Delivery mode for the extremely premature fetus: a statement of the Prematurity Working Group of the World Association of Perinatal Medicine

Recent retrospective publications suggested that cesarean delivery may be beneficial for the extremely premature fetus. However, several different factors should be taken into account when deciding the optimal delivery for these infants. The Prematurity Working Group of the World Association of Perinatal Medicine has recently published some recommendations on this topic.
Overall, the evidence available to date are retrospective in nature, thus limiting the quality of the information. Of note, the results of the available studies are mixed: while several studies suggest that cesarean delivery is associated with improved survival of extremely preterm fetuses, many others do not show this association. Moreover, some methodological problems seem to arise when comparing the different studies.
Another important issue is the decrease in morbidity, like intracranial hemorrhage (ICH). Again, the available results seem to be mixed and, overall, these data do not provide enough scientific evidence to support a recommendation for cesarean delivery as a method to decrease the incidence of ICH in the extremely preterm fetus. The Prematurity Working Group reached the same conclusions for extremely preterm fetus with fetal growth restriction: until further evidence is available, cesarean delivery in this circumstance should be limited to the occurrence of fetal heart rate abnormalities or other evidence of non-reassuring fetal status.
The difficulty in evaluating the scientific literature on this topic is compounded by some other issues. First, a decision for cesarean delivery requires that labor is active and delivery is imminent. Unfortunately, it is still not possible to reliably determine when a patient is truly in labor and delivery is imminent, due to the varying dynamics of preterm labor. For instance, especially with tocolysis, patients can be 6 cm or more dilated, but do not deliver for days. Of note, retrospective studies showing the benefits of cesarean delivery in extremely preterm infants were unable to consider the negative impact of the prospective decision to perform cesarean. In fact, adding a week or more to the intrauterine life of the fetus increases the chance for survival without handicap approximately by 3% per day. Another issue that should be considered is the impact of cesarean delivery on the health of women. Cesarean delivery, especially at an extremely preterm gestational age, increases the risk of morbidity and mortality to the woman and her future fetuses, due to placenta previa/accreta, major obstetric hemorrhage, uterine rupture, fetal death, peripartum hysterectomy and maternal death during subsequent pregnancies.
Last, a policy of recommending cesarean delivery for the very premature fetus might increase health care costs.
In conclusion, although there are studies suggesting that cesarean delivery of the extremely premature infant may be associated with a lower mortality and lower incidence of ICH, the evidence is not strong and conclusive enough to recommend routine cesarean delivery in this population. In addition, the difficulty in determining when delivery is imminent and the possible detrimental effects on maternal and fetal health in future pregnancies further strengthen this position.

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