Dorothy Cunningham (plaintiff) v. The Governor and Guardians of the Coombe Lying-in Hospital, Paul Bowman, Gerard Hurley, Siobhán Ni Scannaill and Bernard Stuart (defendants).
Negligence - Medical - Preliminary issue - Liability - Plaintiff's twin boys died in womb and delivered stillborn prior to due date - Whether negligence arising from the medical treatment given to pregnant woman - Significance of different types of twin in womb - Application of the 'but for' test.
The High Court (before Miss Justice Macken): judgment delivered September 5th, 2005.
The true test for establishing negligence in diagnosis or treatment on the part of a medical practitioner is whether he has been proved to be guilty of such failures as no medical practitioner of equal specialist or general status and skill would be guilty of if acting with ordinary care.
The High Court so held in finding the fourth and fifth defendants negligent, and the first defendant vicariously liable in negligence.
Edward S. Walsh SC, Simon Boyle SC and Thomas Teehan BL for the plaintiff; Aongus O'Brolchain SC and John Hennessey BL for the first and fourth defendants; Murray McGrath SC and Samantha Cruess-Callaghan BL for the second and third defendants; Mary Irvine SC and Sara Moorehead SC for the fifth defendant.
Miss Justice Macken said the plaintiff's claim arose in circumstances where the plaintiff's twin boys died in the womb and were delivered stillborn just prior to the date they were due to be born in August, 1998. The plaintiff was a married woman in her forties; she had one child born in 1993. The plaintiff and her husband tried for another child, which did not happen initially, but after certain treatment, the plaintiff became pregnant again in 1997. The plaintiff was referred by the second defendant, an obstetrician, to the third defendant, a radiologist, for the first scan of the pregnancy. This was taken in January, 1998. The first defendant is a long-established maternity hospital. The plaintiff was registered there in February, 1998, under the care of the second-named defendant.
As part of the monitoring of her pregnancy, the plaintiff underwent further scans, which were of prime relevance. The scans were arranged in the ultrasound unit, and performed either by the fourth defendant, a sonographer, or by the fifth defendant, a consultant obstetrician. The scans were taken in February, May, June and July of 1998. The plaintiff made a number of regular visits to the hospital in the summer of 1998. The plaintiff, when 38 weeks pregnant, was seen by the second-named defendant on August 12th when she requested that her babies be delivered by Caesarean section. The second-named defendant decided delivery would be induced on August 20th, if she was not then in labour. On August 17th, the plaintiff reported that having felt strong movement, she now had no feeling of movement at all, and was advised to go to the hospital immediately. She arrived late in the evening, when it was confirmed that there was no heartbeat from either baby, and that both babies were dead. She was sent home and returned the following day when the babies were delivered, stillborn. After the death of the twins, the plaintiff and her husband had meetings with the second-named defendant and others in the hospital. They made various inquiries with a view to finding out what might have happened, and over the course of the following months, answers were sought from several parties to questions raised in writing by the plaintiff.
Miss Justice Macken said that the proceedings commenced by plenary summons on June 18th, 2001, seeking damages for, inter alia, negligence, mental distress and the treatment of the plaintiff during and after the pregnancy. The negligence pleaded included failure to diagnose chorionicity antenatally, failing to read the ultrasound properly, failing to review ultrasound films properly, managing the pregnancy as if the twins were dichorionic rather than monochorionic, failing to check for or diagnose twin to twin transfusion syndrome and failing to give the plaintiff advice and/or counselling. All the defences denied any breach of duty, and those of the second and third defendants pleaded that no claim for wrongful death under the Civil Liability Act 1961 lay against them. At the commencement of the hearing in the matter, it was agreed by all parties that the issue of liability, solely in respect of the medical aspects of the case, should be dealt with as a preliminary issue. This judgment was confined to that sole issue, and did not cover the discrete legal defences raised under the Civil Liability Act 1961, or those invoking the Statute of Limitations. In the course of the hearing, the plaintiff's claim against the third defendant was struck out on consent.
