**1. Introduction**

186 From Preconception to Postpartum

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The incidence of breech presentation is 3-4% (Enkin et al 1995). It is still debated what is the best performance. In particular, both the role of the external cephalic version and the birth type have been extensively debated.

In contrast to cephalic presentations, breech presentations has a higher mortality and morbidity due to the associated incidence of prematurity, congenital malformations or intrapartum asphyxia. Thus, many efforts have been made in order to establish the best performance regarding the birth type: either vaginal delivery (in those women selected after evaluating different fetal and pelvic parameters) or the elective caesarian. On the other hand, the external version can be also considered. (American College Obstetricians and gynecologist [ACOG], 2001). It aims to avoid the vaginal delivery or caesarian complications by turning a breech presentation into a cephalic presentation.

Breech presentation is an independent factor associated with higher morbidity (Royal College of Obstetricians and Gynaecologists [RCOG], 2006). In fact, a high prevalence rate in children disabilities after breech presentation (16%) has been registered both in vaginal and caesarean delivery (Danielian et al, 1996).

Traditionally, there has always been a general agreement on the preference of caesarian delivery instead of a elective vaginal delivery in case of breech babies in the following circumstances: feet first, large fetus, intrapartum risk of loss of fetal well-being, congenital malformations (meaning a mechanical problem for a vaginal delivery) or in case of inexperienced obstetricians.

Some obstetricians advocate caesarean intervention in order to reduce the perinatal risks associated with breech presentation. Unfortunately this is based on their personal experience, medical legal aspects and non-randomized studies. Nevertheless, other obstetricians still advocate for vaginal delivery in selected cases, as it may reduce the maternal morbidity and the use of medical resources. In 2000, the results of a multicentric and randomized clinical study conducted by *Hannah* et al. in collaboration with *The Term Breech Trial* were published in *The Lancet* (Hannah et al, 2000). In this study, the caesarean delivery was highly recommended in breech babies at term. The Cochrane database also published a meta-analysis including *Hannah*'s project (Hofmeyr

The External Version in Modern Obstetrics 189

A. B. C.

Fig. 1. A. Frank breech (65-70%) The baby's legs are flexed at the hip, his or her knees are extended and feet next to the head. This is the most common type in pregnancies at term. **B.** Complete breech (5%) In this case, the baby's hips and knees are flexed. The fetus positions

Incomplete breech (-30%) The baby has one or both knees flexed so that baby's legs (not his or her bottom) are poised to deliver first. This type is common in preterm deliveries.

From the etiologic point of view, the breech presentation could be caused by situations

Fetal factors: Prematurity, low weight, multiple pregnancy, structural anomalies,

Maternal factors: Primiparous women, uterine malformations that change the uterus

 Ovular factors: Anomalies of placental insertion (placenta previa), short umbilical cord and the changes in the amniotic fluid volume (both oligohydramnios and

The incidence of breech presentation is closely related to the gestational age. In the case of single-gestation pregnancies, the preterm delivery is probably the aspect that contributes the most to a breech presentation at delivery. Before the 28th week, the incidence is almost 10 times higher than at term, and almost 12% of preterm deliveries show breech presentation. However, 50%-80% of the cases do not show any etiologic factor responsible for the breech

The article: "Elective caesarean vs. vaginal delivery with breech presentation at term: The International Term Breech Trial", was a randomized trial published by Hannah et al. in The Lancet magazine in 2000. The conclusions of the study were immediately adopted by the

The purpose of the study was to create a clinical guideline based on the evidence regarding the best performance to follow with respect to breech presentation. The study was carried

presentation (Sociedad Española de Ginecología y Obstetricia [SEGO], 2001).

is the same as in the vertex presentation but, in this case, the polarity is reversed. **C.**

avoiding or hampering the spontaneous cephalic version.

normal morphology, previous tumour, pelvic stenosis.

**4. The term breech trial: Clinical practice implications** 

medical society, leading to a great change in obstetric practice.

chromosomopathies, reduced fetal mobility.

polyhydramnios).

et Hannah, 2003). This analysis concluded that the elective caesarean reduces both the perinatal and neonatal morbidity and mortality at the expense of a moderate increase in maternal morbidity.

This study led to a worldwide change in medical practice. Several national recommended the caesarean delivery in term breech babies. In fact, in many American and European countries, this performance has become the only one to be considered.

In view of this opinion about avoiding the vaginal delivery in breech babies by using the caesarian delivery, there has been a growing interest in retaking the external version performances in order to reduce the caesarian delivery frequency.

Definitely, the external version has become more and more relevant as well as a controversial and a topical issue since this is a valid option against the elective caesarian. It has been shown that its use significantly reduces the vaginal delivery frequency as well as the caesarian delivery frequency in breech presentation in full term pregnancies. In spite of this fact, the external version is still not implemented in many countries.

This review article aims to discuss the complications in breech babies and the use of external version as an alternative (regarding the process itself, the conditions and the right moment to perform it, its contraindications, its adverse effects, etc.).
