The role of nonstress tests, fetal biophysical profile, and contraction stress tests in the outpatient management of insulin-requiring diabetic pregnancies

An audit on a routine antenatal nonstress testing program in pregnant women with preexisting diabetes

INTRODUCTION

The objective was to evaluate the effectiveness of routine (planned) antenatal nonstress tests (NSTs) in pregnant women with preexisting diabetes.

MATERIAL AND METHODS

A retrospective single-center study of 642 consecutive pregnancies in women with preexisting diabetes who gave birth to a singleton ≥22 weeks. Weekly planned NSTs were commenced at 33-35 weeks. In pregnancies with maternal-fetal complications, the initiation and frequency of the planned NST were individualized. Daily maternal assessment of fetal activity was recommended from 28 weeks, and decreased fetal activity indicated an unplanned NST. Data were collected from medical records, and local and regional databases.

RESULTS

In total, 3016 planned NSTs were performed, with a median of five (range 0-12) tests per pregnancy. Ninety-five planned NSTs (3.1%) were abnormal, a finding confirmed by retesting the same day in eight cases (8.4%), thus leading to delivery. Complications were present in seven of these eight pregnancies, whereas no fetal movements for the last 3 days were reported when the planned NST was performed in the eighth pregnancy. When specifically asked, five of the eight women stated that they had observed decreased fetal activity preceding the planned NST. In 86 pregnancies (13.4%), maternal perception of decreased fetal activity indicated in total 127 unplanned NSTs. The combination of decreased fetal activity and further obstetrical assessment led to delivery in 10 of these pregnancies (11.6%). One stillbirth occurred at 37 weeks in a pregnancy complicated by fetal achondroplasia and polyhydramnios, where the weekly planned NSTs had been normal. The overall stillbirth rate was thus 1.6/1000.

CONCLUSIONS

Routine use of planned antenatal NSTs does not appear to be indicated in pregnancies in women with preexisting diabetes in the absence of maternal-fetal complications.

Continuous objective recording of fetal heart rate and fetal movements could reliably identify fetal compromise, which could reduce stillbirth rates by facilitating timely management

Stillbirth currently affects approximately 1 in every 200 pregnancies in the United Kingdom. Fetuses may exhibit signs of compromise as part of a stress response before stillbirth, including reduced fetal movements (RFM) and fetal heart rate (FHR) alterations. At present, and despite widespread use, current fetal monitoring is not associated with a reduction in perinatal mortality rate (PMR) as signs of fetal compromise are not adequately detected. This may be attributed to inaccuracies resulting from manual interpretation of results or subjective assessment of fetal activity. In addition, signs of compromise often occur only hours or days before fetal death, so may be missed by current monitoring methods, which are performed intermittently. A significant consideration is that correct identification of these signs and consequent intervention can result in the delivery of a healthy baby, thus preventing stillbirth. A hypothesis is presented, proposing prompt detection of fetal compromise with the use of 24-hour continuous objective fetal monitoring. With focus placed on obtaining long-term FHR and fetal movement data, prior interest has been found in developing devices for this purpose. However, introduction into clinical practice has not been achieved. Investigation of the hypothesis will begin with the design of a device to record the mentioned parameters, followed by an appropriate validation process. Should development and testing be successful, an eventual comparison in PMR with the use of continuous fetal monitoring vs current monitoring would address the hypothesis. It is suggested that a timely yet reliable indication of fetal wellbeing obtained via long-term monitoring would allow prompt and appropriate obstetric intervention and consequently reduce PMR.

Sonographic evaluation and the pregnancy complicated by diabetes

Sonography is a fundamental tool in the management of pregnancies affected by maternal diabetes. Purposeful use of ultrasound in each trimester provides an invaluable amount of information about the developing fetus including gestational age and growth patterns, anatomical structure and function, assessment of fetal well-being, and prediction of adverse outcome. There are great ongoing research efforts in this field of prenatal diagnosis and management, yet even more are needed.

Ductus venosus velocimetry in monitoring pregnancy in women with pregestational diabetes mellitus

OBJECTIVE

The purpose of this research was to assess the ability of ductus venosus (DV) Doppler velocimetry to predict adverse perinatal outcome in pregnancies complicated by pre-existing diabetes mellitus.

