Tap chi THONG TIN Y Dl/OC Sdthdng8ndm 2010
VAI TRO CUA DOPPLER VOI XU TRI THAI CHAM PHAT TRIEN TRONG TU CUNG Dao Thi Hoa
Thai cham phat trien trong tu1 cung la nguyen nhan thu'dng gap, gay tiT vong thai va nhieu benh ly scf sinh. Xac dinh chfnh xac tudi thai cd vai trd quan trpng chan doan thai cham phat trien. Theo ddi thai bang cac chi so sieu am, Doppler dpng mach va mdi day la Doppler tinh mach, trong dd cd Doppler d'ng Arantius, la phUdng phap tot de danh gia tuan hoan thai, cho phep sang Ipc nhu'ng thai cd nguy cd cao va giup li/a chpn thdi die'm thi'ch hdp de lay thai ra.
I. DAT VAN BE
Thai cham phat then trong tu" cung la tinh trang thai nhi bi suy dinh dddng ngay tCf khi con nam trong tir cung. Thai dugc coi la cham phat then trong tif cung khi Udc trgng lUdng thai nam dudi dudng bach phan vi thd 10 va chu vi bung nam dUdi dudng bach phan vi thd 2,5. Khi thai dii thang cd can nang dUdi 2.500g la thai cham phat trien trong td cung.
Cac so do: dUdng kinh lUdng dinh, chu vi vdng dau, chu vi bung thai, chieu dai xUOng diii la nhdng yeu to cha'n doan tinh trang thai [6].
Thai cham phat trien trong td cung ddng hang thd 2 trong so cac nguyen nhan gay benh ly va td vong sd sinh, chi sau thai non thang. Thai cham phat trien trong td cung chiem khoang 5% thUdng hgp thai nghen, ty le nay thay ddi theo dac diem dia ly, dan cU, chiing tdc va phu thudc vao dudng bach phan vi ap dung so sanh. DUa vao trgng lUdng sd sinh de danh gia theo ddi tinh trang ciia tre, ngUdi ta nhan thay: neu tre de dii thang cd can nang dUdi 2.500g thi nguy eg td vong sd sinh se tang gap 30 lan so vdi nhdng tre cd can nang nam tren dUdng bach phan vi so 50 va nguy cd td vong se tang td 70-100 lan neu tre cd can nang dUdi 1.500g, vi vay, phat hien dUdc va danh gia diing tinh trang thai cham phat trien trong td cung rat cd y nghTa vdi thay thuoc, benh nhan va vdi xa hdi [9],
Nguyen nhan thai cham phat trien trong td cung: do giam tuan hoan td cung-thai, giam lUu lugng tuan hoan banh rau, thai bat thUdng, benh ly man tinh ciia me. Neu nguyen nhan do thai hoac rau thai thi thudng nguy cd
tai phat d lan cd thai sau thap. NgUdc lai, trong trudng hdp nguyen nhan do me bi benh nhU: benh he thong, benh ly than thi can phai cd theo ddi dac biet va quan ly chat che d lan cd thai sau [3].
Danh gia diing tudi thai la yeu to quan trgng trong cha'n doan thai cham phat then trong td cung. DUa vao ngay dau tien cua thang kinh cudi ciing neu benh nhan cd kinh nguyet deu hoac dUa vao ngay giao hdp, ly tudng nhat la xac dinh tudi thai bang sieu am td tuan 8 den tuan thd 13.
Nguyen nhan thai chet d nhu'ng trUdng hdp thai cham phat tried trong td cung thudng do suy thai man. De thich nghi vdi tinh trang thieu oxy, thai se tu dieu chinh lUdng tuan hoan, Uu tien cho nao, tim va thUdng than vi vay cd mdt so tham do tuan hoan thai cho thay nguy cd nay; nhu chi sd tam trUdng bang khdng (absent end diastolic flow) va dau hieu dao ngUdc tuan hoan (reverse flow-RF) cua ddng mach ron, thay ddi Doppler dgng mach nao, Doppler tinh mach Arantius la nhu'ng yeu to nguy cd rat cd gia tri. Doppler dgng mach ron rat cd gia tri cha'n doan nguyen nhan thai cham phat trien.
II. VAI TRO CUA DOPPLER 1. Phan ti'ch pho Doppler
Pho Doppler phan anh huyet ddng ciia ddng chay dua vao cac chi sd [1,6].
* 777/ tam thu. do luc co bdp ciia tim, van tdc ddng chay cao. Van toe tdi da ddng mau the hien bang chi so dinh tam thu (peak systolic velocity- PSV).
' ThS., Benh vien Phu san Trung Uclng
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Tap chi THONG TIN YDUOC Sd thdng 8 nam 2010
* Thi tam trutfngr. ddng chay dddc duy tri do sU co bdp cua thanh mach nen cd van toe thap hdn. Oe danh gia ddng chay thdi ky nay, ngUdi ta dd toe dp cuoi tam trUdng (end dyastolic velocity-EDV). Chi so khang (resistance index-RI) phan anh trd lut cua thanh mach. Ty le S/D (systole/diastole). Chi so dip (pulsatility index-PI).
