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Contents: Original Research

Examining the Association of Obesity With Postpartum Tubal Ligation

Byrne, John J. MD, MPH; Smith, Emma M. MD, MPH; Saucedo, Alexander M. MD; Doody, Kaitlin A. MD; Holcomb, Denisse S. MD; Spong, Catherine Y. MD

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doi: 10.1097/AOG.0000000000003935
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Unintended pregnancy remains a serious public health problem in the United States, which adds significant financial and logistical stress to families. These pregnancies are associated with multiple adverse maternal and fetal outcomes that disproportionately affect low income and minority women.1–3 Lack of access to effective family planning services is a critical risk factor for unplanned pregnancy.4 Although it is recommended that contraception be initiated within 6 weeks of delivery, postpartum visit attendance is reportedly as low as 49.4%, with only 48% of women receiving contraception at any time from delivery to 99 days postpartum.5 One option for women who have completed childbearing is tubal sterilization, which remains one of the most commonly used contraceptive method in the United States.6 In the states of Texas and California, postpartum tubal ligation rates have been identified to be as high as 10.2% and 6.7%, respectively.7 Offering this procedure during hospitalization for delivery makes it available to women who face obstacles to follow-up care.

When the procedure is performed in the postpartum period, it routinely consists of a bilateral midsegment partial salpingectomy obtained using mini-laparotomy. This is considered to be a permanent method of birth control, estimated to be more than 99% effective.8 Furthermore, findings from the U.S. Collaborative Review of Sterilization revealed the cumulative 10-year risk of pregnancy after postpartum partial salpingectomy was 7.5 per 1,000 procedures, and risk of ectopic pregnancy was 1.5 per 1,000 procedures.8,9 The risks of this procedure include those of any surgery such as anesthetic complications, surgical site infections, bleeding, bowel injury and vascular injury, as well as the risk of ectopic pregnancy. Interestingly, approximately 50% women who intend immediate postpartum tubal ligation do not receive the procedure.10–12 A variety of reasons have been identified, with body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) being a primary risk factor. In a prospective study by Flink-Bochacki and colleagues, women with BMIs of 40 or higher were 3.71 times more likely to not undergo a tubal ligation than those with normal-weight BMIs.13 This may be the result of a perception of increased risk of surgical complications, longer operative time, or difficulty in successful completion of the procedure.14

Although operative complications in the obese population have been identified to be higher in general from the surgical literature,15 there are currently no studies examining the risks of postpartum tubal ligation, the rates of procedure completion, complications, and subsequent pregnancy among obese women. We hypothesized that the risk of complication rises with increasing BMI. We aimed to identify the effect of BMI on postpartum tubal ligation safety and estimate the rates of procedure complication.

METHODS

Women who received obstetric care at Parkland Hospital and underwent a postpartum tubal ligation after vaginal delivery from August 2015 and March 2019 were studied in a single-institution, retrospective review. Parkland Hospital is operated by the Dallas County Hospital District and serves as a safety net hospital for Dallas County, Texas. Of the women who deliver at Parkland Hospital, 94% have received prenatal care at an affiliated clinic.16

Patients were identified from the electronic labor and delivery surgery scheduler, which was established in August 2015. Inclusion criteria were women who underwent a postpartum tubal ligation after a vaginal delivery between August 2015 and March 2019. Exclusion criteria were women who underwent planned additional surgery at the time of postpartum tubal ligation—for example ovarian cyst removal or hernia repair. As part of standard prenatal care offered within the Parkland Hospital and Health System, all patients receive information regarding postpartum contraception options, and preferences are recorded in their medical record. Patients who express an interest in postpartum tubal ligation are identified during their prenatal care and complete both hospital and federal consent forms. Most tubal ligations are performed on postpartum day 1, and all patients scheduled for the procedure are assessed by a physician before surgery.

Tubal ligations are routinely performed by resident physicians using the Parkland-type tubal ligation, which is a bilateral midsegment partial salpingectomy through a 2–3 cm infra-umbilical incision.17 Data were extracted by all co-investigators. To ensure accuracy of the information, a convenience sample of approximately one-third of the original extraction underwent a second review of the extraction performed by selected authors (J.J.B., D.S.H., C.Y.S.). Morbidity events were then re-reviewed by investigators (J.J.B., C.Y.S.) to confirm the accuracy. Additionally, incomplete transection was also confirmed through review of the weekly reports by the pathology department.

