Isaac Blickstein, MD

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       According to B. Russell’s “bad luck” mathematical paradox, a  decision is bound to be false if based on the probability of success of  another decision. Thus, a decision to perform a cesarean section

  (CS) based on the probability of a successful vaginal delivery (VD) is  likely to be wrong. Obviously, the converse statement is equally true,  leading to a ‘no win situation’, where any decision might prove to be  wrong. Since the rate of twins and higher order multiples is reaching  epidemic dimensions in most developed countries, the mode of delivery  becomes a pertinent question, in which the crucial variable is the  probability of a VD in twins. 





       There are three possibilities: all twins are candidates for a VD,  none are candidates for VD (i.e., all should undergo CS), and some are  candidates for VD. Any equation that includes probability estimation is  prone to serious confounding. An incomplete list of confounders may  include:

       (1) Fertility history – with increasing rates of twins following  assisted reproduction, the proportion of previously infertile women  delivering twins is increasing, leading to higher rates of so-called  “premium pregnancies” for which, any mode of delivery except CS  (justified or not) may be declined. 

       (2) Obstetrical history – there is at least a 1:5 to 1:10 chance that a given multiparous parturient carrying twins

 had a previous CS, which by large excludes her from VBAC (although VBAC in twins is not contraindicated in 50% of the cases).

       (3) Obstetrical skills – concerns about singleton breech delivery  have been extrapolated to twin births which include at least one breech  or transverse lying twin in 50 to 60% of the cases. Operative  deliveries, especially for twin B need some manual dexterity and  experience. More CSs for twins will decrease the experience in VD,  leading to a vicious circle in favor of CS. Clinicians who are less  experienced in twin delivery are likely to report on adverse outcome  following VD more often, or opt for a combined delivery when encountered  with subtle difficulties in delivering twin B. 

       (4) Age and size – generally, twins are delivered earlier and are  smaller than singletons: two-thirds of twins are delivered before 36  weeks’ gestation (including 14% at <33 weeks) and half are LBW  (including 10% VLBW by singleton standards). For these ostensibly  friable twins, any mode of delivery except CS (justified or not) may be  declined. 

       (5) Maternal complications – the increased rate of maternal  complications during pregnancy is a frequently used argument in favor of  an elective “day-time” CS. 

       Taken together, it seems that one may find an indication for CS in  almost every twin pregnancy. Admittedly, the higher the CS rate in  general, the more negligible is the contribution of CS in all twins to  that rate. Thus one may question the wisdom of VD in any pair of twins. 





       Research has not quantified the attributed risk of most of the  above mentioned confounding variables and, indeed, focused on rather  simple ones.

       Presentation and size. Combinations of presentation, comprising  vertex (Vx), breech and transverse, are usually grouped into four  categories: 

       Vx-Vx (~40%), Vx-Non-Vx (~30%), Non-Vx-Vx (~20%), and Non-Vx- Non-Vx (~10%). 

       - Vx-Vx pairs are considered appropriate candidates for VD (with few exceptions related to size and/or gestational age);

       - Vx-Non-Vx are considered conceivable candidates for VD (with many exceptions related to size and/or gestational age);

       - Non-Vx-Vx and Non-Vx- Non-Vx are generally considered as an  indication for CS, mainly due to lack of evidence about the safety of VD  in breech-first pairs. Studies, which showed no difference in outcome  for VD were criticized as having low statistical power or being  non-randomized. 

       Indeed, as with singleton breeches, a randomized study of adequate  sample size is not anticipated, and therefore, one must rely on  retrospective data. Recently, we have conducted a multi-center  collaboration of a large sample of breech-first twin pairs delivered in  13 European centers. The data indicated that when breech-first twin  weighed <1500 g, there is
       a 2.4-times higher risk of depressed (<7) 5-min Apgar scores  and a 9.5-times risk for neonatal mortality in VD as compared with CS.  However, CS did not improve outcome when breech-first twin weighed  >1500 g. Importantly, no case of “locked twins” has been  encountered. 

       VBAC. Studies on Vaginal Birth After Cesarean have shown that  Vx-Vx and some Vx-Non-Vx pairs may be vaginally delivered. Anticipation  for intrapartum manipulations, such as podalic version has generally  excluded cases from VBAC.

       Discordance. Significant intertwin size differences, per se, do  not indicate CS. Nonetheless, discordance has been an argument against  VD of Vx-Non-Vx pairs in whom twin B is smaller. 

       Labor induction. The over-distended uterus is a relative  contraindication for labor induction. However, recent studies suggested  that pre-induction ripening of the cervix is effective and safe.  Unfavorable cervical conditions seem to be no longer an obstacle for VD  in appropriate candidates. 

