SẢN PHỤ KHOA

1. THAI GIA THANG
GS.TS.BS. Nguyen Duy Tai, PCS.TS.BS. Vii Thi Nhung
MT)C TIEU BAI GIANG
1. Trinh bay ilrr17c tinh chdt va tdn sudt cila thai gia thdng.
2. Ki tl1wc ccic nguyen nhdn va ca chi thai gia thong.
3. Trinh bay tl1wc b?nh sudt va ttr sudt thai gia thong.
4. Trinh bay tl1wc hu·&ng xfr tri thai gia thong.
DJNHNGHiA
Thai kY dt1 ngay !hang binh thm'mg keo diti 38-42 tufin. Thai gia !hang hay con gQi lit thai qua
ngay la thai ky keo dai hon 42 tufin hay tren 294 ngity kS tlr ngay dftu ClJa kY kinh cu6i ma thai
nhi chua duqc sanh ra dai l14
l.
Tftn sm'lt xuiit hi~n thai gill thing lit tlr 6%-12% cite thai ky vit mang theo no sv gia tang
nguy cacao cho con, nhung kh6ng anh huang d~n my f
21
. Sau 42 tuftn thi banh nhau b~t dftu
gill vii suy. 6 Hoa Ky, gftn 28% cite thai ky chiim dm gifra tuftn thu 40 vii 41. Co 6% thai nhi
duqc sanh & tu6i thai tu 42 tdn tr& len ll
3
J. M(t nghien cuu & 13 qu6c gia Au Chau v€ tY I~
sanh thai gill thang cho thiiy ty l~ nay riit thay d6i tlr 0,4% (0 Ao vii Bi) d~n 8, I% (0 Dan
Mlchi121
. Tftn suiit thai gia thing bi anh huang b&i nhi€u y~u t6. M(lt trong nhfrng y~u t6
quan tr9ng la S! sieu am s&m d~ xac djnh tu6i thai. Sien am s&m giup lam giam tY I~ can thi~p
thai gill !hang so v&i nhfrng tru&ng hqp tinh ngay dv sanh can cu vao ngily dftu cua kY kinh
cu6i (OR 0.68, 95% CI 0.57-0.82) rs1, vi khi bi~t chinh xac tu6i thai thi nguai ta kh6ng d~ thai
keo dai vii lam giam ty l~ thai gill thang ru I0% xu6ng con I%-3%. l!OJ
NGUYENNHAN
Nguyen nhiin Clla thai gia thang chua bi~t ro:
156
I. Nguyen nhiin thuang nhiit cua thai giit !hang la do S! tinh toan kh6ng chinh xac tu6i
thai vi:
• Kinh kh6ng d~u.
• Thai gian 11,mg trung tr~.
• Khong nh& ngity kinh ch6t.
2. Suy thuqng th?n thai nhi.
3. V6 s9 (kh6ng kem da 6i)
4. Thieu Placental sulfatase anh huang den sv chuy~n h6a Estrogen & nhau thai, la m(lt
b~nh hi~m di tmy~n theo gen l~n lien k~t v&i nhi~m s~c th~ X.
5. Giam 16u hydroxy dehydroepiandrosterone beta sulfate (ti€n chftt cua Estriol).

2. Thai gia thiing
6. Cac yiu tb nguy ca: Beo phi l7
l, con so, thai nhi trail1
l, di truybn, c6 tibn su thai gia
thang trong cac !!in thai tru6'c.[?]
SINH B"f.NH LY HQC
Vai tro cua trvc dmn d6i - tuy~n yen - tuy~n thuqng th*n thai nhi trong co- ch~ gay
chuy~n d~ [!OJ
Kich holt t[lc du6'i d6i - tuy§n yen - tuy@n thugng th$n thai nhi dil.n din Sl ti€t nhibu ACTH.
