Obstetric and neonatal outcomes in women with internal and non-internal adenomyosis

Is there a relationship between the location of adenomyosis lesions and obstetric and neonatal outcomes?

A total of 466 women diagnosed with adenomyosis via transvaginal ultrasound between January 2019 and December 2021 were included. Inclusion criterion was a clinical pregnancy (natural conception or ART) achieved within 2 years after diagnosis; patients were followed up until a definitive pregnancy outcome. Women were divided into internal and non-internal adenomyosis groups based on the location of the adenomyosis lesion. Obstetric and neonatal outcomes were compared. Adjusted ratio ratios (aORs) and 95% confidence intervals were calculated by multivariate analysis. Outcomes were adjusted for age, gravidity, mode of conception, history of hysteroscopy and presence of ovarian endometriosis.

A total of 251 women (53.9%) presented with internal adenomyosis compared with women with non-internal adenomyosis (n = 215). The internal adenomyosis group were older (35.0 ± 4.3 versus 34.2 ± 4.3 years, P = 0.029) and had more pregnancies. After adjusting for confounders, the internal adenomyosis group had a lower likelihood of live birth (aOR 0.43, 95% CI 0.29 to 0.64, P < 0.001) and a higher risk of early spontaneous miscarriage (aOR 2.27, 95% CI 1.29 to 4.10, P = 0.005). Among women who had live births, women in the internal adenomyosis group had a higher risk of preterm premature rupture of membranes (aOR 3.06, 95% CI 1.37 to 7.27, P = 0.008) and a small for gestational age infant (aOR 2.73, 95% CI 1.24 to 6.32, P = 0.015).

Women with internal adenomyosis face a higher risk of adverse obstetric and neonatal outcomes; affected patients should be referred early to a high-risk clinic for intensified surveillance and individualized management to improve maternal and infant outcomes.