Results
During the two-year study period, 1442 consecutive women with suspected
early pregnancy complications attended the Early Pregnancy Assessment
Unit for a total 1711 ultrasound scans that were all carried out by a
single clinician. When women presented for more than one pregnancy
during the study period, only findings from the first pregnancy were
included in the data collection. Of the 1442 women, 101 (7.0%, 95% CI
5.7 – 8.3) were excluded from the data analysis as they did not undergo
a transvaginal ultrasound scan. The median age of the 1341 women
included in the final data analysis was 33 years (range 16 – 51), the
median parity was 0 (range 0 - 9) and the median BMI was 23.3 (range
15.8 – 56.2). 1233/1341 (91.9%, 95% CI 90.5 – 93.4) women conceived
spontaneously and the remaining 108 women conceived after fertility
treatment. There were 72 women with a previous diagnosis of
endometriosis, 44 of whom had undergone surgical excision of the
disease. The indications for attendance at the Early Pregnancy Clinic
are provided in the supplementary material (Table S1).
Evidence of ovarian endometriomas and/or deep endometriosis was found in
a total of 66/1341 (4.9%, 95% CI 3.8 – 6.2) women. Demographic
characteristics of women with and without ultrasound evidence of
endometriosis are shown in Table 1. We found ovarian endometriomas in
9/66 (13.6%, 95% CI 5.3 – 21.9) women, 33/66 (50.0%, 95% CI 37.9 -
62.1) had deep endometriosis and 24/66 (36.4%, 95% CI 24.8 – 48.0)
had evidence of both ovarian and deep endometriosis. In women with
ovarian endometrioma, 26 cysts were identified in the right ovary and 22
in the left ovary. In the 57 women with endometriotic nodules, the most
common site was the rectovaginal space (n = 50) and in the region of the
uterosacral ligaments (n = 37). The median number of nodules was 2
(range 0 - 7). Bowel involvement was diagnosed in 17/57 (29.8%, 95% CI
17.9 – 41.7) women with deep endometriosis and 2/57 (3.5%, 95% CI 0
– 8.3) had evidence of bladder/vesicouterine involvement.
For 33/66 (50%, 95% CI 37.9 – 62.1) women with evidence of
endometriosis, this was a new diagnosis made for the first time during
their early pregnancy scan. The remaining 33 women were aware of the
diagnosis prior to their pregnancy. A further 39/1341 (2.9%, 95% CI
2.0 – 3.8) women reported a previous diagnosis of endometriosis, of
which 32/39 (82.1, 95% CI 70.1 – 94.1) had undergone surgical
treatment. However, none of these 39 women had evidence of active
endometriotic lesions on ultrasound at the time of their attendance to
the early pregnancy unit.
The proportion of women with endometriosis who conceived after fertility
treatment (21.2%, 95% CI 12.1-33.0) was much higher compared to women
without endometriosis (7.5%, 95% CI 6.1-9.0). A total 8/33 (24.2%,
95% CI 9.6 – 38.8) of women with known endometriosis conceived
following fertility treatment which was similar to 6/33 (18.2%, 95% CI
5.0 – 31.4) women with a new diagnosis (p = 0.5540).
The list of all gynaecological diagnoses following pelvic ultrasound
examination are documented in Table 2. In 33/66 (50%, 95% CI 37.4 –
62.6) women with evidence of endometriosis, endometriosis was an
isolated abnormality. In the remaining 33 women, concomitant
abnormalities were also noted on pelvic ultrasound examination (Table
3).
The results of a univariate analysis suggested that the presence of
endometriosis was significantly associated with infertility, low parity,
congenital uterine anomalies, fibroids and adenomyosis. The largest
effect was for congenital uterine anomalies, where the odds of
concurrent endometriosis was five times higher than in women without.
There was also some difference between ethnicities. The results of the
univariate analysis are included in the supplementary material (Table
S2). The results of a multivariate analysis examining these associations
is shown in Table 4. The analysis suggested that ethnicity, infertility,
congenital uterine anomalies and fibroids were associated with the
presence of endometriosis. After adjusting for these variables, there
was no further evidence that either parity or adenomyosis were
associated with the presence of endometriosis. East Asian women had the
highest chance of endometriosis, with odds over 50% higher than for
Caucasian women. Women that conceived following fertility treatment had
a higher endometriosis risk, with the odds being over three times higher
than those who did not undergo fertility treatment. The presence of
congenital uterine anomalies remained strongly associated with the
presence of endometriosis.