Screening for gestational diabetes mellitus in adolescent Hispanic Americans.

OBJECTIVE: To determine the incidence of gestational diabetes mellitus (GDM) in an adolescent Hispanic American population. STUDY DESIGN: A retrospective review of 326 women < 20 years of age who identified themselves as Hispanic American was conducted and the incidence of gestational diabetes determined. RESULTS: Thirty adolescent Hispanic Americans (9.2%) had an abnormal result (> or = 140 mg/dL) after 50-g, one-hour oral glucose challenge testing. These women underwent three-hour oral glucose tolerance tests, and five met the criteria for GDM. The incidence of GDM in this population was 1.5% (5/326) (95% confidence interval, 0.6, 3.7). CONCLUSION: The incidence of GDM in adolescent Hispanic Americans is so low that universal screening may not be warranted.

A randomized comparison of extra-amniotic saline infusion and intracervical dinoprostone gel for cervical ripening.

OBJECTIVE: To compare extra-amniotic saline infusion to intracervical dinoprostone gel for preinduction cervical ripening. METHODS: Women with Bishop scores less than 5 were assigned randomly to either extra-amniotic saline infusion (n = 26) or intracervical dinoprostone gel (n = 26) for preinduction cervical ripening. A sample size of 50 would have 80% power to detect a 10-hour difference in the mean time from start of cervical ripening to delivery for the two methods of intervention, with a type I error of .05. RESULTS: The study populations were similar in age, gestational age, and initial Bishop score. They differed in parity, with 22 nulliparas in the extra-amniotic saline infusion group versus 13 in the dinoprostone gel group (relative risk [RR] 1.69, 95% confidence interval [CI] 1.11, 2.57). The number of women achieving a favorable Bishop score at 6 hours was greater with extra-amniotic saline infusion (n = 20) than dinoprostone gel (n = 9) (RR 2.14, 95% CI 1.22, 3.75). Mean time from start of ripening to delivery was 25.9 hours with extra-amniotic saline infusion and 30.2 hours with dinoprostone gel (P = .25). Birth weight, Apgar scores, umbilical artery pH, and infectious morbidity were similar between groups. CONCLUSION: More women achieved a favorable Bishop score at 6 and 12 hours after the start of cervical ripening with extra-amniotic saline infusion compared with dinoprostone gel. Saline infusion is as safe as dinoprostone gel for preinduction cervical ripening.

Fetal heart rate characteristics at 25 to 28 weeks' gestation.

The objective of this article is to define normative fetal heart rate (FHR) tracing characteristics between 25-28 weeks' gestation in a low-risk population with normal pregnancy outcomes and to determine which criteria best determine FHR reactivity. Continuous FHR tracings were reviewed from 188 low-risk women participating in a trial of the Mammary Stimulation Test (MST) at 25-28 weeks' gestation. A reactive tracing required the presence of > or =two accelerations in 20 min. Different acceleration criteria were evaluated based upon the width of the acceleration (short vs. long) and the amplitude of the acceleration (10 vs. 15 bpm). Seventy-one percent of the FHR tracings were reactive using the higher amplitude (15 bpm), short criteria. This number increased significantly to 92% when the lower amplitude (10 bpm), short criteria were used (p <0.01). As gestational age advanced, there was a trend toward increased reactivity irrespective of which criteria were used, but these differences were not significant. Reducing the acceleration amplitude criteria to 10 bpm in preterm pregnancies will maximize the number of reactive nonstress tests. This is advantageous because it would improve test specificity and decrease the false-positive rate. Our findings need to be prospectively validated in a high-risk population.

Screening for gestational diabetes mellitus in adolescent pregnancies.