Miss Justice Macken said that the difference between monochronic and dichorionic twins was, according to the plaintiff's case, critical to the manner in which the plaintiff's pregnancy ought to have been managed and monitored. From the point of view of scanning, twins present in several possible ways. Firstly, they may present in one "sac", inside of which there are two fetuses, but no other apparent membrane, at least not in the very early stages of pregnancy. If the twins are scanned at a very early state and present with this single membrane, it is a chorionic membrane and the twins are considered to be monochorionic. At a slightly later stage, there will become more apparent an amniotic sac inside the chorionic membrane. Where there is a single chorionic membrane surrounding both babies, there may in turn be a single undivided amniotic sac carrying both babies, or alternatively, there may be two separate amniotic sacs, each carrying a baby. Twins who have a single chorionic membrane and a single amniotic sac are known as monochorionic monoamniotic twins and seemingly are rare. Twins with a single chorionic membrane and two amniotic sacs inside it are know as monochorionic diamniotic twins and are more common. The plaintiff was expecting monochorionic diamniotic twins. On the other hand, at the early stage of pregnancy twins may present in two separate sacs or membranes which may appear simply to be "joined", in layman's terms, back to back, so to speak, or with the separate membranes touching along their length as the twins are scanned. These are also chorionic membranes. Such cases, with two chorionic membranes, one twin in each, the inside amniotic sacs, when they do become apparent, will obviously also be separated. These are known as dichorionic twins.
It was accepted by all parties that the plaintiff was expecting monochorionic babies. It was also accepted that of the four scans taken in the hospital, the first and fourth reported to the obstetrician that the pregnancy was of dichorionic twins, the other two containing no reference to chorionicity. The pregnancy was handled and the plaintiff was at all times monitored, on the basis that the twins were dichorionic. In effect, her monochorionic twin pregnancy remained undiagnosed. It was also common case that had the twins been delivered by Caesarean section or been otherwise induced, sooner than they were, it was likely, indeed even certain, that both babies would have survived birth and been born alive. All parties agreed that up to the end of the first trimester, the clearest indicator as to the type of twins involved, is the inter twin membrane. It was also agreed that while it is possible to distinguish one type of twin from the other in the second trimester, the exercise at that stage is much more difficult, and/or the results much less reliable, mainly because the appearance of the inter twin membranes in the two types of twin lessens or is less readily assessed as the pregnancy advances.
The significance of the difference between monochorionic and dichorionic twins arises from the fact that there is a greater chance that the blood supply, whichis in some way shared between them in the case of the former, may transfuse from one baby to the other, in a condition known as twin to twin transfusion. The transfusion of the blood from one twin to another may cause the receiving twin to become stressed from the amount of blood received, with an adverse or even fatal consequence, due to the heart having to work very much harder. Miss Justice Macken said that scans of the type in dispute in the case are taken in what is called "real time", by moving an instrument or probe over the body, and by noting the characteristics of the three dimensional representation of what is being scanned. At any particular point during this exercise, the scanning can be stopped, and a "still" or image can be taken of what is then appearing on the screen. Sometimes the images are taken to record particular features, or support conclusions or comments in the report prepared on a scan. The fourth-named defendant said it was not the practice in the hospital to take stills or images during the course of the scanning for the purpose of supporting comments or conclusions, while the third defendant indicated that in his practice, in which one of the scans was carried out, it was the norm to do so.
Miss Justice Macken said that once the scan is completed, a report is compiled, recording indicia found during the course of the scan. Before the court, there were a report by way of letter from the third to the second named defendant, computer generated reports of the various scans taken, and also "stills" taken during the scans, as well as thermal prints of some of the "stills". The evidence also established that, in general, every twin who is scanned will be assessed inter alia, for the fundal growth of each twin, or crown length, which is the growth between the top of the head and the bottom of the torso, for the presence of increased amniotic fluids which might be indicative of certain abnormalities, as well as for any evidence of discordant growth between one twin and another.
Miss Justice Macken said that the case of Dunne v National Maternity Hospital IR 91 was invoked by a number of parties in their submissions. Miss Justice Macken said she proposed to accept the principles set out in that case as appropriate. In particular, she noted that the true test for establishing negligence in diagnosis or treatment on the part of a medical practitioner is whether he has been proved to be guilty of such failures as no medical practitioner of equal specialist or general status and skill would be guilty of if acting with ordinary care. The plaintiff's claim, on the medical negligence issues, was in summary, as against the hospital and the fourth named defendant that by reason of the substandard reading and analysis of the scans, the chorionicity of the twins was not determined, or was wrongly identified, as against the fifth defendant, as supervisor of the fourth named defendant, that he was responsible for her negligent scan. As a result the twins were incorrectly managed as if the twins were dichorionic. The twins died from twin to twin transfusion syndrome. There was evidence of polydramnios in the placenta at the 28-week stage, which is indicative of the onset of that syndrome. A scan carried out at the 32-week stage was ambiguous on this. The existence of polyhydramnios was not discovered by either the fourth or fifth defendant, and was not reported by either to the second defendant. If the death was not caused by twin to twin transfusion syndrome, it was caused by foetal growth restriction, or discordant growth as between the twins. Again this was not discerned or reported.
