Maternal Blood Loss Research Articles

Trial of Labor Following Cesarean Delivery

To examine several variables that may affect the success rate for a trial of labor after previous cesarean delivery, as well as those affecting the rate of uterine rupture. Between June 1, 1990 and December 31, 1991, we performed a consecutive, prospective study of 593 pregnant women who had had at least one abdominal delivery in the past, and attempted a trial of labor in each. Particular attention was given to the success rate of vaginal delivery, the type of previous uterine incision, use of oxytocin, estimated maternal blood loss, 5-minute Apgar scores, and reason for the previous cesarean operation. Four hundred seventy-eight patients (81%) had a successful vaginal delivery. Oxytocin induction or augmentation was successful in 46 of 67 (69%) and 117 of 167 cases (70%), respectively. Estimated maternal blood loss was less than 500 mL in 453 cases (95%). Five patients (0.8%) experienced true uterine rupture, resulting in severe neurologic sequelae in one infant. The only consistent indication of uterine rupture was an abrupt and prolonged fetal bradycardia. The majority (463; 97%) of infants who were delivered vaginally had 5-minute Apgar scores of 8 or greater. Our success rate of 81% suggests that a trial of labor after previous cesarean delivery is a safe and desirable option, but only after thorough patient counseling. An abrupt and persistent fetal bradycardia may be the only indication that uterine rupture has occurred.

Management of Term Breech Presentation

Management of Term Breech Presentation

Effect of the Birth Chair on Duration of Second Stage Labor And Maternal Outcome

The effect of delivering in a birth chair on duration of second stage labor, perineal swelling, incidence of episiotomies, lacerations, hemorrhoids, and maternal blood loss was examined in a prospective quasi-experimental study. The sample consisted of 55 primiparous women, 37 to 41 weeks gestation, with normal pregnancy and labor; 22 delivered on a traditional delivery table (DT) and 33 in a birth chair (BC). Comparisons were made between groups for mean duration of second stage labor, mean time bearing down in the delivery room, mean maternal blood loss, frequency of instrument-assisted deliveries, frequency of episiotomies and lacerations, and frequency of perineal swelling and hemorrhoids. The two groups were statistically similar for weight of infant. No significant difference was found between groups for mean duration of second stage labor (BC M = 55 minutes, DT M = 43 minutes) or mean time bearing down (BC M = 60 minutes, DT M = 53 minutes). No difference was found in the amount of blood loss between the two groups as measured by the mean difference in the pre- and postdelivery hemoglobin (BC M change = 1.4 Gms, DT M change = 1.8 Gms). The lack of significant differences in blood loss may be due to the fact that the angle of the birth chair was lowered during or after delivery in 88% of the cases. The incidence of instrument-assisted deliveries (BC = 7, DT = 6), episiotomies (BC = 27, DT = 20), lacerations (BC = 17, DT = 5), and hemorrhoids (BC = 14, DT = 4) was similar between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the Birth Chair on Duration of Second Stage Labor, Fetal Outcome, and Maternal Blood Loss

The effect of delivering in a birth chair on duration of second stage labor, fetal outcome, and maternal blood loss was examined in a retrospective study. The sample consisted of 60 primiparous women, 37 to 41 weeks gestation with a normal pregnancy and labor, 30 delivering on a traditional delivery table and 30 delivering in a birth chair. Comparisons were made between groups for mean duration of second stage labor, mean Apgar scores at one and five minutes, and mean maternal hemoglobin and hematocrit values during the pre- and post-partum periods. No significant difference was found between delivery table and birth chair groups for mean duration of second stage labor (birth chair, X = 60 minutes versus delivery table, X = 43 minutes, t = 1.66, p = .10). Mean Apgar scores at one and five minutes were nearly identical. Statistically significant differences existed between groups in mean maternal hemoglobin and hematocrit values. Both the mean hemoglobin and the mean hematocrit upon admission were significantly higher in the birth chair group (p less than .027). However, postpartally the birth chair group had significantly lower mean hemoglobin and hematocrit values (p less than .025). These findings suggest that the birth chair, as an alternate delivery method, is safe in terms of fetal outcome but presents no advantage to the mother in terms of shorter second stage labor. Further investigation of maternal blood loss is recommended to rule out possible untoward effects.

X-ray pelvimetry and trial of labor after previous cesarean section. A prospective study.

