This article was downloaded by: [Emory University] On: 30 July 2015, At: 10:32 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London, SW1P 1WG
Journal of Obstetrics and Gynaecology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ijog20
Session 1-Fetal Medicine Published online: 09 Jun 2015.
To cite this article: (1997) Session 1-Fetal Medicine, Journal of Obstetrics and Gynaecology, 17:1, S9-S12 To link to this article: http://dx.doi.org/10.1080/714891999
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions
ORAL PRESENTATIONS The abstracts for the oral presentations appear in order of
Downloaded by [Emory University] at 10:32 30 July 2015
presentation
Session 1Ð
Fetal Medicine
Journal of Obstetrics and Gynaecology (1997) Vol. 17, Supplement 1, S10± S12
The value of ® rst trimester scanning for the detection of fetal malformations
Downloaded by [Emory University] at 10:32 30 July 2015
D. L. ECONOMIDES and B. J. WHITLOW Royal Free Hospital, Pond Street, London NW3 2QG O f 2801 low risk women who underw ent transabd ominal or transvag inal sonogra phy in the ® rst trim ester (11±14 w eeks), includin g a detailed survey of fetal anatom y and m easurem ent of nuchal transluc ency, there w ere 25 m ajor structur al abnorm alities (inciden ce 0´9% ); of these 72% (18/25) were diagnos ed by the ® rst trim ester scan and 16% (4/25) were diagnose d in the second trim ester. There were also 16 chrom osom e abnorm alities and 81% (13/16) were diagnos ed in the ® rst trim ester either because of a nuchal transluc ency greater than the 99th centile for gestation al age (44% ; 7/16) or due to the presence of structura l abnorm alities (38% ; 6/16). In conclusi on, the m ajority of fetal structura l abnorm alities and chrom osom al defects can be diagnos ed follow ing ® rst trim ester sonogra phy.
Detection of fetal RNA in maternal blood as a strategy for non-invasive prenatal diagnosis R. AL-MUFTI, C. HOWARD, N. M. FISK and P. R. BENNETT Institute of Obstetrics and Gynaecology, Queen Charlotte’s and Chelsea Hospital, Royal Postgraduate Medical School, London A ttem pts at non-inv asive prenatal diagnos is using fetal cells in the maternal circulati on have been ham pered by non-spe ci® city of the sorting techniqu es and the low yield of fetal cells. W e have previou sly used polym erase chain reaction of R hesus (R h) D gene on magnetica lly sorted nucleate d erythroc ytes in Rh D negative wom en to determ ine fetal Rh D status, but achieved suboptim al results due to contam ination. W e have propose d that use of R T-PCR to amplify R h D message should increase sensitivi ty due to greater copy num ber, and reduce D NA contam ination by amplifying across intron-ex on boundar ies and have dem onstrated its applicab ility in RN A dilution experim ents. As RN A is unstable , we aim ed to determ ine whether RN A could still reliably be ampli® ed after cell sorting. M odel experim ents were perform ed in w hich Rh D negative adult (non-pre gnant) blood was diluted in R h D positive cord blood, at dilutions of 1 in 1000, 10 4 , 10 5, 10 6 , 10 7 and 10 8. Each dilution was perform ed ® ve times, and ® ve control experim ents, where Rh D negative adult blood w as mixed w ith R h D negative cord blood, were conduct ed to detect false positive results. All 35 experim ents underw ent triple density gradien t centrifu gation, m agnetic cell sorting with anti-C D 71, R NA extractio n, R T-PCR and hem inested am pli® cation using Rh D speci® c prim ers.
