The study from Italy, “Influence of adenomyosis on pregnancy and perinatal outcomes in women with endometriosis,” was published in the journal Ultrasound in Obstetrics and Gynecology.
In the last decade, many studies have reported an association between endometriosis and major pregnancy-related complications, including spontaneous late miscarriage, preterm labor, fetuses small for gestational age (SGA), hypertension, pre-eclampsia, and other issues. But other studies have not reached similar conclusions.
Endometriosis is often accompanied by a diagnosis of adenomyosis, which refers to a condition where the tissue lining the uterus grows into the muscular wall of the uterus.
The reported prevalence of adenomyosis in patients with endometriosis is from 20% to 50%. Previous studies have shown that adenomyosis can lead to an increased risk of adverse events in pregnancy, but few studies have paid close attention to the correlation between adenomyosis and pregnancy outcomes in patients with endometriosis.
Researchers set out to determine whether the maternal and fetal outcomes were different in women with endometriosis alone compared to endometriosis with either diffuse or focal adenomyosis.
Focal adenomyosis occurs in one particular site of the uterus, while diffuse adenomyosis is when the condition is spread throughout the uterus.
Researchers conducted a retrospective analysis of 206 pregnant women with endometriosis, of which 71.8% had endometriosis alone, 18.4% had endometriosis with focal adenomyosis (EFA) and 9.7% had endometriosis with diffuse adenomyosis (EDA).
Conventional risk factors associated with placental insufficiency such as BMI, PAPP-A levels, and mean uterine artery pulsatility index (UtA PI) in the first and the second trimester were found to be significantly associated with EDA, compared to patients with endometriosis alone. There were no statistically significant differences found in EFA patients.
Interestingly, an analysis showed that EDA was the only independent risk factor for babies who were small for gestational age (SGA), with an overall higher risk of 3.74 in women with EDA compared to those with endometriosis alone.
SGA is a term used to describe a fetus that is smaller than average for the number of weeks of pregnancy.
One explanation for this result is that women with adenomyosis have imbalanced blood flow, with higher blood flow to the uterine adenomyosis area and lower blood flow to the placenta, which could lead to the reduced growth of the fetus.
“The current study shows that diffuse adenomyosis in pregnant women with endometriosis is strongly associated with SGA infants,” the study’s authors concluded.
They added that women with EDA should be treated as high-risk patients for placental dysfunction and should be more closely monitored.