Fetal death after normal biophysical profile score: An eighteen-year experience.

OBJECTIVE: It was our goal to determine the false-negative rate of the biophysical profile, characterize an 18-year variation in the false-negative rate, examine the relationship between the last normal biophysical profile score and death, and compare the false-negative rate of 2 disparate populations. STUDY DESIGN: Biophysical profile scores of 86,955 patients at 2 medical centers were collected and recorded prospectively. All perinatal deaths occurring within 1 week of a normal score were similarly recorded. The annual false-negative rate, the cumulative false-negative rate, and the ratio of false-negative results in cases of subsequent fetal death to the perinatal mortality rate were calculated. RESULTS: There were 65 fetal deaths among 86,955 fetuses. Over an 18-year study period at one institution, the false-negative rate varied but not significantly. The cumulative false-negative rate was 0.708 per 1000 at one medical center studied and 2.289 per 1000 at the other center. The average interval between last normal score and fetal death was 3.62 days and did not vary significantly between the medical centers. CONCLUSIONS: False-negative results in cases of subsequent fetal death reflect events that are subsequent to the last normal test result. Fetomaternal hemorrhage was the single most identifiable fetal cause of false-negative results in cases of subsequent fetal death. The ratio of the false-negative rate in cases of subsequent fetal death to the perinatal mortality rate should be used as a more objective approach to reporting this value, because the false-negative rate likely reflects the underlying perinatal mortality.

Problems in the detection of intrapartum fetal asphyxia with intermittent auscultation.

We present 4 cases of severe intrapartum fetal asphyxia occurring during spontaneous unaugmented labours at term in low-risk women. In each case the baseline heart rate was completely normal, and the only indication of asphyxia was markedly decreased variability detected with electronic fetal heart rate monitoring. Correct action was taken in 3 cases that probably prevented fetal death or reduced neonatal morbidity. In no case would intermittent auscultation have been able to identify the compromised fetus.

Fetal assessment based on fetal biophysical profile scoring. VIII. The incidence of cerebral palsy in tested and untested perinates.

OBJECTIVE: The intent of this comparative clinical study was fourfold: (1) to determine the incidence of cerebral palsy in a large obstetric population, (2) to compare the incidence of cerebral palsy in patients at high risk referred for and managed according to the fetal biophysical profile score result with the incidence among unreferred and untested patients, (3) to determine the relationship, if any, between the last fetal biophysical profile score and the incidence of cerebral palsy, and (4) to categorize cases of cerebral palsy according to the clinical parameters and the probable time and nature of the damaging insult. STUDY DESIGN: In this retrospective 5-year comparative study (1987 to 1991) the incidence of cerebral palsy was determined by analysis of International Classification of Diseases, Ninth Revision, -coded related medical services. The clinical records were then sought and reviewed in index cases and obstetric, neonatal, and postnatal clinical data were abstracted. Cross-correlation with partial registries was done to confirm completeness of capture of index cases. The population of referred high-risk patients who received serial fetal biophysical profile scoring and were managed according to test results was determined by review of a prospective computer-stored database and by review of patient log books. The population of untested patients was calculated as the residual of total cases minus tested cases. The rate of cerebral palsy for all patients and for the tested and untested population was calculated and compared. The tested and untested perinates were compared for birth age, weight, and assigned timing or etiology of cerebral palsy. In the tested population the distribution of test results by last recorded biophysical profile score was determined and the relationship between the last test result and cerebral palsy and predictive accuracy parameters of the fetal biophysical profile score were calculated. RESULTS: The incidence of cerebral palsy among the 84,947 live births was 3.68 per 1000 live births (313 cases). The rate of cerebral palsy in the 26,290 referred high-risk tested patients was 1.33 per 1000 (35 cases) compared with a rate of 4.74 per 1000 live births in the 58,657 untested mixed low-risk/high-risk patients (278 cases). These differences were highly significant. A significant declining trend in the annual incidence of cerebral palsy was observed in the total population and the untested population, whereas the rate in the tested population remained relatively constant over the 5-year study interval. The differences in the cerebral palsy rate between the tested and untested population were not related to differences in gestational age, birth weight, or assigned timing or etiology category. In the tested population the relationship between the incidence of cerebral palsy and the last test fetal biophysical profile score was inverse, exponential, and highly significant. CONCLUSIONS: Antepartum assessment by fetal biophysical profile scoring is associated with a significant reduction in the incidence of cerebral palsy compared with untested patients. The relationship between the last test score and the incidence of cerebral palsy is inverse and exponential, suggesting that antenatal asphyxia is an important and potentially avoidable cause of cerebral palsy.