Rapid reporting of amniocentesis results using an in situ cover slip culture methodology J. A. CROLLA, T. A. WILKINSON and J. C. K. BARBER Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury SP2 8BJ An in situ ` cover slip’ techniqu e for culturing amniotic ¯ uid sam ples is w ell establis hed in the U .S.A . where reportin g tim es of 7±10 days have been standard for a num ber of years. Historical ly the m ajority of U K laborato ries have cultured cells from am niotic ¯ uid using a ` closed system ’ m ethodolo gy w ith a national average reporting time of 15 days. Tw o years ago our laborato ry decided to adopt the U .S.A . in situ cover slip techniqu e and follow ing an extensiv e pilot study, all amniotic ¯ uid specim ens have been cultured using this method. Over the past 19 m onths, 2900 am niocente sis results have been reported in an average of 8 days, and follow ing further technica l re® nem ents, the reporting tim e over the past 4 m onths has been reduced to 7 days. These results have been achieved w hile m aintaining a virtually 100% success rate and a quality acceptable to an external quality control schem e, N EQA S. All reports are faxed to the referring clinician s so that the anxiety often associat ed with w aiting for am niocente sis results has been reduced to the minim um possible . Furtherm ore, a survey of the antenata l clinics using our service con® rm ed that the vast m ajority of reports are relayed to the patients w ithin 24 hours. W e are now using sim ilar procedu res for the culture of chorion ic villi and solid tissue sam ples, the m ajority of which are also reported in under 8 days. A review of our culture, analysis and reporting protocol s will be presente d, highligh ting the advanta ges of the system .
Prenatal detection of Rhesus D by maternal blood sampling and RT-PCR ampli® cation of D-speci® c messenger RNA D. MILLER, J. HAMLINGTON, J. CUNNINGHAM, G. MASON and R. MUELLER Division of Obstetrics and Gynaecology, Level D, Clarendon Wing, Leeds; General In® rmary, Belmont Grove, Leeds LS2 9NS; and Department of Clinical Genetics, Regional DNA Laboratory, St James’s University Hospital, Beckett St, Leeds LS9 7JT An early and accurate diagnos is of fetal Rhesus (R h) D genotyp e w ould allow anti-D prophyl axis to be focused tow ards those wom en at risk of developi ng antibodi es. To this end, blood sam ples (20 ml) w ere obtained from six Rh D negative w omen suspecte d of carrying an Rh D positive fetus and processe d on disconti nuous Percoll gradient s to enrich for fetal nucleate d red cells. Total R NA w as isolated
Oral Presentations: Fetal Medicine
based diagnosi s is threefol d. Firstly, RNA is far less likely to contam inate a sam ple, reducing the likelihoo d of false positive s. Secondly , RN A tem plates are present in m ultiple copies, increasi ng the sensitivi ty of detectio n. Thirdly, RN A is speci® c to the cells expressi ng it, in this case, erythroi d cells, minim ising interfere nce from m aternal D NA . Provided that m aternal red cells can be selective ly rem oved beforeha nd, it should be possible to determ ine fetal Rh C and Rh E by the sam e route and w ork is currentl y progress ing in this directio n.
m al link betw een fetal movem ents and heart rate accelera tions. No evidence was found linking these differen ces w ith adverse fetal outcom es. O ur evidenc e suggests that fetal physiolo gy is different in diabetic pregnan cies, and thus the criteria of norm ality m ay not be valid and could result in unneces sary interven tion.
Conditional centiles for the serial analysis of the amniotic ¯ uid index
S. R. GRANT, M. D. KILBY, D. H. HOWE, J. M CHUGO and M. J. WHITTLE Division of Fetal Medicine, Academic Department of Obstetrics and Gynaecology, and the Department of Radiology, Birmingham Women’s Hospital, Edgbaston, Birmingham B15 2TG
P. OWEN and S. OGSTON Departments of Obstetrics and Gynaecology and of Epidemiology, University of Dundee Downloaded by [Emory University] at 10:32 30 July 2015
S11
The ultrason ic evaluati on of amniotic ¯ uid volum e is an im portant com ponent of the biophysi cal assessm ent of fetal w ell-being . Several m ethods of evaluatin g amniotic ¯ uid volum e are describe d includin g the sem i-quanti tative four quadran t amniotic ¯ uid index. Currently availabl e referenc e ranges for the index are based upon either cross-se ctional or longitud inal data sets designe d for categori sing a single index m easurem ent at a given gestatio nal age, but are not appropr iate for quantify ing serial changes of the index in individu al pregnan cies. W e describe the construc tion of conditio nal centiles appropr iate for the serial analysis of the amniotic ¯ uid index. Two hundred and seventy -four low risk voluntee rs underw ent pre-dete rmined, schedul ed serial ultrasou nd m easurem ent of the am niotic ¯ uid index by one observer . The longitud inal nature of this data set perm its the construction of conditio nal centiles for the index. Condition al centiles perm it the am niotic ¯ uid index of an individu al fetus at a given gestatio nal age to be extrapolated to give a range of expected values for the index (express ed as centiles ) at any later gestatio nal age. Exam ples of conditio nal centiles based upon 4-w eek separati ons are presente d graphica lly. These conditio nal centiles perm it the future appropri ate evaluatio n of time depende nt changes in amniotic ¯ uid index to be made.