The primary outcome was defined as a composite morbidity, which included blood transfusion, aborted procedure, intraoperative complications (bleeding requiring additional surgery, extension of incision), anesthetic complication (high spinal, bronchospasm, postdural puncture headaches requiring blood patch, and allergic reaction to anesthetic), postoperative complication (deep wound infection, venous thromboembolism, ileus, small bowel obstruction, acute intestinal herniation, peritonitis), return to operating room, incomplete transection of fallopian tube, and subsequent pregnancy. If any individual had more than one event, this was counted as only one event for the composite morbidity. For example, if one individual had a deep wound infection requiring return to the operating room, this was counted as one event for the composite morbidity.

We compared demographic characteristics, complications, and reproductive outcomes across maternal BMI categories. Maternal BMI was stratified as follows: underweight or normal weight (BMI 24.9 or lower), overweight (25–29.9), class I obesity (30–34.9), class II obesity (35–39.9), and class III obesity (40 or higher). Body mass index was derived from height obtained at the first prenatal visit or hospital encounter and weight obtained on admission to labor and delivery. If weight on admission was not available, weight from the final clinical visit before delivery was used. Body mass index at time of delivery was chosen because it reflects maternal habitus at time of the procedure and accounts for weight gained during the pregnancy. Because there is no standard definition of obesity in pregnancy, definitions from the National Institutes of Health were used.18 Comparisons were made using t test, χ2, Wilcoxon rank-sum test, and analysis of covariance as appropriate. The study was approved by the Institutional Review Boards at the University of Texas Southwestern Medical Center and Parkland Hospital.

RESULTS

From August 2015 to March 2019, 3,670 women met inclusion criteria. Of these, 263 were underweight or normal weight (BMI 24.9 or lower), 1,044 were overweight (25–29.9), 1,371 had class I obesity (30–34.9), 689 had class II obesity (35–39.9), and 303 had class III obesity (40 or higher) at the time of admission (Fig. 1). Additionally, 11 patients were super-morbidly obese (50 or higher). The mean BMI in our study population was 32.2.

Fig. 1.
Fig. 1.:
Body mass index (BMI) distribution, composite morbidity, and history of prior abdominal surgery by BMI class. Morbid events occurred in 0.9–3.0% of patients and were not significantly different across BMI category. Prior abdominal surgery ranged from 13.7% to 20.8% across BMI category. 95% CI is displayed as the whiskers on the figure.Byrne. Association of Obesity With Postpartum Tubal Ligation. Obstet Gynecol 2020.

Maternal demographics and select clinical characteristics are shown in Table 1. The mean age at the time of the procedure was 32 years. Most women were Hispanic, and the majority had given birth at least three times (87.6%, including the delivery on admission). All women received a postpartum tubal ligation using the Parkland technique, with the exception of one who underwent ligation using the Filshie clip ligation owing to inability to safely complete the procedure. Prior abdominal surgery occurred in 16.7%, with the highest rates of prior abdominal surgery in those with class III obesity (Table 1 and Fig. 1). Neuraxial anesthesia was the most common anesthesia type used in the different BMI categories (Table 1).

Table 1.
Table 1.:
Maternal Demographic and Clinical Characteristics Across Body Mass Index Categories

Composite morbidity occurred in 49 (1.3%) women and was not significantly different across BMI categories (P=.07) (Fig. 1 and Table 2). The morbidity components are outlined in Table 3. There were 11 individuals who had multiple events (two events occurred in 10 women; three events occurred in one woman). There were no deaths or complications leading to death among the patients who underwent tubal ligation. There were also no morbidity events in women in the super-morbid obese category (n=11).

Table 2.
Table 2.:
Primary Composite Outcome and Breakdown of Morbidity Events Across Body Mass Index Categories
Table 3.
Table 3.:
Morbidity Events Associated With Postpartum Tubal Ligation

To further address the question related to obesity, nonobese and obese patients were compared (Table 4). There were 19 (1.5%) composite morbidity events in the nonobese cohort and 30 (1.3%) compositive morbidity events in the obese cohort.

