INTRODUCTION

India is the first country to launch National Family Planning Programme in 1952, that aimed at fertility regulation for decreasing the birth rates so as to stabilize the population at a certain level that would upgrade socioeconomic and health profiles.¹ Female sterilization is the permanent method of contraception. It is most popular, highly effective, relatively safe, and the most commonly accepted method among eligible Indian couples. Annually, over 4.1 million female sterilization procedures are done in India Health Management Information Systems (HMIS) 2013–2014. Emergence of National Health Mission of Government of India and increase in numbers of institutional deliveries have increased the scope for postpartum sterilization (PPS).² The two common surgical techniques for female sterilization are minilaparotomy and laparoscopic tubal occlusion.

Though permanent, these methods carry a small risk of failure and occurrence of pregnancy; according to Indian data it is less than 1 pregnancy per 100 women (5/1,000) over first year after sterilization and over 10 years it is approximately 2 pregnancies per 100 women (18–19/1,000).² US collaborative Review of Sterilization (CREST study 1996) reported that cumulative 10 years probabilities of failure were highest for spring clips and lowest for postpartum minilaparotomies. Relative risk for failure for postpartum partial salpingectomy was 1.0 and for silicon rubber band application (Falope ring) was 2.3.³

Failures may be due to variation in characterstics of women, operator's skills, operating center, sterilization method, tubal abnormalities, surgical errors (occlusion or ligature of round ligament or only one side of tube), and spontaneous recannalization that leads to partial or complete tubal patency. Whatever may be the reason for sterilization failures, it causes drastic physical, psycological, and socioeconomic burden on the woman and her family and also technical and economic burden on the institution. So frequent audits are very important.

We conducted a retrospective data analysis of failures reported between October 2011 and September 2016 at our institution.

AIM

The aim of the article was to study the changing trends of female sterilization failures reported during past 5 years (October 2011–September 2016), their etiological factors, and outcome of pregnancies resulting due to failure at a tertiary care teaching hospital.

MATERIALS AND METHODS

A retrospective cross-sectional study was conducted that included all women who had reported sterilization failure in the family planning unit of the Department of Obstetrics and Gynaecology in our institution during a 5-year span from October 2011 to September 2016. Data were collected from case records maintained in the Family Planning Unit and Medical Record Department. Prior ethical clearance was taken from the institution ethical committee of our institution. Information regarding age, obstetric and medical history, type and place of sterilization, sterilization failure interval, period of gestation at the time of diagnosis, method of diagnosis, site of pregnancy, further management of current pregnancy, and contraception were documented.

RESULTS

Total number of sterilizations performed in last 5 years was 6,064. There was a slight decline in the number of sterilizations from 1,399 in 2011–2012 to 1,107 in 2015–2016. Laparoscopic ligations have decreased from 42.7 to 34.1% and postpartum partial salpingectomies have increased from 46 to 55.6% over the last 5 years (Graph 1). Total number of sterilization failures reported was 68. Failure rate was 0.9% in 2011–2012, that had increased to 1.7% in 2013–2014 and thereafter decreased to 0.7% in the current year (Table 1).

A total of 58.8% women belonged to 26 to 30 years of age, 47 (69%) were below 30 years, and oldest women reported was 42 years. Thirty-nine (57.3%) women already had three children and three (4.4%) women had four living children at the time of failure. Thirteen (19%) women presented in second trimester and among them four (5.9%) were beyond upper limit of medical termination of pregnancy (MTP); 3 (4.4%) women presented with ectopic gestation, out of which one woman had unruptured ectopic pregnancy who had undergone sterilization concurrent with lower segment cesarean section (LSCS) 8 years back and 2 women presented with ruptured ectopic gestation (one woman underwent interval lap ligation 9 years back and other had concurrent with LSCS 3 years ago) (Table 2).

Laparoscopic ligation failures occurred in 50 (74%) women and nonlaparoscopic sterilization failures were 18 (26.4%) (Graph 2).

Graph 1:

Sterilizations done in 5 years

Graph 2:

Method of previous sterilization

Total number of sterilizations performed by the consultants in last 5 years was 742, by senior resident 2,545, and junior resident 2,777. Out of this, failures by consultants were 5 (0.6%), senior resident 29 (1.13%), and junior resident 35 (1.2%) (Table 3).

