Uterine Atony

Question 1

What is uterine atony?

Answer 1

Failure of the uterus to effectively contract and retract after complete or incomplete delivery of the placenta, which can lead to severe postpartum bleeding from the myometrial vessels

Question 2

What are the risk factors of uterine atony?

Answer 2

Risk factors that cause over-distension of uterus:
Multiparity
Multiple pregnancy
Post-term pregnancy
Instrumental delivery
Anatomical abnormalities (i.e., fetal, uterine, abnormal placental implantation)
Large for gestational age newborn (e.g., > 4000 g)
Poor myometrial contraction following prolonged or rapid and forceful birth

Question 3

What are the clinical features of uterine atony?

Answer 3

Abnormal vaginal bleeding

Soft, enlarged (increased fundal height), boggy ascending uterus

Question 4

How is uterine atony diagnosed?

Answer 4

Clinical diagnosis

Question 5

What is the treatment for uterine atony?

Answer 5

(General measures )Monitoring, adequate large-bore IV access (≥ 16 gauge), and an ice pack
Fluid therapy (with intravenous crystalloid solutions)
Oxygenation
Bimanual uterine massage
(Uterotonic agents as needed) IV oxytocin (diluted in saline) / IM carboprost tromethamine (if the patient does not suffer from asthma) / IM methylergonovine (if no hypertension or arterial disease is present) / Prostaglandins such as misoprostol (useful when injectable uterotonic agents are unavailable or contraindicated)
Tranexamic acid
(Last resort) Hysterectomy