**3. Results**

The results obtained from fetuses with malformations were compared with those from control fetuses, with normal growth and morphology.

The means and standard deviations were calculated for all 53 fetuses and per sub-group, with a minimum of 3 cases per category of malformation. When a type of anomaly is presented only by one or two fetuses, the results are given individually.

#### **3.1 Gasometric and acid-base parameters in the umbilical venous blood (tables 2 and 3, figure 1)**

The results were compared with norms established in the control population for the gestational age considered, as the pH, pO2 and SaO2 decrease physiologically in the UVB during gestation, whereas the pCO2 and the bicarbonate concentration rise (Bon et al., 1997).

The acidemia and hypoxemia statuses were defined by pH and pO2 values beyond a standard deviation below the mean, and the hypercapnia statuses by pCO2 values higher by more than one standard deviation to the mean.

The pH and the pCO2 remain within normal limits, while the plasma bicarbonate

This sub-group is characterised by a state of acidemia, hypoxemia and hypercapnia in 3

The mean pH and pO2 are significantly decreased and the mean pCO2 significantly

One case in particular of severe acidosis (pH of 6.99), both gaseous and metabolic, was observed in a fetus presenting a complex cardiopathy, with a complete atrioventricular

The gasometric and acid-base balance was however found to be normal in two fetuses, one of which presented a transposition of the main vessels and the other an abnormal

The pH, pO2, SaO2, and bicarbonate concentration are on average significantly lower than

A state of acidemia, often gaseous and metabolic, is present in 5 cases, and a state of

Also noted is one case of acidemia (pH of 7.18), associated with hypercapnia (pCO2 of 7.99 kPa), in the presence of microcephaly linked to a cytomegalovirus (CMV) infection.

The pH and the pO2, and likewise the bicarbonate concentration of the UVB, are lower in a fetus presenting a major cystic adenomatoid malformation of the left lung, type 2, with the

The third clinical case (pulmonary hypoplasia with amniotic band syndrome) is associated with acidosis (pH of 7.20) with hypercapnia (pCO2 of 7.22 kPa); at birth, the infant presented

The gasometric and acid-base balance is normal in 3 cases. However, in the presence of ascites with the complication of fetoplacental anasarca, we found acidosis (pH 7.10), which was essentially metabolic (bicarbonate concentration of 14.9 mmol/l), and severe hypoxemia

In the case of type 1 adenomatoid malformation, the biological balance is normal.

concentration was found to be raised in 2 cases.

increased, when compared with the control group values.

**3.1.4 Malformations of the central nervous system (n=11)** 

These anomalies are found in fetuses with hydrocephaly or spina bifida.

**3.1.3 Cardiac malformations (n=5)** 

cases out of 5.

pulmonary venous return.

those of the control group.

**3.1.5 Pulmonary malformations (n=3)** 

generalised cyanosis and acute respiratory distress.

This subgroup is characterized by scattered results.

start of hydrops and hydramnios.

hypoxemia in 6 cases.

**3.1.6 Ascites (n=4)** 

(pO2 of 1.20 kPa).

canal.

Only the pO2 and the SaO2 of the entire group (n=53) are significantly reduced when compared to the norms of the control group, whereas the other parameters have not significantly changed.


However, the results are scattered and were analysed by sub-group.

The results are expressed as means and standard deviations.

n = number of samples

\*\* p < 0.01

\*\*\* p < 0.001

Table 2. Gasometric and acid-base parameters in the umbilical venous blood (number of cases 3).

#### **3.1.1 Renal malformations (n=14)**

Four cases of moderate hypoxemia (pO2 between 3.1 and 4.04 kPa) were found in the following pathologies: one case of Prune Belly syndrome, two cases of bilateral obstructive uropathy, and one case of multicystic renal dysplasia.

The pH is still within normal limits, whereas the pCO2 is elevated in one case, associated with an increase in the plasma bicarbonate concentration.

The bicarbonate level is reduced in 3 cases, lying between 18 and 20 mmol/l.

#### **3.1.2 Digestive malformations (n=8)**

The pO2 value is low for 3 fetuses, including 2 cases of duodenal stenosis and one case of oesophagus stenosis with hydramnios.

The pH and the pCO2 remain within normal limits, while the plasma bicarbonate concentration was found to be raised in 2 cases.

#### **3.1.3 Cardiac malformations (n=5)**

166 From Preconception to Postpartum

Only the pO2 and the SaO2 of the entire group (n=53) are significantly reduced when compared to the norms of the control group, whereas the other parameters have not

Controls Malformations (entire group) Renal malformations Digestive malformations Cardiac malformations Malformations of the central

7.31 0.033

> 5.79 0.67

21.73 1.86

> 5.53 1.61

> 0.67 0.19

n 73 53 14 8 5 11 3 4

7.31 0.023

> 6.02 0.58

22.77 1.44

4.35\*\* 1.16

0.54\*\* 0.16

Table 2. Gasometric and acid-base parameters in the umbilical venous blood (number of

Four cases of moderate hypoxemia (pO2 between 3.1 and 4.04 kPa) were found in the following pathologies: one case of Prune Belly syndrome, two cases of bilateral obstructive

The pH is still within normal limits, whereas the pCO2 is elevated in one case, associated

The pO2 value is low for 3 fetuses, including 2 cases of duodenal stenosis and one case of

The bicarbonate level is reduced in 3 cases, lying between 18 and 20 mmol/l.

7.22\*\* 0.130

7.62\*\* 2.05

22.92 3.73

4.01\*\* 1.27

0.43\*\* 0.22

nervous system

7.24\*\* 0.125

> 6.52 1.60

20.04\*\* 2.66

4.38\*\* 1.20

0.53\*\* 0.24

Pulmonary

malformations

7.23 0.049

> 6.47 0.65

20.23 1.72

> 5.30 1.92

> 0.61 0.24

Ascites

7.28 0.107

> 5.65 0.45

19.97 3.42

> 4.47 2.38

> 0.54 0.35

However, the results are scattered and were analysed by sub-group.

significantly changed.

pH 7.31

n = number of samples

pCO2 (kPa)

HCO3- (mmol/l)

pO2 (kPa)

SaO2

\*\* p < 0.01 \*\*\* p < 0.001

cases 3).

0.054

5.99 0.85

22.16 1.90

> 6.02 1.69

> 0.71 0.18

**3.1.1 Renal malformations (n=14)** 

**3.1.2 Digestive malformations (n=8)** 

oesophagus stenosis with hydramnios.

7.28 0.090

6.17 1.27

21.46 2.45

4.89\*\*\* 1.60

0.58\*\*\* 0.23

The results are expressed as means and standard deviations.

uropathy, and one case of multicystic renal dysplasia.

with an increase in the plasma bicarbonate concentration.

This sub-group is characterised by a state of acidemia, hypoxemia and hypercapnia in 3 cases out of 5.

The mean pH and pO2 are significantly decreased and the mean pCO2 significantly increased, when compared with the control group values.

One case in particular of severe acidosis (pH of 6.99), both gaseous and metabolic, was observed in a fetus presenting a complex cardiopathy, with a complete atrioventricular canal.

The gasometric and acid-base balance was however found to be normal in two fetuses, one of which presented a transposition of the main vessels and the other an abnormal pulmonary venous return.