METHODS

This was a prospective study conducted at a tertiary referral obstetric facility in Brisbane, Australia. The study group included women with pregestational diabetes mellitus who delivered in the hospital between 1 January 1995 and 31 December 2006. The DV Doppler index was defined as abnormal if the DV peak velocity index for veins (PVIV) was equal to or greater than the 95(th) percentile for gestation. Adverse perinatal outcome included one or more of the following criteria: small-for-gestational-age infant; Cesarean section for non-reassuring fetal status; fetal acidemia at delivery; a 1-min Apgar score of <or= 3; a 5-min Apgar score of < 7; hypoxic ischemic encephalopathy; and stillbirth or neonatal death. The maternal characteristics and perinatal outcomes of pregnancies with normal or abnormal DV Doppler indices were compared.

RESULTS

Eighty-two pregestational diabetic pregnancies were studied and an abnormal DV-PVIV was identified in 25 (30.5%). Adverse perinatal outcome was identified in eight of 25 (32.0%) pregnancies with an abnormal DV-PVIV compared to seven of 57 (12.3%) pregnancies with a normal DV-PVIV (P < 0.05). The sensitivity of the DV-PVIV in predicting adverse perinatal outcomes in pregestational diabetic pregnancies was 53.3%, the specificity was 74.6%, the positive predictive value was 32.0% and the negative predictive value was 87.7%.

CONCLUSION

It may be useful to include DV-PVIV in the antenatal screening of pregnancies complicated by pregestational diabetes.

Reducing stillbirths: screening and monitoring during pregnancy and labour

BACKGROUND

Screening and monitoring in pregnancy are strategies used by healthcare providers to identify high-risk pregnancies so that they can provide more targeted and appropriate treatment and follow-up care, and to monitor fetal well-being in both low- and high-risk pregnancies. The use of many of these techniques is controversial and their ability to detect fetal compromise often unknown. Theoretically, appropriate management of maternal and fetal risk factors and complications that are detected in pregnancy and labour could prevent a large proportion of the world's 3.2 million estimated annual stillbirths, as well as minimise maternal and neonatal morbidity and mortality.

METHODS

The fourth in a series of papers assessing the evidence base for prevention of stillbirths, this paper reviews available published evidence for the impact of 14 screening and monitoring interventions in pregnancy on stillbirth, including identification and management of high-risk pregnancies, advanced monitoring techniques, and monitoring of labour. Using broad and specific strategies to search PubMed and the Cochrane Library, we identified 221 relevant reviews and studies testing screening and monitoring interventions during the antenatal and intrapartum periods and reporting stillbirth or perinatal mortality as an outcome.

RESULTS

We found a dearth of rigorous evidence of direct impact of any of these screening procedures and interventions on stillbirth incidence. Observational studies testing some interventions, including fetal movement monitoring and Doppler monitoring, showed some evidence of impact on stillbirths in selected high-risk populations, but require larger rigourous trials to confirm impact. Other interventions, such as amniotic fluid assessment for oligohydramnios, appear predictive of stillbirth risk, but studies are lacking which assess the impact on perinatal mortality of subsequent intervention based on test findings. Few rigorous studies of cardiotocography have reported stillbirth outcomes, but steep declines in stillbirth rates have been observed in high-income settings such as the U.S., where cardiotocography is used in conjunction with Caesarean section for fetal distress.

CONCLUSION

There are numerous research gaps and large, adequately controlled trials are still needed for most of the interventions we considered. The impact of monitoring interventions on stillbirth relies on use of effective and timely intervention should problems be detected. Numerous studies indicated that positive tests were associated with increased perinatal mortality, but while some tests had good sensitivity in detecting distress, false-positive rates were high for most tests, and questions remain about optimal timing, frequency, and implications of testing. Few studies included assessments of impact of subsequent intervention needed before recommending particular monitoring strategies as a means to decrease stillbirth incidence. In high-income countries such as the US, observational evidence suggests that widespread use of cardiotocography with Caesarean section for fetal distress has led to significant declines in stillbirth rates. Efforts to increase availability of Caesarean section in low-/middle-income countries should be coupled with intrapartum monitoring technologies where resources and provider skills permit.

