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Risk of respiratory morbidity in term infants delivered by elective caesarean section: cohort study

BMJ 2008; 336 doi: (Published 10 January 2008) Cite this as: BMJ 2008;336:85

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Risk of severe respiratory morbidity in infants delivered by elective caesarean section.

We read with much interest the paper by Hansen et al.1 who
investigated the association between elective caesarean sections and
neonatal respiratory morbidity (transitory tachypnoea of the newborn,
respiratory distress syndrome, persistent pulmonary hypertension of the
newborn) and serious respiratory morbidity (oxygen therapy for more than
two days, nasal continuous airway pressure, or need for mechanical
ventilation) and the importance of timing of elective caesarean sections.

They found that compared with newborns delivered vaginally or by emergency
caesarean sections, those delivered by elective caesarean section around
term have an increased risk of overall and serious respiratory morbidity.

The relative risk increased with decreasing gestational age. However,
among the neonatal respiratory morbidity evaluated in these patients, they
did not evaluated the pneumothorax risk. This is relevant, considering
that persistent pulmonary hypertension, pneumothorax or both conditions
have been noted in 71.4% iatrogenic RDS infants delivered by elective
caesarean section.2

Respiratory morbidity in infants born after elective caesarean section may
be remarkably severe. Recently, we found that neonates delivered by
elective caesarean section showed an increased incidence of pneumothorax
(2.90/1000 births), in comparison with neonates delivered by an indicated
cesarean (1.41/1000 births; OR 3.87; 95% CI 1.86-8.05) or vaginally
delivered (0.39/1000 births; OR 7.95; 95% CI 4.41-14.32). In addition, in
elective caesarean sections there was a significant progressive reduction
in the incidence of pneumothorax from week 37 0/7-37 6/7 onwards (ƒÓ2 for
trend = 1.62, P <_0.01.3 p="p"/>Persistent pulmonary hypertension and pneumothorax represent life-
threatening conditions, that need a prompt recognition and therapy, and
require specialized care offered only at tertiary referral centers. Their
frequent occurrence indicates the need to extend the investigation in
iatrogenic RDS, in an area where the timing of elective caesarean section
have shown to possess a clinical significance.

Vincenzo Zanardo, MD, Stefania Vedovato, MD, and Daniele Trevisanuto,

Department of Pediatrics, Padua University School of Medicine,
35128 Padua, Italy

1. AK, Wisborg K, Uldbjerg N, Henriksen TB. Risk of respiratory
morbidity in term infants delivered by elective caesarean section: cohort
study. BMJ. 2007:335

2.Wax JR, Herson V, Carignan E, Mather J, Ingardia CJ. Contribution of
elective delivery to severe respiratory distress at term. Am J Perinatol

3. Zanardo V, Padovani E, Pittini C, Doglioni N, Ferrante A, Trevisanuto
D.The influence of timing of elective cesarean section on risk of neonatal
pneumothorax. J Pediatr 2007 ;150:252-5.

Competing interests:
None declared

Competing interests: No competing interests

04 January 2008
Vincenzo Zanardo
Aggregated Professor of Pediatrics
Stefania Vedovato, Daniele Trevisanuto
35128 Padua, Italy