1. UMBILICAL BLOOD FLOW INDICES IN PREGNANCIES COMPLICATED BY TYPE 1 DIABETES MELLITUS
Finn Lauszus, Hanne Søndergaard, Carsten Byrialsen, Ervin Kallfa
Obstetrical Dept., Herning Hospital, Denmark

2. What do we do with umbilical indices?
Estimate symptoms of distress in umbilical arteries, i.e. clinical anticipated risk correspondind to physiological signal of distress
Types of measurements:
ratios between peak systolic velocity (A),
end-diastolic peak velocity (B) and
mean velocity (mean). Most common in clinical practice are pulsatility index (PI = (A - B)/mean), resistant index (RI = (A - B)/A), and S/D ratio (A/B).

3. What do we know for sure about umbilical indices
What do we know for sure about umbilical indices ? (Evidence group 1, Cochrane Coll.)
We do umbilical blood flow as an indicator for fetal distress and serial measurements are an established tool used for timing of delivery of fetuses with intrauterine growth retardation (IUGR).
However, the latest review is from 1996, stating: ”The use of Doppler ultrasound in high risk pregnancies appears to improve a number of obstetric care outcomes and appears promising in helping to reducing perinatal deaths.”

4. What did they find?
Doppler ultrasound for fetal assessment in high risk pregnancies by Neilson JP, Alfirevic Z. Cochrane Database of Systematic Reviews 1996, Issue 4.
11 eligable studies
Less inductions (OR=0.85, p<0.006)
Less perinatal deaths (mainly neonatal) (OR=0.71, p<0.06)
Less hospital admissions (OR=0.61, p<0.0001)
Less cesareans for fetal distress (OR=0.36, p<0.0016)
A new review is under way……

5. High risk pregnancies…
For most researchers, ‘high risk’ will include maternal diseases like DM, hypertensive disorders, cardiac, renal and autoimmune disorders. All of these conditions are associated with increased perinatal mortality and morbidity
One shortcoming in fetal conditions of high risk is our inability to discern between IUGR, SGA, and fetuses that are constitutionally small with no increased perinatal mortality and mortality

6. Studies - on T1DM pregnancies
Bracero L 1986 (n=43) Maternal hyperglycemia correlate with S/D ratios
Salvesen DR 1992 (n=14 with nephropathy) Fetuses acidemic and hypoxemic (by amniocenthesis) despite normal umbilical flow values 24 hours before delivery
Zimmermann 1992 (n=53) Vascular resistance declined during the course of pregnancy (measured 3 times range 1-7), no correlation with glycemia
Johnstone FD 1992 (n=128) Abnormal RI is a significant predictor of fetal compromise

7. T1DM-studies cont’d
Yoon BH 1993 (n=24) A strong relationship between the degree of fetal acidemia and hypercarbia (by cordocentesis) and Doppler velocimetry
Grunewald C 1996 (n=24) Decline in pulsatility indices was absent and not influenced by glycemia (measured two times with one month’s interval)
Wong SF 2003 (n=104) Umbilical artery Doppler velocimetry is not a good predictor of adverse perinatal outcomes in diabetic pregnancies (only 54 had scans within one week of delivery, 4 scans from week 28-38).

8. Our study Consecutive, n=129
Weekly measurement, gestational week (total 450), median 4, mean 3.5, range 2-6
Calculations performed on complete data
Umbilical pH measured in 101 at birth
77 delivered before week 37 and 8 before week 34, 42 in week 36

9. Clinical data (1) 107 16 6 129 29 ±5 28 30 ±4 0.50 9±7 14±7 21±5**
Albuminuria
Normo
Micro
Macro
All
ANOVA No
107 16 6
129
Age (yrs) 29 ±5 28 30 ±4
0.50
Duration (yrs)
9±7
14±7
21±5**
10±8
0.0001
Simple/
Proliferative
37/3
9/3
6/0
52/6
HbA1c
(%) in 1st tr.
7.2 ±1.1
7.9
±1.2
7.3
±1.1
0.045

10. Clinical data (2) 70±6# 75±4 80±5 71±6 0.0001 117 ±8 123 ±5 131 ±9**
Albuminuria
Normo
Micro
Macro
All
Anova
DiaBT in 1st tr.(mmHg)
70±6#
75±4
80±5
71±6
0.0001
SysBT in 1st tr.(mmHg)
117 ±8
123 ±5
131
±9**
118 ±9
Clearance in 1st tr.(ml/min)
±28
127
±27
108
±24
129
0.20
Birthweight (g)
3820
± 696#
3144
± 698
3271
± 572
3711 ±728
0.001
BWTratio
1.37
±0.26
1.14
± 0.21
1.18
±0 .15
1.33
± 0.26
0.002
Umb-pH
7.26
± 0.09
7.25
7.32
± 0.5
± 0.9
0.31

11. Albumin excretion rate
Normo-
Micro-
Macro-
All (95% CI)
No. 31
1.10
1.32
1.45
1.15 (0.68,1.72) 87 32
1.13
1.18
1.13(0.70,1,63
101 33
1.05
1.34
1.25
1.09 (0.7,1.6) 93 34
1.09
1.41
1.19
1.14 (0.74,1.68) 85 35
1.03
1.06 (0.71,1.48) 81 36
1.11
1.26
1.04
1.11 (0.53,1.79) 50
107 16 6
129

12. pH and the last PI (within 2 days prior to delivery)

13. pH at birth and PI in week 36 no deliberate coincidence?

14. The best fitting model
According to SPSS

15. Model summary and parameter estimates
R square F
df1
df2
Sig
Constant b1
Linear
.075
7.984 1 99
.003
7.339
-.07
Quadratic
.131
7.389 2 98
.001
7.457
.267
.072

16. Conclusions
No decrease in umbilical arterial flow indices is seen with progressing gestational age from week 32.
We confirm that newborn of diabetic mothers are more likely to have acidemia and that it is associated with umbilical arterial flow indices.

17. Strength and weakness Numbers and consecutive design
Non-randomization, non-blinding
Bias by other (maternal )factors (known or unknown)
Predictive value compared to other variables
If this is standard care what is standard values to aim at?
What are we looking at? Prematurity?