Table 4.
Table 4.:
Comparing Primary Composite Outcome Between Nonobese and Obese Women Who Underwent Postpartum Tubal Ligation

Six subsequent pregnancies were identified: three full-term pregnancies, two ectopic pregnancies, and one pregnancy of unknown location. Of the women who became pregnant after their tubal ligation, all fallopian tubes had been confirmed to be completely transected on pathologic evaluation. Therefore, the pregnancy rate was 1.63 (95% CI 0.6–3.6) per 1,000 procedures performed during the follow up period of 1–5 years. Additionally, there were 12 patients who had fallopian tubes that were incompletely transected on pathologic evaluation. There were no pregnancies in this group.

The mean estimated blood loss was approximately 10.2 mL in all BMI categories (10 in normal-weight BMI and up to 10.2 in class III obesity), which was statistically different (P<.001). A sequential increase in operative time was noted across BMI cohorts, from a median of 23 minutes for women of normal weight to 31 minutes in with class III obesity (Fig. 2, P<.001). In the analysis of length of surgery and BMI, we adjusted for the presence of history of abdominal surgery, revealing a P=.09. Additionally, mean length of stay after tubal ligation was 1.2 days in all BMI categories (1.3 in normal-weight BMI and up to 1.3 in class III obesity).

Fig. 2.
Fig. 2.:
A sequential increase in operative times was noted as body mass index (BMI) increased (P<.001). Further reviewing the relationship between length of surgery in minutes and BMI (kg/m2), we adjusted for the presence of a history of abdominal surgery using analysis of covariance, with presence of a history of abdominal surgery as the two-level covariate (yes or no) revealing P=.09. The scatterplots of the association are stratified by presence of a history of abdominal surgery. The solid lines represent the mean estimate, and the dotted lines represent the 95% CI.Byrne. Association of Obesity With Postpartum Tubal Ligation. Obstet Gynecol 2020.

DISCUSSION

Our study underscores the overall safety of postpartum tubal ligation among overweight and obese women and allows us to make several observations that can better guide contraceptive counseling in this patient population. We found a low rate of surgical complication (composite morbidity of 1.3%) with no significant difference across BMI categories. Even among women who had undergone prior abdominal surgery, there was no association of BMI with the rate of procedural complication. Although there was variability in operative time in all BMI categories, this is likely not clinically relevant as the range in operative time overlapped across groups (Fig. 2). Other surgical metrics, such as estimated blood loss and length of hospitalization after tubal ligation, were found to be no different between BMI categories.

Although previous studies have identified BMI higher than 40 as a significant barrier to this procedure, our findings indicate that, even among women in the highest BMI category, this procedure is safe and effective. Our rate of serious complications is consistent with prior publications; however, there is significant variation between studies with regard to definition of surgical morbidity.9,14,19 For example, other studies have included cystitis and endometritis as surgical complications, which are likely more associated with delivery rather than postpartum mini-laparotomy.14,19 Huber et al19 identified a rate of major complications as 0.4%, which increased to 1.2% with the addition of complications they categorized as minor, such as ileus and wound dehiscence. Our rate of identified subsequent pregnancy is significantly lower than previously reported estimates, at 1.6 (95% CI 0.6–3.6) per 1,000 procedures. We identified a rate of 0.5 ectopic pregnancies per 1,000 procedures. These rates are in contrast to those reported by Peterson et al, who estimated an incidence of 7.5 pregnancies and 1.2 ectopic pregnancies per 1,000 procedures.8,9 Our increase in duration of surgery is consistent with others; Deshpande and colleagues found operative time was 37.7 minutes in women with BMIs of 25 or lower and 48.2 minutes in the women with BMIs of 40 or higher.14 Similarly, they found this to not be clinically relevant.

The strengths of our study include a large sample size, as this is more than twice the size of the postpartum partial salpingectomy cohort in the U.S. Collaborative Review of Sterilization data set.6 Although these data are derived from a single site, there are more than 100 health care professionals (residents of varying levels, fellows, and faculty members) who were involved in the surgeries of these 3,760 patients, thus improving the generalizability of our findings. Furthermore, the majority of the procedures were completed by a second-year obstetrics and gynecology resident under faculty supervision. We believe that the study can be generalized to other tubal ligation forms, such as modified Pomeroy and even possibly salpingectomy, if the mini-laparotomy incision is the same.

