th percentile (7.9% vs 4. 8%, P =.3) of control specimens (>1.43 and >2.23 nmol. mL-1. min-1, respectively) was associated with spontaneous preterm birth. The frequency of combinations of bacterial vaginosis and elevated sialidase activity was similar (P >/=.63 with either cutoff) in case patients and control subjects. Sialidase activity was significantly higher among women with bacterial vaginosis than among those without bacterial vaginosis (1.35 +/- 1.87 vs 0.03 +/- 0.14 nmol. mL-1. min-1, P <.0001). CONCLUSIONS: Elevated cervical fluid sialidase activity at 22 to 24 weeks' gestation did not distinguish women at increased risk for spontaneous preterm birth, nor did it discriminate a subgroup of patients who had bacterial vaginosis associated with spontaneous preterm birth.

Obstetric determinants of neonatal survival: influence of willingness to perform cesarean delivery on survival of extremely low-birth-weight infants. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units.

OBJECTIVE: Our purpose was to evaluate the relationship between the approach to obstetric management and survival of extremely low-birth-weight infants. STUDY DESIGN: In this prospective observational study we evaluated 713 singleton births of infants weighing < or = 1000 gm during 1 year at the 11 tertiary perinatal care centers of the National Institutes of Child Health and Human Development network of maternal-fetal medicine units. Major anomalies, extramural delivery, antepartum stillbirth, induced abortion, and gestational age < 21 weeks were excluded. The obstetrician's opinion of viability and willingness to perform cesarean delivery in the event of fetal distress were ascertained from the medical record or interview when documentation was unclear. Grade 3 and 4 intraventricular hemorrhage, grade 3 and 4 retinopathy of prematurity, necrotizing enterocolitis requiring surgery, oxygen dependence at discharge or 120 days, and seizures were considered serious morbidity. Survival without serious morbidity was considered intact survival. Logistic regression was used to evaluate the influence of the approach to obstetric management, adjusted for birth weight, growth, gender, presentation, and ethnicity. RESULTS: Willingness to perform cesarean delivery was associated with increased likelihood of both survival (adjusted odds ratio 3.7, 95% confidence interval 2.3 to 6.0) and intact survival (adjusted odds ratio 1.8, 95% confidence interval 1.0 to 3.3). Willingness to intervene for fetal indications appeared to virtually eliminate intrapartum stillbirth and to reduce neonatal mortality. Below 800 gm or 26 weeks, however, willingness to perform cesarean delivery was linked to an increased chance of survival with serious morbidity. Although obstetricians were willing to intervene for fetal indications in most cases by 24 weeks, willingness to perform cesarean delivery was associated with twice the risk for serious morbidity at that gestational age. CONCLUSIONS: The approach to obstetric management significantly influences the outcome of extremely low-birth-weight infants. Above 800 gm or 26 weeks the obstetrician should usually be willing to perform cesarean delivery for fetal indications. Between 22 and 25 weeks willingness to intervene results in greater likelihood of both intact survival and survival with serious morbidity. In these cases patients and physicians should be aware of the impact of the approach to obstetric management and consider the likelihood of serious morbidity and mortality when formulating plans for delivery.

Perinatal pathology of interhemispheric cyst with thinned posterior corpus callosum: four cases.

This paper presents four posterior, interhemispheric cerebral cysts found at perinatal autopsy. All cysts appeared to attenuate the overlying posterior corpus callosum. All had a base over the roof of the third ventricle and midbrain with a lining that resembled tela choroidea with the choroid plexus tufts projecting into the lumen of the cyst. Three cases had enlargement of the lateral ventricles. One case had complete communication between the cyst and the posterior lateral ventricles reminiscent of a holoprosencephaly confined to the posterior telencephalon. One case demonstrated a complete VATER association and two others had some features of the VATER association. We hypothesize that this latter relationship suggests an origin for the cysts during blastogenesis.

Pregnancy in a combined liver and kidney transplant recipient with type 1 primary hyperoxaluria.