OBJECTIVE: Our purpose was to determine the incidence of gestational diabetes mellitus in an adolescent population and to determine the cost of screening. STUDY DESIGN: A retrospective review of 509 adolescent pregnancies was performed. The incidence of gestational diabetes mellitus was determined and the cost of screening analyzed. RESULTS: Five hundred nine adolescent pregnancies were screened for gestational diabetes mellitus with a 1-hour, 50 gm oral glucose challenge test. Twenty-three of the screens (4.5%) had positive results at a plasma glucose level of > or = 140 mg/dl. Three-hour 100 gm oral glucose tolerance tests were performed on screen-positive women, six of whom were diagnosed with gestational diabetes mellitus, for an incidence of 1.18%. The cost per case diagnosed was $2733. CONCLUSIONS: The incidence of gestational diabetes mellitus in an adolescent population is low. The cost of universal screening may be prohibitive in this population. Large prospective studies are needed to better analyze outcome data and efficacy of screening in adolescent pregnancies.

Fetal fibronectin levels are elevated in maternal plasma and amniotic fluid of patients with severe preeclampsia.

OBJECTIVE: Our purpose was to investigate levels of fetal fibronectin in maternal plasma, amniotic fluid, and umbilical cord plasma from patients with severe preeclampsia. STUDY DESIGN: The study group comprised 20 patients with severe preeclampsia (group A). An antepartum comparison group was composed of 20 healthy patients matched for gestational age (group B). An intrapartum control group consisted of 20 term normotensive patients (group C). Maternal plasma samples were collected before labor (groups A and B), then immediately after delivery, and again at 20 to 24 hours post partum (groups A and C). Amniotic fluid was also collected in early labor, and umbilical cord blood was collected at delivery (groups A and C). Samples were assayed for fetal fibronectin by a specific enzyme-linked immunoassay. RESULTS: Before labor maternal plasma levels of fetal fibronectin were significantly elevated in preeclamptic patients compared with patients in group B (p < 0.0001). Plasma levels of fetal fibronectin were also increased in preeclamptic patients compared with patients in group C at delivery (p < 0.0001) and post partum (p < 0.05). Additionally, amniotic fluid levels of fetal fibronectin in the preeclamptic patients were significantly increased (p < 0.05). In contrast, umbilical cord plasma fetal fibronectin concentrations from the preeclamptic and control patients were similar. CONCLUSIONS: Fetal fibronectin is elevated in the maternal plasma and amniotic fluid, but not umbilical cord plasma, of patients with severe preeclampsia. These findings suggest an increase in production of fetal fibronectin from chorionic trophoblast in patients with preeclampsia or an abnormal interaction between chorionic trophoblast and decidua with resultant increased leakage into the maternal circulation and amniotic fluid.

Prediction of preterm birth in nulliparous patients.

OBJECTIVE: Our goal was to determine whether the mammary stimulation test combined with a risk scoring system and cervical examination at 26 to 28 weeks' gestation could effectively identify private nulliparous patients at risk for spontaneous preterm birth. STUDY DESIGN: The mammary stimulation test was performed by 267 nulliparous patients with singleton gestations at 26 to 28 weeks. Risk scores were determined by the method of Creasy et al. and cervical examinations were performed at the first prenatal visit and at 26 to 28 weeks. Summary predictive values were calculated for each test, and a stepwise discriminate analysis was performed. RESULTS: Spontaneous preterm birth occurred at < 37 weeks in 26 of 265 (9.8%) patients. The following variables were independently associated with spontaneous preterm birth: positive result of mammary stimulation test, risk score > or = 10, soft cervix at 26 to 28 weeks, bacteriuria, and current smoking. The best discriminate model included positive result of mammary stimulation test, soft cervix, bacteriuria, current smoking, and prior spontaneous abortion(s). This model identified 19 patients as being at risk for spontaneous preterm birth with sensitivity of 35%, specificity of 96%, and positive predictive value of 47%. CONCLUSION: Combining the mammary stimulation test with a cervical examination at 26 to 28 weeks' gestation and routinely obtained prenatal data correctly identified 35% of spontaneous preterm births in nulliparous patients with a positive predictive value of 47%. Prospective validation of this model is warranted.

