Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study J Min, HA Watson, NL Hezelgrave, PT Seed and AH Shennan Volume 48, Issue 1, pages 38–42 Slides prepared Dr Joel Naftalin (UOG Editor for Trainees) Link to free-access article: http://onlinelibrary.wiley.com/doi/10.1002/uog.15925/full

1. UOG Journal Club: July 2016
Ability of a preterm surveillance clinic to triage risk of preterm
birth: a prospective cohort study
J Min, HA Watson, NL Hezelgrave, PT Seed and AH Shennan
Volume 48, Issue 1, Date: July, pages 38–42
Journal Club slides prepared by Dr Joel Naftalin
(UOG Editor for Trainees)

2. Ability of a preterm surveillance clinic to triage risk of preterm birth: a
prospective cohort study
Min et al., UOG 2016
Background
• Preterm birth and its consequences are the biggest cause of neonatal
morbidity and mortality
• Preterm delivery is difficult to predict in asymptomatic women, even if
they are high risk
• Clinical history, measurement of cervical length and fetal fibronectin
have all been used to try and accurately predict preterm labor
• More accurate prediction of preterm labor could lead to the more
efficient use of prophylactic interventions and treatments

3. To identify whether a preterm surveillance clinic (PSC) risk-stratifies
asymptomatic high-risk women accurately
Objective
Ability of a preterm surveillance clinic to triage risk of preterm birth: a
prospective cohort study
Min et al., UOG 2016

4. Patients and Methods
• This was subanalysis of a large observational study (Evaluation of Quantitative
Instrument in the Prediction of Preterm birth)
• Women with a singleton pregnancy who were asymptomatic but high risk for
preterm delivery were seen between 23+0 and 28+0 weeks’ gestation
• Fetal fibronectin and cervical length measurement were used in conjunction
with clinical history to assess risk
• Following the assessment, women deemed high risk were admitted to hospital
and managed according to local protocols
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016

5. Patients and Methods
• Inclusion criteria were:
o previous late miscarriage (16 to 23+6 weeks)
o previous preterm birth (<37 weeks)
o previous preterm prelabor rupture of membranes (<37 weeks)
o previous cervical surgery (e.g. LLETZ, cone biopsy)
o uterine abnormality
o cervical length <25mm on transvaginal ultrasound
• Exclusion criteria were:
o vaginal bleeding
o preterm prelabor rupture of membranes in index pregnancy
o multiple pregnancy
o cervical dilation ≥ 3cm
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016

6. Patients and Methods
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016
•A comparison was made between
women who were managed as
outpatients and those who were
admitted after assessment
• Outcomes compared were:
o gestational age at delivery
o stillbirth/neonatal death
o admission to NICU
o birth weight
o respiratory distress syndrome
o intraventricular hemorrhage
o 5-min Apgar score <7

7. Statistics and analysis
• The primary outcomes were mean gestational age at delivery and delivery <30
weeks
• Secondary outcomes were mean birth weight and delivery <34 and <37 weeks
• All categorical variables were compared using the chi-square test with statistical
significance set at P <0.001 (multiple hypothesis testing)
• Student’s t-test was used to compare the average maternal age, average
gestational age at delivery and average birth weight
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016

8. Results
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016
There were statistically significant differences between the two groups whereby the rate
of cervical surgery was higher in the outpatient group and the rate of second-trimester
miscarriage was higher in the inpatient group

9. Results
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016
Table showing outcomes in 1130 asymptomatic pregnant women at high risk of preterm
birth and either admitted to hospital (inpatient) or managed as an outpatient

10. Results
• Women admitted following assessment at the PSC were significantly more
likely to deliver before 30 weeks (relative risk, 27.6 (95% CI, 15.0–50.1)) than
were women who were not admitted
• Despite their risk factors, women who were not admitted had a low rate of
preterm delivery before 30 weeks (1.32%), comparable to the background rate
in England and Wales (1.2% deliver < 31 weeks)
• The mean gestational age at delivery in those managed as outpatients was
significantly higher than in those admitted (38.4±2.5 vs 31.2 ±5.6 weeks;
P<0.0001)
• All secondary outcomes were consistent, with worse clinical outcomes in the
group of women managed as inpatients
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016

11. Conclusion
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016
• PSCs measuring cervical length and quantitative fetal
fibronectin accurately triage asymptomatic high-risk
pregnant women, enabling those at highest risk of
adverse outcome to be identified for elective admission to
hospital and appropriate management

12. Strengths
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016
• The study used prospectively collected data
• The study contained a large group of asymptomatic women who were at high
risk for preterm birth
• The study used an already established treatment protocol

13. • The two groups underwent substantially different management which may
have impacted the measured outcomes
• The authors imply that discretion was occasionally used when deciding
whether or not to admit women from the clinic
• The study did not evaluate medium- and long-term neonatal outcomes
Limitations
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016

14. • Can this data be extrapolated to asymptomatic high-risk women attending general
antenatal clinics rather than specialist preterm birth clinics?
• Given the significant differences between the two groups with regards to history of
second-trimester miscarriage and cervical surgery, might the clinic protocol be adapted
to give different weightings to these factors?
• Does our increasing reliance on objective tests (e.g. fetal fibronectin and cervical length)
blunt our clinical judgment?
• How can we reduce the social and emotional burden on women being admitted to
hospital from as early as 23 weeks?
Discussion points
Ability of a preterm surveillance clinic to triage risk of preterm birth: a prospective cohort study
Min et al., UOG 2016