BACKGROUND: Little is known about pregnancy outcomes in multiple organ transplant recipients. We present a case of pregnancy in a patient after liver and kidney transplantation for the genetic disorder of type 1 primary hyperoxaluria. CASE: A 14-year-old Hispanic teenager presented with end-stage renal disease and had a kidney biopsy that revealed hyperoxaluria. A liver biopsy revealed type 1 primary hyperoxaluria. After a year of dialysis and worsening renal status, she underwent a combined orthotopic liver and kidney transplant. The patient subsequently became pregnant, but she required no antihypertensive therapy throughout the prenatal or postpartum period and showed no signs of renal or liver graft rejection. She delivered by cesarean at 38 weeks. CONCLUSION: Combined liver and kidney transplant recipients who become pregnant can have a successful outcome.

Evidence of increased intrauterine bone resorption in term infants of mothers with insulin-dependent diabetes.

Infants of diabetic mothers (IDMs) have lower bone mineral content than control subjects at birth. We measured cord blood propeptide of type I procollagen (PICP), a marker of bone formation, and telopeptide of type I collagen (ICTP), a marker of bone resorption, in 25 term IDMs and 20 term control subjects. Concentrations of ICTP were higher in IDMs than in control subjects; there was no difference in PICP concentrations. We conclude that osteoclastic activity appears to be higher in IDMs than in control subjects in utero.

Umbilical artery aneurysm: prenatal diagnosis and management.

BACKGROUND: An umbilical artery aneurysm is an extremely rare lesion. The purpose of this report is to describe the prenatal sonographic characteristics of such a lesion and potential obstetric complications. CASE: A 26-year-old woman, gravida 2, para 1, at 30 weeks' gestation was referred for an ultrasound examination because of "an abnormality of the umbilical cord." An ellipsoid cystic lesion was noted in a single umbilical artery. Doppler and color flow Doppler examinations demonstrated nonpulsatile and turbulent blood flow within the lesion, consistent with a diagnosis of umbilical artery aneurysm. The aneurysm increased in size over time with a progressive decrease in amniotic fluid volume. Despite reassuring bi-weekly antenatal testing and planned delivery by 36 weeks' gestation, the fetus died in utero, probably because of acute umbilical venous compression by the aneurysm. Autopsy confirmed the presence of a large calcified aneurysm of a single umbilical artery. Dissection of the aneurysm demonstrated anatomical patency of the entire artery. The umbilical vein was histologically normal, as were sections of the artery. CONCLUSION: Although extremely rare, an umbilical artery aneurysm is a potentially lethal anomaly. We recommend delivery as soon as fetal lung maturity is assured when this diagnosis is made prenatally.

Prenatal diagnosis of fetal left ventricular aneurysm: a case report and review.

Fetal echocardiography in a 30-year-old black woman, gravida 4, para 3, demonstrated left ventricular aneurysm. This was confirmed by color flow pulsed Doppler techniques. After delivery, neonatal echocardiography and magnetic resonance imaging further confirmed the diagnosis. The infant was followed closely and underwent surgical correction at 8.5 months of age. Before surgery, cardiac catheterization demonstrated normal hemodynamic function. A review of the literature revealed a paucity of information. Issues of prenatal diagnosis, antenatal surveillance, method of delivery, and neonatal follow-up are not well defined in either the obstetric or pediatric cardiology literature. A rationale for our approach to this complex problem is presented.

Minor congenital malformations in infants of insulin-dependent diabetic women: association with poor glycemic control.

A prospective study of 171 insulin-dependent diabetic pregnant women was undertaken to establish the relationship of glycemic control with minor congenital malformations. Each live-born infant was assessed systematically by two independent examiners using a standardized checklist. There were 32 infants with minor congenital malformations (18.7%). There were significant differences in mean glycohemoglobin A1 between the group with minor congenital malformations and the group without congenital malformations at 12, 16, and 20 weeks, but not at 8 or 24 weeks. Logistic regression analysis showed that maternal age, race, gravidity, White class, duration of diabetes, maternal vasculopathy, and cigarette smoking were not significant variables correlated with minor congenital malformations. Because glycohemoglobin levels from 12-20 weeks are believed to reflect glycemic control from approximately 6-20 weeks, we conclude that poor glycemic control during late embryogenesis and early fetal development is associated with an increased risk of minor congenital malformations. We speculate that improvement of glycemic control during this period should decrease the risk of minor congenital malformations.

Histopathology of spontaneous abortion in diabetic pregnancies.