Miss Justice Macken said that three general issues arose in relation to scanning. Firstly, the practice in Ireland as to the percentage of babies scanned for chrionicity in 1998. Secondly, the accuracy of such scanning, and finally, the question of how often during the course of a monochorionic pregnancy such scans should take place and whether that frequency should be the same or different as the frequency in the case of dichorionic twins. Expert evidence was given that scanning to determine chorionicity was common in 1998, and was done in every multiple birth in the UK at the time. Further expert evidence was to the effect that only 50 per cent of all babies were scanned for chorionicity. On that first issue, Miss Justice Macken said that there was on the evidence a difference in rates of scanning of twin babies in general, both as between hospitals in Ireland, as well as between Ireland and England. However, having regard to the fact that the plaintiff's twins were in fact scanned for chorionicity, and reported on several times, the difference in practices was of little or no relevance. As to the accuracy of the scan, expert evidence was that scanning accuracy varied from the 80 to 90 per cent range, up to a possible 100 per cent. Such accuracy, even at the lower level of 80 per cent, can be considered as meaning that the scanning exercise is highly reliable. Given the high degree of accuracy, as well as the fact that the most frequent scans were carried out in the specialist unit at the hospital, the court found that persons receiving the reports were, all other things being equal, entitled to rely on their contents. As to the content of the scans, the plaintiff's case was that both the scans and the conclusions drawn from them, were wrong, in that not only did the fourth named defendant negligently fail to diagnose monochorionicity, but she also negligently diagnosed the twins as being dichorionic. Furthermore, the plaintiff claimed in brief, that the fifth-named defendant , as the director of the ultrasound unit and the supervisor of the fourth named defendant, was negligent in failing to take the appropriate steps to resolve the conflict between the findings of monochorionicity of the third named defendant and those of the fourth named defendant, but instead had negligently overruled or ignored the correct findings of the third named defendant and adopted or stood over the negligent diagnosis of the fourth named defendant.
Miss Justice Macken said she accepted the expert evidence that at the very early stages in a pregnancy, it may not be possible to discern an amniotic membrane because of where it may lie. Secondly, with regard to the images, on the preponderance of evidence, the images clearly permitted a diagnosis of monochorionicity to be made. As to the report of the fourth named defendant on the scan, the court found, from the evidence adduced, that the phrase "thick in places", used in connection with the membrane, was not a clear description of the appearance of the inter twin membrane in the course of the scan, and while it might be a phrase used by the fourth named defendant and accepted by her supervisor, it was not either an appropriate indicator or criterion, nor a correct or accurate description of the true position.
The court also found that the inter twin membrane was not "thick" in the sense in which "thick" is understood in the field of scanning, despite the contention to the contrary. Miss Justice Macken said the expert evidence, especially when read in conjunction with the publications produced in court, was clear. A dichorionic twin pregnancy presents in the manner outlined above. This means necessarily that the inter twin membrane will be made up of layers of chorionic membrane, together with layers of the amniotic membranes, that is to say, four layers, at the time the later membranes become discernible. The evidence was that an artefact in scanning can give the impression that something may appear thick, and the explanation for this, while technical, was nevertheless clear. However, it must be this very possibility which requires the sonographer or radiologist to be especially alert to its existence and, therefore, not to diagnose on the basis of something being "thick in places" rather than a membrane which is, in fact, "thick" or "thin", as the case may be, along the length of the inter twin membrane. The evidence that the notation "thick in places" necessarily implied that it would also be "thin in places" was notchallenged. This would be indicative, on the evidence, of a monochorionic diamniotic pregnancy, as was in fact the case. In those circumstances, the fourth named defendant either did not carry out the scan correctly, or she did not read the real time scan correctly, at a time when it was accepted that it was possible to do this with a very high degree of accuracy. Miss Justice Macken said that at the very least, the phrase "thick in places" could not reasonably, and without negligence, have excluded a monochorionic pregnancy, and, therefore, could not form a proper or valid basis for the conclusion actually reported, namely "suggesting dichorionic twins". The court thus found that the fourth named defendant was negligent with regard to the reading of the scan and the conclusions drawn therefrom.
