Adenomyosis increases risks of adverse obstetrical outcomes

Adenomyosis increases risks of adverse obstetrical outcomes | Image Credit: © Tom - © Tom - stock.adobe.com.

According to a recent study published in the American Journal of Obstetrics & Gynecology, adenomyosis is associated with negative obstetrical and neonatal outcomes.

Adenomyosis presents as myometrial invasion of endometrial tissue, and may cause chronic pelvic pain, abnormal uterine bleeding, and dysmenorrhea. Certain estimates report adenomyosis presence in up to 20% of women, and data has indicated it causes adverse reproductive outcomes.

It has been hypothesized that adenomyosis impacts the obstetrical function of the uterus. Aberrant uterine contractility may cause uterine hyperstimulation and atony, placental retention, and failure to progress.

A lack of uniform diagnostic criteria, along with about 1/3 of women being asymptomatic, lead to complications in adenomyosis diagnosis. This makes it difficult for a consensus on obstetrical complications of adenomyosis to be made. 

Many studies linking adenomyosis to obstetric complications had limitations, reducing their generalizability. Currently, adenomyosis is not considered a high-risk factor for complicated pregnancies, and no guidelines exist for managing pregnant women with adenomyosis.

To evaluate the prevalence of obstetric and neonatal complications in women with histopathologic adenomyosis, investigators conducted a retrospective observational population-based cohort. Dutch population-level data from 1995 to 2018 was used in the analysis.

Participants were divided into a study group and a control group. The study group included women aged 18 to 50 years with an adenomyosis diagnosis in the Dutch nationwide pathology databank from 1995 to 2018 and pregnancy outcomes in the Dutch national perinatal registry (Perined). 

The control group was comprised of women of the same age group as the study group with pregnancy outcomes registered in the Perined who did not have a histopathologic adenomyosis diagnosis. Women without a pseudonymized personal identifier in the perinatal registry were excluded from the analysis.

Adverse obstetrical outcomes were the primary measure of the study. These included preterm birth (PTB), mode of delivery, placental retention, failure to progress, postpartum hemorrhage (PPH), small for gestational age (SGA), hypertensive disorders of pregnancy (HDPs), and fetal growth restriction (FGR).

Neonatal outcomes were also evaluated, including low Apgar scores, perinatal mortality, neonatal asphyxia, and neonatal intensive care unit admission. Data on patient age at hysterectomy, year of hysterectomy, and endometriosis diagnosis was gathered from pathologic reports.

There were 7925 pregnancies linked to obstetrical outcomes and 4,615,803 not linked to histologically confirmed adenomyosis. Of these, 548,852 were excluded.

Primiparous women were seen in 65.8% of the histopathologic adenomyosis group compared to 55% in the no histopathologic adenomyosis group. Subfertility was also seen in 4.7% more on the histopathologic adenomyosis group, along with increased rates of pregnancy after assisted reproductive technology. Maternal mortality did not significantly differ between groups.

Signs of premature labor such as premature contractions, preterm premature rupture of membranes, and cervical insufficiency were seen more often in women with adenomyosis. Women in the adenomyosis group were 2.2% more often diagnosed with premature labor or threatened prematurity. However, PTB prevalence was lower in this group.

Patients with adenomyosis also presented with a significantly greater prevalence of HDPs, along with a 0.5% greater prevalence of FGR and a 3.5% greater prevalence of SGA.

In women with adenomyosis, failure to progress in labor had an adjusted odds ratio (aOR) of 1.24. The prevalence of premature rupture of membranes over 24 hours was also more common in this group. The aOR for cesarean delivery (CD) was 1.73 in this population and 1.54 for emergency CD.

Antepartum hemorrhage was less prevalent in women with adenomyosis, while miscarriage was more prevalent and risks of hyperemesis gravidarum were increased. After adjusting for cofounders, a slightly increased risk of PPH was also found in this population. Adenomyosis was also associated with an increased risk of endometriosis.

Increased risks of placental retention, placenta previa, and placental abruption were seen in women with adenomyosis. However, only increased risks of placenta previa and placental retention remained after adjusting for cofounders.

Neonatal outcomes adversely impacted by adenomyosis included birthweight and fetal distress during labor. However, neonatal mortality and Apgar scores at birth were not associated with adenomyosis.

These results indicated adverse obstetrical and neonatal impacts from adenomyosis. Investigators recommended further studies evaluate the extent of this association.

Reference

Rees CO, van Vilet H, Siebers A, et al.The ADENO study: ADenomyosis and its Effect on Neonatal and Obstetric outcomes: a retrospective population-based study. American Journal of Obstetrics & Gynecology. 2023;229(1):49.E1-49.E12.doi:10.1016/j.ajog.2022.12.013