This study reviewed the histopathology of endometrial curettings following spontaneous abortion in diabetics and controls. The two groups did not differ significantly for an array of histologic features. The relationships between histopathology and diabetic White class, diabetic nephropathy or retinopathy, first trimester hemoglobin A1 percentage, and first trimester serum magnesium level were studied. The only significant correlation found was between diabetic retinopathy and decidual congestion with the presence of venous fibrin.

Perinatal asphyxia in infants of insulin-dependent diabetic mothers.

Infants of diabetic mothers are thought to be at risk for perinatal asphyxia. We hypothesized that the following are significant risk factors for perinatal asphyxia: poor third-trimester glycemic control, diabetic vascular disease (nephropathy, retinopathy) appearing in pregnancy, pregnancy-associated hypertension, smoking, prematurity, fetal macrosomia, and maternal hyperglycemia and hypoglycemia within 6 hours preceding delivery. We prospectively studied 162 infants born to 149 diabetic mothers (White classes B through R-T). Perinatal asphyxia was defined clinically as fetal distress during labor (late decelerations, persistent fetal bradycardia, or both), 1-minute Apgar score less than or equal to 6, or intrauterine fetal death. Forty-four infants (26.7%) had perinatal asphyxia. The presence of perinatal asphyxia did not correlate with third-trimester glycemic control, pregnancy-associated hypertension, smoking, fetal macrosomia, or maternal hypoglycemia before delivery, but it did correlate significantly with nephropathy appearing in pregnancy, maternal hyperglycemia before delivery, and prematurity. We speculate that (1) the appearance of diabetic vasculopathy (nephropathy) during pregnancy is accompanied by placental vascular disease and subsequently by fetal compromise and (2) in pregnancy complicated by diabetes, maternal and subsequently fetal hyperglycemia before delivery leads to fetal hypoxemia.

High spontaneous premature labor rate in insulin-dependent diabetic pregnant women: an association with poor glycemic control and urogenital infection.

The incidence of spontaneously occurring premature labor in insulin-dependent diabetic pregnancies is unclear, because previous studies have been confounded by a high rate of iatrogenic prematurity. The purpose of this study was to determine, in a large population of insulin-dependent diabetic pregnant women, the rate of spontaneous occurrence of premature labor and the various factors that may affect it. We hypothesized a priori that spontaneously occurring premature labor occurs at a high rate in insulin-dependent diabetic pregnant women, mainly because of poor control of diabetes during pregnancy, and is related to the presence of polyhydramnios and hypomagnesemia. One hundred forty-five insulin-dependent diabetic women undergoing 181 pregnancies were recruited since 1978 in an interdisciplinary prospective study. The goals of glucose control were a fasting blood glucose less than 100 mg/dL and a 90-minute postprandial glucose less than 140 mg/dL. The rate of spontaneous premature labor, 31.1%, was significantly higher (P less than .01) than that in a control population managed by the same obstetricians in similar clinical settings (20.2%). The following variables were not significantly associated with the onset of premature labor: maternal age, parity, gravidity, diabetic class according to White, presence of renal disease or retinopathy, previous elective abortion, chronic hypertension or pregnancy-induced hypertension, cigarette smoking, first-trimester or post-20 weeks' gestation vaginal bleeding, maternal serum magnesium concentration, or polyhydramnios.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous abortion among insulin-dependent diabetic women.

A prospective study was undertaken to evaluate the frequency of spontaneous abortion in clinically apparent pregnancies among insulin-dependent diabetic women evaluated prior to pregnancy. The study was done in 132 pregnancies occurring in 91 diabetic women. The spontaneous abortion rate was 30%; 70% of the pregnancies progressed beyond 20 weeks. The abortion rates for Classes B, C, D, and F through RT were 0%, 25%, 44%, and 22%, respectively. Initial serum levels of the beta-subunit of human chorionic gonadotropin above 6000 mIU were usually associated with favorable outcome while levels below 6000 mIU were not predictive of outcome. Data from this study suggest that the risk of spontaneous abortion among insulin-dependent diabetic women may be substantially higher than for the general population. Higher abortion rates were generally associated with more advanced White classification of diabetes. Age at diagnosis was the only factor which showed a significant contribution to the risk of abortion.

Uterine vascular effects of estetrol in nonpregnant ewes.

