Preterm labour

Question 1

Define preterm labour.

Answer 1

Onset of contractions that cause progressive cervical dilation at < 37 weeks GA

Question 2

Give 6 non-modifiable risk factors of preterm labour.

Answer 2

• History of preterm birth (greatest risk factor)
• Cervical insufficiency
• Short cervical length
• Multiple gestations
• Polyhydramnios
• Preterm premature rupture of membranes (PPROM)
• Antepartum hemorrhage caused by:
  Placenta previa
  Placental abruption
• Uterine anomalies (e.g., anomalies of Mullerian duct fusion, uterine fibroids)
• Black individuals of non-Hispanic origin
• Congenital abnormalities of the fetus
• Acute systemic inflammation

Question 3

Give 6 modifiable risk factors.

Answer 3

Maternal and fetal conditions
Infections (e.g., urinary tract infections, STIs, vaginal infections )
Hypertensive pregnancy disorders (e.g., preeclampsia, HELLP syndrome)
Diabetes mellitus, gestational diabetes

Lifestyle and environmental factors
Smoking
Substance use (e.g., heavy alcohol use, heroin, cocaine)
Maternal or fetal stress
Maternal age (≤ 18 years, > 35 years) [10]
Low maternal pre-pregnancy weight
Short interval between pregnancies (< 18 months)

Question 4

What are the clinical features of preterm labour?

Answer 4

• Regular uterine contractions and associated symptoms of labor (e.g., lower back pain)
• Loss of mucus plug (bloody show)
• Cervical effacement and/or cervical dilation
• Rupture of membranes

Question 5

How is preterm labour diagnosed?

Answer 5

Clinically diagnosis

Transvaginal ultrasound for cervical length (short cervix ≤ 2.5 cm)

Cervicovaginal fetal fibronectin (fFN) test
Used to help differentiate between true preterm labor and false labor
Elevated levels in cervical secretions are associated with an increased risk of preterm delivery.