Antenatal testing: diabetes mellitus

Diabetes complicating pregnancy is a problem for which fetal surveillance testing is considered to be the standard of care. In response to the unacceptable frequency of stillbirth in such pregnancies, fetal testing historically was first introduced to manage women whose pregnancies were complicated by diabetes. Essentially all forms of antepartum testing have been used to assess fetal well-being during the third trimester of pregnant diabetics. The contraction stress test became established as the "gold standard," yet other testing protocols have been used successfully. It is clear that control of diabetes throughout gestation, not just in the later stages, is more important for optimal outcome than is a specific form of fetal testing. Biweekly testing has become the standard and with well-controlled diabetics, allowing the gestation to continue until the onset of spontaneous labor, even when the gestation exceeds 40 weeks, is appropriate management with normal testing.

Antepartum fetal surveillance and timing of delivery in the pregnancy complicated by diabetes mellitus

Pregnancies complicated by diabetes mellitus are associated with an increased risk of fetal and neonatal risks compared with pregnancies in the healthy gravida. Data suggest that stillbirth and perinatal mortality may be increased as much as 5 times for patients with insulin-dependent diabetes than in the general population. Pregnancies complicated by preexisting diabetes should undergo twice weekly surveillance with nonstress test or biophysical profile or a combination of both. Doppler studies should be reserved for those patients with vascular disease, intrauterine growth restriction, or hypertensive disorders.

Placental biopsy by frozen section: does it have a role in evaluation of fetal well-being?

AIM

To assess the effectiveness of post-partum placental biopsy and frozen section evaluation in diagnosing pregnancy disorders.

STUDY DESIGN

Between January and July 1998, biopsies were carried out on 100 newly delivered placentas. Biopsies were carried out using a 14-gauge needle, and frozen section evaluations were reviewed. These were compared to the standard evaluation of histological evaluation of the whole placenta sections. Specimens were evaluated by standard placental pathologic criteria.

RESULTS

Villous oedema which is associated with antenatal hypoxia was observed with a sensitivity of 78%, and specificity of 97%, yielding a positive predictive value of 84% in frozen section compared to standard placental evaluation. No statistical difference was observed in the evaluation of dysmaturity, intravillous fibrin agglutination and chronic villitis between frozen sectioning and whole placenta sections. Increased syncytial knots were detected with a sensitivity of 45% and specificity of 98%.

CONCLUSION

Placental biopsy by frozen sectioning might be a useful and quick method of evaluation for placental pathology. Theoretically, fetal status could be more precisely evaluated by combining prenatal placental biopsy by permanent section with conservative ante-partum well-being tests.

Fetal monitoring in type 1 diabetic pregnancies

Stillbirth and perinatal mortality rates are 5 times greater for an insulin-dependant diabetic mother than in the general population. Neonatal and infant mortality rates are 15 and 3 times greater, respectively. In addition, macrosomia is a major problem resulting in both fetal and maternal injury. Fetal monitoring is considered mandatory in such pregnancies. The rational approach would be to use surveillance strategies based on the underlying pathophysiology. However, in the diabetic pregnancy, the underlying pathophysiology is poorly understood and is likely to be multifactorial. Thus, in practice, a pragmatic approach is followed using methods that are applied in other high-risk pregnancies although the pathophysiology is different. Given the limitations in the predictive power of many fetal monitoring methods and the lack of randomised controlled trials, it is not surprising that there is no agreement over the best way to monitor fetal health in diabetic pregnancies. This article analyses the evidence regarding the value of these tests and proposed protocols for their use in the context of the diabetic pregnancy.

Fetal biophysical profile

This article begins with an outline of the theoretic basis of the fetal biophysical profile, the method for the biophysical profile score (BPS), and the timing and frequency of testing. The article further discusses the clinical management based on test scores; modified methods of the BPS; and clinical application, predictive accuracy, and impact on outcome of BPS. The authors specifically examine the relationship between BPS and cerebral palsy. They conclude with a discussion of adult sequelae and fetal adaptation to asphyxia.

Fetal heart rate patterns in pregnancies complicated by maternal diabetes

OBJECTIVE

To compare the fetal heart rate (FHR) pattern between fetuses of well controlled diabetic and non diabetic mothers using a computerized analysis of FHR.

