Arcuate Uterus as an Independent Risk Factor for Adverse Pregnancy Outcomes

Area of Science:

• Reproductive Medicine
• Maternal-Fetal Medicine
• Gynecologic Imaging

Background:

• The arcuate uterus, a common uterine anomaly, has been debated regarding its clinical significance.
• Previous studies have yielded conflicting results on the association between arcuate uterus and adverse pregnancy outcomes.

Purpose of the Study:

• To estimate the association between arcuate uterus and pregnancy outcomes.
• To compare pregnancy outcomes in women with arcuate uterus versus controls from a similar high-risk cohort.

Main Methods:

• Retrospective cohort study of women with singleton pregnancies from 2005-2020.
• Inclusion criteria: singleton pregnancy ≥20 weeks with arcuate uterus diagnosis.
• Controls: randomly selected women (3:1 ratio) with singleton pregnancies and no uterine anomaly from the same practice.

Main Results:

• Women with arcuate uterus (n=37) had significantly higher rates of spontaneous preterm birth (<37 weeks) (10.9% vs. 3.0%) and fetal growth restriction (20.0% vs. 7.3%).
• Increased need for vaginal progesterone (5.5% vs. 0.6%) and antenatal corticosteroids (16.4% vs. 5.5%) was observed in the arcuate uterus group.
• Lower mean birthweight (3,028.1g vs. 3,257.2g) was associated with arcuate uterus, despite similar BMI and weight gain.

Conclusions:

• Arcuate uterus is associated with significantly increased risks of spontaneous preterm birth, fetal growth restriction, and lower birthweight.
• The findings suggest arcuate uterus is a risk factor for adverse pregnancy outcomes, not merely a normal anatomical variant.
• Management of pregnancies with arcuate uterus should consider these potential risks.