* Cac mach mau khao sat:
- Dpng mach td cung: binh thudng sau 26 tuan khong cdn dau hieu khuyet tien tam trUdng (notch), ty le S/D<2,5. Gpi suy tuan hoan td cung-rau khi ton tai khuyet tien tam trUdng hoac cd sdng dao ngUdc tien tam trUdng, S/D>2,5.
- Dpng mach ron: phd cuoi tam trUdng xuat hien td cuoi tuan 18, tang dan cho tdi het thai ky. Ty le S/D giam dan ve cudi khi thai tren 34 tuan S/D< 3. S/D tang cad, trd khang banh rau tang se lam tang nguy cd benh ly thai, tien lupng xau neu xuat hien dad ngupc hoac khdng cd ddng cudi tam trUdng.
- Dpng mach nao gida: phd Doppler cd PSV cao, EDV thap, PI>1,45, benh ly khi <1.
- Ty so RI giua ddng mach nao va dpng mach ron: thudng EDV cua dpng mach nao gida luon thap hPn EDV dpng mach ron d bat ky tud'i thai nao, vi vay, RI cua dpng mach nao gida luon cao hPn dpng mach ron.
- Khao sat tTnh mach: ong tTnh mach cd vai trd rat quan trgng vdi thai nhi, mau giau oxy qua ong tinh mach, di tat qua gan, qua lo bau due xudng that trai, cung cap mau trut tiep cho nao thai. Phd' Doppler ong tinh mach gom 3 pha: S, tam thu that; D, tam trUdng that; a, nhi phai co bdp cudi tam trUdng tao phd ngUdc. Binh thudng S bang khoang 50- 60cm/s, a>0. Doppler ong tTnh mach bat thudng khi a<0.
2. Doppler tien lifting thai cham phat Men trong tif cung
Nhieu nghien cdu chi ra rang, neu chi sd tam trUdng bang khdng va dau hieu dao ngUdc tuan hdan cua dpng mach ron rat cd gia tri, bao hieu suy thai man va thai co nguy cd td vong
(td khoang 26-60%) [7], Nhuhg thai nay khdng chi cd nguy cd td vong cao ma cdn cd ty le di chdng than kinh va van dpng cung rat cao.
Theo Montenegro va cdng sii [7], khoang thdi gian td khi cd dau hieu EDV bang 0 den khi cd bieu hien bat thUdng tim thai la 26 ngay (trung binh 7 ngay). Khoang thdi gian nay dac biet thay ddi, phu thudc vao tinh trang thai va mpt so yeu to nhU: tud'i thai, tud'i cang nhd thi khoang each cang dai, tinh trang cad huyet ap cua me, dac diem cac xung Doppler thu dUdc.
Hecher va cpng su', khi nghien cdu ket qua sieu am, Doppler, bieu do nhjp tim thai trong vdng 24 gid trUdc khi dinh chi thai nghen hoac trUdc khi thai chet trong td cung ciia 93 trUdng hpp, nhan thay ty le td vong chu sinh tang rd ret cd y nghTa thdng ke neu Doppler Arantius va dao dpng tim thai bat thudng (69%) trong khi dd nhdm khdng cd hoac chi cd mdt dau hieu tren thi ty le td vong thap hdn han (7%) (p=0,002) [5].
Trong 44 trUdng hpp cd dau hieu dad ngUpc tuan hoan ciia dpng mach ron, Brodszkij [2] thay cd 35/44 trUdng hdp thai cham phat then trong td cung, 19/44 trUdng hpp thai chet trong td cung va 7/44 td vong sau sinh.
Nghien cdu ciia Ferrazi, 26 trUdng hdp Doppler dpng mach ron benh ly xuat hien khi tudi thai trUdc 32 tuan thi sau khoang 15-16 ngay se xuat hien nhip tim thai phang. Theo sau EDV bang 0 la bat thudng Doppler dgng mach nao, nhdng thay do'i nay xuat hien 4-5 ngay trUdc khi xuat hien nhip tim thai phang.
Nhdng bat thudng Doppler xay ra mupn bao gom: rdi loan Doppler Arantius, RF tuan hoan ron, tiep theo la roi loan tuan hoan phdi gay ra dao ngUpc tuan hoan ong Arantius, cuoi cung dan den roi loan tuan hoan chii. Nghien cdu nay cung chi ra ba bien dpc lap lien quan den td vong sau sinh: tud'i thai, trpng lupng thai va nhu'ng thay ddi mudn ciia Doppler [4].