STUDY DESIGN

Weekly fetal surveillance was performed in 99 fetuses of mothers with diabetes class A, 21 fetuses of mothers with diabetes class B-R, and 55 fetuses of non-diabetic women, starting at 30 weeks' gestation. All diabetic patients were well controlled. Fetal surveillance included a computerized analysis of the FHR, umbilical and uterine Doppler velocimetry, and a biophysical profile. Changes of FHR variation, frequency of FHR accelerations, and umbilical and uterine Doppler velocimetry were calculated using a regression analysis for each patient. The average slopes and the intercept at 30, 34, and 38 weeks' gestation of these variables were compared among the three groups.

RESULTS

The slope of FHR variation and the frequency of accelerations had a lower rate of increase during the third trimester in fetuses of mothers with diabetes class A (0.84 +/- 0.25 ms/week and 0.06 +/- 0.02/20 min/week, respectively) compared with fetuses of non-diabetic mothers (1.34 +/- 0.55 ms/week and 0.5 +/- 0.1/20 min/week, respectively). In fetuses of mothers with diabetes class B-R, FHR variation did not change with gestation (-0.011 +/- 0.2 ms/week) with a small increase in the frequency of accelerations (0.02 +/- 0.004/20 min/week). While no differences were observed at 30 weeks' gestation, FHR variation and the frequency of accelerations were significantly reduced at 34 weeks' gestation in fetuses of mothers with diabetes class B-R compared with fetuses of non-diabetic mothers (P < 0.01). At 38 weeks' gestation, fetuses of mothers with diabetes class B-R and diabetes class A had both significantly reduced FHR variation as well as frequency of accelerations compared with fetuses of non-diabetic mothers (P < 0.01). The rate of decrease of the umbilical and uterine artery S/D ratios were similar among the three groups.

CONCLUSIONS

The FHR pattern appears to be different in fetuses of well controlled diabetic mothers when related to fetuses of non-diabetic mothers. Disease specific standards should be considered for interpretation of FHR patterns in diabetic pregnancies.

Fetal surveillance and timing of delivery in pregnancy complicated by diabetes mellitus

Protocols for antepartum fetal assessment in pregnancies complicated by diabetes mellitus are an important part of a care program that allows most of these pregnancies to reach term, ensuring fetal maturation. Maternal assessment of fetal activity serves as an efficient screening test in most surveillance programs. These programs have used primarily biophysical testing consisting of the nonstress test, cardiac stress test, or biophysical profile. Doppler studies have been investigated as an adjunct for identifying fetal compromise. These studies may prove most valuable in cases of maternal vascular disease. The success of these protocols continues to be predicated on careful regulation of maternal glycemia through aggressive therapy with insulin and diet. Reassuring tests of fetal condition are present in most diabetic women and, therefore, permit fetal maturation to occur prior to delivery.

Antepartum surveillance in diabetic pregnancies: predictors of fetal distress in labor

OBJECTIVE

Our purpose was to evaluate an antepartum testing program based on twice-weekly nonstress testing and amniotic fluid evaluation in pregnancies complicated by diabetes mellitus and to weight the test components in the prediction of fetal distress requiring cesarean delivery.

STUDY DESIGN

During the 4-year period of 1987 through 1990, 2134 women with pregnancies complicated by diabetes underwent antepartum testing. Of these 1501 women (class A1, n = 505; A2-diet, n = 305; A2-insulin, n = 580; B, n = 71; C to D, n = 29; R to F, n = 11) were delivered within 4 days of their last test. Categoric analysis of data was performed according to diabetic class, fetal heart rate results, and the presence of decreased, normal, or increased amniotic fluid assessment. A univariate logistical regression was first conducted with cesarean delivery for fetal distress as outcome variable by use of the following variables: fetal weight and sex, diabetic class, gestational age at delivery, presence of additional indications for antepartum testing, largest vertical pocket, amniotic fluid index (summation of the four quadrants of the largest vertical pocket), nonstress test reactivity (two accelerations of > or = 15 beats/min of 15 seconds' duration), presence of decelerations (> or = 15 beats/min for 15 seconds) during the nonstress test, and the interactions of the nonstress test with deceleration, largest vertical pocket, and amniotic fluid index. Multivariate analysis was then applied to predict the best model.

