Signs of Labour
During the last three weeks of pregnancy or previous to onset of labour certain changes take place which serve as useful means to determine the approach of labour (pre-labour).
This is the sinking of the uterus, and it takes place 2-3 weeks before term. It occurs as a result of softening of the pelvic bones, the symphysis public widens, the pelvic floor relaxes, softens and sags by as much as 4cm, therefore allowing the uterus to descend further into the true pelvis. The lower uterine segment stretches, and the fetus’ head sinks further down into the uterus.
This will cause the fundus to drop to a lower level and the uterus becomes more prominent.It leads to engagement of the head in primigravida with good, firm abdominal muscles provided there is no disproportion.
In multiparous women the uterus will sag further forwards and the abdomen becomes pedulous the head may not engage. Walking becomes more difficult and this may also give more to backache or pain in the region of symphysis pubis. Slight discomfort may be experienced in the lower abdomen, groins and thighs. Vaginal discharges also became more profuse at this time. The uterus presses against the bladder, causing more frequency. There is leg cramps & backache due to pressure on the sciatic nerve.
This is due to pressure of the fetal head on the bladder limiting its capacity therefore causing the woman to micturate more often. Sometimes there is mild stress incontinence as a result of laxed condition of the softened pelvic floor which gives rise to poor sphincter control- if the woman laughs, coughs or sneezes some urine may trickle out.
These are eratic, irregular uterine contractions making the uterus to contract without retraction. It is very common with the primigravida. The pain are true but not rhythmic in pattern usually short in duration and not increased in intensity. It is relived by walking. Pain is felt in the Abdomen alone.
Taking up of the cervix may start in the latter 2-3 weeks of pregnancy. Occurs as a result of changes in the solubility of collagen present in cervical tissue, this is aided by alteration in hormones activity particularly oestradiol, progesterone, relaxin, prolactin and prostaglandin. Braxton Hicks contractions which become more stronger also enhance the process. In primigravidae, effacement of the cervix precedes dilatation, but in multigravidae the two occur simultaneously.
Contractions: contraction of the uterus in labour bringsabout effacement, dilatation of the dexart of expulsion of the fetus in labour when the true labour is established the contractions are strong, rhythmic, regular and are felt by the woman as tightening discomfort or actual pains and occurs at 10 minutes internals. At this period the uterus feels hard to touch. At the beginning of labour the contractions are painless, weak lasting 15-30sec duration and infrequent occurring 10-20minutes interval. The pain gradually increases in intensity that is they become stronger, more frequent in duration. In the second stage they occur 5:10min duration, it is intensified with walking and lasting about 40-60sec or more.
Dilatation of the cervical OS: This is the widening of theexternal OS from a tiny circular opening to one sufficiently large enough to permit the passage of the fetal head. It is a gradual process. Progressive dilatation of the cervix is a definite sign of labour.
Show: This is the release of a blood stained mucoiddischarge as the cervix dilates. It is from the operculum, which is the plug of mucus guarding the cervical canal during pregnancy. The blood is from the detached chorion from the wall of the lower uterine segment as it stretches. It can be seen before labour or few hours after labour has started. It follows cervical dilatation.
Rupture of Membranes: This may not be a true sign oflabour as the membranes can rupture days or hours before labour and sometime membranes may not rupture till the end of 1st stage of labour. To confirm if the fluid is urine or Amniotic fluids test with Nitrazine swab which will change from orange to navy blue if it is amniotic fluid. Membranes are thought to rupture as a result of increased production of prostaglandin E2 in the amnion during labour, and force of uterine contractions causing increase in the fluid pressure of the fore waters and lessen of support as the cervix dilates.