  In summary, twin gestations frequently involve maternal and fetal  complications, and are quite often considered as “premium” pregnancies.  Hence, many clinicians that follow the cliche “no high risk pregnancy  should end with a high risk delivery” may deliver twins for many subtle  reasons, other than clear-cut, evidence-based, indications. Thus, the  decision for a CS in twins, intentionally or not, is based on  qualitative variables that were not quantified and on quantitative  variables that suggest no advantage for CS in the majority of cases. 


1. Blickstein I, Schwartz Z, Lancet M, Borenstein R. Vaginal delivery of the second twin in breech presentation. Obstet Gynecol 1987; 69:774-6.

2. Blickstein I, Zalel Y, Weissman A. Cesarean delivery of the second twin after the vaginal birth of the first twin - misfortune or mismanagement ? Acta Genet Med Gemellol 1991;40: 389-94. 

3. Blickstein I. The definition, diagnosis, and management of growth discordant twins: An international census survey. Acta Genet Med Gemellol 1991; 40:345-51.

4. Blickstein I, Weissman A, Ben-Hur H, Borenstein R, Insler V. Vaginal delivery for breech-vertex twins. J Reprod Med 1993; 38:879-882.

5. Blickstein I, Goldman RD, Smith-Levitin M, Greenberg M, Sherman D, Rydhstroem H. The relation between inter-twin birth weight discordance and total twin birth weight. Obstet Gynecol 1999; 93:113-6.

6. Manor M, Blickstein I, Ben-Arie A, Weissman A, Hagay Z. Case series of labor induction in twin gestations with an intrauterine balloon catheter. Gynecol Obstet Invest 1999; 47:244-6.

7. Blickstein I, Goldman RD, Kuperminc M. Delivery of breech-first twins: a multicenter retrospective study. Obstet Gynecol 1999; in press 

8. Blickstein I, Smith-Levitin M. Twinning and twins. In: Current perspectives on the fetus as a patient. Chervenak FA, Kurjak A (eds), Parthenon Publishing, Lancs, 1996; ch. 39, pp. 507-525.

9. Blickstein I. Delivery of twins. In Labor and delivery. Cosmi EV (ed), Parthenon Publishing, Lancs, 1998; pp. 70-73. 

10. Blickstein I, Smith-Levitin M. Multifetal pregnancy. In: Fetal disorders: Diagnosis and management. Petrikovsky BM, (ed.), John Wiley and Sons, Inc., New York, 1998; pp. 223-247.

Articles

According to B. Russell’s “bad luck” mathematical paradox, a decision is bound to be false if based on the probability of success of another decision. Thus, a decision to perform a cesarean section (CS) based on the probability of a successful vaginal delivery (VD) is likely to be wrong.

Cesarean Section for All Twins?

 “It’s April  2003, we’re in Berlin at the Controversies in Obstetrics, Gynaecology and  Infertility Conference and next to me are two world-leading experts on multiple  pregnancy. Please could you introduce yourselves?” 
 
 

 “Well, I  would like to introduce my friend, Louis Keith, who is a Professor at  Northwestern University, Chicago. He is running the Centre of Multiple Births in  Chicago with his twin brother, Donald, and currently he is the Co-President of  the ICS International Society of Twin Studies, author of a zillion papers  related to multiple pregnancy and also with me on two books now and a lot of  papers in the past and in the future.” 
 
 

 “My friend Isaac Blickstein is Professor of  Obstetrics and Gynaecology at the Hebrew University in Jerusalem, a  professorship which he just got this last year and, I must say, a professorship  which is long overdue based on his acknowledged leadership in the world of  multiple pregnancies and those publications I’ve worked with him on; this is our  third book and it has been a pleasure, Isaac.” 
 
 

 “Could you  both tell me, you have almost a lifelong history of collaboration, when and  especially how did it start?” 
 
 

 “Well, it began in Helsingborg, Sweden, where  we met for the first time. It continued in Israel at a meeting that he was  chairman of, but it really began in Copenhagen, Denmark, when I looked at Isaac  and I said, 'Isaac, it’s time that you edit a book for your career' and then  what did you say, Isaac?” 
 
 

 “The idea  came forth and the layout of this book, Iatrogenic Multiple Pregnancy, was  written on napkins of SAS. It was conceived on the ground but born in the air.” 
 
