Study of Post TL Failure Interval

Objective : To assess the institutional Tubal ligation (TL) failure rate and study the pattern of post TL failure interval according to age of woman at TL, type and method, the aetiological events of failure.

Material and Methods : A prospective observational analysis was done on 57 cases of TL failure reporting to our institute over a study period of 5 years from Jan 98 to Dec 2002. The post TL failure interval was graded as early, intermediate and late and were analysed with respect to age of the subject at TL, type (interval/pregnancy related) and method (laparoscopic/minilaparotomy) and the aetiological event seen on repeat TL procedure.

Results : The Institutional failure rate of 3.74 corresponds to the global failure rate of 4/1000 procedures. 65% cases were referrals. A gradual decline was seen over the years. Maximum failure occurs in 26-30 years and para III. Intermediate (i.e. 1-5 years) was the commonest interval followed by late and then early.
Early and late intervals are group specific for age at TLs i.e. 26-30 years and 20-25 years respectively. Pregnancy related TLs failed 2.3 times than the interval TLs. Lap TLs failed early than minilap TLs. No specific pattern of influence noted due to aetiological events of failure on the post TL failure interval.

Conclusion : Age at TL, method and type of TL procedure exhibited a specific pattern of influence on the type of post TL failure interval.

Introduction

Tubal sterilization failure causing a pregnancy may not reflect early and easily usually, as the history of a sterilization procedure is quite blindfolding. Tubal sterilization has a global failure rate of 4/1000 procedures. Pregnancies are known to occur on account of failure of the TL even several years later. This attempted us to study the pattern of the post TL failure interval in the present series.

Aims and Objectives

To study

1. The tubal sterilization failure rate at LTMGH.

2. The commonest type of post TL failure interval.

3. The post TL failure intervals in terms of age at TL, type and method of TL procedure and the aetiological events of failure.

Material and Methods

A prospective observational study was done on 57 consecutive cases of tubal ligation failure cases reporting to our Institution, Lokmanya Tilak Municipal General Hospital and Lokmaya Tilak Municipal Medical College, a major tertiary referral care, 1416 bedded, multispeciality hospital in Mumbai, over a period of 5 years from Jan 98 to Dec. 2002. The parameter for the sterilization failure was taken as a pregnancy event. The inclusion criteria was a pregnancy event reporting to our institute with the tubal ligation procedure performed in the past either at our own institute or any other setup. A registry record of TL failure cases was maintained to document the data. The post TL failure interval was taken as the time elapsed since the TL procedure and the failure event of pregnancy dated to the last menstrual period. This interval was graded as follows:

1. Early = less than one year

2. Intermediate = equal to or more than 1 year

3. Late = more than five years.

These three intervals were analysed with respect to the subject’s age at time of TL procedure, type of the TL (i.e. interval or pregnancy event related), method of the TL (i.e. laparoscopic or minilaparotomy) and aetiology of the failure event.

Results and Discussion

Failure Rate

Total in-house TL procedures = 5337

Total no of TL failure cases = 57

Number of referral cases = 37

Number of institutional cases = 20

Institutional failure rate = 3.74/1000

procedures

The institutional failure rate of 3.74 corresponds to the global failure rate of 4/1000 procedures.1 65% of our cases were referral cases, as our institution is a major tertiary level care centre in Mumbai. The sources of the cases showed 64.92% were from the urban setups where 50.87% came from the public sector and 14.05% from the private sector. We had 35.08% from the rural areas where 29.82% came from the public and 5.26% from the private sectors.

Distribution of Cases

1. Year wise

Table 1 shows the chronology of cases yearwise that shows a gradual decline in in-house failure rate from year 1998 to 2002 except in the year 2000. In 2000, the number of failures, both referral and in-house and the total number of TL procedures performed in-house were maximum reflecting on the 5.28 failure rate. Also overall referral cases doubled the in-house ones.

2. Age and Paritywise

Table 2 depicts the age and paritywise distribution of cases showing 77% cases were from the 26-35 years age group, whilst 23% belonged to the less than 25 and more than 35 age groups. In our series 43.85% women underwent TL before 25 years of age, equating to 44% reported by the NFHS - 2 survey of 1998. 87.7% women underwent TL by the age of 30 years in comparison to 79 documented by NFHS - 2 study.²

Paritywise, in the present study, the third paras were at maximum risk of failures.

3. Post TL failure interval

Majority of the cases failed after intermediate interval (80.7%) followed by the late (10.52%) and then the early interval (8.77%) in our series.

A) Age at TL

Table 3 shows the correlation of the 3 intervals with the subject’s age at the time of the TL procedure. 84.4% of the failures occur in the 21-30 years groups, this being the age of maximum sexual activeness and high fertility potential for failure. 12.3% failures occurred in more than 31 years age at TL. The 20-25 years age group of 26-30 years have a shift from intermediate to the early intervals. The early and late intervals exhibited to be age group specific belonging to 26-30 years and 20-25 years of groups respectively. The intermediate interval is the least in the 20-25 years group.

B) Type and Method of TL

The pregnancy related performed TL procedures failed 2.3 times than the interval type of TL (refer Table 4). 80% of both these types of TL failed in the intermediate interval of 1-5 years. In the interval (non pregnancy related) type of TL, 12.5% fail in the early interval period whilst 6.25% fail in the late. This is exactly reversed in the pregnancy related type of TL where 12.19% failed late and 7.3% early. Lactational amenorrhoea that delays the fertility potential to return may be the contributory factor preventing early intervals in the pregnancy related type of TLs in the Indian scenario where lactation does continue upto 1 year.

