Pudendal and paracervical block

The aim of this leaflet is to provide information on a pudendal and paracervical block during childbirth.

Paracervical anaesthesia is used to relieve the pain of childbirth during the opening period of childbirth. The most effective analgesic effect is provided by paracervical block analgesia in repeat births. The method is also good for first-time mothers. Insensitivity to pain is achieved in up to 75% of cases.

The heartbeat of the foetus is recorded for at least 20 minutes before the procedure and 30 minutes after the procedure.

A special Kobak needle is used to perform paracervical block anaesthesia, (Figure 1). The drug is administered between contractions of the uterus on both sides of the vaginal vault. The analgesic effect starts immediately and lasts between 1.5 and 2 hours. If necessary, the procedure can be repeated. The most commonly used drug is ropivacaine.

Figure 1: Paracervical block diagram, adapted for Macarthur et al 2001

Advantages of a paracervical block: simple and fast; does not have a blood pressure lowering effect; no post-procedure headaches; paracervical anaesthesia does not affect childbirth; safe for both mother and foetus.

Possible side effects: In 1–3% of cases, a transient slowing of the foetal heartbeat may occur, which may last between 1–30 minutes. The exact mechanism of its formation is unknown, but it is believed that this may be due to the release of the drug into the mother’s bloodstream. In this case, the heartbeat of the foetus is monitored until normalisation. In very rare cases, it is necessary to complete childbirth via caesarean section. When the drug enters the mother’s bloodstream, the woman giving birth may develop a toxic reaction, which is manifested by a decrease in blood pressure, a slowdown in heartbeat, and a loss of consciousness. These dangerous side effects are extremely rare.

Pudendal block

A Pudendal block is the anaesthetising of the pudendal nerve in the late stages of childbirth. It can be used as an alternative to epidural analgesia in the delivery period of childbirth, although the analgesic effect is more modest. A Pudendal block can also be used to sew tears after childbirth.

The Kobak needle is also used for the pudendal block. The drug is lidocaine. The doctor injects the medicine into the area of the pudendal nerve through the vagina. As with a paracervical block, the effect of the pudendal block may not always be sufficient, as the anatomy of the pudendal nerve varies from one individual to another, and in up to half of the cases the analgesic effect may be only one-sided. Side effects are rare.

Source: Guidelines of the Estonian Society of Gynaecologists for pain relief during childbirth and the postpartum period. 21.01.2024

ITK1234

Approved by the decision of the Care Quality Commission of Aktsiaselts Ida-Tallinna Keskhaigla on 30.10.2024 (protocol no. 14-24)