Computer analysis of fetal heart recordings. Normal criteria may not be valid indicators of fetal well-being in diabetic pregnancy D. G. TINCELLO, K. M. EL-SAPAGH and S. A. WALKINSHAW Liverpool Women’s Hospital, Crown Street, Liverpool L8 7SS Electroni c fetal heart rate m onitorin g has becom e routine practice in the assessm ent of high risk pregnan cy. Computer analysis has standard ised the interpre tation of recordings and reduced interobs erver bias. Criteria have been identi® ed which accurate ly predict fetal com prom ise. W e exam ined 233 cardioto cograph recordin gs (Sonicaid 8000 system ) from 38 diabetic pregnan cies and discover ed differences in the m ean values of m ost of the com puterise d criteria com pared with norm al. M ean heart rate w as higher at all gestation al ages (differen ce 5´6 beats/m inute at 33±36 w eeks gestatio n, 95% C I 4´7±6´4). Short-term variatio n (a
The active management of `stuck’ twin pregnancies using therapeutic amniocentesis
The objectiv e w as to assess ultrasou nd m ethods in the evaluati on of the oligo-po lyhydra mnios sequenc e w ith acute hydram nios around the large tw in and virtual oligohydram nios in the sm aller tw in. T he design was a prospec tive study in a tertiary referral fetal diagnost ic centre in the W est M idlands. N ine consecu tive cases were referred for evaluati on and treatm ent to the Birmingham W om en’ s H ospital betw een October 1994 and January 1996. T he m ain outcom e m easures were the survival of twin sets after serial therapeu tic amniocente sis. In four of the nine pregnan cies both tw ins survived ; one pair died in the neonatal period; and the other four pairs all suffered intra-ute rine death before reaching a gestatio nal age when delivery was conside red a viable option. The m edian num ber of ` am nioreduc tions’ perform ed was ® ve (CI 2´51±6´59). In this series the re-accum ulation of urine in the bladder of the ` stuck’ twin was predicti ve that both twins w ere likely to survive, with a sensitiv ity of 100% . Not only did this seem to be predictiv e of survival of the sm all ` stuck’ twin, but also of the larger tw in. Serial am nioreduc tion is an effective method of m anagem ent in ` stuck tw in’ syndrom e. The ultrasoun d visualisa tion of a fetal bladder in the small tw in m ay be a prognos tic indicato r as to overall survival of both tw ins.
The changes in placental magnetic resonance with gestational age: a tool for the identi® cation of growth restriction? K. R. DUNCAN, R. MOORE, P. A. GOWLAND, I. R. JOHNSON and P. N. BAKER Departments of Obstetrics and Gynaecology and the Magnetic Resonance Centre, University of Nottingham Intra-ute rine grow th restricti on is characte rised by abnorm al placenta tion. A sensitive and speci® c test for assessm ent of placenta l function has yet to be develop ed. M agnetic resonanc e im aging measurem ents, referred to radiolog ically as T 1 and T 2 , can be abnorm al in patholog ical processe s. W e hypothe sised that these measurem ents could provide a non-inva sive m ethod for placenta l assess-
S12
British Maternal and Fetal Medicine Society Abstracts
Downloaded by [Emory University] at 10:32 30 July 2015
Placental T 1 and T 2 decrease d during norm al pregnan cy by 7´1 m s/w eek (r 5 2 0´51, P , 0´01) and 4´3 m s/w eek (r 5 2 0´61, P , 0´01). Three out of four intra-ute rine grow th retardat ion T 1 values lay below the 5th centile, and ® ve out of six intra-ute rine grow th retardati on T 2 m easurem ents had values below the norm al regressio n line.
T his dem onstrate s hum an placenta l relaxatio n times for the ® rst tim e. A decrease of both param eters through out norm al pregnan cy is dem onstrate d. Pregnanc ies com plicated by intra-ute rine grow th restrictio n have abnorm al T 1 values and reduced T 2 values for that gestation al age.
