THE EFFECT OF LABOUR PAIN IN CAESAREAN DELIVERY ON NEONATAL AND MATERNAL OUTCOMES IN A TERM LOW-RISK OBSTETRIC POPULATION Meryem Kurek EKEN1 Gülçin Şahin ERSOY2, Sinem ÇETİNKAYA2, Çetin ÇAM3, Ateş KARATEKE3 1.Adnan Menderes University Obstetric and Gynecology Department Aydın- Turkey 2. Kartal Dr. Lütfi Kırdar Education and Research Hospital Obstetric and Gynecology Department-İstanbul –Turkey 3. Zeynep Kamil Maternity and Children Education and Research Hospital Obstetric and Gynecology Department –İstanbul –Turkey

Introduction Planned cesarean delivery (CD) is an approach often preferred by obstetricians, and the frequency is increasing in many countries With the increase in CD, an increase in maternal mortality and maternal and especially neonatal respiratory morbidity has been reported [1]. Due to the recent sharp increase in rates of elective CD, an effective evaluation of neonatal effects and outcomes is important The two basic mechanisms that form the maturity of the lungs in full-term infants are the increased blood perfusion of the lungs together with the clearing of excess fluid in the alveoli [2].

The aim of this study was to determine whether there was an association between the start of labor or labour pain and fetal umblical cord cortisol, thyroid hormone levels and cord pH in terms of caeserean cases in a low risk obstetric population.

Material & Method This prospective cross sectional study comprised 219 patients, divided into two groups according to the presence of labor and related labor pain before cesarean section.Our analysis was restricted to a sample of low-risk obstetrical women. All patients in both groups were applied cesarean section > 38 weeks gestational age due to previous CD. The cord blood pH,fT3, fT4, TSH, cortisol and neonatal Apgar scores were compared.

Results A comparison of the groups for cord blood fT3, fT4, TSH levels revealed no significant differences (p>0.05). However, fetal cord blood pH and cortisol levels were found to be higher in the study groups than the control group (p<0.01, p<0.01 respectively). Neonatal transient tachypnea was significantly higher in the elective group (p=0.047) where as maternal morbidity showed no difference (p>0.05)

Table 1: Baseline characteristics and differences of maternal and neonatal outcomes of the groups Parameters Study Group (n=101) Mean± Sd Control Group (n=118) Mean ±Sd P# Age (year) 29.75±4.49 30.67±4.30 0.092* BMI (kg/m2) 30.49±0.59 30.45±0.63 0.742* Gestational age (week) 38.57±0.67 38.74±0.67 0.058* Cervical dilatation (cm) 2.16±0.37 N/A Cervical effacement 51.09±5.81 Gravida 2.97±0.87 2.98±0.84 0.867* Parity 1.71±0.75 1.70±0.74 0.942* Apgar 1st minute, Median (Range) 8.0 (5-9) 8.0 (4-9) 0.906* Apgar 5th minute,Median (Range) 9 (7-10) 0.847* Neonatal weight (kg) 3291.98±362.66 3376.86±412.53 0.145** PreopHb(gr/dl) 10.97±0.11 10.95±0.16 0.692** PostopHb(gr/dl) 9.69±0.05 9.70±0.05 0.464**

Table 2: Thyroid, pH, Cortisol and TTN differences between study and control groups. Parameter Study Group (n=101) Mean±Sd Control Group (n=118) # p pH 7.33±0.02 7.30±0.02 <0.001** fT3(pmol/L) 2.52±0.50 2.50±0.49 0.781* fT4(pmol/L) 12.09±1.26 12.15±1.24 0.705* TSH (uIU/mL) 5.45±1.47 5.75±1.54 0.138* Cortisol (ug/dL) 8.98±2.96 7.26±1.68 Transient Tachypnea (TTN) Positive, n (%) 15 (12.7) 5 (5.0) 0.047*** Transient Tachypnea (TTN) Negative, n (%) 103 (87.3) 96 (95.0)

Discussion & Conclusion In the current study, it was observed that fetal respiratory morbidity was reduced in the group with labour pain.The caesarean applied after the onset of labour pain could be a reason for the significant increase in fetal cord cortisol values in term neonates. In conclusion, although it would seem to be rational to perform a caesarean section after the onset of labour pain in cases with a planned caesarean and a history of c-section delivery, with respect to maternal complications, especially in those with a history of more than one caesarean or those who have started active labour, there is a need for further prospective studies.

References 1. Hansen AK, Wisborg K, Uldbjerg N, Henriksen TB. Risk of respiratory morbidity in term infants delivered by elective caesarean section: Cohort study. BMJ 2008; 336:85–7 2. Dileep A, Khan NB, Sheikh SS. Comparing neonatal respiratory morbidity in neonates delivered at term by elective caesarean section with and without dexamethasone: Retrospective cohort study. J Pak Med Assoc.2015; 65: 607-11.