Introduction
Caesarean section is one of the most common surgical interventions in modern obstetrics. Caesarean section is almost certainly one of the oldest operations in surgery, with its origin lost in antiquity and ancient mythology.1 Originally performed only in interests of the mother, is now used quite freely in the interest of the foetus also. Caesarean section, an operation mainly evolved to save a maternal life during difficult childbirth has now increasingly become the procedure of choice in high-risk situations to prevent perinatal morbidity and mortality. Thus an operation initially utilised to save maternal life is today increasingly employed in the interests of the foetus also. The incidence of the caesarean section has doubled or tripled all over the world in the last 15 years. Justification for this trend is the lowering of maternal mortality almost to the point of nil and increasing foetal survival as compared to difficult vaginal deliveries.

Aims and Objectives

1. To compare the caesarean rate of 1981-82 with the rate in 2000-01.
2. To study the changing trends in indications for caesarean section of 1981-82 and 2000-01.

Material and Methods
In this study, 154 cases of caesarean sections done over a period of year 1981-82 were compared with 310 cases of caesarean section done over a period of year 2000-01, at the obstetric department in teaching Hospital Mumbai. Total no of deliveries during 1981-82 were 3033 and during 2000-01 were 2900.

Observation and Analysis

Incidence is statistically significant as p < 0.01. Incidence of caesarean section is 5.07% of total deliveries during the year 1981-82 and it is 10.60% of total deliveries during 2000-01. The incidence has increased by 5.53% and is significant statistically. In 1965, the caesarean delivery rate in the United States was 4.5%. In 1980, the caesarean delivery rate was 16.5%, and it peaked at 24.7% in 1988. Since then, the rate has decreased slightly and was 22.7% (949,000 procedures in 4.18 million births) in 1990.

The incidence of caesarean section is seen to increase in primigravidas as compared to multigravidas. This can be attributed to a greater incidence of caesarean section for: In coordinate uterine action, malpresentations like breech, minor to moderate CPD. In multigravida patients, the above factors are not commonly involved. Incidence of preeclampsia, eclampsia is more common in primigravida and this contributes to liberalization of indications for caesarean sections.

It is seen clearly from this Table that there has been a definite rise in the number of repeat caesarean sections. In a uterus with previous scar there is always a risk to the mother and child and also a risk of rupture of uterine scar in labour.

Menon reported that risk of scar rupture to be 1.8% for lower segment and 5.6% for classical section. It is this small risk of rupture of scar with subsequent maternal and foetal hazards warns us against a prolonged trial of labour.2 Therefore in present series more patients are submitted to repeat section to avoid the risk of scar rupture and subsequent perinatal loss. Incidence of rupture uterus was nil in present series. Patients with previous lower segment operation for a non recurring indication were given a controlled trial of labour, and at the earliest sign of failure to progress or foetal distress, they were taken up for surgery. Vigilant monitoring of foetal heart rate and uterine contraction was done through out labour (Table 4).

There has not been much of a change in the incidence among APH, malpresentation, cord prolapse, bad obstetric history. Patients with IUGR were subjected to caesarean section in present series when it was diagnosed that intrauterine environment was hostile to the foetus. Patients with severe preeclampsia with term pregnancy and who did not respond to medical line of treatment were submitted to caesarean section in the interest of mother as well as the foetus.

Changing Trends Observed
The incidence of caesarean section has increased from 5.07% during 1981-82 to 10.6% in 2000-01. The number of caesarean section is increasing as more attention is focussed on neonatal survival and prevention of trauma to the child during delivery. Limitation to the family size and expectation of a healthy child at the end of each pregnancy has lead to development of newer technologies in antepartum and intrapartum monitoring.3 In the present series use of USG, NST, intrapartum foetal monitoring has lead to increase in diagnosis of foetal distress. The same operation is becoming progressively safer to the mother and child due to better available procedures and antibiotics (Table 5) .

The rising incidence of caesarean section has been a global phenomenon.

Indications of caesarean section mainly seen were:

Foetal distress
In this study, foetal distress forms one of the leading indications in both the series. There has been an increase in the number of caesarean sections carried out for foetal distress in the present series 95 out of 310 i.e. 30.6 per cent as compared to 26 out of 155, i.e. 16.88 per cent in the past series. This increase is significant statistically. In most of the patients there are also an associated indication e.g., prolonged labour, previous caesarean section, cord accidents, cephalopelvic disproportion, etc.

Parameters used for diagnosis:

1. Clinical:
   1. Abnormalities in foetal heart rate i.e. foetal tachycardia or deceleration.
   2. Late deceleration on electronic monitoring.
2. Late deceleration on electronic monitoring.
3. Ultasonography: In present series apart from clinical parameters, uses of ultrasound and non-stress test have also been utilized in diagnosis.

