D o p p l e r a s s e s s m e n t o f t h e f e t o p l a c e n t a l c i r c u l a t i o n a n d f e t a l g r o w t h ; p r e l i m i n a r y r e s u l t s
P . J .H .M . R e u w e r , H . W . B r u i n s e . U n i v e r s i t y H o s p i t a ^ l U t r e c h t , The N e t h e r l a n d s
Flow r e s i s t a n c e of the p l a c e n t a ! v i l l p u s c i r c u l a t i o n was s t u d i e d , u s i n g the P u l s a t i l i t y I n d e x (PI = s y s t . - d i a s t . d i f f e r e n c e d i v i d e d b y the mean v e l o c i t y ) o f D o p p l e r f l o w s i g n a l s f r o m u m b i l i c a l a r t e r i e s . A p r e v i o u s s t u d y c o n f i r m e d t h e i n t r a - a n d i n t e r - o b s e r v e r r e p r o d u c i b i l i t y o f t h e m e t h o d and d e m o n s t r a t e d t h e f e a s i b i l i t y o f t h e s i g n a l p r o c e s s i n g t e c h n i q u e used [ 1 ] .
The aim of the s t u d y was to e s t a b l i s h g e s t a t i o n a l a g e - r e l a t e d PI r e f e r e n c e values in normal p r e g n a n c y and to i n v e s t i g a t e w h e t h e r d i f f e r e n c e s c o u l d b e f o u n d i n i n t r a - u t e r i n e g r o w t h r e t a r d a t i o n s ( I U G R ) .
P a t i e n t s ;
1. 23 normal p r e g n a n c i e s , e x a m i n e d e v e r y two w e e k s f r o m the 16th p o s t m e n s t r u a l week o n w a r d . N o a n t e n ä t a l l y p r e s u m e d o r t r e a t e d c o m p l i c a t i o n s a n d h e a l t h y t e r m i n f a n t s w i t h a p p r o p r i a t e w e i g h t s ( > P 1 0 ) a n d n o p e r i n a t a l m o r b i d i t y . 2 . 1 6 c o m p r o m i s e d p r e g n a n c i e s a s s o c i a t e d w i t h s e v e r e IUGR
( b i r t h w e i g h t < P 2 . 3 ) , . . f i r s t D o p p l e r e x a m i n a t i o n a f t e r c l i n i c a l d i a g n o s i s I U G R .
3. 6 p a t i e n t s e x a m i n e d l o n g i t u d i n a l l y as g r o u p 1 , g i v i n g b i r t h t o small f o r d a t e i n f a n t s « P 1 0 ) .
R e s u l t s ;
- In n o r m a l p r e g n a n c y ( g r o u p 1) the PI d e c r e a s e d w i t h a d v a n c i n g p r e g n a n c y ( f i g . 1 ) , i n d i c a t i n g a p r o g r e s s i v e d e c l i n e o f p l a c e n t a l v a s c u l a r r e s i s t a n c e .
- A l l p a t i e n t s w i t h e v i d e n t IUGR ( g r o u p 2 ) h a d s i g n i f i c a n t l y i n c r e a s e d PI v a l u e s (» 3 S D ) e x c e p t one p a t i e n t0 (PI 1.0 at 31 w e e k s ) g i v i n g b i r t h to a s e v e r e l y m a l f o r m a t e d i n f a n t
( t r i p l o i d y ) , w i t h a n o r m a l p l a c e n t a .
- 5 of the 6 p a t i e n t s of g r o u p 3 had s e r i a l l y i n c r e a s e d PI v a l u e s ( > 2 S D ) . Pi v a l u e s w e r e i n c r e a s e d s e v e r a l w e e k s b e f o r e s u b o p t i m a l f e t a l g r o w t h w a s c l i n i c a l l y p r e s u m e d . T w o e x a m p l e s are shown in f i g . 2 and 3; in these cases s u b o p t i m a l f e t a l g r o w t h w a s n o t p r e s u m e d a n t e n ä t a l l y o n t h e b a s i s o f s e r i a l r o u t i n e e x a m i n a t i o n s ( f u n d a l p a l p a t i o n a n d s o n o g r a f i c f e t o m e t r y ) , w h e r e a s P I v a l u e s .were i n c r e a s e d a s e a r l y as 28 p o s t m e n s t r u a l w e e k s . Several old i n f a r c t i o n s w e r e f o u n d in one p l a c e n t a ( f i g . 2) and the other one
( f i g . 3 ) showed a s y m m e t r i c a l m a t u r a t i o n f a i l u r e .
J.Perinat.Med. 12(198*0 Copyright by Walter de Gruyter & Co., Berlin-New York
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0.6-
16 ^ 2 0 24 28 32 3 6 ^ 4 0 16 20 2Α 28 32 36 40
f i g . 1 f i g . 2 f i g . 3
C o m m e n t ; t h e s e p r e l i m i n a r y d a t a s u g g e s t t h a t t h e P I holds p r o m i s e as a s i m p l e , c l i n i c a l l y u s e f u l m e t h o d f o r e a r l y d i a g n o s i s o f c o m p r o m i s e d f e t o p l a c e n t a l c i r c u l a t i o n . T h i s t e c h n i q u e may e n h a n c e our u n d e r s t a n d i n g on the s u b j e c t of I U G R b y d i s t i n g u i s h i n g p l a c e n t a l v a s c u l a r f r o m n o n - v a s c u l a r p a t h o g e n e s i s . The PI m i g h t be used to e v a l u a t e t h e r a p e u t i c r e g i m e s f o r i m p r o v i n g p l a c e n t a l c i r c u l a t i o n .
F u r t h e r s t u d i e s ; a n e x t e n s i v e s t u d y t o e s t a b l i s h t h e p r e d i c t i v e v a l u e of the PI as a s c r e e n i n g m e t h o d for IUGR has been s t a r t e d . B e s i d e s b i r t h w e i g h t m o r e a c c u r a t e c r i t e r i a f o r o p t i m a l f e t a l g r o w t h such a s P o n d e r a l I n d i c e s a n d s k i n f o l d s are u s e d . The p r o t o c o l w i l l be d i s c u s s e d . In a d d i t i o n , a c o m p u t e r c i r c u l a t i o n model h a s been d e v e l o p e d t o s t u d y t h e n u m e r i c a l c o r r e l a t i o n s o f p l a c e n t a l v a s c u l a r r e s i s t a n c e a n d o t h e r h e m o d y n a m i c p a r a m e t e r s w i t h P I c h a n g e s . S u g g e s t i o n s r e g a r d i n g t h e c o m p u t e r s i m u l a t i o n s t u d y a n d a d d i t i o n a l a n i m a l e x p e r i m e n t s a r e g e n t l y a p p r e c i a t e d .
R e f e r e n c e ;
1 . P . J . H . M . R e u w e r , W . C . N u y e n , H . J . M . B e i j e r , R . Μ . H e e t h a a r , H . W . B r u i n s e , P h . S t o u t e n b e e k , A . A . H a s p e l s . : C h a r a c t e r i s t i c s o f f l o w v e l o c i t i e s i n t h e u m b i l i c a l a r t e r i e s , assessed b y D op pi er u l t r a s o u n d . E u r o p . J . O b s t . . G y n . R e p r o d . B i o l . ( 1 9 8 4 ) A c c e p t e d f o r p u b l i c a t i o n .
J.Perinat.Med. 12(198*0
