Primary cesarean section: a critical analysis.

A detailed analysis of 465 primary cesarean sections (10.4% of total deliveries) performed at St. Mary's Health Center during 1977 and 1978 was undertaken. Cephalopelvic disproportion, malpresentation, and fetal distress were the 3 most common primary indications for cesarean section. An analysis of the effects of fetal monitoring seemed to indicate that the procedure was not a significant factor in increased use of cesarean section.

Fetal femur length, neonatal crown-heel length, and screening for intrauterine growth retardation.

Early ultrasonic diagnosis of intrauterine growth retardation (IUGR) can be very beneficial. However, most methods of ultrasonic diagnosis require an accurate knowledge of gestational age. The current study was designed to prospectively evaluate the relationship between fetal femur length and neonatal crown-heel length, and to study the femur length/abdominal circumference ratio as a method of screening for IUGR. Three hundred twenty-six infants who had undergone real-time ultrasound examination within 72 hours before birth were used for the study. Fetal femur length was compared with neonatal crown-heel length, although the most accurate relationship was geometric (r2 = .7474), and a strong linear relationship was also observed: y(crown-heel length) = 11.887 + 5.158 X (femur length), (r2 = .7067; SD = 3.34 cm). Mean femur length/abdominal circumference ratios were significantly different for average-for-gestational-age (22.33 +/- 1.86%), small-for-gestational-age (23.34 +/- 1.89%), and large-for-gestational-age (20.99 +/- 1.32%) infants, but did not reveal a discriminatory value for the diagnosis of IUGR as positive as that reported by Hadlock et al. The femur length/abdominal circumference ratio should be evaluated further as a screening tool in the diagnosis of IUGR.

Accurate gestational dating.

Gestational age by four ultrasonic parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) was calculated for 210 normal obstetric patients divided into four gestational age groups based on time of first ultrasound examination. Accuracy of the calculations was determined by comparison of each technique and a simple arithmetic average of the four techniques to the gestational age calculated from the Dubowitz examination of the neonate after delivery. The analysis indicated that each ultrasonic technique has certain advantages and disadvantages, but that the simple arithmetic average of the four techniques had the lowest systematic and random error.

Clinical application of fetal weight determination by real-time ultrasound measurements.

The weights of 101 neonates delivered within 72 hours of real-time ultrasound examination were compared with the weight calculated from the ultrasonically measured biparietal diameter and abdominal circumference. A high degree of correlation (4 = .9624) was found between actual and calculated weights. This method of weight estimation has been clinically useful, especially in infants weighing less than 1500 g.

Primary cesarean section: factors related to postpartum infection.

Four hundred sixty-five primary cesarean sections (10.4% of total deliveries) performed during 1977 and 1978 were reviewed and compared with 465 vaginal deliveries to ascertain factors that may be related to postpartum infection. The overall morbidity (19.7%) related to postpartum infection in the primary cesarean section group was statistically different from the 2.4% morbidity in the vaginal group. Cross comparisons of the effect of membrane status, use of internal electronic monitoring, development of postpartum anemia, duration of active labor, and difference in patient populations showed that internal monitoring had little or no effect on the development of postpartum endometritis. However, the development of postpartum anemia, increased time between membrane rupture and delivery, and, most important, a significant difference in patient populations were believed to be related to the development of postpartum endometritis in both groups.

Defining altered fetal growth by second-trimester sonography.

A method of predicting birth weight from a single ultrasound examination between 18-28 weeks' gestation was evaluated prospectively in 315 obstetric patients with singleton pregnancies. Estimated fetal weight at the time of the ultrasound examination was used to predict actual birth weight. At delivery, the percent difference between the projected and actual birth weights was then used to define whether an infant was small, appropriate, or large for gestational age. This method appeared to be accurate and showed identical relationships to the presence of abnormal fetal heart rate patterns in growth-retarded infants as did the traditional birth-weight-for-gestational-age method of defining intrauterine growth retardation.

Ultrasonic diagnosis of altered fetal growth by use of a normal ultrasonic fetal weight curve.

A previously developed normal ultrasonic fetal weight curve was used for antenatal diagnosis of altered fetal growth in 595 patients who had undergone real-time ultrasound examination within 72 hours before birth. Fetal weight was estimated using biparietal diameter and abdominal circumference and plotted on the normal curve. The diagnosis of small for gestational age (SGA) or large for gestational age (LGA) was based on whether the ultrasonic weight fell below or above the normal limits. After delivery, infants were classified as SGA, LGA, or average for gestational age (AGA) by birth weight, and the postnatal diagnosis was compared to the antenatal ultrasound diagnosis. The sensitivity of the technique for the diagnosis of SGA infants was 89.9%; for LGA it was 73.5%. The overall specificity of the technique was 79.8%.

Analysis of variables affecting perinatal mortality: St. Louis City Hospital, 1969-1975.

A marked drop in perinatal mortality at St. Louis City Hospital No. 1 (SLCH) from 1974 to 1975 (39.7 vs 20.6 per 1000 births) prompted a detailed analysis of various factors which might have effected the change. Comparisons were also made between SLCH and St. Mary's Health Center (SMHC), a private hospital affiliated with St. Louis University. The significant drop in perinatal mortality at SLCH in 1975 seems to be due to a combination of various factors: 1) improvement in antepartum care, 2) increase use of cesarean sections, and 3) the influence of intrapartum fetal monitoring.

Vacuum extraction.

In the past twenty years, the vacuum extractor has gained wide use in Europe with an associated decrease in perinatal mortality. There, its use is considered by many to be much safet than a forceps delivery. Certain complications are associated with its use, but in general these are minor and transitory. On analysis, most of the serious complications reported in the literature are considered to be due to other associated factors, or to misuse of the vacuum extractor. Experience with the vacuum extractor in the United States has been minimal, and most authors feel that there are few indications for its use. Perhaps it is time that obstetricians in the United States take a more careful look at the European experience, and give the vacuum extractor a fair trial.