RESULTS

No stillbirths occurred within 4 days of the last antepartum test. However, the corrected stillbirth rate of the entire tested population was 1.4 per 1000. Eighty-five women required cesarean delivery for fetal distress. The factors most predictive of cesarean delivery for fetal distress (p < 0.05, odds ratio and 95% confidence interval) were a deceleration (3.60, 2.14 to 6.06), nonreactive nonstress test (2.68, 1.60 to 4.49), and the interaction of both a nonreactive nonstress test and decelerations (5.63, 2.67 to 11.9). Amniotic fluid assessment by largest vertical pocket or amniotic fluid index were not statistically significant. The multivariate analysis selected the interaction of nonstress test and deceleration as the best significant predictor for cesarean delivery for fetal distress.

CONCLUSION

An antepartum fetal surveillance program using twice-weekly nonstress test and fluid index assessment in pregnancies complicated by diabetes was successful in preventing stillbirth. The absence of fetal heart rate reactivity and the presence of decelerations were predictive of the diagnosis of fetal distress in labor requiring cesarean delivery. Ultrasonographic assessment of amniotic fluid volume was not a significant predictor of fetal distress in labor in the diabetic pregnancy.

Fetal biophysical activities in third-trimester pregnancies complicated by diabetes mellitus

OBJECTIVE

Our purpose was to compare third-trimester fetal biophysical activities in normal and well-controlled insulin-dependent diabetic pregnancies.

STUDY DESIGN

We performed serial bimonthly fetal biophysical studies from 30 to 38 weeks in 18 normal and 18 well-controlled insulin-dependent diabetic pregnancies (White classes B through D). Each study contained 60 minutes of simultaneous ultrasonographic recordings of fetal breathing movements and rates, baseline heart rate, and body movements. Mean daily blood glucose levels of diabetic patients were determined from home monitors; HbA1c was determined every 6 weeks and ultrasonographic fetal growth rates every 3 weeks. Data were compared with t tests, analysis of variance with repeated measures, and chi 2 tests.

RESULTS

Women in the diabetic group maintained good glycemic control and were delivered of normal infants of weights similar to those of nondiabetic gravidas. Their fetuses had higher mean incidences of fetal breathing movement, fetal heart rates, and fetal breathing rates but lower fetal movements and fetal heart rate acceleration counts than did controls throughout the study. Neither short- nor long-term maternal glycemic levels correlated well with fetal biophysical performance.

CONCLUSIONS

In spite of good maternal glycemic control fetuses of diabetic women behaved differently from those of nondiabetic women. Modulation of their biophysical activities may be affected by maternal glycemic status before the last trimester. Different standards might need to be applied to interpret their tests.

Prediction of fetal acidaemia in pregnancies complicated by maternal diabetes mellitus by biophysical profile scoring and fetal heart rate monitoring

OBJECTIVE

To determine whether computer assisted fetal heart rate analysis or the biophysical profile score can provide noninvasive prediction of fetal acidaemia.

DESIGN

Cross sectional study.

SETTING

Harris Birthright Research Centre for Fetal Medicine, King's College Hospital School of Medicine, London.

SUBJECTS

Forty-one women with pregnancies complicated by diabetes mellitus.

INTERVENTIONS

Fetal heart rate (FHR) monitoring with computer assisted analysis, biophysical profile score (BPS) and cordocentesis for measurement of umbilical venous blood glucose concentration and blood gases, up to 24 h before delivery at 27 to 39 weeks gestation.

RESULTS

The mean umbilical venous blood pH was significantly lower than the normal mean for gestation, and was below the 5th centile in 18 pregnancies, including all six cases where the mother had nephropathy and hypertension. The mean pO2 was not significantly different from the normal mean for gestation. There were significant associations between fetal acidaemia and both the BPS (r = 0.46, P < 0.01) and FHR variation (r = 0.42, P < 0.01). However, of the 12 acidaemic fetuses of non-nephropathic mothers, nine had normal BPS and six had normal FHR variation.

CONCLUSIONS

In pregnancies complicated by maternal diabetes mellitus, BPS and FHR variation are of limited value in the prediction of fetal blood pH.

Fetal surveillance in pregnancies complicated by insulin-dependent diabetes mellitus

OBJECTIVE

Our objective was to determine whether maternal vascular disease and/or glycemic control can be related to tests of fetal condition in diabetic pregnancies.

