Ulf Borell

Influence of uterine contractions on the uteroplacental blood flow at term

Abstract The influence of uterine contractions on the utero-placental blood circulation was studied by arteriographic technique in 3 term-pregnant women with malformed fetuses. A marked retardation of blood flow was found to occur during contraction. The degree of retardation varied within different areas of the uterine wall. In those segments in which the retardation was most marked, the blood flow was completely inhibited, whereas in those in which the retardation was slight, incomplete filling of the intervillous space was the only sign of reduction of flow. The cause of the retardation is interpreted as being due, in part, to local compression of the arterial wall by the myometrium. Some arteries exhibited local or generalized reduction in diameter, probably as a result of constriction of the musculature within the arterial wall. No definite alterations in diameter of the spiral arteries could be found in the present investigation. In some areas of the uterus in which the retardation was slight, it might be possible that the main causative factor was compression of the effluent veins.

Effect of uterine contractions on the human uteroplacental blood circulation: An arteriographic study☆

Abstract The blood flow through the uterus and the intervillous space as influenced by uterine contractions was studied in 15 women admitted for therapeutic abortion in the eighteenth to twentieth week of gestation. The study was made by arteriographic technique. Uterine activity was induced by oxytocin infusion and measured by recording the amniotic pressure. It was found that uterine contractions prevented the entrance of the contrast medium into the intervillous space in three quarters of the cases and that in the remainder the space was poorly or only partially visible. The uterine veins were generally not visible. There was a marked prolongation of the period of time during which the intramural arteries and the main branches of the uterine arteries could be seen, indicating retardation of the blood flow on the arterial side. No definite correlation was found between the intensity of the cotraction and the degree of circulatory retardation. The various mechanisms that may control intervillous space circulation are discussed.

The Adnexal Branches of the Uterine Artery

During the last two years we have examined more than 300 cases by pelvic arteriography. In a comparatively large number of arteriograms, the uterine artery was seen to send a branch to the adnexa. The present investigation was carried out to determine whether there is any difference between the radiographic appearance of the adnexal branches of the uterine artery in healthy and diseased adnexa. Such an investigation in human. subjects has not previously been carried out, to the best of our knowledge. It was hoped that pelvic arteriography might provide a new approach to the differential diagnosis between salpingitis, tubal pregnancy and tumours of the ovary.

The Shape of the Fœtal Chest During Its Passage Through the Birth Canal a Radiographic Study

As early as 1918, Warnekros made radiographic studies of the fcetal chest during its passage through the birth canal. He observed that the fetal chest was markedly compressed and elongated when the chest was passing through the muscles of the pelvic floor. Greenhill (1955) and Martius and Bickenbach (1956) confirmed this observation. Their textbooks contain illustrations of the head immediately after expulsion which demonstrate the escape of amniotic fluid and mucus from the infants respiratory tract. These workers believed that this was due to compression of the chest, which at that stage still lies in the true pelvis. Olshausen (1901) expressed the view that respiration is initiated by the release from compression and consequent expansion of the chest immediately following its delivery. As a result thereof air is drawn into the respiratory tract. On the basis of his radiographic findings W a r n e kr o s supported this view. During intra-uterine life amniotic fluid accumulates in the fetal bronchi. Compression of the chest immediately after delivery of the head would therefore be an ingenuous device of nature to clear the fcetal bronchi.

Hormonal influence on the uterine arteries; an arteriographic study in the human.

Experiments on animals have shown that oestrogenic hormone causes uterine hyperaemia. Microscopical studies of human endometrium have shown that the ovarian hormones, especially oestrogenic hormone, evoke hyperaemia of the uterine mucosa. In vestigation of hormonal influence on the uterine arteries and their larger branches has not hitherto been carried out in the human, to the best of our knowledge. As we had available a comparatively large number of cases of arteriography of the true pelvis, carried out for different conditions, in which good visualization of the uterine arteries had been obtained, we were prompted to investigate the problem as to whether changes occur in these arteries under hormonal influence in the human, particularly in regard to the width of the uterine arteries, density of the intramural vessels of the uterus, and velocity of blood flow in the uterine arteries. I t is fully appreciated that in arteriography of the true pelvis it is not possible to study branches smaller in calibre than the arcuate and radial arteries.

