Rapid Responses to:
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Rapid Responses: Rapid Responses published:
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![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
management of twin labour
- Penelope A Price (1 November 2002)
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Management of second twin delivery- Is cesarian section the only option?
- Aparna devi Gumma (2 November 2002)
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Obituary: vaginal twin delivery?
- Andrew J Carlin, Sachin Maiti (3 November 2002)
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Choice for women
- Jill M Walton (5 November 2002)
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reliability of retrospective studies
- angela m hamon (5 November 2002)
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Reply to rapid responses.
- Gordon C Smith (28 November 2002)
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Management of Twin Pregnancy
- Anjan K. Chaudhury, MD, Sandra Fleming, MD and Kristina M. Meuse (12 March 2003)
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Penelope A Price, nurse general practice
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Dear Sir, You attribute death of second twins at term to labour. Did you find any significant differences between an induced labour accelerated with syntocinon compared to spontaneous labour? Competing interests: None declared |
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Aparna devi Gumma, Senior Sho in obs&Gyn rochdale infirmary, rochdale, ol12 9qb
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dear sir, I strongly agree with your view that second twin is at increased risk during labour when compared to first twin. --But to do planned cesarian section for all secind twin delivery not only drastically increases the rate of cesarian sections but also the risk to mother of operative complications and future fertility. --- I think that provided with planned management after evaluating the risk facotrs and careful supervision of the second twin delivery with judicicous use of syntocinon, the need for the cesarian section delivery will come down and the outcome of second twin is good. Competing interests: None declared |
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Andrew J Carlin, Specialist Registrar in O & G Arrowe Park Hospital, CH49 5PE, Sachin Maiti
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We read your article with interest and wish to make the following comments: 1. Elective caesarean section for all term twins will have huge cost implications both for maternity services (1) and maternal health in the short and long term. 2. Since publication of the Term Breech Trial (2), many Obstetricians have questioned whether or not this data should be extrapolated to second twin breech presentations. It would therefore be interesting to know how many of the second twin deaths were breech presentations. 3. Delivery interval between the first and second twin is postulated to be an important association with perinatal morbidity and mortality (3). However, it is unclear from the article whether or not this was a significant factor in any of the reported deaths. 4. Elective internal podalic version immediately following delivery of the first twin for non-vertex second twins has the advantage of reducing twin-to-twin delivery time, is proven to be safe (4) and cost effective (2)and may avoid the problems highlighted in the article. It would be unwise to adopt a universal elective caesarean section policy for all twin pregnancies without closer inspection of the data presented. Further evaluation of alternative modes of delivery and direct comparisons between vaginal and elective caesarean are required. References 1. Mauldin JG, Newman RB, Mauldin PD. Cost effective delivery management of the vertex and non-vertex twin gestation. Am J Obstet Gynecol 1998 Oct;179(4):864-9 2. Mary E Hannah, Walter J Hannah, Sheila A Hewson, Ellen D Hodnett, Saroj Saigal, Andrew R Willan. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet. 2000 Oct 21;356(9239):1375-83. 3. Leung TY, Tam WH, Leung TN, Lok IH, Lau TK. Effect of twin-to-twin delivery interval on umbilical cord blood gas in the second twins. BJOG 2002 Jan;109(1):63-7. 4. Chauhan SP, Roberts WE, McLaren RA, Roach H, Morrison JC, Martin JN. Delivery of the non-vertex second twin: Breech extraction versus external cephalic version. Am J Obstet Gynecol 1995;173:1015-20 Competing interests: None declared |
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Jill M Walton, Hon. Research Consultant, Twins & Multiple Births Association (TAMBA) n/a
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Dear Sirs, Since the difference in mortality at term of the second twin did not differ significantly between planned and non-planned CS delivery (Fischer’s exact test; P=0.22) it seems premature to propose a change in policy to planned CS for term twins. This is based on little more than a handful of events. It would be informative to analyse the data for England & Wales if available at an analogous level of detail, as this would provide numbers of a 10-fold higher order of magnitude than in Scotland. Mothers of twins often receive inconsistent advice from the professionals about their prospective mode of delivery. This should ideally be based on emerging risks as the pregnancy and the labour scenario unfolds, and of course there is insufficient evidence for each scenario (zygosity, pre-eclampsia, gestation, presentation, etc) on which to make an informed choice. A key question for many expectant mothers is the likelihood of having an emergency CS for twin 2 having delivered twin 1 vaginally (the worst of both worlds – a tiring and often risky pregnancy, a tiring labour, a major abdominal operation, two lots of stitches and two new babies to care for). The CS rate for twin deliveries is already at 59% (1). A further move towards planned CS will ultimately lead to loss of skills in delivering twins vaginally, thus decreasing choice for women even further. Reference 1. The National Sentinel Caesarean Section Audit Report. Oct 2001. RCOG Clinical Effectiveness Support Unit. Competing interests: None declared |
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angela m hamon, specialist registrar, obstetrics and gynaecology singleton hospital, SA2 8QA
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Were the case notes in the cases of death of second twin scrutinised to verify gestation? Data bases are notoriously unreliable. Some or all of these may not have been 36+ weeks as stated - these babies may well have been pre-term and more likely to die. There is a risk of bias because babies undergoing elective caesarean section at term probably were the gestation stated (otherwise they would not be undergoing the elective section). Competing interests: None declared |
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Gordon C Smith, Professor of Obstetrics & Gynaecology Department of Obstetrics & Gynaecology, Cambrudge University.