Chat nay kich thich tuyin thu911g th$n thai nhi ti§t nhi€u tien chat Ctla c19 estrogen la
dehydroepiandrostenedione sulfate (DHEAS). DHEAS dugc chuy€n thimh 16u hydroxy
dehydroepiandrosterone iJ gan thai nhi vii dugc dua din nhau de chuy€n h6a thilnh Estradiol,
Estrone vii Estriol. Ngoai DHEAS, tuy@n thugng th$n thai nhi con san xuat nhibu cortisol la
chat kich thich sv tiit corticotropin releasing hormone (CRH), oxytocin, prostaglandins (nh~t
la prostaglandine E2). CRH giup tang ti€t prostaglandins ti.'! t~ bao mang tmg, mang d~m vii
mang bi. Sv tang prostaglandins se dfrn d6n chuy€n dl
Vai tro cua Estrogen trong khOi phat chuy~n d~l10
l: Banh nhau la ngu6n cung dp Estrogen
chinh y~u. N6ng d9 Estrogen tang trong mau mi:: theo tu6i thai. Estrone vii 17~-Estradiol dan
xufit tlr C19 Androgen trong khi Estriol dfrn xufit tlr DHEAS thai nhi. Estrogen kh6ng gay c011
co tU cung nhung kMi phat m9t chu6i nhfrng thay d6i iJ ca tu cung bao g6m sv gia tang sb
lugng th! th€ Prostaglandin, th1 th~ oxytocin, di€u chinh tang nhfrng enzyme chiu trach
nhi~m trong Sl co ca tlr cung (calmodulin, myosin light chain kinase).
Vai tro cua Progesterone trong khOi phat chuy~n d~l10
l: Progesterone gi(1p tlr cung 6· trlng
thai yen nghi trong nua sau cua thai ky b~ng each UC ch@ sv san xuftt prostaglandins va UC ch@
sv bi€u hi~n gen lIO nhfrng protein lien quan d~n sv co cu tlr cung (th1 th€ oxytocin,
prostaglandins...) Ca ch§ tac dlng cua Progesterone c6 le lien quan d~n th! th€ progesterone.
B~ng c6' la khi cho chfit dBi khang tht th€ progesterone la RU-486 h'.1c thai du thang thi lam
tang cun co mcung vii khiJi phat chuy€n dI. Cortisol va Progesterone c6 tac dlng dBi khang
nhau nen v6'i tinh trlng nhi~u cortisol ij nhau thai tru6'c khi chuySn dI se UC ch§ holt d(>ng Clla
progesterone va lIO can co tlr cung.
Nhu v$y, khi co sv suy giam holt d(>ng cua t[lc du6'i d6i - tuy€n yen - tuy@n thu911g th$n
thai nhi, cua nhau thai thi d€u c6 th€ Jam thi~u y~u tb khiJi phat chuy€n dI khi thai da du ngay
ru d6 dfrn d6n thai gia thang.
Nguy ca xay ra cho thai nhi vii tre sa sinh Iii sv phat tri€n h9i chung thai giil thang. H9i
chung nay xay ra khi thai nhi ch~m tang tmiJng nhung viln con 6· trong tlr cung qua ngay dI'
sanh. TY I~ cua hQi chiing thai gia thang la 20%-30% cac tluang hgp thai gia thang, c6 lien
quan din sv gia vii nh6i mau banh nhau. £lieu nay di'in d~n tinh tr(ng kh6ng cung dp d1 oxy
Va chfit bB duang cho thai nhi trong khi nhu ciiu phat tri€n CUa thai van ti§p tlC tang dan d§n
157

3. SAN KHOA
tinh trjng giam luqng ma du6i davit giam kh6i luqng ca khi€n thai suy dinh duang va c6 th~
t-Lr vong trong tlr cung, trong chuySn dI va sau sanh.rzi
Khi thai qua ngity, luqng nu6c 6i giam dfin c6 th~ dfin den thi€u 6i. Thai nhi thieu oxy se
di phan su lam nhu9m xanh day r6n, da, m6ng tay, mitng 6i. Tuy nhien, 70%-80% thai giit
thang kh6ng bi suy nhau thai ma v§n ti€p ti.ic l6n len trong tlr cung, d6i khi tr& thimh thai to
tren 4.000g gay de kh6.
B~nh suftt vit tii' suftt ciia thai gilt thang
VJphia lllf!
Cfin phai can thi~p khi chftm dut thai cy: kh&i phat chuy~n dI, gilc sanh.
Sang chftn am dIO khi sanh ducrng du6i vi thai to kc::t vai (3,3% so v6i 2,6% d6i v6i
thai dt'.1 thang).
Tang nguy ca m6 lfty thai (MLT): 14% so v6i 7% athai du thang f7
l va cac bi€n chtrng
cua m6 I§y thai nhu nhiem trung, bang huy€t, thuyen t~c mjch do huy€t kh6i, t6n
thuang cac tjng phtl khac (ru9t, bang quang). [J]
VJphia con
Thai ch~m tang tm&ng trong tlr cung.
Nguy ca chen ep r6n do thiSu 6i.