STUDY DESIGN

A total of 114 women with insulin-dependent diabetes who used a memory-based glucose reflectance meter were prospectively evaluated. Nonstress testing was begun weekly at 28 to 30 weeks and twice weekly at 32 weeks. A nonreactive nonstress test was followed by a biophysical profile in all cases.

RESULTS

A total of 1676 nonstress tests was performed (14.7 +/- 3.2 tests per patient). Eight percent (n = 134) were nonreactive, necessitating a biophysical profile. A comparison of ambulatory glucose profile data, including mean blood glucose level, variation, and excursions from the median, revealed no significant differences in patients with reactive versus nonreactive nonstress tests. Ten patients, including eight with vascular disease, were delivered because of abnormal test results of fetal condition. Nephropathy or hypertension was associated with intervention for fetal well-being in 8 of 20 women (40%) with these risk factors. Only 2 of 94 patients (2%) without nephropathy or hypertension required delivery because of abnormal results of fetal testing (p less than 0.001). One fetal death occurred. No significant differences in the various glycemic parameters were found in women delivered for suspected fetal jeopardy versus the nonintervention group.

CONCLUSION

Pregnancies complicated by vascular disease are at greatest risk for abnormal results of fetal testing that necessitate early delivery. Women without vascular complications and with maintenance of good glycemic control rarely have fetal compromise.

Diabetes and pregnancy

Prior to the introduction of insulin, a vast majority of pregnancies complicated by diabetes ended in perinatal death, with an associated risk of maternal death. Currently, virtually all diabetic women can undergo pregnancy with the expectation of good maternal and fetal outcome. However, many challenges still remain in preventing congenital anomalies and macrosomia.

Fetal surveillance in insulin-dependent diabetic pregnancy: predictive value of the biophysical profile

Ninety-eight insulin-dependent diabetic pregnancies underwent monitoring by means of 978 biophysical profiles from 28 weeks' gestation until parturition. Only 2.9% of the 978 tests had abnormal results (score less than or equal to 7). When performed within 2 days before birth, a normal biophysical profile predicted the 1-minute Apgar score to be normal in 92% and 5-minute Apgar score in 99%. When all biophysical profiles ever performed were included, the predictive value improved to 100%. The baby's first cry within 1 minute after birth was predicted in 95%. Furthermore, the predictive value of a normal biophysical profile regarding the absence of ominous intrapartum cardiotocographic patterns was excellent (95%). The specificity was in general good (80% to 90%), but the predictive value of abnormal test results and sensitivity were almost without exception poor. It seems that the very low rate of abnormal biophysical profiles indicates that obstetric interventions were made immediately after the occurrence of the first sign of fetal jeopardy; thus improved results were obtained.

Fifteen years of experience with antepartum fetal testing

The introduction of antepartum fetal heart rate testing occurred in the very early 1970s. This article describes the evolution of testing within the Los Angeles County/University of Southern California Medical Center and encompasses a 15-year time period between 1971 and 1985. During this time approximately 200,000 patients were delivered of their infants. Fetal surveillance increased from less than 1% to current levels of 16% of patients. The antepartum fetal death rate was evaluated as a measure of evaluating the usefulness of antepartum testing. The fetal death rate after antepartum testing in selected high-risk patients was significantly less than that found in those patients not tested. The questions that might be raised regarding broader application of this technique and potential benefits are stated.

Reassessment of White's classification and Pedersen's prognostically bad signs of diabetic pregnancies in insulin-dependent diabetic pregnancies

The classification systems developed over 20 years ago by White and Pedersen identified diabetic pregnancies at increased risk for perinatal mortality. To assess whether these same criteria would currently be valid, 199 diabetic pregnancies with deliveries from 1977 to 1983 were reviewed. Perinatal mortality rates for White's Classes B gestational (n = 72), B (n = 27), C (n = 67), and D + F + R (n = 33) were 2.9%, 11.1%, 14.9%, and 21.1%, respectively (p less than 0.05). White's classes were also predictive of pulmonary morbidity (12.5%, 18.5%, 22.4%, and 42.4%, respectively). The presence of one or more of the prognostically bad signs of pregnancy (n = 76) increased the perinatal mortality rate to 17.1% versus 7.3% among insulin-dependent diabetic pregnancies without prognostically bad signs (p less than 0.05). The presence of any prognostically bad signs of pregnancy was also predictive of pulmonary morbidity in general (31.6% versus 16.3%, respectively) and hyaline membrane disease in particular (13.2% versus 4.1%, respectively). Thus with use of modern obstetric management and medical care of the pregnant diabetic patient, both White's classification and Pedersen's prognostically bad signs of pregnancy continue to be predictive of perinatal mortality.