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Dear Sir I am grateful to all who submitted letters and took an interest in this paper and will attempt to do justice to their questions. Regarding the question of Penelope Price, we do not have data on whether labour had been induced with oxytocin. However, the principal finding was of discordance between the first and second twin and both twins would have been exposed to oxytocin induction. Regarding the response of Dr. Gumma, I agree that caesarean section carries it own risks. But for a woman to make an informed choice she has to have the best assessment of the individual risks and then she makes a decision which reflects her priorities. What I have attempted to do in this paper is to quantify as accurately as possible the risks of perinatal mortality related to delivery. This is clearly one issue that should be taken in the context of all other available information. Regarding Dr Carlin and Dr Maiti, I will address each point in turn. 1. The caesarean section rate for twins already exceeds 50%. The authors do not discuss the relative costs of emergency and planned caesarean section. Even assuming they are correct that there will be “huge” cost implications, if a woman is given this information and wishes a planned caesarean delivery would they really propose to force her to undergo vaginal birth? 2. The source of our information was a national database and therefore we lacked very detailed information. Although there is a field for presentation, we could not be certain that this was the presentation of the second twin prior to the delivery of the first twin or following the delivery of the first twin. The presentation changes in 20% of cases following vaginal birth of the first twin, as I elaborated on in the full version of the paper. This issue requires further analysis. 3. The interval between delivery of the first and second twin is not recorded in the database. Studies using nationally collected data will simply never include this level of detail. The issue regarding both points 2 and 3 is that the data presented demonstrate what happened in Scotland over the study period: i.e. there was an excess of death at term among second twins. Identifying the problem is the first step in finding a solution. The solution may involve discrimination of twins according to presentation or recommendations regarding maximum intervals between first and second twin deliveries. The main message of my paper was that in the presence of current practice there was a significant risk to the second twin. How practice can best be changed to addressed this risk can only be a matter for speculation in the absence of further evidence. 4. The study that the author cites describes the outcome of 23 breach extractions. It is frankly misleading to describe this study as showing that breech extraction is safe because it is underpowered to detect virtually any significant outcome. I do not propose that a policy of universal elective caesarean section should be followed for all twin pregnancies. I propose that women should be informed of the absolute risk to the second twin and be allowed to make up their own minds. Regarding the comments of Dr Walton, while it would certainly be useful to have larger numbers, our study was powered to detect an increased rate of perinatal mortality in the second twin at term. What would be more valuable would to have more detailed information about the exact circumstances of the death. If further observational data were required, a case control study of perinatal deaths amongst twins born at term would be more informative than merely conducting a larger retrospective cohort study. Moreover, Dr Walton also ignores the fact that the same data are not available for England and Wales and that her proposal is, therefore, purely hypothetical. Regarding the issue of planned caesarean sections leading to a loss of skills of delivering twins vaginally, I am not proposing that all women be instructed to have a planned caesarean section. I am proposing that women should be informed of the approximately 1 in 300 risk of death associated with vaginal birth of their second twin at term. If a woman decides that the risk is unacceptable is Dr Walton advocating that she be encouraged to attempt vaginal delivery in order to maintain the skills of her obstetrician or midwife? Finally, regarding the point of Dr Hammond, it would perhaps be unwise to dismiss summarily all databases as “notoriously unreliable”. Clearly there is going to be enormous variability in the reliability of information stored. A previous quality assurance exercise on the SMR2 data has indicated that gestational age is correctly documented in 94.4% of cases. Moreover, since the gestational age is the same for both twins, Dr Hammond would have to elaborate on why some degree of error of estimated gestation would result in a systematic excess of deaths among vaginally delivered second twins documented as being born at term. Competing interests: None declared |