Amongst the pregnancy related type of TL failures, the puerperal and medical termination of pregnancy (MTP) cases dominated the caesarean and abortal ones. The MTP-TL failures, the puerperal and MTP cases dominated the caesarean and abortal ones. The MTP - TL failures doubled the caesarean ones however the intermediate interval was same in both the groups. Puerperal and caesarean have more late than early and post MTP - TLs have more early than late intervals. Our series also supports the Shepherd (1974), Husbands and Pritchards (1970) findings that caesarean tubal ligations don’t find the highest failure rates.³

Electrocoagulation method is reported to be the commonest method of failure of TL but our series did not have any case done by this method. 33.4% of cases were laparoscopic TLs performed with silastic bands and 66.6% minilaparotomy TLs (all modified Pomeroy’s method except for 1 of Madlener’s method). 80% cases failed in intermediate interval in both method groups. Lap TLs failed 15.78% early and 5.26% late however minilap failed late (13.15%) more than early (5.26%).

C) Aetiological events

Table 5 reflects 3.5% failures occurred, as existing pregnant state was not detected during the TL procedure. Our series had 1 case where amenorrhoea was not ascertained and the other case where an MTP was performed in a cornual ectopic gestation. To minimise this, we recommend timing the TL procedure in the follicular phase of the menstrual cycle. Lichter and Coworkers (1986) reported that reliance on dilatation and curettage during the TL is less effective.⁴ Hence a urine pregnancy test or ELISA should be done on the day of the TL procedure. In case of negative evacuation noted when the urine pregnancy test (UPT) is positive, it is mandatory to inspect the tubes and the uterine fundus to rule out the possibility of an early ectopic gestation.

Intermediate interval occurs in majority of all the causes. Slipped band has caused a pregnancy after a period of 14 years in our series. Surprisingly Human errata in identification of the structure ligated (i.e. round ligament instead of the tubes) failed in the intermediate interval in both cases. Improper loop and recanalisations also had maximal intermediate intervals. These technical imperfections failed more early 6.1% than late 4.07% and this group contributed to nearly half of all the cases. Seven cases refused a repeat surgical intervention opting for oral contraceptive (OC) pills or intrauterine contraceptive device (IUCD) and hence the cause remained unknown to us; whilst 7.01% cases were idiopathic and all failed in the intermediate interval. The intervals did not have any specific pattern of influence due to the aetiological events.

Summary

* The TL failure rate is 3.74/1000 procedures.

* 65% cases were referral Vs 35% in-house failures.

* Gradual decline is noted in failure rate except in the year 2000.

* Majority of failures occur in 26-30 year age group and with parity 3.

* Intermediate is the most common interval seen.

* Early and late intervals are group specific for the age at TL.

* Pregnancy related TL failures are 2.3 times the interval TL failures and occur more as late than early intervals.

* Caesarean TLs are not the maximum type of sterilization failures.

* Aetiological factors did not exhibit any specific pattern of influence on the TL interval.

Conclusion

Sterilization failure rate was 3.74/1000 procedure. The age at TL, method and type of procedure exhibit a specific pattern of influence on the type of failure interval. Intermediate being the commonest of all the 3 intervals.

The present series invites to throw more light using a larger database on the correlation of factors on the post TL failure interval.

Acknowledgements

We thank our dean Dr. ME Yeolekar to permit the use of our hospital data for publication, the LTMGH post partum programme under which the study was done, and Mr. Toraskar accountant and storekeeper (post partum programme) who maintained the data registry.

References

1. Peterson Herbert, et al. Tubal sterilization - Telinde’s operative gynaecology 8th ed, Lippincott Raven Philadelphia, 1997;544.

2. Timing of sterilization, chapter 5 family planning, National Family Health Survey - II. International Institute for population sciences. 1998-99; 146-47.

3. Chaudhary SK, Motashaw ND. Female sterilization - open surgical methods. A comprehensive textbook of practice of fertility control, 3rd ed. BJ Churchill Livingstone 1992;168.

4. Lichter ED, Laft SP, et al. Value of routine dilatation and curettage at the time of interval sterilizations. Obstet Gynecol 1986; 67 : 763.

5. Chaudhary SK. Female sterilization - open surgical methods, A comprehensive textbook of practice of fertility control, 5th ed. BJ Churchill Livingstone 2001;184.

6. Lipscomb GH, Spellman JR, Ling FW. The effect of same day pregnancy testing on the incidence of luteal phase pregnancy. Obstet Gynecol 1993; 82 : 411.

NORMAL LEVELS OF AMINOTRANSFERASE DON'T RULE OUT LIVER DISEASE

High normal levels of serum aminotransferase concentration may be a warning of liver disease. Kim and colleagues followed up more than 142 000 people in Korea for eight years. Even within the normal range of aminotransferase concentration (35-40 IU/L), men with concentrations of 30-39 IU/L had a significantly higher risk of dying from liver disease than people with concentrations < 20 IU/L. People with high normal aminotransferase activity may need to be observed and further investigated for liver disease, say the authors, and normal limits may need to be lowered in some populations.

BMJ, 2004; 328 : 983.