Miss Justice Macken said that having regard to the expert evidence that save perhaps where an obstetrician is also a radiologist, or has expertise in ultrasound, the report from a scanner will in most cases be the only document available to the obstetrician which will give an indication as to chorionicity. Thus, Miss Justice Macken found that the second named defendant was entitled to rely on the report of the fourth named defendant. The court also referred to a letter on the plaintiff's file, of a previous scan conducted by the third named defendant, the report on which earlier scan contradicted that of the fourth named defendant. In those circumstances, on the evidence, it would have been usual to call for a second opinion. The court found, on the preponderance of the evidence, that the proper practice dictated that the fourth named defendant should either have checked with the third named defendant (the author of the contradictory report), or should have referred the matter to the fifth defendant (her immediate supervisor).
A further issue with regard to scanning, concerned the scans carried out by the fourth named defendant's immediate supervisor, in May and June of 1998. The issue which arose in relation to the fifth named defendant, and the claim made against him, was, inter alia, whether or not he should have remained silent, having checked for chorionicity, and having on file two reports which were diametrically opposed in terms of diagnosis, and also whether he should be responsible for the scans taken by his junior, the fourth named defendant. The fifth named defendant said he had significant faith in the fourth named defendant, and that her assessment coincided with his own, which he had carried out independently. In cross-examination of a number of witnesses, it became clear that the third named defendant's report could not have meant anything other than monochrionicity. Miss Justice Macken said she was satisfied that the fifth named defendant knew, or ought to have known, that the third named defendant's report was unequivocal in its assessment. The evidence was that where there is any doubt about a chorionicity finding, the practice is that the twin pregnancy will be treated as monochorionic, because of the higher risks involved in these types of twins, so as to ensure the monitoring and treatment of the twins meets that possible higher risk. The fifth named defendant had therefore, at the time of his scan in May 1998, a clear diagnosis of monochorionicity from the third named defendant, his own assessment which put the thickness of the membrane at the borderline between the two types of twins, and the fourth named defendant's assessment suggesting dichorionic twins. While the fifth named defendant indicated that he had no doubt, he ought to have had a doubt, and ought not to have ignored the diagnosis of the third named defendant. Miss Justice Macken thus found the fifth defendant negligent in failing properly to investigate the conflict between the different findings on chorionicity. The fifth named defendant was also negligent in permitting the incorrect finding in respect of the twins to remain as the only assessment presented to the second named defendant.
Miss Justice Macken then turned to the claim in relation to the second named defendant's failure to deliver the twins when requested to do so, or to so earlier than full term. There is no doubt that the plaintiff was feeling very uncomfortable in the late stages of her pregnancy, and was a little anxious, as was clear from the evidence and her additional visits to the hospital during this period. The court was satisfied, on the evidence, that there is no obligation on the obstetrician to accede to a request for a Caesarean section by a pregnant mother. It is a medical decision, which in the absence of negligence, which was not established, was within the entitlement of the obstetrician to decide. The plaintiff submitted that had the twins been correctly diagnosed as being monochorionic, they would in fact have been born earlier, and would have been born alive. Dr Bowman gave evidence that had he known on August 12oh that the twins were monochorionic, he would have made arrangements to deliver the twins within a day or perhaps two days. The plaintiff invoked the "but for" theory enunciated in the Law of Torts McMahon and Binchy, 3rd edition, 2001. The plaintiff contended that the loss of the twins was caused by the negligence of the fourth and fifth named defendants to diagnose and notify the second named defendant of the true chorionicity of the twins. Miss Justice Macken said she was satisfied that there was no legal obligation on an obstetrician to deliver twins of the type the plaintiff was carrying, at any particular stage in the pregnancy. Nor was there an obligation on the second named defendant to deliver immediately after August 12th.
However, it was clear that the second named defendant knew the complications of a monochorionic pregnancy, that had he known the plaintiff had this type of pregnancy he would have had a "lower threshold" for intervention, and that he would have delivered the twins within a day or so of August 12th. In those circumstances, the court was satisfied that the negligence of both the fourth and fifth named defendants caused the twins to be still born in that, but for their negligence, the twins would have been delivered and would have survived birth.
The first named defendant was sued as the hospital in which the ultrasound unit was operated and from which the negligent scanning emanated. As the fourth named defendant was an employee of the hospital, it was therefore liable for her negligence.
Solicitors: David Walsh and Co. (Mullingar) for the plaintiff; Coffey & McMahon (Dublin) for the first and fourth defendants; Hayes & Sons (Dublin) for the second and third defendants; McCann Fitzgerald (Dublin) for the fifth defendant.