Khi thai vuqt qua 42 tufin, ty l~ tu vong chu sinh (thai ch€t luu, thai ch€t sau sanh)
tang tir 4-7/1.000 so v6i 2-3/1.000 thai sanh atufin thu 40 r10
1. TY l~ ru vong gftp 4 lfin
khi sanh luc 43 tufin va gftp 5-7 Ifin khi sanh luc 44 tufin so v6i sanh luc 40 tufin.
Thai to 2: 4.500g chi€m 3,5%-10% thai gia thang nh§t la n€u me:: c6 dai thao duang,
beo phi. NSu sanh nga am d(lo c6 thS bi kc::t vai bi€n chtrng gay xuang don, li~t dam r6i
canh lay, 80%-90% phIC h6i sau ) nam.f4
l
HI duang huy€t, co gi~t, suy ho h§p sau sanh do hit 6i ph:ln su.
CHAN DOAN
Chua c6 tieu chuiln Jam sang hay c~n lam sang nao giup chiln doan chinh xac thai gia thang
ma chi c6 thS xac dinh thai du tnr6ng thanh hay chua ho~c c6 nguy ca suy thai hay kh6ng d~
c6 hu6ng xu tri thich hqp.
Lam sang
Xtic dinh tuBi thai:
• Hai b~nh su:
a. Ngay dfiu ct'.ia I<Y kinh cu6i cling: c6 gia tri d6i v6i nhfrng I<Y kinh d€u.
b. Chu I<Y kinh deu hay kh6ng, dai hay ng~n d~ lo(li tru chiln doan sai do chu I<Y
kinh dai.

4. Thai gia thang
c. Ngily b~t dftu cam thfry thai may tuong i'.mg v&i thai 5 thang d6i v&i thai con so,
4 thang d6i v&i con r~.
d. Ngay kham thai dftu tien va tu6i thai u&c luqng vi10 li'.1c d6 d€ xem tu6i thai
u&c luqng trong Ii'in kham thai d6 c6 phu hgp v&i kY kinh ch6t hay kh6ng.
• Khao sat c~n lam sang: Ki€m tra k~t qua sieu am tm&c 24 tuftn tu6i thai se cho u&c
lm;mg tu6i thai d~ cho u&c tinh ngay di! sanh kha chinh xac hon la chi can cu tren
ngay di'iu cua ky kinh cu6i cling.
Danh gia tinh tr1,1ng suy thai
a. Tri~u chling ca nang: thai ph1 theo doi d~m cu dc)ng thai hang ngay cho thfry thai
may yeu, may it.
Cam thfry bmg nh6 di hay kh6ng l&n hon.
b. Tri~u chling thl!c th~: bb cao tU cung khong tang hay tang ri'it it.
c. Khao sat c~n lam sang (Xem them phftn dinh tu6i thai):
• Sieu am u&c luqng can thai, danh gia de) tang tru6ng thai nhi theo bach phan vi
• Banh gia sue kh6e thai:
Non stress test (NST) 2 - 3 lftn/tufrn (xem them bili danh gia sue khoe thai
nhi trong thai ky qua theo doi nhjp tim thai bftng monitor san khoa) d~ xem
c6 dap ling (thai khong suy) cho gia tri tien doan am la 99,8% [SJ, hay
khong dap ling (nghi nga c6 suy thai).
Oxytocin challenge test (OCT) (xem them bili danh gia sue khoe thai nhi
trong thai ky qua theo doi nhip tim thai biing monitor san khoa). TY I~
dum1g tinh gia khoang 47,9% nhung t)' I~ am tinh gia thfrp khoang 2,8%[rn
N~u OCT duffi1g tinh thi thuang chi'im dut thai kY biing m6 !fry thai.
Sieu am do chi s6 nu&c 6i (AF!) 2-3 lftn/tuftn [3
•
6
•
9
L
Thi~u 6i: 0 - 5cm.
Binh thuang: 5,1- 25cm.
Ba 6i: > 25cm.
Ho~c do xoang 6i l&n nhat:
Thi~u 6i: 0- 2cm.
Binh thuang: 2, l - 8cm.
Ba 6i: > 8cm.
Soi 6i: nu&c 6i bfrt thuang khi c6 mau xanh hay vilng ua (do l~n phiin su)
chling to thai suy truang di~n.
ChQC do 6i d~ quan sat mau s~c nu&c 6i, lam cac xet nghi~m d€ djnh cac
thilnh phftn c6 trong nu&c 6i nhfim danh gia de) tm&ng thimh cua thai (dinh
n6ng de) bilirubin, creatinin, acid uric, tinh t)' l~ t~ bilo cam, xet nghi~m
danh gia muc de) tru&ng thimh ho hfrp thai nhi).
