John A. Read

Reproducibility of the oral glucose tolerance test in pregnancy

This prospective investigation evaluated the reproducibility of the 100 gm oral glucose tolerance test. Sixty-four obstetric patients with greater than or equal to 135 mg/dl on the 50 gm oral glucose screening test were scheduled for the 100 gm test. All patients repeated the oral glucose tolerance test in 1 to 2 weeks. Both tests included a preparatory diet, and testing conditions were identical. There were no significant differences in the mean test values at each testing interval when the entire study population was considered. Patients were then divided into four groups according to the outcome of the two tests. Forty-eight of 64 (75%) had normal results at each testing period (group 1); 11 of 64 (17%) had initially normal results and abnormal results on retest (group 2); 3 of 64 (5%) had initially abnormal results and normal results on retest (group 3); 2 of 64 (3%) had abnormal results at both testing phases (group 4). There were no significant differences between oral glucose tolerance test results within groups 1 and 4. However, significant differences occurred within groups 2 and 3 between the two tests. Group 2 patients had a greater frequency of an abnormal 1-hour value on the test than group 1 patients (p = 0.001). Overall, the reproducibility of the oral glucose tolerance test was 78% (50 of 64). We recommend the oral glucose tolerance test be repeated when the 1-hour value is abnormal or when the fasting blood sugar, 1-hour, and 2-hour values are near the upper end of the normal range.

Risk Factors for Preterm Delivery in a Healthy Cohort

To examine whether risk factors differed among subgroups of preterm (<37 weeks of gestation) deliveries, we studied a cohort of 1,825 enlisted servicewomen who delivered from 1987 through 1990 at four U.S. Army medical centers. Preterm deliveries were classified by length of gestation (<29 weeks, 29–32 weeks, 33–36 weeks) and clinical course [medical indication, idiopathic preterm labor, or preterm rupture of membranes (PROM)]. We abstracted medical records for information on age, race, army rank, marital status, gravidity, parity, the babys sex, maternal prepregnancy height and weight, gestation at entry to prenatal care, alcohol drinking and smoking, time since and outcome of preceding pregnancy, surgery performed during pregnancy, anemia, and diagnoses of uterine abnormalities, sexually transmitted diseases, and urinary tract infections. We used proportional hazards analysis to evaluate associations for each subgroup of preterm delivery. The relative odds associated with a history of preterm delivery in the preceding pregnancy ranged from 3.1 for deliveries due to preterm labor or PROM to 6.2 for deliveries that occurred during 29–32 weeks; none of the other factors was consistently associated across the subgroups of preterm delivery. The paucity of associations is consistent with the conclusion of other investigators that most of the causes of preterm delivery are unknown.

Hydrops Fetalis and Premature Closure of the Ductus Arteriosus: A Review

The purpose of this report is to describe a case of nonimmune hydrops fetalis that resulted from an unusual congenital heart defect, premature closure of the ductus arteriosus. In this fetus, the ductal closure was not associated with other heart defects such as tetralogy of Fallot or truncus arteriosus, nor was it related to maternal use of nonsteroidal antiinflammatory agents. Despite adequate digitalization of the mother, the fetus died of congestive heart failure at 29 weeks of gestation. Autopsy confirmed stricture of the ductus in association with enlargement of the foramen ovale and marked dilation of the right atrium and main pulmonary artery.

Significant fetal bradycardia during antepartum heart rate testing

Reviewed were 800 patients who underwent antepartum fetal heart rate testing. Significant fetal bradycardia (less than 90 beats per minute for longer than 50 seconds or a decrease of 40 beats per minute below baseline for longer than 50 seconds) was evaluated relative to its relationship to fetal outcome. Twelve fetuses exhibited significant bradycardia during monitoring. All of these babies, when delivered within a short period of time after the tracing, showed manifestations of ongoing intrauterine jeopardy. The finding of significant fetal bradycardia during antepartum testing should prompt further evaluation and consideration for delivery.