August 29, 2024 Author : Pedro Manso The best position for the baby for a vaginal birth is cephalic presentation, that is, with the head facing down. Most babies - more than 95% - are in this position by 36 weeks of gestation. External cephalic version is a manipulation maneuver of the baby through the mother's abdominal wall with the purpose of positioning it in cephalic presentatio n for birth. This maneuver may be an option to consider when a baby is in a breech position (sitting) or transverse position, to increase the likelihood of a vaginal birth. Can all pregnant women do it? Most pregnant women with fetuses in a breech or transverse position can undergo this maneuver. However, there are situations that contraindicate it , such as: All circumstances in which a vaginal birth is not indicated; Non-reassuring fetal status, fetal growth restriction; Severe pre-eclampsia; Presence of two or more coils of umbilical cord surrounding the neck; Vaginal bleeding due to placental abruption; Rupture of membranes; Multiple pregnancy. When is it external cephalic version performed? On average, the success rate of external cephalic version is 50%, reaching the maximum value when it is performed at 36-37 weeks . If it is performed earlier, the risk of premature birth and position reversal is greater; after 38 weeks, it is more difficult mainly because the baby's volume makes it difficult to do. Furthermore, until 36 weeks there is still a high chance that the baby will adopt a cephalic presentation on its own. The success rate is slightly lower in first pregnancies. When the baby is in a transverse position, the probability of success of the maneuver is greater than in a breech presentation (sitting). When there is an anterior placenta, the probability of success is lower because it is more difficult to palpate the fetus and mobilize it. If the baby's back is facing forward, the maneuver is difficult and if the head is easily palpable, the maneuver is easier. When the maneuver is performed successfully, 97% of babies remain in the cephalic position until birth . How external cephalic version is performed This maneuver must be performed in a hospital environment, with the capacity to perform an emergent cesarean section . Before the procedure is done: An ultrasound to confirm the baby's position, quantify amniotic fluid, and assess the location of the umbilical cord and placenta. A cardiotocogram (CTG) to assess the baby's heartbeat and uterine contractions with sensors placed on the belly. The maneuver is performed with the pregnant woman lying on her back, with a slight tilt to the left. With his hands on the pregnant woman's belly, the doctor presses on the baby's buttocks and head so that he makes a movement similar to a somersault. No more than 3 attempts are made . External cephalic version is a safe and well-tolerated maneuver. There may be some discomfort that varies from pregnant woman to pregnant woman. After the maneuver, whether successful or unsuccessful, a new CTG evaluation is carried out and anti-D immunoglobulin is administered if the pregnant woman is Rh negative. Risks and complications of external cephalic version Complications of external cephalic version are rare . In general, they are limited to a transient decrease in the baby's heart rate, or, even more rarely, premature rupture of membranes and light vaginal bleeding. In 0.45% of external cephalic versions, placental abruption or a sustained decrease in the baby's heart rate may occur, involving the rapid performance of a cesarean section. Therefore, external cephalic version should only be performed in a hospital context that allows for an immediate cesarean section. Meet the obstetrics-gynecology clinical team from Hospital da Luz. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
