VP07.01: How adenomyosis changes throughout pregnancy: a retrospective study

To study how adenomyosis modifies in pregnancy and to correlate these changes to maternal and fetal outcomes. Retrospective cohort study including 254 women between 2016 and 2020. Inclusion criteria were: ≧1 transvaginal ultrasound (TV-US) (performed before conception/1st trimester) to assess the presence of adenomyosis, ≧1 scan available per trimester (if ongoing pregnancy) and complete information of maternal and neonatal outcomes. Exclusion criteria were: twins, uterine malformations or fetal anomalies. Adenomyosis was diagnosed with ≧1 criteria from the MUSA classification or the adenomyosis consensus classification system at TV-US. 144 (86.27%) 26 (89.65%) 54 (81.81%) 2 (100%) 226 (85.28%) 1 (100%) 23 (13.77%) 3 (10.34%) 12 (18.18%) 39 (14.71%) 1 (0.003%) 167 (63.01%) 29 (10.94%) 66 (24.90%) 2 (0.007%) The globular aspect of the uterus was the commonest sign reported in 79% women with adenomyosis in the 1st trimester: it progressively disappeared, being present in 38% and 2% women in the 2nd and 3rd trimester respectively and again visible in the post-partum in 65% women. Asymmetrical thickening (30%) and cysts (23%) were also reported in the 1st trimester and disappeared during pregnancy. Adenomyosis was associated with miscarriage (OR 5.9 95%CI 2.4-14.9, p < 0.001) also when considering only normal conception (OR 5.1 95%CI 1.8-14.2, p = 0.002) or correcting for maternal age (aOR 5.9, CI95% 2.3-15.2, p < 0.001). GA at delivery was significantly lower in women with adenomyosis compared to controls (P = 0.004). Caesarean sections (CS) rate was higher than in controls (OR 2.5, CI95% 1.3-4.8, p = 0.007) and this was confirmed (OR 2.4 CI95% 1.1-5, p = 0.02) also after excluding women with previous CS. Signs of adenomyosis can be identified in pregnancy and progressively disappear during gestation but are clinically relevant: adenomyosis was associated with an increased risk of miscarriage. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.