Estetrol is produced by the fetal liver and has been suggested to be a sensitive indicator of fetal well-being. Although the uterine vascular effects of estrogens (17 beta-estradiol, estriol, and estrone) have been extensively investigated in our laboratory and those of others, the ability of estetrol to dilate the ovine uterine vasculature is not presently known. The present experiment was designed to compare the vasoactivity of estetrol to that of a second pregnancy-associated estrogen, estriol. Five nonpregnant oophorectomized ewes were chronically instrumented with catheters in the femoral artery, femoral vein, uterine arteries, and electromagnetic flow probes on both uterine arteries. Upon recovering from operation, animals received unilateral intra-arterial (uterine) injections of either estriol (0.1, 0.3, 1, and 3 micrograms) or estetrol (1, 3, 10, and 30 micrograms). Ewes received only one dose of either estetrol or estriol daily and all doses were given in a randomized order. Uterine blood flow responses were continuously monitored and the time of onset, peak, and duration were recorded. The time of onset (38 +/- 2 minutes), time of peak response (75 +/- 1 minute), and duration (189 +/- 7 minutes) were approximately equal to those observed for estriol. On the basis of the data obtained in the present study we have determined that estetrol is 15 to 30 times less potent than estriol as a uterine vasodilator.

The use of amniotic fluid 3-methyl histidine to creatinine molar ratio for the diagnosis of intrauterine growth retardation.

To determine if the amniotic fluid 3-methyl histidine to creatinine molar ratio (3MH:CR) could prove useful for the antepartum detection of intrauterine growth retardation (IUGR), the 3MH:CR was determined retrospectively in 3 groups of human amniotic fluids. Group A consisted of amniotic fluids from pregnancies yielding IUGR fetuses whose birth weight was less than or equal to the tenth percentile for gestational age; group B consisted of amniotic fluid from pregnancies yielding infants whose birth weight was greater than the tenth but less than or equal to the 25th percentile for gestational age; group C consisted of amniotic fluids from pregnancies yielding infants whose birth weight was greater than the 25th but less than or equal to the 75th percentile for gestational age. The mean 3MH:CR x 10(-3) for groups A, B, and C were 15.9 +/- 1.9, 5.4 +/- 0.8, and 6.2 +/- 0.5, respectively. The mean 3MH:CR x 10(-3) was statistically different between groups A and B (P less than or equal to .001) and between groups A and C (P less than or equal to .001), but not statistically different between the 2 control groups. Employing an upper limit of normal of 8 for the 3MH:CR x 10(-3), 13 of 15 IUGR neonates were correctly identified as IUGR, and 23 of 27 neonates were correctly identified as being of normal birth weight for gestational age (sensitivity 86.7%, specificity 85.2%, incidence of correct diagnosis 85.7%). No consistent relationship was shown to exist between maternal serum and amniotic fluid 3-methyl histidine level. There was no statistically significant relationship between 3MH:CR x 10(-3) and gestational age. The comparison of the data generated in this study to that obtained with previously reported ultrasonic and biochemical techniques suggests that the amniotic fluid 3MH:CR ratio may prove helpful in establishing the antenatal diagnosis of IUGR, particularly in cases where the gestational age is uncertain.

Clinical experience with a screening program for gestational diabetes.

Screening for abnormal glucose metabolism was carried out in 2,077 pregnant women. Historical or clinical risk factors for gestational diabetes were present in 959 women (group 1). The remaining 1,118 patients composed group 2. A 50 gm oral glucose load and a 1-hour serum glucose determination with a threshold of 150 mg/dl were used as a glucose challenge screening test (GCT). Patients with an abnormal GCT underwent an oral glucose tolerance test (GTT). Group 1 patients underwent screening at the initial clinic visit or when the clinical risk factor was first recognized, with repeat screening at 28 to 32 weeks if the initial testing was normal. Group 2 patients were screened at 28 to 32 weeks. In group 1, 69 patients (7.2%) exhibited an abnormal GCT and 14 (1.5%) demonstrated an abnormal GTT. In group 2, 68 patients (6.1%) exhibited an abnormal GCT and 16 (1.4%) demonstrated an abnormal GTT. These incidences are not statistically different. The estimated costs per patient screened and per case of gestational diabetes detected were $4.75 and $328.96, respectively.