Fetal surveillance in diabetic pregnancy.

The focus of monitoring in diabetic pregnancy is no longer the prevention of fetal mortality, owing to the impressive benefits of strict maternal glucose control. Against this background, fetal monitoring must account for congenital anomalies, fetal mortality and severe morbidity as a result of metabolic consequences of hyperinsulinism, the exponential effect of diabetes when other maternal complications are present, and peripartum problems of the macrosomic infant, of delayed lung maturation, birth trauma and neonatal hypoglycemia. Thus, a broad range of potential fetal problems with varying maternal complications requires individualized, serial observation with multiple-format, properly validated tests. There has been recent progress: definition of the population at risk, clarification of pathophysiology, application of multiple-format tests, and evaluation of neonatal impacts; further precision may be developed with specific fetal tests. This review deals with the continued fine tuning of this critical area of perinatal medicine.

Fetal assessment based on the fetal biophysical profile score: relationship of last BPS result to subsequent cerebral palsy.

OBJECTIVE: The prime intent of this study was to determine the relationship if any between the last fetal biophysical profile score and the risk of cerebral palsy at age 3 years. The secondary objective was to examine the clinical characteristics of infants with cerebral palsy whose obstetric management included serial fetal biophysical profile scores. STUDY DESIGN: The incidence of a high risk pregnant population whose antenatal assessment was by serial fetal biophysical profile scoring was determined by cross-referencing two discrete data bases. The completeness and reliability of the data bases was confirmed by secondary audit. Obstetrical, neonatal and post-natal clinical records of index cases of cerebral palsy were subsequently reviewed, categorized and analyzed. RESULTS: Fetal biophysical profile scores (BPS) were recorded in 22,336 high risk pregnancies: 27 patients delivered an infant subsequently identified as having cerebral palsy (rate 1.21 per 1000). The relationship between last BPS result and cerebral palsy was inverse, exponential and highly significant (R2 = 0.987; p < 0.001). Affected infants with a last abnormal BPS result were significantly more likely to exhibit fetal distress (88.8%), acidosis (77.7%), and have neonatal seizures (88.8%). Antenatal asphyxia was the apparent cause of cerebral damage in 29.6% of cases. CONCLUSION: The last fetal biophysical profile score is a predictor of the risk of cerebral palsy.

Differences among obstetricians in caesarean section rates.

This retrospective study examined the Caesarean section rates of 15 obstetricians at 1 hospital delivering 5,559 nulliparas with a single cephalic baby of birth-weight > or = 2,500 g. There was a wide variation in obstetricians' Caesarean rates, whether considering all their deliveries (5.5% to 20.1%), deliveries of their own patients (8.9% to 28.2%), or deliveries of their colleagues' patients (4.5% to 17.9%). There was no relation between Caesarean rates and perinatal outcome. The different Caesarean section rates among the obstetricians could not be explained by institutional factors, physician convenience, patient differences, or self-serving economic incentives.

High cervical spinal cord injury in neonates delivered with forceps: report of 15 cases.

OBJECTIVE: To inform obstetricians of a serious complication of forceps rotations of 90 degrees or more--high cervical spinal cord injury in neonates. METHODS: We reviewed the obstetric aspects of 15 cases of high cervical spinal cord birth injury diagnosed during 1982-1994 at two tertiary-care children's hospitals in Canada. RESULTS: The common feature in all cases was a forceps cephalic delivery, almost always a rotation of 90 degrees or more from the occipitoposterior or occipitotransverse position. CONCLUSION: High cervical spinal cord injury in neonates is a rare but specific complication of forceps rotation.