The benefits of X-ray pelvimetry and electronic monitoring of fetal heart rate and intra-uterine pressure were studied prospectively in order to predict the likelihood of a successful vaginal birth after previous cesarean section (CS). In 1982, a total of 369 parturients (7% of all deliveries) who had previously undergone CS were studied. Trial of labor (TL) was allowed in 160 cases (43.4%) and planned repeat CS was performed in 209 patients (56.6%). Patients in the TL group were compared with a matched control group. One hundred and fifty patients (94%) in the TL group gave birth by the vaginal route. There were no differences in the duration of the first and second stage of labor, duration of ruptured membranes (ROM), maternal blood loss or the incidence of CS and vacuum extraction between the TL group and the control group. Rates of low Apgar score (less than 7) at 1 and 5 min were the same in both groups. Intensive fetal monitoring during the course of labor, together with X-ray pelvimetry in selected cases, markedly reduced the incidence of acute repeat CS with no change in the overall rate of successful vaginal delivery compared with our previous results.

Pain relief in labor by transcutaneous electrical nerve stimulation. A prospective matched study.

The study evaluated transcutaneous electrical nerve stimulation (TNS) for pain relief in labor, used in parallel with conventional methods. The investigation comprised 566 vaginally delivered women, 283 of whom were given TNS. Pain relief was evaluated with a questionnaire which the women answered shortly after delivery. With a statistical multivariate technique, it was concluded that TNS has a specific effect on pain localized to the back. Few women in either the TNS or the control group reported good relief of pain localized to the suprapubic region. Nitrous oxide-oxygen mixture was used less often in the TNS group than in the controls. Duration of labor and maternal blood loss were comparable in the two groups. The babies borne by primiparae in the TNS group tended to have better Apgar scores. Fewer babies of primiparae in the TNS group required observation for two days or more on the neonatal ward than was the case with the controls. However, the electrical stimulation could not be used optimally as it interfered with monitoring the fetal heart rate in half the cases. It is concluded that although TNS has a good effect on low-back pain and seems to have no negative effects on the mother or child, it is only a complement to conventional methods.

Fetal lamb lung phosphatidylcholine: Response to asphyxia and recovery

Acute fetal asphyxia resulting from maternal blood loss and hypotension causes a reduction in the incorporation of precursors into disaturated phosphatidylcholine, the principal lipid in the pulmonary surfactant. Treatment of the maternal hypotension is associated with return of fetal lung DSPC synthesis to control levels by 72 hours.

667 THE EFFECT OF PRENATAL ACETYL SALICYLIC ACID (ASA) INGESTION ON MATERNAL AND NEONATAL HEMOSTASIS

The effect of prenatal ASA ingestion on hemostasis was investigated in 59 maternal-neonate pairs. Group I consisted of 36 control pairs in whom a negative ASA drug history was substantiated by normal maternal and neonatal platelet aggregations and values for the prostaglandin byproduct malonyldialdehyde (MDA). Group II consisted of 16 pairs in whom a positive history for maternal ASA ingestion was confirmed by the expected abnormalities in platelet aggregations and MDA. Group III comprised 7 maternal-neonate pairs where maternal ASA ingestion occurred within 6 hours post partum. All groups were evaluated for hemostatic abnormalities. Maternal blood loss was considered excessive, if a drop of >10% between initial and discharge hemoglobin occurred (vaginal delivery), or >25% (C section). In Group I, no maternal hemostatic abnormalities were noted, although 1/34 neonates demonstrated facial ecchymoses. In 10/16 Group II pairs where maternal ASA ingestion had occurred 0-5 days prior to delivery, clinical evidence of bleeding occurred in 90% (9/10) of the infants, and 60% (6/10) of the mothers. In contrast, in 6/16 Group II pairs, where ASA ingestion had occurred 6-10 days prior to delivery, no abnormalities were found. Group III infants were normal, although 57% (4/7) mothers in this group bled abnormally. ASA ingested in the 5 days prior to delivery, or immediately post partum, is associated with hemostatic abnormalities in both mother and neonate.

The effect of ligating a uterine artery on fetal and placental development in the rat.

The left or right uterine artery was ligated in 100 rats on Day 4, 5, 6, 7, 8, 9, 10 or 12 of gestation. Uterine arterial ligation had no apparent effect on survival, malformation or sex ratios of fetuses examined on Day 22. There was a small decrease in fetal weight and an increase in placental weight particularly after ligation on Day 9. Placental hypertrophy, as an adaptation to impaired uterine circulation, is discussed, The mammalian fetus relies almost wholly on the placenta for its nutrition, respiration and excretion. Its rate of growth is thought to be modified by the functional capacity of the placenta however, the possibility that fetal demand may in turn affect the growth and function of the placenta has received little consideration. Yet placental hypertrophy has been observed in chronically anemic women (Beischer et al., 1968) and in rats following acute maternal blood loss (Bruce and Cabral, 1975); conditions in which an increased functional capacity might be needed to compensate for a reduction in blood 02 content or arterial perfusion pressure. In the rat each uterine horn is supplied by a uterine artery, a branch of the ovarian artery and small branches from the vesical artery. These

Effects of maternal blood loss on embryonic and placental development in the rat.

