Is end-stage deceleration of the fetal heart ominous?

The "30-minute rule" for expedited delivery: fact or fiction?

Initially developed from hospital feasibility data from the 1980s, the "30-minute rule" has perpetuated the belief that the decision-to-incision time in an emergency cesarean delivery should be <30 minutes to preserve favorable neonatal outcomes. Through a review of the history, available data on delivery timing and associated outcomes, and consideration of feasibility across several hospital systems, the use and applicability of this "rule" are explored, and its reconsideration is called for. Moreover, we have advocated for balanced consideration of maternal safety with rapidity of delivery, encouraged process-based approaches, and proposed standardization of terminology regarding delivery urgency. Furthermore, a standardized 4-tier classification system for delivery urgency, from class I, for a perceived threat to maternal or fetal life, to class IV, a scheduled delivery, and a call for further research with a standardized structure to facilitate comparison have been proposed.

Clinical features of abruptio placentae as a prominent cause of cerebral palsy

BACKGROUND

Although abruptio placentae causes hypoxia in the infant and thus leading to cerebral palsy (CP), its incidence and clinical features at a nationwide level have not been demonstrated.

AIMS

To determine the proportion of abruptio placentae among antenatal and intrapartum causative factors leading to cerebral palsy (CP) and clinical features of such abruptio placentae.

STUDY DESIGN

A review was conducted in 107 infants with CP in whom CP was determined to be due to antenatal and or intrapartum hypoxic conditions by the Japan Council for Quality Health Care until April 2012.

RESULTS

Abruptio placenta was responsible for 28 (26%) of the 107 CP infants, and was the single leading causative factor of CP. Of these 28 women, 22 (79%) exhibited non-reassuring fetal status on admission to obstetric facilities at 36.2 ± 2.6 weeks of gestation and had neonates with umbilical cord arterial blood pH (base excess) of 6.728 ± 0.164 (-25 ± 5.4 mmol/L). In these 22 women, strong abdominal pain and/or profuse vaginal bleeding occurred 159 ± 99 min prior to admission to an obstetric facility, and the interval until delivery after admission was 47 ± 31 min. Hypertension or isolated proteinuria preceded clinical events in one (4.5%) and five (23%) of these 22 women, respectively.

CONCLUSIONS

Abruptio placentae was responsible for CP in one quarter of all cases determined to be due to antenatal and/or intrapartum hypoxic conditions in Japan. New strategies to shorten the interval until admission to an obstetric facility after onset of symptoms are urgently needed.

Impact of the severity of fetal distress on decision-to-delivery intervals for assisted vaginal delivery

To correlate the severity of fetal distress assessed retrospectively using the Dublin intrapartum fetal monitoring classification, with decision-to-delivery intervals (DDI) and neonatal outcome, a prospective 3-month study of 78 consecutive instrumental deliveries was conducted. There were 66 cardiotocographs (CTGs) with an 83% majority agreement on classification: it was agreed 95% of deliveries should be expedited for the 58 interpretable CTGs. Although the more abnormal CTG patterns resulted in shorter DDIs and greater neonatal acidaemia, there were no significant correlations. Acidosis was present in 14% with a suspicious, or 22% an ominous CTG pattern. Delivery as a trial in theatre doubled the DDI at 41.5 +/- 22.7 (mean +/- SD) min, compared with 18.1 +/- 8.1 min in the labour room (p < 0.0001), with one case of severe acidosis in the former group. The prolonged DDI with a trial of delivery in theatre could adversely compromise the already 'distressed' fetus and should be used only when clearly indicated.

The effect of early second stage bradycardia on newborn status

In the present study 45 patients with intrapartum cardiotocograms showing prolonged fetal bradycardia during the early second stage of labor were included. Bradycardia persisted for 180 s or more with either rapid or prolonged return to baseline, without loss of variability and rise of baseline fetal heart rate (FHR). The mean duration of bradycardia was 5.0 +/- 1.3 min. In the group with normal FHR tracings the rate of normal delivery (73.3%) was significantly higher than that of the group with fetal bradycardia (26.7%, P < 0.0001). We also noted a significantly higher rate of cesarean section (44.4%) in patients with abnormal FHR tracings, compared to that (11.1%) of parturients with normal FHR tracings (P < 0.001). In all cases blood samples were obtained from the umbilical cord artery, immediately after delivery. Only in two cases with abnormal FHR tracing umbilical cord artery was the pH less than 7.20. We conclude that in most cases, prolonged fetal bradycardia in the early second stage with the characteristics described above is well tolerated by a mature fetus.

Acid accumulation during end-stage bradycardia in term fetuses: how long is too long?

OBJECTIVE

To estimate the existence and degree of fetal accumulation of acid during end-stage bradycardia as reflected by the base deficit. This may set a criterion for proper intervention during labour.

SETTING

Maternity unit of the Tel Aviv Medical Centre.

SUBJECTS

Forty-three consecutively born term infants whose mothers were delivered by vacuum extraction were analysed: 27 because of end-stage bradycardia and 16 controls whose mothers were delivered electively because of maternal indications.

MAIN OUTCOME MEASURES

Analysis of umbilical arterial cord blood for pH, PCO2 and base deficit. The base deficit was compared between the groups using the two-tailed Student's t test, and was correlated with variables of fetal heart rate monitoring using the Pearson correlation coefficient.