An Arteriographic Study of the Blood Flowthrough the Uterus and the Placenta at Midpregnancy

An arteriographic study of the influence of uterine contractions on the blood circulation through the human uterus and the intervillous space has recently been published (B o r e 11, F e r n s t r o m, Ohlson and Wiqvist, 1964). The study was carried out on women in midpregnancy admitted to the hospital for therapeutic abortion. Uterine contractions were induced by intravenous infusion of oxytocin. In order to obtain strong uterine contractions the oxytocin doses had to be kept at very high levels. Such large oxytocin doses may influence the myometrium, as well as the muscle fibres of the utero-placental vessels, unphysiologically and hence give an incorrect picture of the circulatory events. The present investigation of the utero-placental blood circulation was carried out by the same technique as that used in our previous study, the difference being that uterine contractions were induced by intraamniotic injection of hypertonic saline. On comparing the data obtained from the oxytocin-induced cases with those of the saline-induced there turned out to be no significant differences between the groups. This fact permitted pooling the data for analysis. Thus the combined series of 22 patients offered the opportunity to give a more complete and quantitative description of the circulatory events associated with uterine contractions at midpregnancy.

Diagnostic value of arteriography in cases of placenta previa

Abstract Arteriography was performed in 160 cases in which placenta previa was suspected on clinical grounds. In 97 per cent the procedure enabled the correct diagnosis to be made. No noteworthy complications attributable to the examination occurred. Arteriography permits early diagnosis of placenta previa and thereby makes possible prompt admission of the patient and care in hospital until she has been delivered. Maternal mortality was nil, and the perinatal death rate was 17 per cent.

The Mechanism of Labour in Face and Brow Presentation: A Radiological Study

Most of our knowledge of the mechanism of labour in face and brow presentation has been gained from clinical observations during labour and delivery, and from examination of the infant’s skull and caput succedaneum after delivery. However, the information obtained, even with repeated ’ pelvic examinations, is incomplete as only a small part of the fetal head is accessible during labour. It was shown in an earlier paper (Borell and Fernstrom, 1957) that more complete and reliable data are obtained by radiological examination during labour. Such studies afford precise information (i) on the position of the fetal head in the birth canal; (ii) on the presenting cranial diameter; (iii) on the movements and attitude of the foetal head; (iv) on the degree and type of moulding. A series of 16 cases of face and brow presentation have been studied radiologically during labour and the findings are reported here.

Membrane-Like Structures in the Uterine Cavity: A Hysterographic Study

Abstract. (1) In a series of 6 000 hysterograms 23 cases of thin regular membrane‐like structures in the uterine cavity were found. They were situated either in the upper or lower part of the cavity and were 1–2 mm thick. (2) The membranes were found mostly in the secretory phase. They were in some cases present on one examination but absent on the following, with no intervening surgery. They were also found to disappear spontaneously during one examination. (3) Two cases of extensive irregular filling defects in the uterine cavity seen at hysterography are described. These defects had the characteristics generally ascribed to adhesions, yet in 1 case they were seen to disappear during the course of a single examination, and in the other case they were found to have disappeared from one examination to the next without intervening surgery. (4) It is stated that these defects are of functional and not organic nature. The diagnosis of adhesions cannot, therefore, be based on one hysterography alone, but requires confirmation of some kind.

The Movements in the Mechanism of Disengagement with Special Reference to the Attitude of the Fœtal Head

Radiographic studies of the movements in the mechanism of labour during the stage of expulsion have shown:(i) that the head was flexed during its passage through the lower part of the birth canal and at the time of disengagement, except a few cases where it was less acutely flexed.(ii) that impingement of the sub-occipital part of the head on the lower border of the symphysis pubis does not occur, the head gliding continuously downwards.(iii) that the mechanism of labour just described results in the smallest circumference of the head, i. e. the sub-occipitobregmatic diameter presenting in the lower part of the birth canal.