Perinatal outcome in relation to second-stage duration.

OBJECTIVE: The second stage of labor has been thought of as a time of particular asphyxial risk for the fetus. This perceived risk has been invoked to justify arbitrary time limits and high rates of operative vaginal delivery. The purpose of this study was to determine whether perinatal outcome worsened as the second stage lengthened. STUDY DESIGN: Over a 5-year period at one university teaching hospital, 6041 nulliparous women reached the second stage of labor with a live singleton cephalic fetus with birth weight > or = 2500 gm. A retrospective review of perinatal morbidity and mortality was performed and the results related to the duration of the second stage. RESULTS: The second stage lasted > 3 hours in 11% of nulliparous women and > 5 hours in 2.7%. There were no perinatals death unrelated to anomaly. There was no significant relationship between second-stage duration and low 5-minute Apgar score, neonatal seizures, or admission to the neonatal intensive care unit. CONCLUSION: Operative intervention in the second stage is not warranted merely because some set number of hours has elapsed.

Prenatal diagnosis of ring chromosome 6.

An amniocentesis was performed on a gravida 1, para 0 23-year-old female because of high maternal serum alpha-fetoprotein and nuchal thickening/cystic mass apparent on the fetal ultrasound. Detailed ultrasound examination revealed multiple anomalies including brain abnormalities. The fetus was found to have a mosaic female karyotype: 45,XX, - 6/46,XX,r(6) (p25q27) (62 per cent:38 per cent). This is the first report of a prenatally diagnosed case of ring chromosome 6.

Fetofetal transfusion in triplets.

A case of fetofetal transfusion syndrome (FFTS) in a monochorionic triplet pregnancy, in which all three fetuses shared a common circulation, is reported. All babies were born alive, although two died within two days of delivery. This case highlights the problem of FFTS with accompanying high perinatal morbidity and mortality in naturally occurring monochorionic triplet gestations.

Fetomaternal hemorrhage following funipuncture: increase in severity of maternal red-cell alloimmunization.

OBJECTIVE: To determine the prevalence of fetomaternal transplacental hemorrhage after funipuncture and its effect on maternal red-cell alloantibody levels. METHODS: The prevalence and size of transplacental hemorrhages at the Health Sciences Centre were studied in two groups of patients: 174 women who were not alloimmunized or were carrying fetuses whose red cells were negative for the antigen to which they were immunized, and 122 women who were alloimmunized and carrying fetuses whose red cells were positive for the antigen to which they were immunized. In the alloimmunized group with affected fetuses, we surveyed the incidence of maternal antibody increase in titer by two or more doubling dilutions and the Rh(D) antibody increase (in microgram/mL of serum) of more than 50% after funipuncture. RESULTS: One hundred of the 174 women (57.5%) in the nonimmunized group and 69 of the 122 women (56.6%) in the immunized group had evidence of transplacental hemorrhages ranging in volume from 0.03 mL to greater than 5 mL of fetal red blood cells. In the latter group, antibody titer increases of 2 to 9 and doubling dilutions occurred in 37 of 74 women (50%) in whom such measurements were carried out. Increases of anti-D exceeding 50% occurred in 44 of 53 women (83%) in whom quantitative measurements were assayed. CONCLUSION: Funipuncture carries a high risk of fetal transplacental hemorrhage. In the immunized woman carrying an antigen-positive fetus, this will increase the level of her antibody and probably increase the severity of hemolytic disease in her fetus. In alloimmunized women, funipuncture should rarely be carried out to determine the fetal antigen status. Serial amniocenteses combined with careful serial ultrasound observation of the fetus are safer. Funipuncture should not be done in alloimmunized women before the cord vessels are of adequate size to allow immediate intravascular fetal transfusion, if required.

