Perinatal risk factors for neonatal asphyxia in Vali-e-Asr hospital, Tehran-Iran

Background: Asphyxia is a medical condition in which placental or pulmonary gas exchange is impaired or they cease all together, typically producing a combination of progressive hypoxemia and hypercapnea.
Objective: In addition to regional differences in its etiology; it is important to know its risk factors.
Materials and Methods: This is a case-control study, all neonates born from May 2002 to September 2005 in Vali-e-Asr Hospital were studied. 9488 newborns were born of which 6091 of the live patients were hospitalized in NICU. 546 newborns were studied as case and control group. 260 neonates (48%) were female and 286 neonates (52%) were male. Among the neonates who were admitted, 182 of them were diagnosed with asphyxia and twice of them (364 newborns) were selected as a control group. The variables consist of; gestational age, type of delivery, birth weight, prenatal care, pregnancy and peripartum complications and neonatal disorders.
Results: Our studies showed that 35 (19.2%) patients had mild asphyxia, 107 (58.8%) had moderate asphyxia and 40 (22%) were diagnosed as severe asphyxia. Mean maternal age was 34.23±4.29yr; (range: 23-38 yr); and mean of parity was 2±1.2; (range: 1-8). Risk factors in our study included emergent Caesarian Section, preterm labor (<37w), low birth weight (<2500g), 5 minute Apgar (less than 6), need for resuscitation, nuchal cord, impaired Biophysical Profile, neonatal anemia, and maternal infertility.
Conclusion: All risk factors listed above play a role in asphyxia. The majority of these factors are avoidable by means of good perinatal care.