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Anjan K. Chaudhury, MD, Director, Fetal Diagnostic Center, Boston University School of Medicine Dowling 322, One Boston Medical Center Place, Boston, MA 02118, Sandra Fleming, MD and Kristina M. Meuse
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The November 2002 issue of the BMJ [BMJ 2002; 325:1004 (2 November)] presents G C Smith's et al. article, Birth order, gestational age, and risk of delivery related perinatal death in twins: a retrospective cohort study, which raises several issues regarding the analysis and presentation of their data. According to Smith et al., the birth registries of 4545 women were analyzed. Of these women, 671 delivered via planned caesarean sections, while the remaining 3874 delivered either vaginally or by an emergency caesarean. A total of 454 of the 671 planned caesarean sections were delivered at term, reportedly resulting in no perinatal deaths of either the first or second twin. The remaining 217 women who delivered via planned caesarean were unaccounted for and were presumably preterm deliveries. Because the outcomes for these deliveries are not presented, the data set may be skewed and biased. The indications for such planned preterm deliveries should have been provided, whether or not the outcomes for these pregnancies were to be included in the final analysis. Another issue raised by this article is that 1438 of the 3874 pregnancies delivered "by means other than planned caesarean section" were preterm with the exact mode of delivery unspecified. Assuming that some of these births were attributed to vaginal deliveries, one must wonder why preterm women were allowed to endure labor associated with vaginal delivery, as such deliveries have previously been shown to significantly augment the risk of perinatal mortality. This is supported by the fact that 46 of these cases resulted in the death of either the first or second twin, while 42 cases resulted in the death of both twins. A third concern is that 7 of the 9 deaths resulting from term delivery, via means other than planned caesarean section, were attributed to intrapartum asphyxia. As indicated by Smith et al., 5 of these deaths were the result of "obstetric mechanical causes" (i.e. uterine rupture, malpresentation, cord compression), yet these women were allowed to proceed with vaginal delivery of both twins. It was not reported what methods, if any, were used to monitor labor. Had appropriate measures, such as ultrasonography, fetal monitoring, and the presence of an attending or senior registrar, been taken, it is unlikely that these women would have been allowed to deliver vaginally. Furthermore, since such complications predispose any pregnancy to an increased risk of perinatal mortality, the outcomes of these 5 cases should not be included to determine whether or not the risk of death is associated with mode of delivery. Smith et al. conclude that there is a significant difference in the risk of perinatal death for second twins born at term, as compared to first twins. Unfortunately, they fail to acknowledge that the increased risk is more likely attributable to the causes mention above and not the direct result of delivery. The failure to properly analyze data prevents any conclusions about the relationship between the mode of delivery and an increased risk of perinatal mortality from being made. It is our opinion that in the presence of an experienced physician, utilizing continuous fetal monitoring, it is possible for successful vaginal delivery of second twins as vertex presentation or immediate breech extraction, provided these are concordant twins, they are not monoamniotic, and there are no maternal contraindications to labor.1, 2 We hope that the Canadian multi-center randomized controlled trial, which is in the process of recruiting centers, will be able to determine whether or not there is in fact an increased risk of adverse perinatal outcome associated with delivery of twins via means other than planned caesarean section. As long as these centers have a dedicated staff of physicians capable of doing total breech extractions and willing to closely monitor such deliveries during labor, this study will be able to accurately establish the relationship between the mode of delivery of twins and the incidence of adverse outcomes. References 1. Gocke SE, Nageotte MP, Garite T, Towers CV, Dorcester W. Management of the nonvertex second twin: Primary cesarean section, external version, or primary breech extraction. Am J Obstet Gynecol 1989; 161:111-114. 2. Rabinovici J, Barkai G, Serr DM, Mashiach S. Randomized management of the second nonvertex twin: Vaginal delivery or cesarean section.Am J Obstet Gynecol 1987; 156:52-56. Competing interests: None declared |
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