RESULTS

The base deficit was greater in newborns who had end-stage bradycardia than in controls (11.02 vs 5.01, P < 0.0001). The duration of loss of short term variability in fetal heart rate during end-stage bradycardia correlated positively with the base deficit (r = 0.8, P < 0.0005). Conversely, the time until the loss of short term variability during end-stage bradycardia correlated negatively with the base deficit. The length and the depth of the bradycardia and their product, had a weaker correlation with the base deficit.

CONCLUSIONS

End-stage bradycardia, which presumably reflects fetal hypoxia, is associated with acidaemia in the umbilical artery at birth in some fetuses. The fetuses who are predisposed to acidaemia, as reflected by an increased base deficit, are those who lost their fetal heart rate variability during end-stage bradycardia for more than 4 min or started to lose this in less than 3 min from the beginning of the end-stage bradycardia. Operative vaginal delivery should be reserved for these indications.

Benefits and risks of episiotomy: a review of the English-language literature since 1980. Part II

Mediolateral and, to a lesser degree, midline episiotomies substantially increase the amount of blood loss at delivery; in fact, simple avoidance of episiotomy may be the most powerful means the delivery attendant has to prevent excessive intrapartum hemorrhage. The long-term morbidity of the anal sphincter damage induced by episiotomy, particularly midline, has generally been underestimated in both its frequency and severity. Other potential fetal and maternal complications of episiotomies, although rare, are numerous and serious. The overall degree of risk that accompanies this procedure could only be justified by a clear and overriding benefit, which, as discussed under "Benefits" earlier in this review, does not appear to exist.

Benefits and risks of episiotomy: a review of the English-language literature since 1980. Part I

The professional literature on the benefits and risks of episiotomy was last reviewed critically in 1983, encompassing material published through 1980. This paper reviews the evidence accumulated since then. (Part II follows in this issue.) It is concluded that episiotomies prevent anterior perineal lacerations (which carry minimal morbidity), but fail to accomplish any of the other maternal or fetal benefits traditionally ascribed, including prevention of perineal damage and its sequelae, prevention of pelvic floor relaxation and its sequelae, and protection of the newborn from either intracranial hemorrhage or intrapartum asphyxia. In the process of affording this one small advantage, the incision substantially increases maternal blood loss, the average depth of posterior perineal injury, the risk of anal sphincter damage and its attendant long-term morbidity (at least for midline episiotomy), the risk of improper perineal wound healing, and the amount of pain in the first several postpartum days.

Episiotomy and perineal trauma during childbirth

A study was conducted to assess the frequency of episiotomy and spontaneous tears in 807 primiparas during singleton births. The incidence of episiotomy was 50%, spontaneous tears 22% and intact perineum 28%. A significantly lower frequency of episiotomy (P less than 0.001) as well as epidural anaesthesia (P less than 0.001) was found among immigrant women. There were no indications registered for 58% of the episiotomies. The non-episiotomy group experienced more clitoris/labia tears (P less than 0.01). On the other hand there was a tendency towards an increased risk for second and third degree tears, 4.2% in the episiotomy group compared to 1.7% in the non-episiotomy group (P = 0.06). Haemorrhage (greater than 600 ml) was more frequent in the episiotomy group than in the non-episiotomy group (P less than 0.001). We conclude that there is little support for the claim that episiotomy prevents tears in normal deliveries, and that the rationale for the practice of episiotomy is in need of reappraisal.

The effect of the duration of the second stage of labour on the acid-base state of the fetus

A prospective study was made in 153 patients with a second stage of labour lasting 1 to 120 min. Maternal venous, umbilical artery and vein blood were analysed for acid-base variables and lactate levels. Blood was obtained immediately at delivery. Fetal heart rate monitoring data and blood test results were related to the duration of the second stage of labour and clinical outcome. In primiparae and multiparae there was a steady rise in umbilical artery lactate levels, with duration of second stage of labour, P less than 0.025 and P = 0.023, respectively. The median umbilical artery pH decreased significantly from 7.31 in patients with a second stage of labour that lasted less than or equal to 15 min to a pH of 7.25 in patients with a second stage of labour that lasted more than 30 min. Changes in PO2 and PCO2 were not statistically significant.

Maternal half-sitting position in the second stage of labor

The maternal half-sitting and supine position during the second stage of fullterm labor was compared in 100 women who, after identical opening phases in supine position, randomly delivered in half-sitting (50 degrees, n = 50) or supine position (n = 50). The whole duration of the second stage of labor or the time spent in active pushing did not differ between the groups. Vacuum extraction was needed twice (4%) in the group delivering in half-sitting and six times (12%) in the group delivering in supine position. Vaginal tear occurred in one mother in both groups. Early decelerations in fetal cardiotocography were seen 22 times in half-sitting and 14 times in supine group (p less than 0.05). However, late decelerations were seen in only one mother with half-sitting, as compared to five mothers with supine position. Four infants of mothers giving birth in supine position had 1 minute APGAR scores 7 or less, whereas all infants of mothers delivering in half-sitting position had APGAR scores higher than 7. Subjectively the mothers liked more the half-sitting position. We conclude that a women can deliver in half-sitting position without maternal or fetal risks.