In high-risk pregnancies, e.g., in cases of severe pre-eclampsia, bad obstetric history, non-stress test was carried out when patient was near term and ultrasonography examinations were done serially to detect foetal maturity. Colour Doppler showing severe foetal compromise, reverse of diastolic flow also was taken for sections. This has reflected in the perinatal mortality rate. There is a decrease in number of stillbirths in present series dramatically.

Introduction of uninterrupted foetal heart rate monitoring has resulted in an increase rate of caesarean section in many hospitals.5 At Women’s Centre, Winipeg, Incidence of caesarean section has increased from 8.2 per cent in 1978 to 20.4 per cent in 1979 and foetal distress has contributed significantly to this increase.

Repeat caesarean section
Incidence of repeat caesarean sections in present series in 80 out of 310 sections i.e. 25.80 per cent and in 1981-82 it was 28 out of 155 sections i.e., 18.10 per cent. The increase is statistically significant.Patients with previous two caesarean sections were not given trial of labour at all and were subjected to caesarean section when they were term. Out of 28 cases presenting as repeat caesarean section in 1981-82, five were of previous two caesareans as compared to 18 amongst 80 during 2000-01. Provided the first operation was carried out for a non-recurring cause and obstetrical situation near to term in the succeeding pregnancy is normal, a trial of labour is given to all the patients. Patients with an adequate pelvis, a known history of transverse lower uterine segment scar and normal vertex presentation were considered suitable for vaginal delivery. In patients with previous two caesarean sections an ultrasonographic examination was done to determine foetal maturity before taking them for elective caesarean section. In 17 yrs studied (1973-89) section rate has increased from 6.06% to 11.97%. Here however the mean repeat caesarean section incidence is 38.13%. The increase in caesarean section is caused mainly by an increase in primary sections. (University College of Galeway).

Trial of labour after a lower segment caesarean section should be given in an institution where it is possible to change over from vaginal delivery to caesarean section within a very short time. The obstetrician must stay with the patient through out the labour and constant monitoring of foetal heart rate is obligatory. Good uterine action, early engagement of the vertex, progressive dilatation and effacement of cervix with descent of the head were taken as factors indicating successful vaginal delivery. At the earliest sign of foetal distress if conditions for vaginal delivery are not satisfied, labour should be terminated by caesarean section. Vaginal bleeding even though small may be indicating of commencing rupture.⁶

Breech presentation
Incidence of breech presentation as an indication for caesarean section has increased from 9 out of 155 in 1981-82 to 30 out of 310 in 2000-01. This has contributed significantly as in the main factors responsible for the increase in caesarean sections during last 10 yrs.

Flanagan and co-workers (1987) selected 244 women with a variety of breech presentation (72% were frank breech) for a trial of labour, and there was a cord prolapse in 45, foetal distress not due to cord prolapse was diagnosed in another 5% selected for vaginal deliveries.7 Overall 10% of women identified for vaginal birth underwent caesarean section for foetal jeopardy. Apgar scores, especially at 1 min, for vaginally delivered breech infants are generously lower than when elective caesarean section is performed.

Primigravida presenting with breech: During 1981-82 all the primigravida presenting with breech were given vaginal delivery if there were no other associated factors e.g., contracted pelvis, footling breech, large baby, etc. Whereas in present series all the primigravidas with breech were subjected to caesarean section. These patients were submitted to an ultrasonographic examination prior to surgery to rule out any congenital malformation. In multi parous patients presenting with breech a decision to perform caesarean was taken after estimating the breech score suggested by Zatuchini and Andros. There is statistical evidence to the effect that scores of three or less are associated with high incidence of foetal morbidity and prolonged labour is frequent. It is subjected that a score of three or less is an indication for caesarean section. Cheng and Hannah (1993) found a three to four fold significantly higher perinatal mortality rate and neonatal morbidity due to trauma in planned vaginally delivered infants.8 Other risk factors, which were taken into account, were: Elderly primigravida, precious baby, infertility conception, and post term toxaemia of pregnancy.

The current trend is to employ caesarean section more frequently especially in primipara, as it is only by this method the obstetrician can avoid the risks of cord compression, cord prolapse, birth trauma and asphyxia which accounts so heavily for perinatal morbidity and mortality in breech.

In Galeway study patient who had a primary caesarean section for breech presentation 93.4% were delivered following a trial however in patients having breech presentation with previous caesarean section scar, the consensus is that they should have repeat caesarean section.

