EFFECT OF VAGINAL PH ON EFFECTIVENESS OF MISOPROSTOL FOR CERVICAL RIPENING

Abstract

BJECTIVES
The objective of this study was to assess the influence or effect
of vaginal pH on the effectiveness of misoprostol as a means of
cervical ripening.

Specific objectives were:
1. To determine whether vaginal pH will affect the dose of
misoprostol that will achieve cervical ripening.
2. To assess the effect of vaginal pH on the interval between
application to cervical ripening.
3. To assess the effect of vaginal pH on the interval between
application to onset of uterine contractions.
4. To assess the effect of vaginal pH on the interval between
application and delivery of the baby
Other outcome measures such as the dose of misoprostol and
feto-maternal adverse effects in relation to vaginal pH were assessed.
Commented [DF1] : I am not certain this was the way this was written in your proposal!
Methodology
It was a cross-sectional descriptive study of women scheduled
for induction of labour at UCH between December 2010 and January
2011. A total population survey of the women planned for induction
was done.
Eighty women who consented to the study had their vaginal pH
determined before insertion of first dose of misoprostol and based on
the result they were categorised into first group of women with vaginal
pH< 5 and the second group of women with vaginal pH≥5. The women
had their labour supervised by the obstetric team in the Labour ward.
A data collecting sheet was used by the investigator to collect data
relating to demographic characteristics, labour effects, outcomes of
the induction. Data collected was entered into Microsoft Excel (2007)
spread sheet and analysed using the SPSS version 17. Quantitative
variables were summarized as means and standard deviation while
qualitative variables were represented as proportions. The Chi square
test and Fisher’s exact test were used to test for associations between
categorical variables. Continuous variables were compared using
independent t test. Linear regression analysis was conducted to derive
significant predictors of misoprostol effect and adjust for the influence
of confounding variables.
Results
The demographic characteristics of the women in the two
groups were comparable. Their mean age was 30.46 ± 4.21 years.
Most of the women (61%) had vaginal pH < 5. There was no
significant difference in the mean dose of misoprostol required in the
two groups of women (p = 0.413). There was also no significant
difference in the oxytocin dose in the two groups of women.
Mean duration between insertion of first dose of misoprostol and
delivery in women with pH < 5 was 928 ± 422 minutes while it was
943± 494 minutes in women with pH ≥ 5. (p = 0.839).
Mean duration to onset of contraction in the first group of
women was 446±259 minutes while it was 496±360 minutes in the
second group of women (p=0.532). Mean duration to cervical ripening
in the first group was 360 ± 220 minutes while it was 540 ±
301minutes in the other group. (p = 0.178)
Women with lower vaginal pH group had more of vaginal
delivery compared to those in the higher group. The high vaginal
group had higher proportion of women having caesarean delivery (p =
0.002). There were no significant differences in adverse outcomes in
the mothers and the neonates in the two groups of women.
Parity was a significant predictor for interval to onset of
contraction, cervical ripening and delivery.
Conclusion
There appears to be no significant difference in the interval to
onset of contractions, cervical ripening and delivery in the two pH
groups however the women with high vaginal pH tend to have higher
rates of caesarean section compared to women with lower vaginal pH.

EFFECT OF VAGINAL PH ON EFFECTIVENESS OF MISOPROSTOL FOR CERVICAL RIPENING