Incidence Of Epidural Analgesia Research Articles

Perinatal Outcomes and the Role of Obstetric Anesthesia Interventions

(Lancet 2023;401:2038–2039) This editorial discusses multiple recent studies that investigated perinatal outcomes and the impact of anesthetic interventions. A prior study published in the Lancet in 2022 reported poorer perinatal outcomes for neonates born to Black women compared to those born to White women. Another study examined nearly 450,000 deliveries and found an association between neonatal outcomes (Apgar <7 at 5 min, need for neonatal resuscitation, and neonatal admission to the intensive care unit) and maternal use of epidural analgesia. The authors of this editorial examined their own data regarding the incidence of obstetric anesthetic procedures among different ethnic groups and found that compared to White British women who had vaginal birth, incidence of epidural analgesia among Bangladeshi, Pakistani, Black African, and Black Caribbean women was much lower. They noted that similar disparities can be found in the United States and reiterated the socioeconomic and systemic disparities as one likely cause for poor neonatal outcomes, suggesting that offering equal access to neuraxial analgesia across all populations could lead to improved neonatal outcomes for Black women.

Repeat instrumental delivery: how high is the risk?

The objective of this study was to investigate whether a history of previous instrumental delivery imposes a higher risk of operative delivery in subsequent pregnancies. The outcome of labour in 108 women with 1 previous instrumental delivery was compared to that of 216 randomly-selected controls delivered in the same period. There was no difference between these 2 groups of patients in maternal age, height, parity, gestational age, incidence of induction of labour, incidence of epidural analgesia, or birth-weight of the babies. The incidence of instrumental delivery was found to be 8.3% among the study group, which was significantly higher than that of 2.3% among the control cases (relative risk = 3.6, 95% CI 1.24 to 10.5). This increase in risk of operative delivery was independent to the indications for or the type of instrumental delivery in previous pregnancies. We conclude that women with 1 previous instrumental delivery are at a higher risk of repeat operative delivery. This may have implication in assessing patients for home delivery.

Epidural analgesia for low risk labour determines the rate of instrumental deliveries but not that of caesarean sections

Summary We analysed retrospectively the link between the incidence of epidural analgesia and the frequency distribution of instrumental delivery, caesarean section, labour induction and parity in a selected group of women with a low risk labour profile in all (85) obstetric units in Flanders (Northern Belgium). A group of 104 932 women with presumed low risk labour profile was subjected to analysis. The main outcome measures were the incidence of obstetric intervention in each obstetric unit in relation to the extent of their use of epidural analgesia. There was a wide variation in the rate of epidural analgesia (3-75%), labour induction 'for convenience' (4-48%) and instrumental delivery (4-50%) among the Flemish obstetric units. The incidence of instrumental delivery in a given unit was greatly influenced by the rate of epidural analgesia and labour induction for convenience (P < 0.001). However, the incidence of caesarean section in a given unit was not determined by either the rates of epidural, labour induction, attempted instrumental delivery or the size of the unit.

Fetal heart rate and neonatal condition related to epidural analgesia in women reaching the second stage of labour

The relationship between epidural analgesia and a number of labour and delivery factors, relevant to fetal and neonatal condition, was considered in a prospective study of 200 labours reaching the second stage of labour. The group was representative of the hospital population with regard to the proportion of nulliparous women, the incidence of instrumental vaginal deliveries and the incidence of epidural analgesia (37%). The 8% of labours requiring fetal blood sampling during the first stage, and the labours with fetal heart rate (FHR) decelerations in the hour prior to second stage (25%) and during pushing (50%) were significantly more likely to have been given an epidural. Nulliparity (55%), induced labour (34%), a first stage longer than eight hours (37%), a second stage longer than 60 min (43%), maternal pushing for longer than 36 min (50%), forceps delivery (28%) and a 1 min Apgar score less than 7 (12%) were also factors associated with significantly higher rates of epidural analgesia whereas meconium (15%), a small baby (16%) and umbilical arterial metabolic acidaemia (13%) were not. FHR decelerations in labours reaching the second stage with an epidural reflect adjustments to fetal cardiovascular control and not acidaemia.