Tr~c db sinh v~t ly (di~m s6 Manning) cho gia trj tien doan am la 99,9%. l5
l
159

5. SAN KHOA
- Dinh luQ'Ilg n(>i ti€t Estriol trong nu6c ti€u d€danh gia tinh tn,mg sue khoe
thai han la d!nh tu6i thai.
XU'TRi
Thai ky tir 40 d~n 41 tuiin
Htr6ng diin thai phI theo doi Ctr d(>ng thai. N€u thai may it hay may y€u thi cho nh~p vi~n.
Trong b~nh vi~n: xac d!nh d(> tru&ng thanh va tinh trlng sue khoe thai nhi.
N€u co tinh trlng suy thai thi m6 lfty thai.
N€u co dftu hi~u nghi nga suy thai (sieu ilm co thi€u 6i, NST khong dap i'.rng) thfc hi~n
OCT d€ xac d!nh sue khOe thai. N€u OCT duang tfnh thi phai chftm dlr! thai kY b~ng each m6
I§y thai. N~u OCT ilm tinh vii cac xet nghi~m cho thfty thai du tru6ng thanh thi chftm dlr! thai
cy.
Thai ky tir 41 - 42 tuiin
Thai phI theo doi ctr d(>ng thai.
Thfc hi~n NST, tr~c d6 sinh v~t ly, sieu ilmdanh gia tinh tr?ng nu6c 6i, OCT:
N€u NST khong dap i'.rng, thi€u 6i (AF! ::; 5) thi m6 lfty thai.
N€uNST co dap i'.rng, OCT am tinh, c6 tU cung chua x6a ma thi chftm dlr! thai cy.
Pilll'O'ng phap ch§m dut thai ky
Truong hqp c6 ch6ng chi d!nh sanh nga ilm d?o thi m6 lfty thai.
N~u c6 chid!nh sanh nga ilm d?o thi kh&i phat chuy€n d?.
Tien lugng kha nang ti€n tri€n cua chuy€n dI b~ng chi s6 Bishop
Bang chi s6 Bishopr1
1
El9 m& co tii cung (cm)
El9 x6a co tii cung (%)
M~t dQ c6 tii cung
HLl'&ng c6 tii cung
El9 l9t cua ng6i thai
160
N~u t6ng s6 di€m
< 5
5-6
~ 7
0 diem 1 diem 2diem
0 1-2 3-4
< 30 40-50 60-70
Ct:rng vi:ra M~m
Sau Trung gian Trll'ci'c
-3 -2 -1 - 0
Kha nang gilc sanh thftt b?i.
Tien hrQ'Ilg sanh nga ilm d?o de d~t.
Tien luQ'Ilg sanh nga ilmdlo.
3diem
5-6
~80
+1,+2

6. Thai gia thang
Theo Hmmg d~n quac gia v~ cac djch V( cham soc sfrc khoe sinh san-Bi} y t€, 2009111
Khoi phlit chuyen di.i b~ng cac phuang phap sauday:
1. B6c tach mimg 6i.
2. B§m6i: dn danh gia s6 luqng vii mau s~c djch 6i. Phai theo doi nhip tim thai trn&c vii
ngay sau khi b§m 6i. C6 th~ b§m 6i dan thufrn ho~c k€t hqp v&i truy€n oxytocin.
3. B6ng Foley. Bua m(>t thong Foley qua !6 trong c6 tfr cung. Born !Om! huy€t thanh
m~n 0,9% lam phbng b6ng cao su ti.io ap lfc giup cho c6 ru cung x6a vii mo. Khi c6 tlr
cung mo dm;rc 3cm, thong se tr tu(>t ra ngoai vii cu(>c chuyen dI du9c khc'Ji phat. C6
the k€t hqp VOi truy€n finh ffil;ICh oxytocin n€u cfm.
4. Prostaglandin (chi duqc ti€n hanh tl;li ca so c6 phiiu thu~t.) Prostaglandin giup c6 tlr
cung chin mubi va m€m.