Immunoreactive tumor necrosis factor-alpha is elevated in maternal plasma but undetected in amniotic fluid in the second trimester.

OBJECTIVE: We investigated the participation of the cellular arm of the immune system in adaptation to pregnancy by assessing plasma and amniotic fluid levels of the cytokine tumor necrosis factor-alpha. STUDY DESIGN: Fifty-five healthy pregnant women who underwent second-trimester genetic amniocentesis at a mean gestational age of 17.0 +/- 1.4 weeks composed study group A. Blood was drawn from each patient before amniocentesis, and an aliquot of amniotic fluid was obtained for this study. Twenty-one healthy patients at a mean gestational age of 35.5 +/- 4.8 weeks composed study group B, and blood was obtained from each patient at an outpatient prenatal visit. Twenty-two healthy, nonpregnant women of reproductive age composed the control group (C). All specimens were stored at -70 degrees C and collectively assayed for tumor necrosis factor-alpha by a specific enzyme-linked immunoassay. RESULTS: All patients in group A had a normal karyotype and all patients in groups A and B had uneventful pregnancies. Tumor necrosis factor-alpha was detected in the plasma of 43 of 55 (78.2%) patients in group A compared with 7 of 21 (33.3%) patients in group B (p < 0.001); tumor necrosis factor-alpha was not detected in any of the 22 women in group C. The median plasma tumor necrosis factor-alpha level for group A was 135 pg/ml (range 0 to 625 pg/ml) compared with 0 pg/ml (range 0 to 110 pg/ml) in group B (p < 0.001). Tumor necrosis factor-alpha was not detected in any of the amniotic fluid specimens studied. CONCLUSIONS: Levels of tumor necrosis factor-alpha were elevated in the plasma but not detected in the amniotic fluid of normal pregnant patients in the second trimester. These findings suggest involvement of the cellular branch of the immune system and its products, the cytokines, in the normal adaptation of the mother to the fetal allograft, with a possible role in regulating trophoblast growth and invasion.

Tumor necrosis factor-alpha is elevated in plasma and amniotic fluid of patients with severe preeclampsia.

OBJECTIVE: Our purpose was to investigate whether markers for activation of the immune system are present in patients with preeclampsia by assessing maternal plasma and amniotic fluid for tumor necrosis factor-alpha and interleukin-1 beta. STUDY DESIGN: Twenty-one patients with severe preeclampsia composed the study group (group A). An antepartum comparison group was composed of healthy nulliparous patients not in labor and matched for gestational age (group B). Another control group consisted of term nulliparous patients in labor with uneventful pregnancies (group C). Maternal plasma samples were collected from all patients at recruitment and from patients in groups A and C immediately after delivery and again 20 to 24 hours post partum. Amniotic fluid was also collected from patients in groups A and C during labor. All samples were collectively assayed for tumor necrosis factor-alpha and interleukin-1 beta by specific enzyme-linked immunoassays. RESULTS: Before labor tumor necrosis factor-alpha was detected more frequently in the plasma of preeclamptic patients than in the plasma of patients in group B (12/16 vs 5/16, p < 0.05) and in higher concentrations (median 35 pg/ml vs median 0 pg/ml, p < 0.05). Although tumor necrosis factor-alpha was frequently detected in the plasma of patients in group C in early labor (16/20), concentrations were higher in the four preeclamptic patients first sampled in early labor (210 pg/ml vs 65 pg/ml, p < 0.05). Similarly, amniotic fluid levels of tumor necrosis factor-alpha were increased in preeclamptic patients compared with control patients. At delivery tumor necrosis factor-alpha was more likely to be identified in the plasma of preeclamptic patients and was found in higher concentrations, but by 20 to 24 hours post partum measurements in the preeclamptic and control patients were similar. There were no differences in the frequency with which interleukin-1 beta was detected or the concentration of interleukin-1 beta in any of the samples. CONCLUSIONS: Tumor necrosis factor-alpha is increased in the plasma and amniotic fluid of patients with severe preeclampsia. These data are suggestive of a role for abnormal immune activation in the pathophysiologic mechanisms of preeclampsia.