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Tap chi THONG TIN Y DlfOC Sothdng 8 ndm 2010
Trong trUdng hpp toe do ddng tam trUPng bang khdng, Werner thay rang, sau khi xuat hien gian ddng mach nao giua thi dao dpng tim thai se giam. Neu thai khdng dupe lay ra se xay ra hien tupng mat tiT dieu chinh cua nao, gian mach, suy tuan hoan, phu nao, cac roi loan khdng hoi phuc [10].
3. Gia tri chan doan nguyen nhan thai chim phat trien trong tit cung
TrUdng hpp thai cham phat then trong td cung, neu cd Doppler dpng mach td cung benh ly thi hudng tdi nguyen nhan do bat thUdng tuan hoan me. Doppler dpng mach td cung binh thudng hudng tdi chan doan nguyen nhan do thai, rau thai [8].
Mpt so trUdng hpp benh nhan khdng lam Doppler trUdc sinh (chay mau nhieu, thai lUu) thi tham do sau dd van cd gia tri, nhat la trong trUdng hpp khdng lam dupe giai phau benh ly.
Theo Cynober va cdng sU thi it khi dau hieu Notch (khuyet tien tam trUPng) xuat hien ngay d ngay dau sau sinh (11%) nhUng ty le nay | tang nhanh nhdng ngay sau dd, khoang 57%
xuat hien d ngay thd 4. Neu cd dau hieu nay thi dUdc cho la benh ly [3],
III. KET LUAN
Tdc dp cuoi ddng tam trUdng bang 0 va dao ngUdc tuan hoan dpng mach ron la yeu to nguy CP cao dU bao thai chet trong td cung va benh ly thai. Doppler dpng mach nao va Doppler tinh mach Arantius rat cd gia tri, cho phep tien lupng, dUa ra hudng xd tri thich hdp. Quyet dinh san khoa (lay thai ra, keo dai them thdi gian theo ddi hay bd thai) se dUa tren trieu chdng lam sang, ket qua sieu am va Doppler. Doppler dpng mach td cung cd gia tri chan doan nguyen nhan thai cham phat trien
trong td cung, ngay ca trong trudng hpp thai da chetlUu.
TAI LIEU THAM KHAO
1. Nguyln Quang Trong: Sieu am Doppler utig dung trong san phu khoa. Sieu am san khoa thu'c hanh. Nha xuat ban Y hoc 2010, tr.322-337.
2. Brodszki J., Andrade H.E., Gudmundsson S., Dubiel M., Mandruzzato G.P., Laurini R., Marsal K.: Can the degree of retrograde diastolic flow in abnormal umbilical artery flow veledty wavefcrms predict pregnancy dutcome? Ultrasound
Obstet Gynecol. 2002 Mar, 19,3, pp.229-234.
3. Cynober E.: Valeur prenostique du Doppler dans la prise en charge des RCIU. Les JTA (Journees de TecniquesAvancees)juin, 2010, pp.56-62.0 4. Ferrazzi E., Bozzo M., Rigano S., Bellotti M.,
Morabito A., Pardi G., Battaglia F.C., Galan H.L.: Temporal sequence of abnormal Doppler changes in the peripheral and central circulatory systems of the severely growth-restricted fetus.
Ultrasound Obstet Gynecol. 2002 Feb, 19, 2, pp. 140-146.
5. Hecher K., Bilrdo CM., Stigter R.H., Ville Y., Hackloer BJ., Kok HJ., Senat M.V., Visser G.H.: Monitoring of fetuses with intrauterine growth restriction: a longitudinal study. Ultrasound Obstet Gynecol, 2001 Dec, 18, 6, pp. 564-570.
6. Molik D.: Deppler untrasound in Obstetrics and Gyneceldgy. Spriger 2005
7. Montenegro N., Santos F., Tavares E., Matias A., Barros H., Leite L.P.: Outcdme of 88 pregnancies with absent or reversed end-diastolic blood flow (ARED flow) in the umbilical arteries. Eur
J Obstet Gynecol Reprod Biol. 1998 Jul, 79, 1, pp.43-46.
8. Quarello E., Nizard J., Ville Y.: Indication of Doppler evaluatidn in the Ductus Venosus in the management of intrauterine growth restricted fetuses. Gynecologie Obstetrique &
Fertilite Volume 35, Issue 4, April 2007, pp. 343-351.
9. Turan O.M., Turan S., Gungor S., Berg C, Moyano D., Gembruch U., Nicolaides K.H., Harman C.R., Baschat A.A.: Progression of Doppler abnormalities in intrauterine growth
restriction. Ultrasound Obstet Gynecol. 2008, 32, 2, pp.160-167.
10. Weiner Z., Farmakides G., Schlman H., Penny B.: Central and peripheral hemedynamic changes in fetuses with absent end-diastolic velocity in umbilical artery: correlation with computerized fetal heart rate pattern. Am J Obstet Gynecol. 1994 Feb, 170, 2, pp.509-515.0 11