 

 “Exactly, because when I suggested it to  Isaac, he said somehow or other in the words that came out, the words iatrogenic  pregnancy came out, and I said, that’s it, that is your book and he looked at me  like I was insane, probably many of the viewers would say, yes, you’re right,  Isaac, he’s nuts, but aside from that, that was a topic that became obvious to  us because there was nothing on it in a monograph form and then came the flight  to Dusseldorf to see a mutual colleague, Hugo Verhoeven, for dinner and by the  time we landed, we put the pile of napkins on the plate and said, Hugo, what do  you think, this is the outline for the new book on iatrogenic pregnancies and it  came to pass.” 
 
 

 “Yeah, and  then we continued with the collaboration on the triplet book which was published  a few months ago and this idea came from Louis actually, because we witnessed  this tremendous increase in triplets in the United States. This kind of multiple  pregnancy, this kind of obstetric challenge, is indeed the most important thing  now in perinatal medicine. 
 
 The most important, in our view at least, and Louis got the collaboration with  the company in the United States that sponsored our research, extensive research  of their database and I think without their help and without knowing the  material at hand, nobody before could analyse samples of more than 60 triplets,  100 triplets, and for the first time we analysed 3,000 sets of triplets and it  is the cornerstone of this triplet book.” 
 
 

 “Yes, and when the company asked us to do the  analysis, I remember saying to them distinctly, well, we could do the analysis,  I know the right person, meaning you, but the question is how do you present it  so that it isn’t just another paper that lies on your desk and the way to do it  was to build a book around this analysis in which we tried to do everything we  could to get the world’s best authorities to write about every aspect of triplet  pregnancies and it’s about 600 pages this book, something like that.” 
 
 

 “And then we  come to revision of your first book and I think it will be the textbook on  multiple pregnancy, forthcoming next year.” 
 
 

 “Next year, 2004, if everybody is willing and  able to contribute their chapter on time. It will have 84 chapters.” 
 
 

 “At least, and it will represent not a  revision but a complete re-write with very few carry-overs from the first book.  Obviously, the chapter on conjoined twins isn’t going to change except we are  going to add to that a chapter by a young man in Poland who was instrumental in  the successful separation of a set of twins and it shows you really what can be  done now by internet and e-mail because the analysis of the children  pre-operatively was directed by a Doctor Scott Adsik at the Children’s Hospital  of Philadelphia in a series of e-mails to a former student of mine in Lublin,  Poland, who got every one of the tests performed in Lublin, digitised all the  results, sent them by e-mail, they were downloaded in Philadelphia, interpreted  in Philadelphia, the most complex types of tele-medicine that you could imagine,  and then the children were brought over courtesy of LOT Airlines, met at the  airport by the Polish counsel, whisked through customs and everything, every  courtesy was given, and they were ultimately successfully separated at the  Children’s Hospital of Philadelphia. 
 
 At the time, they were very skittish about having the newspapers know and there  was no publicity, but now that it’s over and now that the children are running  around like two other children of their age with very minimal scars, this is  going to be added to that chapter. But the rest of the chapters are essentially  new.” 
 
 

 “Yes, I  agree, because everything changed during the last decade, since 1995, when your  first book appeared because I think there are few topics in medicine that got so  much energy in it from all parts involved. I mean reproductive medicine is  nothing similar to what it was ten years ago. Neonatal medicine is nothing  similar to what it was ten years ago and perinatal medicine, ultrasound,  everything, is nothing like what it was before, so we had to change, even if the  outline is approximately similar, every chapter would be totally revised where  we would recognise or developed previously.” 
 
 

 “And I think that the situation with  multiples, of which twins are clearly the most common, is a worldwide epidemic,  there is no other terminology to explain it. Not only are women older when they  want to get pregnant, but many of them need help and, of course, you have all of  these twins. 
 
 When I’ve been studying the literature on twins since the mid-70s, you know, a  dataset of a 1,000 sets of twins in the mid-70s was an astronomical number, but  now there are many community hospitals when they want to review their data  internally, they have a 1,000 sets of twins in the last decade, so you just have  to put all this information together in a compendium.” 
 
 

“I totally  agree with you. I suppose that is what happened in terms of higher-order  multiples. I think that in one year, there were more high-order multiples  delivered in the United States than in the previous decade and 1998 was the  hallmark of the triplets. In 1998 alone there were more triplets born to mothers  over 35 than in the entire decade before and no other adjective like epidemic  can describe it. I mean, it is also contagious because it comes from one country  to another and from one developing country to another developing country and now  all countries have their own rate of infertility and couples want their children  and the risk of high-order multiples or multiples with infertility treatment is  equal, whether it is in the United States or in India, it is the same risk.” 
 