Mammary stimulation test predicts preterm birth in nulliparous women.

OBJECTIVE: This prospective clinical trial was designed to assess the ability of the mammary stimulation test to predict preterm birth in a private nulliparous population. STUDY DESIGN: The mammary stimulation test was performed between 26 and 28 weeks' gestation by 267 nulliparous women with singleton pregnancies. Test results were blinded to both patient and referring physician. Pregnancy outcome data were collected from the perinatal database and medical records. RESULTS: The mammary stimulation test was positive in 45 of 266 (17%) patients. Delivery occurred at < 37 weeks in 27 patients (10.2%) and at < 34 weeks in five (1.9%). The mammary stimulation test demonstrated a sensitivity of 37%, a specificity of 84%, a positive predictive value of 20%, and a negative predictive value of 92% for delivery at < 37 weeks' gestation. For delivery at < 34 weeks' gestation the mammary stimulation test had a sensitivity of 60%, a specificity of 82%, a positive predictive value of 6%, and a negative predictive value 99%. The odds ratio for delivery at < 37 weeks was 3.0 (95% confidence interval 1.3, 7.1), and for delivery at < 34 weeks the odds ratio was 7.0 (95% confidence interval 1.1, 43.0). One third of preterm deliveries were secondary to idiopathic preterm labor, and the mammary stimulation test was positive in 77.8% (seven of nine) of these pregnancies. Patients with a positive test were more likely to require observation in labor and delivery for preterm uterine contractions (34% vs 4.3%, p < 0.01), and they were more likely to demonstrate change at cervical examination (14% vs 2%, p < 0.01). CONCLUSION: In this population traditionally considered to be at low risk for preterm birth a positive mammary stimulation test was useful in identifying patients at risk for preterm uterine activity and preterm birth. Equally important was the identification of women who were at low risk for preterm birth.

Elective and routine induction of labor. A retrospective analysis of 274 cases.

A retrospective analysis of elective induction of labor at term and routine induction after 42 completed weeks' gestation was conducted to assess neonatal and maternal outcome in a low-risk obstetric population at a tertiary care facility. In 1989, 639 labor inductions were performed at the Christ Hospital and Medical Center. Two hundred one inductions were performed between 37 and 41 6/7 weeks' (elective induction), while 73 were performed at 42 weeks' gestation and beyond (routine induction). Cervical status was ascertained on admission. Patients undergoing routine induction had a longer second stage of labor as compared to patients undergoing elective induction. Otherwise the duration of labor and membrane rupture did not significantly differ between the two groups. Nulliparous patients with an unfavorable cervix who were induced electively had a trend toward a higher cesarean section rate than nulliparas with an unfavorable cervix induced routinely. There was no difference between the elective and routine induction populations with respect to the incidence of fetal distress, neonatal outcome or maternal outcome. Respiratory distress syndrome was noted in three cases, all secondary to meconium aspiration and all from the elective induction group. The incidence of birth weight > or = 4,000 g was equal in the elective and routine induction groups, and no birth weights < or = 2,500 g were recorded. No cases of iatrogenic prematurity were noted, either. When compared to routine induction after 42 weeks' gestation, there is no advantage to elective induction, especially in nulliparous patients with unfavorable cervixes.

Neonatal morbidity after preterm delivery in the presence of documented lung maturity.

