Obstetrical outcome following epidural analgesia in 506 consecutive deliveries.

We relate the experience of 506 consecutive deliveries under epidural analgesia in the same hospital, by the same obstetrician (JSS). 336 patients delivered without epidural analgesia during the same period. In the epidural group (n = 506), 93 patients had a normal spontaneous vaginal delivery, 357 had a low forceps, 22 had a mid-forceps, 4 had an assisted breech extraction, and 30 delivered by cesarean section. There were 24 cases (out of 506) of significant hypotension; all of them responded to an intravenous bolus of ephedrine. There was one case of accidental dural puncture that was treated with a blood patch. The degree of pain relief obtained by the epidural was deemed satisfactory in 456 patients (90%). The primary cesarean section rate in patients who received an epidural was not higher than that in patients who did not. Eleven newborns in the epidural group had one-minute Apgar scores between 4 and 6, but they all had excellent Apgar scores at five minutes. None had a one-minute Apgar score below 4. We conclude that epidural analgesia is a safe and highly effective method of pain relief during labor.

Respiratory distress syndrome: differential effects of prenatal steroid therapy and prolonged rupture of the membranes.

We studied the incidences of respiratory distress syndrome (RDS) and of severe RDS and the survival rate in premature newborns who received a complete prenatal course of betamethasone (N = 49) and in those who did not receive the steroid (N = 546). We also studied the same parameters in steroid-untreated prematures who had prolonged rupture of the membranes (greater than or equal to 24 h, N = 91), and in those who did not (N = 448). We found that the incidences of RDS and severe RDS were significantly lower and the survival rate significantly higher in steroid-treated babies than in untreated babies at 28-32 weeks of gestation (29% vs. 58%, P less than 0.01; 21% vs. 46%, P less than 0.03; and 83% vs. 49%, P less than 0.01, respectively). We also found that untreated babies born after prolonged rupture of the membranes at 28-32 weeks had significantly lower incidences of RDS and severe RDS than untreated babies without prolonged rupture (43% vs. 64%, P less than 0.02; 30% vs. 51% P less than 0.02, respectively). Between 28 and 32 weeks, steroid-treated babies did not have significantly lower incidences of RDS and severe RDS than untreated babies born after prolonged rupture of the membranes (29% vs. 43%, P greater than 0.2; 21% vs. 30%, P greater than 0.3, respectively). The data indicate that between 28 and 32 weeks gestation, the protection against RDS that is provided by prenatal treatment with betamethasone is not superior to that provided by prolonged rupture of the membranes alone.

Pregnancy in a non-communication rudimentary uterine horn.

A case of pregnancy in a rudimentary uterine horn is presented. The pregnancy ended in fetal demise at the end of the second trimester. The diagnosis was missed by ultrasonography on two occasions and was made only at laparotomy following failure to initiate uterine contractions. Histologic examination of the myometrium of the rudimentary horn revealed extensive interstitial fibrosis. A high index of suspicion of pregnancy in a rudimentary horn is recommended whenever adequate ecbolic infusions fail to induce myometrial contractions.

Delivery of the low birthweight and the very low birthweight breech: cesarean section or vaginal delivery?

We studied neonatal survival rates, APGAR scores, and length of hospital stay in 199 singleton breeches weighing 1000-2500 grams at birth. We found that in the birthweight range of 1000-1750 grams, breeches who were delivered by cesarean section had a significantly higher survival rate (74%) than those who were delivered vaginally (36%, p less than 0.01), however, in the birthweight range of 1751-2500 grams, there was no significant difference in the survival rates between breeches delivered abdominally and those delivered vaginally. The 1-minute and the 5-minute APGAR scores and the length of the hospital stay were not significantly different between the abdominal and the vaginal delivery groups in either birthweight range. The data indicate that the very low birthweight breech (less than or equal to 1750 grams) may benefit from a prophylactic cesarean section.

The Apgar score: is it enough?

One thousand thirty-two neonates were evaluated with umbilical venous and arterial blood samples drawn at delivery for assessment of pH, PO2, PCO2, and base deficit. These values were statistically correlated with Apgar scores in all of the neonates studied. Infants were divided into Apgar groupings (group A, greater than or equal to 7 at one and five minutes; group B, less than 7 at one minute, greater than or equal to 7 at five minutes; group C, less than or equal to 7 at both one and five minutes). Generally, umbilical artery and umbilical venous data were parallel. The differences in means for pH, PO2, PCO2, and base deficit was significant when group A was compared with group B in both umbilical artery and umbilical venous data. However, a severe degree of biochemical disturbance must take place before significant association with neonatal depression can be made. It appears that umbilical blood biochemical data are related to fetal metabolic status before birth but only modestly influence the one-minute Apgar score.

Hydranencephaly: prenatal and neonatal ultrasonographic appearance.

The prenatal diagnosis and postpartum confirmation of hydranencephaly is discussed. The need for an adequate knowledge of fetal cranial anatomy when performing obstetric sonography is stressed.

Observations on perinatal heart rate monitoring. II. Quantitative unreliability of Doppler fetal heart rate variability.

Fifty-three fetal heart rate (FHR) tracings obtained by direct ECG monitoring during labor and 24 simultaneous external Doppler FHR tracings were analyzed for the quantitative assessment of baseline FHR variability. The beat-to-beat difference in FHR subsumed by 90% of all beat-to-beat changes within a tracing was taken as the index of variability of that tracing. This index correlated well with the visual assessment of variability for both internal ECG records (Spearman rank correlation coefficient, rs, = 0.71) and external Doppler records (rs = 0.78). However, there was no correlation between the variability index of the Doppler FHR records and that of simultaneous ECG FHR records (r = 0.11, p greater than 0.6). This finding casts doubt on the use of the presence of "normal" FHR variability as a sign of fetal well-being during antepartum FHR monitoring with current Doppler equipment.