This study is retrospective in nature and is limited by electronic medical record documentation. Additionally, our follow-up is constrained to a short (1–5 years) time period. The study is also limited to those who were able to undergo the procedure, which may remove the highest risk individuals (ie, increased BMI and history of multiple abdominal surgeries). Although our study is based on almost 4,000 patients, this may not be generalizable to the entire U.S. population, because other centers may use other surgical techniques such as the Pomeroy or modified-Pomeroy type of postpartum tubal ligation or complete salpingectomy. Although it is a large sample size, the small sample of women in the highest BMI category the ability to generalize the conclusion of nonsignificance. Put another way, there was a trend to increased complications with the highest BMI group, which may be statistically significant if the sample size were larger. Additionally, rates of postoperative complications and subsequent pregnancy are limited to women who return to our institution and those who receive care at outside facilities that have medical record agreements with our institution.

Even among patients within the highest BMI category, postpartum tubal ligation remains a safe and reasonable option for women. Counseling should include a discussion of a composite morbidity rate of 1.3% and a risk of subsequent pregnancy of 1.6 in 1,000 procedures. For the woman who is appropriately counseled and desires permanent contraception, BMI should not impede her access to the procedure.

REFERENCES

1. Kost K, Lindberg L. Pregnancy intentions, maternal behaviors, and infant health: investigating relationships with new measures and propensity score analysis. Demography 2015:52:83–111.
2. Finer LB, Sonfield A. The evidence mounts on the benefits of preventing unintended pregnancy. Contraception 2013;87:126–7.
3. Gipson JD, Koenig MA, Hindin MJ. The effects of unintended pregnancy on infant, child, and parental health: a review of the literature. Stud Fam Plan 2008;39:18–38.
4. Dehlendorf C, Rodriguez MI, Levy K, Borrero S, Steinauer J. Disparities in family planning. Am J Obstet Gynecol 2010;202:214–20.
5. Thiel de Bocanegra J, Braughton M, Bradsberry M, Howell M, Logan J, Schwarz EB. Racial and ethnic disparities in postpartum care and contraception in California's Medicaid Program. Am J Obstet Gynecol 2017;217:47.e1–7.
6. Daniels K, Daughtery J, Jones J, Moscher W. Current contraceptive use and variation by selected characteristics among women aged 15-44: United States, 2011-2013. Natl Health Stat Rep 2015;86:1–14.
7. Potter JE, Stevenson AJ, White K, Hopkins K, Grossman D. Hospital variation in postpartum tubal sterilization rates in California and Texas. Obstet Gynecol 2013;121:152–8.
8. Peterson JB, Xia Z, Hughes LJ, Wilcox LS, Tylor LF, Trussell J. The risk of pregnancy after tubal sterilization: findings from the U.S. Collaborative Review of Sterilization. Am J Obstet Gynecol 1996;174:1161–70.
9. Peterson HB, Xia Z, Hughes JM, Wilcox LS, Tylor LR, Trussell J. The risk of ectopic pregnancy after tubal sterilization. U.S. Collaborative Review of Sterilization Working Group. N Engl J Med 1997;336:762–7.
10. Access to postpartum sterilization. Committee Opinion No. 530. American College of Obstetricians and Gynecologists. Obstet Gynecol 2012;120:212–5.
11. Benefits and risks of sterilization. ACOG Practice Bulletin No. 208. American College of Obstetricians and Gynecologists. Obstet Gynecol 2019;133:e194–207.
12. Chan LM, Westioff CL. Tubal sterilization trends in the United States. Fert Steril 2010;94:1–6.
13. Flink-Bochaki R, Flaum S, Betstadt SJ. Barriers and outcomes associated with unfulfilled requests for permanent contraception following vaginal delivery. Contraception 2019;99:98–103.
14. Deshpande NA, Labora A, Sammel MD, Schreiber CA, Sonalkar S. Relationship between body mass index and operative time in women receiving immediate postpartum tubal ligation. Contraception 2019;100:106–10.
15. Gynecologic surgery in the obese woman. Committee Opinion No. 619. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;125:274–8.
16. Leveno KJ, McIntire DD, Bloom SL, Sibley MR, Anderson RJ. Decreased preterm births in an inner-city public hospital. Obstet Gynecol 2009;113:578–84.
17. Pritchard JA, MacDonald PC. Williams obstetrics. 15th ed. New York, NY: Appleton-Century-Crofts; 1976.
18. Expert Panel on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Executive summary of the clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults. Arch Intern Med 1998;158:1855–67.
19. Huber AW, Mueller MD, Ghezzi F, Cromi A, Dreher E, Raio L. Tubal sterilization: complications of laparoscopy and minilaparotomy. Eur J Obstet Gynecol Reprod Biol 2007;134:105–9.
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