The current status of intrapartum fetal monitoring.

Intensive intrapartum fetal monitoring, using direct fetal EKG leads and intrauterine pressure sensing transducers, seems to add another level of care for the fetus. As with other laboratory aids or devices, fetal monitoring data should not be exclusively relied on in decision making processes. When used with other modern monitor aids, such as scalp pH, it can aid immensely in the management of both normal and complicated labors. When fetal heart rate patterns remain normal throughout labor there can be a high degree of confidence that the fetal outcome will be good. If abnormal patterns occur, however, great care should be taken in interpreting these data, and it should be combined with the overall status of the mother and the fetus, and used together with the clinical acumen of the physician in determining a method of approach to the management of intrapartum situations. Continuous monitoring techniques can and should be applied in the neonatal nursery for intensive neonatal management and care (79,80). As experience is gained in clinical fetal monitoring and as new techniques and methods become available, intensuve intrapartum fetal monitoring will become an increasingly important and significant technique for management of labor (4, 139).

Perinatal mortality in the St. Louis metropolitan area.

Statistical data in fetal, neonatal, perinatal, and infant mortality were collected from various sources for the St. Louis metropolitan area (St. Louis City and St. Louis County). The overall perinatal mortality rate of 25.8 for the St. Louis metropolitan area in 1973 compares favorably with the national rate of 25.5 in 1973. The prematurity rate at St. Louis City Hospital (SLCH) is almost three times that of St. Mary's Health Center (SMHC), 12.7 in contrast to 4.8. Both the neonatal and perinatal mortality rates at SLCH are about twice the rate of SMHC, neonatal 19.5 versus 7.4 and perinatal 31.7 in contrast to 19.6. Prematurity and its complications still seem to be the leading cause of neonatal mortality. With modern obstetrical and intensive neonatal care, the survival rates for low birth weight infants has improved markedly. The combined survival rates at SLCH and SMHC, 1972 through 1974 for infants weighing 501-1,000 gms 28 percent; 1,001-1,500 gms, 74 percent; 1,501-2,5000 gms, 95.5 percent; and greater than 2,500 gms. 99.7 percent. Recent studies have shown that the long-term prognosis for these low birth weight infants, in terms of neurological or intellectual sequelae is good. Thus, a more aggressive approach to the management of perinatal problems can be expected to yield excellent results.

The diagnosis of altered fetal growth.

The antenatal recognition of altered fetal growth should be an important goal for every obstetrician, because significant neonatal complications can be associated with both ends of the spectrum of altered growth. This article discusses the problems related to altered fetal growth, the difficulty in defining and diagnosing it, and some of the methods available for its antenatal diagnosis.

Middle cerebral artery blood flow in the fetus and central nervous system complications in the neonate.

OBJECTIVE: To evaluate the ability of blood flow (S/D) ratios in the fetal middle cerebral artery (MCA) to predict the occurrence of central nervous system (CNS) complications (bleeding and/or ischemia) in the neonate, and compare MCA flow to other tests of fetal well-being. STUDY DESIGN: This was a retrospective, observational, cross-sectional clinical outcome study of high-risk patients, evaluated in the Perinatal Center of the author's institution, who underwent antenatal testing with non-stress test (NST) and Doppler studies (including studies of the fetal umbilical artery and MCA) within 1 week of delivery. MCA flow was converted to multiples of the mean, and appropriate parametric and non-parametric statistics were used to compare MCA flow to the presence or absence of CNS complications. Comparisons were also made for the other tests of fetal well-being. RESULTS: CNS complications occurred only in infants who were delivered at less than 37 weeks of gestation (n = 14/131) and the analysis was limited to these 131 patients. Univariant analysis showed that only the NST correlated with CNS complications (OR = 5.46 (1.48-22.16)) and logistic regression confirmed the association. Neither increased diastolic flow in the MCA nor the presence of shunting correlated with CNS complications. CONCLUSIONS: This study confirms previous reports that fetal shunting, with decreased resistance and increased flow in the CNS, is a benign adaptive mechanism for the fetus under stress and not an increased risk for CNS complications. A non-reactive NST, however, is a very late sign of fetal compromise and is significantly associated with the risk of developing CNS complications.

Significance of exaggerated fetal heart rate accelerations during active labor.

One hundred fifty-three of 1,289 patients (11.9%) monitored during labor were identified as having exaggerated fetal heart rate accelerations (EFHRAs), defined as accelerations of the fetal heart rate above the baseline of 30 beats/min or greater and lasting at least 30 seconds. Comparisons of patients with and without EFHRAs showed that the only difference between the two groups was a higher percentage of nulliparous patients in the EFHRA group. Comparisons of intrapartum complications showed a decreased incidence of meconium staining and an increased percentage of abnormal labor patterns in the EFHRA group. Comparisons of neonatal outcome statistics showed lower perinatal morbidity and higher mean birth weight in the EFHRA group.

Ultrasonically estimated weight and gestational age. Predictors of neonatal respiratory distress syndrome.

Information from 504 women who had undergone real-time ultrasound examination within 72 hours of childbirth was used to evaluate the relationship between the product of ultrasonically estimated fetal weight (in kilograms) times ultrasonically estimated gestational age (in weeks) and neonatal morbidity and mortality. If this product was greater than 40, there were no neonatal deaths (excluding severe congenital abnormalities); if the product was greater than 80, there were no cases of significant respiratory distress syndrome. These data may prove to be highly useful in the rapid evaluation of preterm labor or other obstetric complications.