OBJECTIVE: Our purpose was to determine the incidence of significant neonatal morbidity in fetuses with documented pulmonary maturity delivered before 37 weeks' gestation. STUDY DESIGN: A retrospective review of 213 pregnancies with documented fetal lung maturity (lecithin/sphingomyelin ratio > or = 2.0 or phosphatidylglycerol present) and delivery before 37 weeks was performed. The incidence of neonatal respiratory distress syndrome, bronchopulmonary dysplasia, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, infectious morbidity, hyperbilirubinemia, and admission to the special care nursery was determined for those pregnancies with intact membranes and preterm premature rupture of membranes. RESULTS: Serious neonatal morbidity declined with advancing gestational age and was less common after 32 completed weeks of pregnancy. Although the frequencies of respiratory distress syndrome, grade 3 or 4 intraventricular hemorrhage, and necrotizing enterocolitis were 19.4% (12/62), 8.1% (5/62), and 4.8% (3/62), respectively, at < or = 33 weeks' gestation, one case of respiratory distress syndrome, one case of grade 3 intraventricular hemorrhage, and one case of necrotizing enterocolitis occurred in the 151 neonates born at > or = 34 weeks' gestation. CONCLUSIONS: In spite of fetal lung maturity major neonatal morbidity was observed in our patient population. These data relating neonatal morbidity to gestational age are useful in the critical decision regarding timing of delivery.

Sonographic diagnosis of congenital heart disease: comparison between the four-chamber view and multiple cardiac views.

OBJECTIVE: To report our experience in the detection of congenital heart disease using both the four-chamber view of the heart as part of the standard obstetric ultrasound examination and multiple cardiac views as part of the detailed targeted examination. METHODS: All admissions to Children's Memorial Hospital of Northwestern University Medical Center with the diagnosis of congenital heart disease between June 1988 and April 1992 were identified (N = 1947). These admissions were matched to deliveries (N = 19,321) that occurred at Prentice Women's Hospital during the same period; of these, 10,004 had at least one obstetric ultrasound examination. All fetuses were scanned either with the standard obstetric ultrasound type of examination, featuring only the four-chamber view of the heart, or by the detailed targeted imaging type of study, featuring multiple cardiac views. The type of examination performed was based on the specific request of the attending obstetrician or gynecologist. RESULTS: Thirty-three neonates who had at least one obstetric ultrasound examination were treated for congenital heart disease. An additional five pregnancies were terminated secondary to serious fetal heart defects. When only the four-chamber view was visualized, 11 of 33 fetuses (33.3%) with confirmed congenital heart disease were detected. CONCLUSIONS: Assessment of the outflow tracts is crucial for detection of many forms of congenital heart disease. However, before this is accepted as the standard of care, both the obstetric and radiologic communities should develop their skills in cardiac imaging. Only then can this sophisticated type of cardiac examination be offered to pregnant women.

Placenta accreta is associated with elevated maternal serum alpha-fetoprotein.

OBJECTIVE: To determine whether placenta accreta/percreta/increta is associated with elevation of second-trimester maternal serum alpha-fetoprotein (MSAFP) levels. METHODS: We reviewed the medical records of 44 women who had emergency cesarean hysterectomy. Twenty women had placenta accreta/percreta/increta (study group) and 24 underwent cesarean hysterectomy for other indications (control group). Pertinent maternal and neonatal variables were abstracted from the prenatal records and hospital charts. Chi-square and Fisher exact tests were used to analyze categorical variables. Student t test was used to analyze continuous variables. RESULTS: Nine of 20 patients (45%) with placenta accreta/percreta/increta and none of 24 subjects in the control group had an elevated MSAFP value (P < .001). Maternal estimated blood loss was also significantly greater in the study group (4469 +/- 1851 versus 1885 +/- 1113 mL; P < .0001), as was the number of blood units transfused (7.7 +/- 4.7 versus 3.0 +/- 2.2; P < .001). None of the other examined variables were different between the groups. CONCLUSIONS: A significant association exists between placenta accreta/percreta/increta and elevated MSAFP values. Patients with an unexplained elevation of MSAFP may have an increased risk for placenta accreta and associated blood loss at cesarean hysterectomy.