Cesarean scar pregnancy IS an ectopic pregnancy

We read with interest the Opinion article by Professor Timor-Tritsch1, in which he criticizes the recommendation of the European Society of Human Reproduction and Embryology (ESHRE) working group in their recent publication, ‘Terminology for describing normally sited and ectopic pregnancies on ultrasound . . . ’, to classify Cesarean scar pregnancy as a type of ectopic pregnancy2. The impetus for developing this new classification of ectopic pregnancies was the recognition that the recent exponential increase in the number of conservative uterine surgical procedures, such as Cesarean sections and myomectomies, has led to a dramatic rise in the number of pregnancies which are developing within the confines of the uterus, but either completely or partially outside the uterine cavity and extending into the myometrium. His first argument against a Cesarean scar pregnancy being ectopic is that it is ‘within the anatomic boundaries of the uterus, while an ectopic pregnancy is not’. This contradicts his own previous publications in which he described cervical and interstitial pregnancies as ectopic, despite them being located within the anatomic boundaries of the uterus3,4. He is also content with labeling rudimentary horn pregnancies as ectopic, although these pregnancies are also within the boundaries of the uterus, albeit the uterus is formed abnormally. His second argument is that, in some cases, a scar pregnancy could result in a live birth. However, every type of ectopic pregnancy has the potential to result in live birth, as has been reported widely in the literature. What sets an ectopic pregnancy apart from a normally sited pregnancy is the risk of severe harm to maternal health due to the pregnancy developing in an abnormal place. If we followed the logic of Professor Timor-Tritsch’s argument, a live 12-week abdominal pregnancy should not be classified as ectopic because there is a high chance that it could result in a live birth. Not only does this defy common sense, it could also endanger unnecessarily the woman’s life by preventing the clinician from intervening early and protecting the mother’s health. Lastly, he raises concerns about patient safety due to in appropriate labeling of scar pregnancies as ectopic. His view, publically supported only by his close associate Professor Steven Goldstein, is that tubal and ‘non-tubal’ ectopic pregnancies should be treated differently and that calling a scar pregnancy ectopic would encourage clinicians to treat them in the same way as they do tubal ectopics. It is hard to understand the logic behind this reasoning. Every ectopic pregnancy represents a unique clinical challenge, and the management plan is not determined by terminology, but by clinical presentation, the precise anatomical location of the pregnancy, the surgical and other available expertise and the woman’s preferences. In most cases, there is a choice of different management options, which may include expectant, medical or surgical treatment. It is very odd to assume that clinicians providing early pregnancy care would be prevented from offering their patients balanced advice and safe and appropriate care just because a condition is labeled differently. The abundance of robust evidence showing that scar implantation is a major complication of pregnancy, caused by growth of the pregnancy outside the uterine cavity, prompted the Royal College of Obstetricians and Gynaecologists, in its guideline on ectopic pregnancy (which was written by six and peer-reviewed by 38 international experts), to classify Cesarean scar pregnancy as a type of ectopic pregnancy5. A recent Delphi consensus endorsed by 19 international experts also supported classifying a scar pregnancy as ectopic6. The ESHRE working group on development of terminology for ectopic pregnancies received 204 responses from the individual participants in the first round of consultation, followed by 213 comments from four organizations and 27 individuals2. The vast majority of responders supported the proposed classification of ectopic pregnancy as uterine or extrauterine, with scar pregnancies being included in the subgroup of uterine ectopics. There were only two comments which criticized the classification of a Cesarean scar pregnancy as ectopic, and these were posted by Professors Timor-Tritsch and Goldstein. Despite his reservations about the terminology, it is important to stress that Professor Timor-Tritsch is fully aware that Cesarean scar pregnancy is a potentially very serious complication of pregnancy and a precursor of abnormally adhered placenta7. He has even gone further than most and advocated routine early first-trimester transvaginal ultrasound screening for scar pregnancies, as ‘failure to identify a Cesarean scar pregnancy .... can have catastrophic consequences’8. To conclude, we do not disagree with Professor Timor-Tritsch in recognizing the importance of early detection and the need for effective treatment of Cesarean scar pregnancies. The term ‘ectopic pregnancy’ has been introduced in clinical practice to alert clinicians that they may be faced with a complex and potentially difficult clinical condition which has potential to harm maternal health. By labeling scar pregnancy as ectopic, we believe that we will stimulate clinicians to develop the skills and expertise necessary to diagnose and treat these pregnancies safely and effectively. Should we succumb to Professor Timor-Tritsch’s argument, we would inadvertently create an impression that scar pregnancy is simply a variant of normal and therefore of no particular concern. This would remove the necessity from clinicians to develop the competence necessary for their detection and treatment. Another, more ominous, but presumably unintended, consequence of his argument is the risk that, in countries with a more restrictive approach to termination of pregnancy (including some states in the USA), labeling scar pregnancies as a variant of normal could be used to limit women’s choice regarding the management of these abnormal pregnancies. This would inevitably result in many women suffering severe, life-threatening complications and loss of their fertility, which would be