Differences in twins: the importance of birth order.

Despite the clinical impression that firstborn twins do better than second-born twins, recent reports have shown no difference in perinatal mortality between them. In order to evaluate differences in twins, more sensitive means than perinatal deaths are necessary. This study examines differences between 80 firstborn and second-born twin pairs with respect to Apgar score, umbilical venous and arterial blood gas, and acid-base data. The umbilical venous and arterial blood PO2, PCO2, base deficit, pH, and lactic acid concentration were measured in paired samples and compared with the paired t test and chi 2 when applicable. Statistically significant differences favoring twin A, the firstborn, were found in 1-minute Apgar score, umbilical venous pH, PO2, and PCO2, and umbilical arterial PO2. The other factors in umbilical venous and arterial blood did not show statistically significant differences. When these parameters were examined with respect to route of delivery, monochorionic and dichorionic twins, interval between twins, and vertex twins only, with the possible effects of malpresentation eliminated, the results persistently favored the firstborn twin. Thus it is unequivocally demonstrated that there are substantial differences at birth favoring the first twin, despite similar perinatal mortality for both. The data suggest that the second-born twin has potentially greater susceptibility to hypoxia and trauma.

Acidosis in the vigorous newborn.

Simultaneous measurements of maternal arterial and umbilical cord blood pH, PCO2, and base deficit at delivery were studied in 168 live-born infants and their mothers. The correlations between maternal and umbilical parameters were highly significant (P less than .001) and were greater in vigorous than in depressed newborns. Mothers of vigorous acidotic infants had a lower pH and a higher base deficit than those of vigorous nonacidotic infants (P less than .001). However, the maternal-fetal differences were wider in the vigorous acidotic than in the vigorous nonacidotic newborns for all three parameters, and in both umbilical vein and umbilical artery (P less than .001). The data indicate that maternal acidosis accounts only partially for the acidosis observed at the time of delivery in the apparently normal fetus. With neonatal depression, the degree of acidosis is not dependent on maternal pH but on other factors. These factors may be influenced by maternal acidosis, but they are the major reasons for the neonatal depression, not the maternal acidosis.

Outcome of fetuses with lactic acidemia.

Umbilical arterial lactate, pH, PO2, PCO2, and base deficit were measured at delivery of 468 live-born infants. The correlation between the 1-minute Apgar score and lactate (r = -0.34) was comparable to that between the 1-minute Apgar score and pH (r = 0.30). The multiple correlation coefficient between the 1-minute Apgar score and all five parameters combined (lactate, pH, PO2, PCO2, and base deficit) was 0.36. This was not significantly higher than the simple correlation coefficient for pH alone (0.30). Similar correlation coefficients were noted for the 5-minute Apgar score. The dividing point between normal and pathologic lactate levels was 3.70 mmol/L. A pH less than 7.20 and a lactate level greater than or equal to 3.70 mmol/L had the same sensitivity, specificity, and positive and negative predictive values for low Apgar scores (less than 7). While pH and lactate are equally correlated with fetal outcome, their combination with each other and with other blood gas parameters does not predict outcome better than either pH or lactate alone.

Placental contribution to lactate production by the human fetoplacental unit.

Umbilical cord blood levels of lactate, base deficit, and pH were measured in 452 liveborn infants. In vigorous newborns, the mean umbilical arterial and venous concentrations of lactate were lowest with elective cesarean section, higher with cesarean section performed during labor, and highest with vaginal delivery (P less than .001). This suggests a rise in the fetal lactate level in response to labor. However, there was no concomitant increase in the mean umbilical arteriovenous lactate differences, indicating that both fetus and placenta increase their lactate production proportionately with labor. Depressed newborns had higher umbilical lactate levels than vigorous newborns irrespective of the method of delivery (P less than .001). Depressed newborns also had a higher mean umbilical arteriovenous lactate difference than vigorous newborns (P less than .001). This suggests that, under conditions that lead to neonatal depression, the fetus is the major source of the increased lactate produced, with a smaller contribution from the placenta. The fetal lactate level may be a good indicator of fetal stress in labor.

Human maternal-fetal lactate relationships.

This study attempts to determine the major source of lactate in the normal and in the depressed human fetus, in order to assess the applicability of fetal blood lactate measurement for the evaluation of fetal stress during labor. We obtained umbilical arterial and venous blood samples at delivery in 132 liveborn infants, together with simultaneous maternal radial arterial samples. All samples were analyzed immediately for pH, blood gases, and lactate. In vigorous newborns (1-minute Apgar score greater than or equal to 7), umbilical arterial and venous lactate levels were lowest with elective cesarean section done before the onset of labor, higher with cesarean section performed during labor, and highest at the time of vaginal delivery (p less than 0.001, Tab. I). Fetal lactate levels were also significantly higher than maternal levels in vigorous newborns (p less than 0.01), the lactate difference between umbilical artery and maternal artery being lowest with elective cesarean section, higher with cesarean section performed during labor, and highest with vaginal delivery (p less than 0.02, Tab. II). Depressed newborns (1-minute Apgar score less than 7) had higher umbilical lactates and higher fetal-maternal lactate differences than vigorous newborns (p less than 0.01, Tab. III). Our results indicate that the blood lactate levels in both mother and fetus increase with labor and reach their highest values at the time of vaginal delivery. The lactate levels are highest in the umbilical artery, lower in the umbilical vein, and lowest in the maternal artery before the onset of labor.(ABSTRACT TRUNCATED AT 250 WORDS)