British Journal of Obstetrics and Gynaecology October 1971. Vol84. pp 132-136
NONSPECIFIC DECELERATIONS IN FETAL HEART RATE DURING HIGH-RISK PREGNANCY BY
J. B. TRIMBOS AND
M. J. N. C. KEIRSE Department of Obstetrics and Gynaecology, University of Leiden, University Hospital, Rijnsbuvgerweg 10, Leiden, The Netherlands
Summary Solitary nonspecific decelerations in fetal h e a t rate occurring in three patients during antepartum cardiotocography are described. The decelerations were nonspecific in that they were neither variable nor late nor associated with maternal hypotension. All occurred in pregnancies complicated by hypertension and placental insufficiency. In the three patients described, the fetus lived for at least three days after the first nonspecific deceleration was observed. Although solitary nonspecific decelerations may indicate danger to the fetus from placental insufficiency, these decelerations should not be considered as an indication for immediate delivery.
METHODS A Hewlett-Packard 8020A cardiotocograph with narrow ultrasound beam was used for simultaneous recording of fetal heart rate (FHR) and uterine activity. Patients were placed in a semirecumbent position and recordings were of at least 30 minutes duration. Birth weights, placental weights and ratios of placental weight to birth weight (placental index) were compared to the data compiled for our community by Kloosterman (1970).
WOMENwho have experienced one or more intrauterine fetal deaths run an increased risk of stillbirth in subsequent pregnancies (Stevenson and Warnock, 1959; Fedrick and Adelstein, 1977). Antepartum cardiotocography (CTG) is increasingly being used to obtain more accurate information on fetal well-being (Lee et al, 1975; Tushuizen et al, 1974; Rochard et al, 1976; Fisher, 1976; Flynn apd Kelly, 1977) and the necessity for early delivery (Tushuizen et al, 1974; Fisher, 1976). Unfortunately correlation between CTG data and the fetal state is virtually impossible in the antepartum period. Hence only abnormal patterns which were not acted upon may help to clarify their clinical significance. This study deals with unusual CTG patterns which were believed to be ominous but could not lead to immediate delivery. The abnormal CTG patterns were encountered in patients with a history of hypertension, placental insufficiency and stillbirth.
CASEHISTORIES Patient I Mrs V.D., aged 31, had had four previous pregnancies but no living children. Each of the pregnancies had ended in fetal death successively at 22, 27, 23 and 22 weeks gestation. She had received no antenatal care during her first pregnancy and each of the subsequent pregnancies had been complicated by hypertension and proteinuria. She was found t o 132
have unilateral renal agenesis. Between pregnancies she was normotensive and there were no malformations of the genital tract on hysterography . In this fifth pregnancy, the patient was first seen at 6 weeks gestation, was found to be hypertensive and was treated with salt restriction, methyldopa and, occasionally, diuretics. She refused admission to hospital but with rest and treatment at home her blood pressure remained well controlled (125 to 140/80 to 85 mm Hg). Urea and creatinine levels remained normal but plasma uric acid at 24 weeks was 0.53 mmol/l and remained at this level throughout pregnancy. Although there was a gradual retardation of fetal growth, the patient only agreed to hospitalization at 29 weeks gestation when the blood pressure was 170/100 mm Hg and there was proteinuria (0.1 g/24 hours). Cardiotocography on the first day in hospital, five days before eventual delivery (day -5), showed a reduced variability and no acceleration of the FHR with fetal movements. A solitary dip in the FHR to 60 beats/minute lasting for 3 minutes was observed on day -4 (Fig. 1).
considered to be in great jeopardy and amniocentesis was performed. Since the L/S ratio was only 1 '7, the CTG was repeated twice daily over the next few days, showing a gradually decreasing variability. The solitary dip seen on day -4 did not occur again. Amniocentesis was repeated after 3 days (day -1) and in view of an improved L/S ratio (1.9) Caesarean section was performed on day 0 at 30 weeks gestation. A girl of 950 g (5th to 10th centile) was born. The placenta weighed 110 g (