The current role of daily serum estriol monitoring in the insulin-dependent pregnant diabetic woman

This retrospective analysis of the use of serum estriol levels for antenatal assessment was performed in an effort to determine if routine, late third-trimester, daily serum estriol monitoring of insulin-dependent pregnant diabetic women can still be justified. Estriol profiles of 170 diabetic pregnancies, managed under a consistent protocol of weekly contraction stress tests and daily serum estriol assessments, were reviewed. A total of 4612 estriol determinations were performed. Nearly 4% of the estriol determinations showed a 35% fall from the mean of the previous three highest consecutive values. Forty-seven percent of the patients had at least one fall of this magnitude. Eighty-five percent of the fetal heart rate tests performed in association with an estriol fall were normal. A fall in estriol was not found to be associated with a higher risk of having a positive contraction stress test, either at the time the estriol fall was recognized or at any time during the patient's antepartum course. Although use of this strict protocol combining the use of weekly contraction stress tests and daily serum estriol determinations provided a safe method of antepartum assessment, there is little evidence to support the routine use of daily serum estriol monitoring in insulin-dependent pregnant diabetic women.

Management of diabetes mellitus in pregnancy

During the past decade, our major objective in the management of pregnancies complicated by diabetes mellitus has become normalization of maternal and, therefore, fetal glucose levels. For most women with insulin-dependent diabetes, this goal may be achieved through the use of multiple insulin injections combined with an appropriate dietary intake. The results of such therapy can now be accurately assessed by means of home glucose monitoring. Patients with gestational diabetes can be properly treated only if they are first identified. Therefore, all pregnant women should be tested for this disorder because screening based on past obstetric history or clinical criteria alone may miss up to 50% of patients with gestational diabetes. Between 1980 and 1984, the perinatal mortality rate reported in the American literature for more than 800 insulin-dependent patients was 21 per 1000, with more than 50% of these deaths resulting from major malformations. Such data emphasize the need to achieve maternal euglycemia before conception, as poor maternal control has been associated with teratogenesis. Prepregnancy assessment should also include a thorough evaluation of maternal vasculopathy.

Antepartum fetal monitoring in insulin-dependent diabetic pregnancies

In order to minimize unexplained stillbirths in insulin-dependent diabetic pregnancies, fetal well-being was assessed by antepartum monitoring while development of pulmonary maturity was awaited. Antepartum monitoring consisted of outpatient nonstress tests beginning at 32 weeks' gestation. Fetuses with nonreactive nonstress tests were further evaluated by contraction stress tests and were delivered if tests were positive. With use of this system there were no unexplained stillbirths during management of 119 insulin-dependent diabetic pregnancies. Of 14 infants delivered because of positive contraction stress tests, six were found to have major disorders; the other eight had no major residual neonatal morbidity. Thus this system of antepartum fetal surveillance: eliminated unexplained stillbirths, identified a subgroup of insulin-dependent diabetic pregnancies with a high rate of major fetal abnormalities, and allowed for identification and subsequent timely delivery of the other distressed fetuses that were at a high risk of neonatal morbidity and/or mortality, such that potential long-term adverse outcomes were avoided.

Obstetric care in diabetic pregnancy

In diabetic pregnancy near-normalization of maternal blood glucose levels improves the perinatal outcome. Strict metabolic control can be achieved by self-monitoring of blood glucose in ambulant praxis. The obstetric supervision may now therefore be organized on an out-patient basis aiming at early recognition of pregnancy complications such as preeclampsia and deviation in fetal growth. For uncomplicated and well-controlled diabetes without vascular complications the obstetric care should be individualized and routine programmes for obstetric surveillance, such as fetal heart rate monitoring and determination of fetal maturity, are usually not necessary. Special attention should, however, be paid to patients with poor metabolic control or vascular complications, particularly in the presence of disturbances of intra-uterine growth.