Int J Gynecol Obstet, 1992, 31: 243-246 International Federation of Gynecology
243 and Obstetrics
Postterm pregnancy: computer analysis of the antepartum fetal heart rate patterns J. Bartnicki”,
and E. Saling”
‘lnsiitule of Perinatal Medicine. Berlin (Germany) and bDepartment of Obstetrics and Gynecology, Khon Kaen University, Khon Kaen (Thailand) (Received September 6th, 1991) (Revised and accepted October IOth, 1991)
Abstract The purpose of this study was to establish reference ranges for numerical fetal heart rate (FHR) data in postterm pregnancy and to compare them with the patterns of fetuses under undisturbed condition at term. FHR was analysed on-line by Sonicaid Computer System 8000. A statistically signt$cant decrease in the number of accelerations and decrease of variation in postterm pregnancy was observed. The duration of high variation (high episodes) in the 42nd week of gestation was statistically lower than in the pregnancy at term. These observations should be taken into account by clinicians in the interpretation of FHR records in postterm pregnancy.
Keywords: Postterm pregnancy; Fetal heart rate; Computer analysis of cardiotocogram. Introduction Postterm pregnancy ranges in frequency from 7 to 12% and is associated with increased perinatal morbidity and mortality [5,8]. Computer analysis of cardiotocogram (CTG) in such cases, which is a more objective and precise method of CTG assessment should be of particular importance to the clinicians. A software package for such analysis has been 0020-7292/92/%05.00 0 1992 International Federation Printed and Published in Ireland
commercially available since 1989 (System 8000, Oxford, Sonicaid Ltd, Chichester, UK). The purpose of our study was to establish reference ranges for FHR patterns in postterm pregnancy and compare them with the patterns of normal fetuses at term. Materials and methods Informed consent was obtained from 120 pregnant women with 39-42 completed weeks of gestation. The duration of gestation was measured from the first day of the last menstrual period. Gestational age was expressed in completed weeks. The following WHO definitions were used for gestational age: (1) Term: from 37 to less than 42 completed weeks (2) Postterm: 42 completed weeks or more The characteristics of the study groups are given in Table 1. Each patient fulfilled all of the following criteria: (1) Spontaneous, regular menstrual cycles with known menstrual dates (2) Early ultrasound examinations (3) A singleton fetus with no obvious abnormalities (4) No uterine contractions (5) No meconium in amniotic fluid (6) The four-quadrant sum of amniotic fluid pockets was above 8 cm Article
Bartnicki et al. Table 2. FHR parameters in computer-cardiotocogram tween 39 and 42 completed weeks of pregnancy.
Table 1. Characteristic of the study groups. Gestational age (completed weeks) Postterm
No. of patients No. of records Neonatal depression and acidosis (Apgar score