Pregnancy- Induced Changes In Some Ventilatory Indices In Enugu, South East Nigeria

ABSTRACT

Pregnancy is essentially a physiological process, which

involves a great number of physiological changes, affecting

virtually all the organ systems in the body. Literature is sparse on

the changes in ventilatory function during pregnancy in our

locality. The objective of this study is to establish the value of

Forced Vital Capacity (FVC), Forced Expiratory Volume in one

second (FEV1), FEV1/FVC ratio and Peak Expiratory Flow Rate

(PEFR) during pregnancy.

The study is a descriptive cross sectional study carried out at

the antenatal and booking clinics of the University of Nigeria

Teaching Hospital (UNTH), Ituku-Ozalla, Kenechukwu specialist

hospital Enugu and Chukwuasokam maternity hospital in Emene.

Two hundred (200) normal pregnant women and 100 non-pregnant

women were recruited. A standard Spirometer (Micro lab ML3500

MK8, Cardinal Health Germany 234 GMBH) was used to

determine the ventilatory function. The mean FVC was 2.93 ± .73

litres in the non-pregnant state but decreased significantly as

pregnancy progressed to 2.55± .51 litres in the 3rd trimester. The

percentage predicted also decreased significantly from 100.70±

31.11% in the non-pregnant state to 82.30± 19.01 % in the 3ird

trimester (P=0.000). The mean FEV1 was 2.55±0.62 litres per

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second in the non-pregnant state but decreased significantly, as

pregnancy progressed to 2.24±0.45 litres/second in the 3rd

trimester. Furthermore, the percentage predicted decreased

significantly from 102.02± 30.70 31.11% in the non-pregnant state

to 82.89±18.32 % in the 3rd trimester (P=0.000). The mean PEFR

was 5.38±1.44 litres in the non pregnant state but decreased non

significantly as pregnancy progressed to 5.18± 1.42 litres in the

3rd trimester (P=0.883). However, the percentage predicted

decreased significantly from 93.4 ± 32.16 % in the non pregnant

state to 79.39 ± 20.90 % in the 3rd trimester (P=0.014). The mean

FEV1/FVC was 87.56± 2.87 % in the non-pregnant state but

increased significantly, as pregnancy progressed to 91.30± 1.91 %

in the 3rd trimester. The percentage predicted was 107.37 ± 3.88

% in the non pregnant state, 102.97 ± 1.24 % in the 1st trimester,

109.56 ± 5.33 % in the second trimester and 105.77 ± 5.82% the

3rd trimester ( P=0.000). The FVC and the percentage predicted

and the FEV1 and the percentage predicted were within normal

range in the non-pregnant and during pregnancy. However, the

values decreased significantly, as pregnancy progressed. The

decrease in FEV1 during pregnancy is not of same magnitude as the

decrease in FVC. Consequently, the FEV1/FVC ratio increased, It

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can therefore be said that physiological restriction occurs during

pregnancy.