5. B§m 6i k€t hqp v&i truy€n oxytocin (chi duqc ti€n hanh tl;li ca so c6 phiu thu~t.) -
Theo doi vii di€u chinh s6 gi9t de dl;lt duqc s6 can co phu hop v6i Sf ti€n trien c1a
chuyen dl;l.Theo doi: tim thai, can co tlr cung, d(> mo c6 tlr cung, d(> l9t ci'.1a ngoi d~ c6
thai d(> XU tri kip thoi. N€u cu(>c de chi huy keo dai qua 6 gia ma khong ti€n tri~n t6t
thi phi'ii phiiu thu~t I§y thai. Tai bi€n c6 the g~p la vfJ tlr cung, thai suy ho~c ru vong do
theo d6i khong t6t, can thi~p mu(>n.
Sau khi sanh: dn danh gia tinh tn;mg tre sa sinh theo phan d9 thai gia thang d~ c6 hu&ng
theo d6i va di€u tri ll;li khoa Nhi sa sinh nhfit la n€u c6 d§u hi~u thai ch~m tang trn611g, thai
suy hay hit 6i phan su thi dn Bae si Nhi c6 m~t khi sanh de h6i sue dip cuu kip thai.
KETLU~N
Thai gia thang la m(>t thai k)' nguy cacao lam tang b~nh sufit vii 1:lr su§t thai nhi. Nguy ca nay
thuang la do thong tin v€ thai di~m c6 thai khong chinh xac. Vi v~y, d~ kh~c ph1c Sf sai s6t
nay, dn khuy€n khich thai phl di sieu am som trong 3 thang dfru cua thai k)' thi Sl" chfin doan
xac dinh tu6i thai se chinh xac vii do d6, tinh duqc ngay df sanh, nh6 v~y se khong c6 tinh
tqmg thai ky keo dili d€n giil thang.
TAI LI~U THAM KHAO
1. B(> Y t€ "Cdc phurmg phdp gay chuydn dl;i" Hu6ng dfin qu6c gia v€ cac dich Yl cham
s6c sue kh6e sinh siln-B(> Y t€, 2009, tr 151-153.
2. Calvin J Hobel (2010) "Obstetric complications Pretem1 labor, PROM. JUGR.
Postterm pregnancy and IUFD "Hacker and Moore's Essentials of Obstetrics and
Gynecology 5th 2010, 146-159.
3. Chamberlain PF, Manning FA, Morrison 1, Harman CR, Lange JR. Ultrasound
evaluation of amniotic fluid volume. I. The relationship of marginal and decreased
amniotic fluid volumes to perinatal outcome. Am J Obstet Gynecol. 1984;150:245- 9.
161

7. SAN KHOA
162
4. Charles R B Beckmann, Frank W Ling, Barbara M Barzansky (2008) Chapter
23 "Postterm pregnancy" Beck.mann's obstetrics and gynecology 61
h edition published
in collaboration with ACOG, 219-222.
5. Donald Briscoe, Hayley Nguyen, Melanie Mencer et al (2005) "Management of
Pregnancy Beyond 40 Weeks' Gestation" Am Fam
Physician. 2005 May 15;71(10):1935-1941.
6. Magann EF, Nolan TE, Hess LW, Martin RW, Whitworth NS, Morrison JC.
"Measurement of amniotic fluid volume: accuracy of ultrasonography techniques".
Am J Obs/et Gynecol. 1992;167: 1533-7.
7. M Gala!, I Symonds, H Murray, F Petraglia, R Smith (2012) "Postterm pregnancy"
FVV in OBGYN, 2012, 4(3): 175-187.
8. Neilson JP. (2000) "Ultrasound for fetal assessment in.early pregnancy". Cochrane
Database Syst Rev 2000;:CD000182.
9. Rutherford SE, Phelan JP, Smith CV, Jacobs N. (1987) "The four-quadrant
assessment of amniotic fluid volume: an adjunct to antepartum fetal heart rate
testing. " Obstet Gynecol. 1987;70(3 pt 1):353-6.
10. Victoria Snegovskih, Joong ShinPark, Errol R Norwitz (2006) " Endocrinology of
parturition"Endocrinol Metab Clin N Am 35 (2006) 173-191.
11. Weingold AB, DeJesus TP, O'Keiffe J. (1975)"0.xytocin challenge test." Am JObstet
Gynecol. 1975 Nov 1;123(5):466-72.
12. Zeitlin J, Blonde) B, Alexander S, et al.(2007) "Variation in rates ofpostterm birth in
Europe: reality or artefact?" BJOG 2007; 114:1097.
13. National Vital Statistics Reports. Births: Final data for 2009
www.cdc.gov/nchs/data/nvsr/nvsr60/nvsr60_01.pdf(Accessed on May 31, 2012).
14. World Health Organization. International Statistical Classification of Diseases and
Related Health Problems. Geneva, 2006.