The effects of acute loss of maternal blood on embryonic and placental development was examined in 50 rats on Days 8 or 9 of gestation. Blood was withdrawn from conscious, cannulated rats over a 1-min period at 1-0 or 2-0 ml/100 g body weight. These degrees of blood loss were expected to produce a mild (about 50%) and severe (about 80%) reduction in uterine blood flow, respectively, for at least 15 min. There was no evidence that loss of blood affected either fetal survival and malformation rates or fetal weights and sex ratios. The anaemia resulting from haemorrhage lasted no longer than 6 days. Placental weights were 11% higher in rats losing 2-0 ml blood/100 g than in controls (P less than 0-05). It appears that the 8- or 9- day rat embryo is highly resistant to the partial reduction in uterine blood flow, maternal anaemia and other possible challenges induced by maternal loss of blood at levels sufficient to affect the mothers.

Regulating factors in the transfer of iron across the rat placenta.

The effect of maternal blood loss on the iron uptake of the foetectomized placenta has been studied. Normal pregnant rats were used as controls. It is suggested that the rate of maternal blood flow and plasma iron concentration primarily controls placental iron uptake independent of the presence of a foetus. Starch gel electrophoresis and fluorescent antibody techniques have been employed to investigate foetal rat synthesis of transferrin. The onset of synthesis at the commencement of the last third of gestation is probably important in creating a viable system for foetal plasma iron turnover which, under the control of the foetal erythroid marrow, is responsible for the high rate of iron transfer from the placenta to the foetus.

RADIOLOGICAL CASE OF THE MONTH.

CLINICAL HISTORY.—A male infant weighing 3,860 gm (8 lb 8⅓ oz) was the product of a full-term uneventful pregnancy and labor. The delivery was said to be traumatic with forceps rotation. There was no significant maternal blood loss during delivery. At birth, intraocular hemorrhage of the right eye and a right facial paralysis and contusions of the scalp and face were noted. The infant seemed to be doing well until the age of 60 hours at which time he had an apneic spell, appeared extremely pale, and a firm mass was palpated in the right flank. The hemoglobin concentration was 9 gm/100 ml and culture of the blood yielded no growth. The infant was given intramuscular penicillin and streptomycin and referred to the Los Angeles Childrens Hospital at the age of 66 hours. On admission, the infant had a good cry and appeared fairly vigorous. Pertinent positive physical findings were:

Correlation of blood loss with blood volume and other hematological studies before, during, and after childbirth

P OSTPARTUM hemorrhage is today a major cause of maternal morbidity and mortality.l, 2 Previous hematologic and blood volume studies of the normal pregnancy and puerperium at the Royal Victoria Hospital showed that the loss of circulating blood due to childbirth greatly exceeded the obstetrician’s estimate. The present study was initiated to explain this discrepancy and to determine in greater detail the blood loss in normal delivery. Many observers have measured blood loss during the third stage of labor, using receptacles to collect. blood escaping from the vagina and perineum. Table I demonstrates the wide variations found in fifteen reported series.3-1” The average blood loss ranged from 150 to 600 ml. At the Royal Victoria Hospital the blood loss in normal delivery is commonly estimated at 200 ml. 01’ less by the attending obstetrician. Tysoe and llowensteinll followed the serial blood volume changes of a group of women during pregnancy and for two months post partum at the Royal Victoria Hospital and were impressed with the marked diminution of total red cell volume after delivery (Fig. 4). In recent years the T-1824 dye-hematocrit, carbon monoxide, red cell differential agglutination, and radioactive tracer methods of blood volume determination have been applied to the measurement of blood loss resulting from surgical operations, traumat,ic injuries, battle casualties, and gastrointestinal hemorrl~age.l”-‘” A number of authors have used one or more of these methods in measuring blood volumes in pregnancy and the puerperium. Table II is a composite table computed from their data.“, =, z.i, ~3 z7 Although the number of cases reported in each series was small, their close agreement seems significant,. The average apparent blood loss by these methods ranged from 810 to 1,250 ml. These findings suggested that maternal blood loss from the active circulation occurring after delivery is greater than is commonly believed and led to the following studies.