Sterilization failure interval in 27 (40%) women was within 1 year, out of which 4 (5.9%) occurred within 6 months, 2.9% failures occurred after 10 years. Longest interval reported was at 19 years (Table 4).

Thirty-four women (50%) underwent MTP with minilap for the current pregnancy, 14 (20.6%) women continued the pregnancy, and 5 (7.3%) were lost to follow-up (Table 5).

Etiology of failure was divided into improper and proper techniques based on previous intraoperative records, resterilization intraoperative findings, and histopathological examination of the tubes (Table 6). Out of total 68 failures, etiology could be determined in 43 women and in 25 women it was not possible either due to lack of previous sterilization records or because they opted for copper T, vasectomy, or were lost to follow-up. Thirty-four women underwent improper techniques, which included 27 women undergoing faulty laparoscopic ligation (Table 7), and 4 tubectomies performed concurrent with repeat LSCS were suboptimal as evident by intraoperative records (Table 8).

DISCUSSION

Chances of failures are more in younger groups due to high fecundity. Peterson et al³ observed that 62% women reporting with failures were less than 28 years old and another study also quoted that 65% were below 30 years.⁴ In our study, 69% women were below 30 years.

Date et al⁴ reported that 24.29% women presented after 20 weeks gestation and continued pregnancy, 5.71% underwent LSCS. Our study showed 5.9% presented after 20 weeks and 20.6% continued pregnancies.

If pregnancy occurs after failed sterilization particularly beyond 2 years, then ectopic gestation should always be ruled out because early failures have less damaged tube compared with late failures, which occurs due to spontaneous recanalization or tuboperitoneal fistula formation. Recanalization occurs along with formation of blind pouches and slit-like spaces where sperm can pass through, but fertilized ovum gets trapped and this causes ectopic gestation.⁵ Tuboperitoneal fistula is associated with focal endometriosis, which is considered as a point of implantation.⁶

Date et al⁴ found that 4.6% ectopic occurs within 1 year and 7.5% occurs between 1 and 5 years, Bhatnagar⁷ reported that the rate of ectopic following tubectomy is 5.3%, which suggests that the relative risk is 4–16 times higher than general population. Our study found overall 4.4% of occurrence of ectopic and none within 1 year; after 5 years it was 2.9%.

Peterson et al³ found 64% failures, and Varma and Gupta⁸ found 71% failures were due to laparoscopic sterilization. Date et al⁴ found 59% failures were due to minilap; however, no significant difference between the methods was found by Kulier et al.⁹ Our study found 74% laparoscopic failures.

Shah et al¹⁰ found that 92.3% ectopic pregnancies were due to previous sterilization done with pregnancy events like MTP, puerperium, postpartum, etc., and stated that this may be associated with increased risk of failure compared with interval sterilization, because tubes are edematous and congested which may lead to incomplete occlusion by Falope ring (which has inner diameter of 1 mm and outer diameter 2 mm and is inadequate for pregnant tube). This may be overcome by milking tube by drawing it in and out of applicator sheath several times and observing blanching of loop to ensure complete occlusion. Present study found 32.3% failures had undergone sterilization concurrent with pregnancy events.

Varma and Gupta⁸ classified sterilization failure based on time interval as negligent (failure within 9 months) and non-negligent, and they found 67.1% were negligent and 32.8% were non-negligent failures. They also observed that Filshie clips and rings were predominant methods in negligent failures (71%) as they fail earlier due to nonocclusion or wrong structure compared with diathermy and Pomeroys.⁹ Present study found that 79% were due to improper technique and most of them presented earlier and underwent Falope ring.

CONCLUSION

Female sterilization failure can occur at any age, interval, and by any method. It causes drastic socioeconomic and psychological burden on the woman and her family. Failures can be minimized by strictly adhering to standard guidelines (Reference Manual for female sterilization 2014, Ministry of Health and Family Welfare Government of India). Ligations should be performed or supervised by experienced surgeons, and concurrent with pregnancy events must be avoided and proceeded to laparotomy if conditions like adhesions obscuring the visualization of entire tube or tubes are transected and are not suitable during laparoscopy. Since luteal pregnancy rate was 4.4%, contraception in prior cycle should be advised or urine pregnancy test must be done on the day of sterilization. There should be proper documentation and counseling of sterilized women regarding chances of failure and reporting within 2 weeks of missed menses.