Journal of Obstetrics and Gynaecology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ijog20
Session 1-Fetal Medicine Published online: 09 Jun 2015.
To cite this article: (1997) Session 1-Fetal Medicine, Journal of Obstetrics and Gynaecology, 17:1, S9-S12 To link to this article: http://dx.doi.org/10.1080/714891999
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions
ORAL PRESENTATIONS The abstracts for the oral presentations appear in order of
Downloaded by [Emory University] at 10:32 30 July 2015
presentation
Session 1Ð
Fetal Medicine
Journal of Obstetrics and Gynaecology (1997) Vol. 17, Supplement 1, S10± S12
The value of ® rst trimester scanning for the detection of fetal malformations
Downloaded by [Emory University] at 10:32 30 July 2015
D. L. ECONOMIDES and B. J. WHITLOW Royal Free Hospital, Pond Street, London NW3 2QG O f 2801 low risk women who underw ent transabd ominal or transvag inal sonogra phy in the ® rst trim ester (11±14 w eeks), includin g a detailed survey of fetal anatom y and m easurem ent of nuchal transluc ency, there w ere 25 m ajor structur al abnorm alities (inciden ce 0´9% ); of these 72% (18/25) were diagnos ed by the ® rst trim ester scan and 16% (4/25) were diagnose d in the second trim ester. There were also 16 chrom osom e abnorm alities and 81% (13/16) were diagnos ed in the ® rst trim ester either because of a nuchal transluc ency greater than the 99th centile for gestation al age (44% ; 7/16) or due to the presence of structura l abnorm alities (38% ; 6/16). In conclusi on, the m ajority of fetal structura l abnorm alities and chrom osom al defects can be diagnos ed follow ing ® rst trim ester sonogra phy.
Detection of fetal RNA in maternal blood as a strategy for non-invasive prenatal diagnosis R. AL-MUFTI, C. HOWARD, N. M. FISK and P. R. BENNETT Institute of Obstetrics and Gynaecology, Queen Charlotte’s and Chelsea Hospital, Royal Postgraduate Medical School, London A ttem pts at non-inv asive prenatal diagnos is using fetal cells in the maternal circulati on have been ham pered by non-spe ci® city of the sorting techniqu es and the low yield of fetal cells. W e have previou sly used polym erase chain reaction of R hesus (R h) D gene on magnetica lly sorted nucleate d erythroc ytes in Rh D negative wom en to determ ine fetal Rh D status, but achieved suboptim al results due to contam ination. W e have propose d that use of R T-PCR to amplify R h D message should increase sensitivi ty due to greater copy num ber, and reduce D NA contam ination by amplifying across intron-ex on boundar ies and have dem onstrated its applicab ility in RN A dilution experim ents. As RN A is unstable , we aim ed to determ ine whether RN A could still reliably be ampli® ed after cell sorting. M odel experim ents were perform ed in w hich Rh D negative adult (non-pre gnant) blood was diluted in R h D positive cord blood, at dilutions of 1 in 1000, 10 4 , 10 5, 10 6 , 10 7 and 10 8. Each dilution was perform ed ® ve times, and ® ve control experim ents, where Rh D negative adult blood w as mixed w ith R h D negative cord blood, were conduct ed to detect false positive results. All 35 experim ents underw ent triple density gradien t centrifu gation, m agnetic cell sorting with anti-C D 71, R NA extractio n, R T-PCR and hem inested am pli® cation using Rh D speci® c prim ers.