 

“And I think that’s one of the points that  we’re going to bring out very clearly in this revision, that it is absolutely  crucial that when women go to any form of assisted reproductive technology that  they be thoroughly informed of these risks. Not only should they go for some of  the more sophisticated manipulative types of therapy, but when they get the  simple drugs like clomiphene citrate, people don’t realise when they go to the  PDR in the United States and look at clomiphene citrate, it will give you the  dose but unless you read the fine, fine print, you won’t realise that the  references for which this dosing is made are forty years old. 
 
 Now, when you think about that, we certainly know that the results that we’re  getting with clomiphene today are not the results that were originally given to  the FDA forty years ago, but this doesn’t come out. It will certainly come out  in the book.” 
 
 

 “Yes, sure,  but I mean in iatrogenic pregnancies, that’s two kinds of iatrogenic multiples,  those who may be avoidable and those who may not be avoidable. I think that once  you stimulate the ovary, whether with clomiphene citrate or with gonadotrophins,  the ovary is stimulated and unless you abort the cycle, you cannot know exactly  how many multiples will come out or if it will be a singleton at all. 
 
 However, the avoidable cases are those in which you are yourself putting in the  number, you are deciding on the number of embryo transfers during an assisted  reproductive technology cycle. For example, in IVF, you are in charge of how  many embryos will be transferred and now the trend is in Scandinavia, for  example, is to minimise the risk of multiple pregnancy, more cycles with less  embryo transfer as opposed to doing everything necessary in order to achieve a  pregnancy and, in many ways, it is existentialistic position of the IVF centres. 
 
 They must have success. If they are not successful in getting a pregnancy, they  don’t have any role in medicine and, at certain times, it may result in a higher  rate of multiple pregnancies which are a complication of the treatment.” 
 
 

 “But this need to have success, I can  certainly understand from the point of view of the IVF centre. But in the last  two or three years, there has been a very critical review of what is success. We  were both in Australia and heard a paper from the people in Sydney, called IVF  Sydney, where they were so alarmed at their 41% twinning rate with, I think it  was two embryo transfers, they decided to do a trial where they only put in one  embryo and they got almost the same success rate in terms of total pregnancy  rate, but they brought the twinning rate down to 6%. 
 
 Now, in that regard, there have been some papers that are in the process of  being written now in the UK, which looks at all of the data for the entire  country and there they have shown it is absolutely economically feasible to put  an upper limit on the number of embryos transferred and spend the extra money on  giving more cycles because they will save so many days in the NICU units and the  costs that are associated with that, that it would pay the National Health  Service of England to give out more cycles and they would still save money  rather than paying these astronomical NICU bills because in the end, it is  society that pays the NICU bills. 
 
 We think of a couple in Israel or in Chicago or wherever, going to an IVF  centre, public or private, they pay or they don’t pay, and you can cost out this  at X, but that’s a given thing and that’s what people have in their mind. They  don’t think about two additional costs: Y and Z. Y is the neonatal intensive  care costs and Z is the lifetime cost of bringing up children who may be  neurologically impaired and whether we want to, we certainly don’t say that this  is wonderful, but we have to admit the truth of it. Not every higher-order  multiple child survives without neurological impairment and you have done some  studies to that effect.” 
 
 

 “Yes. We  calculated the risk of cerebral palsy, the quadriplegic type, which means the  baby or the child can’t move anything except his head and living in the  wheelchair for his lifetime, and the risk is about sixfold increased when there  is transferred three embryos and this idea was picked up by John Kiley from the  National Centre of Health Statistics and he did a study with me and it seems  that assisted reproductive technology in the United States adds 8% to the  cerebral palsy rate and if we do everything for it, every pregnancy, we do  seeing them daily, we do ultrasound weekly, we screen for every virus, every  bacteria, we do whatever is needed for pregnancy, amniocentesis, whatever we do,  we cannot reduce the cerebral palsy rate by 1%. However, with assisted  reproductive technology, we increase the numbers tremendously, 8% increase,  because the main idea is that we cannot avoid prematurity in these high-order  multiples and prematurity is definitely associated with neurological handicap.” 
 
 

 “And with that, perhaps, we ought to bring  this interview to a close and say to our listeners if you want to know more . .  . 
 
 

 “Well, it isn’t a question of buying our book,  it’s a question of looking forward to the publication. Let’s hope that we both  survive going through these 80 chapters to get it out on time in 2004. Thank  you, Isaac.” 
 
 

OBGYN.net Conference Reportingfrom the 4th World Congress on Controversies in Obstetrics, Gynaecology and Infertility

The Expanding World of Multiple Gestations

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Author | Isaac Blickstein, MD

Articles

Cesarean Section for All Twins?

The Expanding World of Multiple Gestations

The Expanding World of Multiple Gestations Video