Obstetric risk factors for poor neonatal adaptation at birth.

Purpose: To identify obstetric risk factors of delivering a neonate with poor neonatal adaptation at birth.

Material And Methods: Nested case-control study. Poor neonatal adaptation was defined for presence of at least: umbilical cord artery pH <7.10, base deficit ≥12 mmol/L, Apgar score at 1' ≤5. Controls were selected from the same population and matched with cases. The association between clinical parameters and poor neonatal adaptation was analyzed by logistic regression.

Results: One hundred and thirty three women (2.1% of all live births) with a neonate presenting a poor neonatal adaptation were matched with 133 subsequent controls. Significant contributions for the prediction of poor neonatal adaptation were provided by maternal age ≥35 years (p ≤ .001, odds ratio (OR) 3.9 [95%CI: 2.3-6.8]), nulliparity (p ≤ .001, OR 3.3 [95%CI: 1.8-6]), complications during pregnancy (p = .032, OR 2.2 [95%CI: 1.1-4.4]), gestational age at delivery <37 weeks (p = .008, OR 5.2 [95%CI: 1.5-17.8]) and cardiotocography category II or III (p ≤ .001, OR 36.3 [95%CI: 16.5-80.1]). The receiver operative characteristic curve was 0.91 [95%CI: 0.87-0.95], and detection rates 82.7% and 89.5% at 10% and 20% of false positive rates, respectively.

Conclusions: Several obstetric risk factors before and during labor can identify a subgroup of newborns at higher risk of a poor neonatal adaptation at birth.