Rapid reporting of amniocentesis results using an in situ cover slip culture methodology J. A. CROLLA, T. A. WILKINSON and J. C. K. BARBER Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury SP2 8BJ An in situ ` cover slip’ techniqu e for culturing amniotic ¯ uid sam ples is w ell establis hed in the U .S.A . where reportin g tim es of 7±10 days have been standard for a num ber of years. Historical ly the m ajority of U K laborato ries have cultured cells from am niotic ¯ uid using a ` closed system ’ m ethodolo gy w ith a national average reporting time of 15 days. Tw o years ago our laborato ry decided to adopt the U .S.A . in situ cover slip techniqu e and follow ing an extensiv e pilot study, all amniotic ¯ uid specim ens have been cultured using this method. Over the past 19 m onths, 2900 am niocente sis results have been reported in an average of 8 days, and follow ing further technica l re® nem ents, the reporting tim e over the past 4 m onths has been reduced to 7 days. These results have been achieved w hile m aintaining a virtually 100% success rate and a quality acceptable to an external quality control schem e, N EQA S. All reports are faxed to the referring clinician s so that the anxiety often associat ed with w aiting for am niocente sis results has been reduced to the minim um possible . Furtherm ore, a survey of the antenata l clinics using our service con® rm ed that the vast m ajority of reports are relayed to the patients w ithin 24 hours. W e are now using sim ilar procedu res for the culture of chorion ic villi and solid tissue sam ples, the m ajority of which are also reported in under 8 days. A review of our culture, analysis and reporting protocol s will be presente d, highligh ting the advanta ges of the system .
Prenatal detection of Rhesus D by maternal blood sampling and RT-PCR ampli® cation of D-speci® c messenger RNA D. MILLER, J. HAMLINGTON, J. CUNNINGHAM, G. MASON and R. MUELLER Division of Obstetrics and Gynaecology, Level D, Clarendon Wing, Leeds; General In® rmary, Belmont Grove, Leeds LS2 9NS; and Department of Clinical Genetics, Regional DNA Laboratory, St James’s University Hospital, Beckett St, Leeds LS9 7JT An early and accurate diagnos is of fetal Rhesus (R h) D genotyp e w ould allow anti-D prophyl axis to be focused tow ards those wom en at risk of developi ng antibodi es. To this end, blood sam ples (20 ml) w ere obtained from six Rh D negative w omen suspecte d of carrying an Rh D positive fetus and processe d on disconti nuous Percoll gradient s to enrich for fetal nucleate d red cells. Total R NA w as isolated
Oral Presentations: Fetal Medicine
based diagnosi s is threefol d. Firstly, RNA is far less likely to contam inate a sam ple, reducing the likelihoo d of false positive s. Secondly , RN A tem plates are present in m ultiple copies, increasi ng the sensitivi ty of detectio n. Thirdly, RN A is speci® c to the cells expressi ng it, in this case, erythroi d cells, minim ising interfere nce from m aternal D NA . Provided that m aternal red cells can be selective ly rem oved beforeha nd, it should be possible to determ ine fetal Rh C and Rh E by the sam e route and w ork is currentl y progress ing in this directio n.
m al link betw een fetal movem ents and heart rate accelera tions. No evidence was found linking these differen ces w ith adverse fetal outcom es. O ur evidenc e suggests that fetal physiolo gy is different in diabetic pregnan cies, and thus the criteria of norm ality m ay not be valid and could result in unneces sary interven tion.
Conditional centiles for the serial analysis of the amniotic ¯ uid index
S. R. GRANT, M. D. KILBY, D. H. HOWE, J. M CHUGO and M. J. WHITTLE Division of Fetal Medicine, Academic Department of Obstetrics and Gynaecology, and the Department of Radiology, Birmingham Women’s Hospital, Edgbaston, Birmingham B15 2TG
P. OWEN and S. OGSTON Departments of Obstetrics and Gynaecology and of Epidemiology, University of Dundee Downloaded by [Emory University] at 10:32 30 July 2015
S11
The ultrason ic evaluati on of amniotic ¯ uid volum e is an im portant com ponent of the biophysi cal assessm ent of fetal w ell-being . Several m ethods of evaluatin g amniotic ¯ uid volum e are describe d includin g the sem i-quanti tative four quadran t amniotic ¯ uid index. Currently availabl e referenc e ranges for the index are based upon either cross-se ctional or longitud inal data sets designe d for categori sing a single index m easurem ent at a given gestatio nal age, but are not appropr iate for quantify ing serial changes of the index in individu al pregnan cies. W e describe the construc tion of conditio nal centiles appropr iate for the serial analysis of the amniotic ¯ uid index. Two hundred and seventy -four low risk voluntee rs underw ent pre-dete rmined, schedul ed serial ultrasou nd m easurem ent of the am niotic ¯ uid index by one observer . The longitud inal nature of this data set perm its the construction of conditio nal centiles for the index. Condition al centiles perm it the am niotic ¯ uid index of an individu al fetus at a given gestatio nal age to be extrapolated to give a range of expected values for the index (express ed as centiles ) at any later gestatio nal age. Exam ples of conditio nal centiles based upon 4-w eek separati ons are presente d graphica lly. These conditio nal centiles perm it the future appropri ate evaluatio n of time depende nt changes in amniotic ¯ uid index to be made.
