MATERIALS AND METHOD
After receiving approval from Ethics Committee of Dokuz Eylul
University, Faculty of Medicine, (Approval date: 14.02. 2011, Number:
2013/03-05) we planned our study as a prospective case-controlled study
between May 2011 and June 2013. Informed consent forms were received
from all pregnant participants. 104 pregnant women complicated by
preeclampsia, 110 healthy pregnant women were recruited in the study.
Preeclampsia diagnosis was made with hypertension (TA
>140/90) and with the identification of 300 mg or more
proteinuria in 24-hour urine. In severe cases of the disease there may
be red blood cell breakdown, a low blood platelet count, impaired liver
function, kidney dysfunction, swelling, shortness of breath because of
fluid in the lungs, or visual disturbances. The patient group we
included in the study was in the class of mild preeclampsia, and we did
not include the patients with these findings in the study.
Singleton pregnancies between 34-42 weeks of gestational with a normal
fetal anatomy were included. Exclusion criteria were as follows;
chorioamnionitis, abnormal fetal karyotype, smoking, alcohol or drug
abuse. All patients were undergoing prenatal doppler ultrasonography and
fetal biometric measurement, and they were assigned to our clinic for
normal vaginal birth during the 34-42 weeks of gestational or emergency
or planned cesarean section (C/S). All of the Doppler measurements were
taken by using Voluson 730 (GE Medical Systems, USA) with a 3.5-MHz
convex transabdominal probe by only one researcher (FA). Doppler
measurements were received from the umbilical artery (UA) and middle
cerebral artery (MCA). Then, systole/diastole ratio (S/D), pulsatility
index (PI) and resistance index (RI) were calculated. A decrease below 2
standard deviations (SD) in MCA PI, an increase above 2 standard
deviations in S/D ratio in umbilical artery, was accepted as an abnormal
doppler finding. The brain sparing impact was defined by the fact that
umbilical artery PI/MCA PI being over 1,08.
Among all the patients included in the study, when the cervical
dilatation reached 5 cm in patients who are expected to have normal
vaginal delivery, maternal venous blood samples were taken into
non-heparinized tubes and centrifuged for IMA measurement. After the
samples had been left for 30 minutes of coagulation, it was centrifuged
for 10 minutes in 3500 rpm. Following the centrifuge, the samples were
kept in -80 oC. Measurement of IMA level was made with a commercial
enzyme-linked immunosorbent assay (ELISA) kit according to the
manufacturer’s instructions (CusoBio Biotech, China). The absorbance was
measured at 450 nm using a microplate reader. IMA concentrations in the
sample were determined by drawing a standard graph of the standards in 6
different dilutions. The IMA results were expressed in IU per
milliliter (IU/ml).
30-minute cardiotocography monitorization of all the patients was
recorded before delivery. The NST data was divided into 2, being normal
and abnormal. The cardiotocography whose heart rate is between 120-160
beats per minute, beat to beat variability between 5-25 and where there
is no deceleration were accepted to be normal.
The presence of fetal hypoxia/acidosis was analyzed by conducting
post-natal umbilical cord blood gas examination and 1-5 minutes of APGAR
scoring. The classification for cord blood gas was made as; pH ≤ 7,0 ,
base excess (BE) ≤16 severe acidosis; pH: 7,01-7,15, BE:15,9-10
moderated acidosis. The classification related with APGAR score was made
concerning study that Li et al. (29), carried out respecting APGAR
scoring and its effect on the neonatal, postnata mortality velocities
and 5th minute Apgar score was accepted as: 7-10; high, 4-6; low, 1-3;
very low.
Because the primary purpose of the power analysis evaluation was to
predict fetal hypoxia, the groups were divided into 2, those whose 5th
minute APGAR score is less than 6 and those over 6. The mean IMA level
of the group 1 is 14,15 IU/ml standard deviation value is 1,54, while
the IMA level of group 2 is 8,24 IU/ml and standard deviation value is
1,64. Because of the strength analysis evaluation made considering these
data, the power of the study was determined as 100%.
Independent t-test was used in the average’s comparison of independent
samples, in defining statistical methods (average, standard deviation,
median, minimum and maximum) serum IMA level, and the correlation of
this value with NST and Doppler ultrasonography, the comparisons among
control and patient groups.Area under the curve (AUC)() was calculated
according to the pH value of fetal cord blood. SPSS version 15.0 was
used for statistical analyzes. The value p < 0,05 was accepted
as statistically significant.