The ripeness of the uterine cervix

The process of softening, shortening and partial dilation of the cervix usually takes place in the days or weeks prior to the onset of labour, but the timing of this process is variable. An unfavourable or 'unripe' cervix is one which has undergone minimal change and is more resistant to attempts at induction of labour. In the first trimester,

Table 23.1 Modified 'Bishop' cervical score

Score

0

1

2

3

Cervical dilation

0

1-2

3-4

5+

(cm)

Cervical length

3

2

1

<1

(cm)

Station of the

-3

-2

-1,0

+1

presenting part or

more

Consistency

Firm

Moderate

Soft

Position

Posterior

Midposition

Anterior

50% of the dry weight of the cervix is tightly aligned collagen, 20% smooth muscle and the rest is ground substance composed of elastin and glycosaminoglycans (Chondroitin, dermatan sulphate and hyaluronidase) [3]. During pregnancy, hyaluronidase increases from 6 to 33%, whereas dermatan and chondroitin, which bind collagen more tightly, decrease. Collagenase and elastase enzymes increase, as do the vascularity and water content.

A standardized method of semiquantitative clinical scoring of the cervix was described by Bishop in 1964 [4], and has since been modified (see Table 23.1). A score of 6 or more predicts the likelihood of successful induction of labour. A score of 5 or less is regarded as being unfavourable for induction of labour, and use of artificial rupture of the amniotic sac and/or oxytocin infusion are unlikely to be successful. More recently, measurement of fibronectin in cervicovaginal secretions has been used to predict the imminence of labour, with variable success.

Was this article helpful?

0 0
Pregnancy Diet Plan

Pregnancy Diet Plan

The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.

Get My Free Ebook


Post a comment