Life without amniocentesis: elevated maternal serum alpha-fetoprotein in the Manitoba program 1986-91.

Pregnant women demonstrating an elevated maternal serum alpha-fetoprotein level are at increased risk for fetal neural tube defect or other anomaly. Diagnostic procedures to evaluate these pregnancies include high-resolution ultrasound and amniocentesis to measure amniotic fluid levels of alpha-fetoprotein and N-acetylcholinesterase. We wished to examine the efficacy of detailed ultrasound examination alone, in evaluation of women with 'unexplained' elevation of maternal serum alpha-fetoprotein. The results showed that no neural tube defects were missed in the assessment of 1325 pregnancies with a raised level of maternal serum alpha-fetoprotein over 6 years, despite complete reliance on ultrasound in 98%. Detailed fetal ultrasound evaluation by experienced personnel is adequate to identify all cases of neural tube defects in a selected high-risk population.

Intrauterine thoracentesis of fetal cystic lung malformations.

Fetal pulmonary malformations comprise a rare but often lethal group of congenital anomalies. Until recently, diagnosis and therapy were directed postnatally and therefore some cases of fetal compromise were inevitably missed. We present 2 cases in which intermittent thoracentesis of fetal cystic lung malformations resulted in a successful outcome. Intrauterine thoracentesis should be considered in the second and third trimester of pregnancy in cases which demonstrate early fetal compromise.

Fetal biophysical profile score. VI. Correlation with antepartum umbilical venous fetal pH.

OBJECTIVE: Our objective was to determine the relationship, if any, between the fetal biophysical profile score and antepartum umbilical venous pH. STUDY DESIGN: This was a prospective observational study conducted concurrently in two centers and involving two discrete high-risk groups of fetuses. Fetal biophysical profile scores were compared with umbilical venous pH values measured in blood obtained by immediate cordocentesis. A total of 493 paired observations of biophysical profile score and pH were made; 104 observations were of fetuses with intrauterine growth retardation and 389 observations were of fetuses with alloimmune anemia. RESULTS: In both data sets there was a highly significant linear correlation between biophysical profile score and umbilical venous pH. Poor biophysical profile score performance (a score of 0 of 10) was always associated with a pH < 7.20, whereas the pH was always > 7.20 when the biophysical profile score was 10 of 10. Sequenced sensitivity of short-term biophysical variables in the detection of acidemia was observed. CONCLUSION: The fetal biophysical profile score accurately predicts antepartum umbilical venous pH.

Maximum possible impact of tocolytics in preventing preterm birth: a retrospective assessment.

Although tocolytic drugs are widely used to try to stop preterm labor, their actual contribution to preventing preterm deliveries is unknown. Since tocolytic drugs are not used at the University of Manitoba, it was possible to estimate the proportion of preterm deliveries that might have been eligible for tocolytic drug therapy. Of 364 consecutive preterm deliveries between 24 and 35 weeks, only 9% would have been eligible for, let alone prevented by, tocolytic drug therapy, and even a smaller percentage of babies would actually have benefitted from their use. The use of tocolytic drugs can, at best, benefit only a very small percentage of babies born preterm. Whether the risks of treatment justify this small benefit is arguable.

Must macrosomic fetuses be delivered by a caesarean section? A review of outcome for 786 babies greater than or equal to 4,500 g.

Because difficult vaginal delivery is more frequent with macrosomic fetuses, some writers recommend routine Caesarean section for the delivery of fetuses greater than or equal to 4,500 g. The purpose of this study was to evaluate the appropriateness of this recommendation. A retrospective review was undertaken to determine how many fetuses born in our hospital weighing greater than or equal to 4,500 g died or were permanently damaged as a consequence of mechanical difficulties at delivery. During a 10-year period, 590 (75%) of 786 cephalic babies weighing greater than or equal to 4,500 g and alive at the start of labour were born vaginally. No baby died or was permanently damaged as a consequence of mechanical difficulties at delivery. Routine Caesarean section for macrosomic fetuses to prevent death or damage from difficult delivery is not warranted by our results.