Cephalopelvic disproportion
Incidence of cephalopelvic disproportion in present series is 8 per cent whereas it was 17.53 per cent during 1981-82. At the Government Hospital for women and children, Madras, during 1954-1961 the incidence of caesarean section for cephalopelvic disproportion was 33.2%, whereas during 1978-79 it was 14.3%. In our study patients with gross degree of disproportion were taken up for caesarean section without a trial of labour but such cases were few. In this series, patients with borderline disproportion were given a trial of labour with continuous intrapartum monitoring. Patients who failed to show progress in labour in spite of good contractions and those who developed foetal distress during labour were subjected to caesarean section.

Meier and Forrew (1982) studied 230 trials of labour and found that, of 107 patients who had primary section was for cephalopelvic disproportion, 67.3% were delivered vaginally and in 31% of which two baby was larger than the one had by caesarean section.

Prolonged labour (uterine dysfunction)
Prolonged labour complicated 12 out of 155 during 1981-82 and 43 cases out of 310 in 2000-01. There is not much change in trend as far as this indication is concerned. This group includes following cases e.g. failure to progress in labour, malposition of foetal head, mild degree of foetopelvic disproportion, prolonged rupture of membranes and incoordinate uterine activity, maternal distress.

Malpresentation
Incidence of malpresentation was 14.9% during 1981-82 and 4% in 2000-01. Out of all malpresentation transverse lie is the commonest.

Eastman lists three common causes for transverse lie:

1. Abnormal relaxation of abdominal wall, resulting from high parity.
2. Pelvic contraction
3. Placenta previa.

Brow presentation is due to any factor, which promotes extension or prevents flexion of foetal head.⁹

Multiple Gestations
During 1981-82 one patient with twin pregnancy was submitted to caesarean section while in 2000-01, 3 patients were submitted to section. It is observed that the apgar score of second twin born vaginally is always significantly lower than that of first. Whereas in caesarean section apgar of both the babies are the same. Twin pregnancy with associated risk factors should be subjected for operative delivery.

Antepartum haemorrhage
In this study 18 cases of 155 during 1981-82 and 14 cases out of 310 in present series had antepartum haemorrhage. Majority of these patients had various degrees of placenta previa. Caesarean section is a better approach from the point of prognosis of infant in these patients (Table 6).

Summary

1. 155 cases of caesarean section performed over a period of one year 1981-82 were studied. Total no of deliveries during that period were 3033. Incidence of caesarean section was 5.07%. These were compared with caesarean sections performed during 2000-01, where there were 310 caesarean sections out of 2900 deliveries. Incidence in this series was found to be 10.6%. The increase in the incidence from 5.07% to 10.6% was found significant statistically as p less than 0.01.
2. Maximum patients were found in the age group 21-25 yrs
3. Most of the patients were primiparas and second paras. Incidence of caesarean sections was seen increasing in primgravida.
4. All patients had undergone lower segment caesarean section.
5. 18% of patients in the past series underwent repeat caesarean section as compared to 25.8% in the present series, and as the p value is less than 0.005 it is statistically significant.
6. Following were the main indications contributing to the rise in the incidence of caesarean section: a) Breech presentation, b) Repeat caesarean section, c) Foetal distress.

References

1. Arora R, Oamaguichi A. J Obst and Gyn of India 1991; 41 : 192.
2. Menon MKK. J Obstet and Gynaec India 1963; 7 : 35.
3. Studd J. Implications of increasing rates of caesarean section. Progress in Obstet and Gynaec., Vol. 6 : 1990.
4. Patwardhan M, Oka M, Mahajan MJ. Obstetrics and Gynaec India 1990; 40 : 210.
5. Shy KK, Luthy DA, Bennett FC, et al. Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurological development of premature infants. N Engl J Med 1990; 322 (9) : 588-93.
6. Tahilramaney MP, Boucher M, Eglinton GS, et al. Previous cesarean section and trial of labor. Factors related to uterine dehiscence. J Reprod Med 1984; 29 (1) : 17-21.
7. Cunningham FG, MacDonald PC, Gant NF (eds). Williams obstetrics. 19th ed. Norwalk, Conn: Appleton and Lange; 1993.
8. Cheng M, Hannah M. Breech delivery at term: a critical review of the literature. Obstet Gynaecol 1993; 82 : 605-18.
9. Sharma U, Acharya U, Saxena S, Mittal G. Foetal outcome in lower segment caesarean section, Journal of Obstet and Gynaecol India 1980; 30 : 69-75.

*Senior Resident; **Professor and Head of Department; BYL Nair Hospital, Mumbai Central, Mumbai.