Tubal Reversal Study Report 2005

Tubal Length and Pregnancy Outcomes

Notice of Study Update

The following is Dr. Berger's report from 2005. The corresponding page of an updated report can be seen at Tubal Reversal Pregnancy Study 2009 - Pregnancy Outcomes.

Pregnancy rates by fallopian tube length

The fallopian tube lengths remaining after a tubal ligation procedure are important determinants of the success of tubal reversal surgery. The average tubal length of a fallopian tube before ligation is approximately 10 cm or 4 inches.

Tubal lengths of the study participants were measured by Dr. Berger during surgery, as is routine for all tubal reversal surgeries performed at Chapel Hill Tubal Reversal Center. The correlation between average tubal length and pregnancy rates is apparent (Table 6). Women with longer tubal lengths had significantly higher pregnancy rates than women with shorter tubes following tubal reversal. Women with tubal lengths 7.5 cm or longer had a pregnancy rate of 77%. The pregnancy rate declined as tubal length decreased, but even women with the shortest tubes (less than 2.5 cm) became pregnant (24%).

**Table 6. Pregnancy Rates by Tubal Length (cm)**
Length	Total Women	Pregnant (No.)	Pregnant (%)
7.5+	305	234	77%
5.0-7.4	1534	1058	69%
2.5-4.9	798	433	54%
<2.5	55	13	24%
Total	2692	1738	65%

Pregnancy outcomes by fallopian tube length

Long tubes were also associated with better pregnancy outcomes than short tubes. Among women with average fallopian tube lengths measuring 7.5 cm or longer, 59% gave birth or had an ongoing pregnancy. Birth/ongoing pregnancy rates declined while miscarriage and ectopic pregnancy rates increased with shorter tubal lengths (Table 7). The ectopic pregnancy rate after tubal reversal is higher than the 2% ectopic pregnancy rate in the general population.

**Table 7. Pregnancy Outcomes by Average Tubal Length (cm)**
Length	Pregnant	Birth/Ongoing	Miscarriage	Ectopic
7.5+	234	137 (59%)	72 (31%)	25 (10%)
5.0-7.4	1058	517 (49%)	380 (36%)	161 (15%)
2.5-4.9	433	157 (36%)	191 (44%)	85 (20%)
<2.5	13	4 *	3 *	6 *
Total	1738	815 (47%)	646 (37%)	277 (16%)

*Percentages are omitted for small sample size.

Pregnancy outcomes by age

Table 8 shows the relationship between age and pregnancy outcome. With increasing age, the percentage of pregnancies resulting in births declined due to an increasing percentage of miscarriages. Among women under age 35, over half of pregnancies resulted in birth or ongoing pregnancy while one third miscarried. The birth rate declined and the miscarriage rate rose significantly for women age 40 and older. There may be an increased risk of miscarriage after tubal reversal, but this is not entirely clear since the miscarriage rate reported in the general population ranges from approximately 20% to 50% depending on a woman's age.

**Table 8. Outcome of Tubal Reversal by Age**
Age	Pregnant	Birth/Ongoing	Miscarriage	Ectopic
<30	310	168 (54%)	104 (34%)	38 (12%)
30-34	709	344 (49%)	238 (33%)	127 (18%)
35-39	608	265 (44%)	245 (40%)	98 (16%)
40+	111	38 (34%)	59 (53%)	14 (13%)
Total	1738	815 (47%)	646 (37%)	277 (16%)