Computer analysis of fetal heart recordings. Normal criteria may not be valid indicators of fetal well-being in diabetic pregnancy D. G. TINCELLO, K. M. EL-SAPAGH and S. A. WALKINSHAW Liverpool Women’s Hospital, Crown Street, Liverpool L8 7SS Electroni c fetal heart rate m onitorin g has becom e routine practice in the assessm ent of high risk pregnan cy. Computer analysis has standard ised the interpre tation of recordings and reduced interobs erver bias. Criteria have been identi® ed which accurate ly predict fetal com prom ise. W e exam ined 233 cardioto cograph recordin gs (Sonicaid 8000 system ) from 38 diabetic pregnan cies and discover ed differences in the m ean values of m ost of the com puterise d criteria com pared with norm al. M ean heart rate w as higher at all gestation al ages (differen ce 5´6 beats/m inute at 33±36 w eeks gestatio n, 95% C I 4´7±6´4). Short-term variatio n (a
The active management of `stuck’ twin pregnancies using therapeutic amniocentesis
The objectiv e w as to assess ultrasou nd m ethods in the evaluati on of the oligo-po lyhydra mnios sequenc e w ith acute hydram nios around the large tw in and virtual oligohydram nios in the sm aller tw in. T he design was a prospec tive study in a tertiary referral fetal diagnost ic centre in the W est M idlands. N ine consecu tive cases were referred for evaluati on and treatm ent to the Birmingham W om en’ s H ospital betw een October 1994 and January 1996. T he m ain outcom e m easures were the survival of twin sets after serial therapeu tic amniocente sis. In four of the nine pregnan cies both tw ins survived ; one pair died in the neonatal period; and the other four pairs all suffered intra-ute rine death before reaching a gestatio nal age when delivery was conside red a viable option. The m edian num ber of ` am nioreduc tions’ perform ed was ® ve (CI 2´51±6´59). In this series the re-accum ulation of urine in the bladder of the ` stuck’ twin was predicti ve that both twins w ere likely to survive, with a sensitiv ity of 100% . Not only did this seem to be predictiv e of survival of the sm all ` stuck’ twin, but also of the larger tw in. Serial am nioreduc tion is an effective method of m anagem ent in ` stuck tw in’ syndrom e. The ultrasoun d visualisa tion of a fetal bladder in the small tw in m ay be a prognos tic indicato r as to overall survival of both tw ins.
The changes in placental magnetic resonance with gestational age: a tool for the identi® cation of growth restriction? K. R. DUNCAN, R. MOORE, P. A. GOWLAND, I. R. JOHNSON and P. N. BAKER Departments of Obstetrics and Gynaecology and the Magnetic Resonance Centre, University of Nottingham Intra-ute rine grow th restricti on is characte rised by abnorm al placenta tion. A sensitive and speci® c test for assessm ent of placenta l function has yet to be develop ed. M agnetic resonanc e im aging measurem ents, referred to radiolog ically as T 1 and T 2 , can be abnorm al in patholog ical processe s. W e hypothe sised that these measurem ents could provide a non-inva sive m ethod for placenta l assess-
S12
British Maternal and Fetal Medicine Society Abstracts
Downloaded by [Emory University] at 10:32 30 July 2015
Placental T 1 and T 2 decrease d during norm al pregnan cy by 7´1 m s/w eek (r 5 2 0´51, P , 0´01) and 4´3 m s/w eek (r 5 2 0´61, P , 0´01). Three out of four intra-ute rine grow th retardat ion T 1 values lay below the 5th centile, and ® ve out of six intra-ute rine grow th retardati on T 2 m easurem ents had values below the norm al regressio n line.
T his dem onstrate s hum an placenta l relaxatio n times for the ® rst tim e. A decrease of both param eters through out norm al pregnan cy is dem onstrate d. Pregnanc ies com plicated by intra-ute rine grow th restrictio n have abnorm al T 1 values and reduced T 2 values for that gestation al age.
