Related Experiment Video
Updated: Sep 10, 2025
A Novel Method for Involving Women of Color at High Risk for Preterm Birth in Research Priority Setting
Published on: January 12, 2018
Variation in risk factors and timing of birth for different types of preterm birth: A historical cohort study
Vanessa El-Achi1,2, James Elhindi1, Sarah Melov1,2
1Reproduction and Perinatal Centre, Faculty of Medicine and Health, University of Sydney, Australia.
Insights
Iatrogenic preterm birth is common, particularly late preterm births. Management of preterm birth varies between hospitals, indicating potential differences in care approaches.
Area of Science:
- Obstetrics and Gynecology
- Perinatal Epidemiology
- Maternal-Fetal Medicine
Background:
- Preterm birth poses significant risks to newborns.
- Understanding risk factors and timing for different preterm birth types is crucial for improving outcomes.
- Iatrogenic, spontaneous, and preterm prelabor rupture of membranes represent distinct pathways to preterm birth.
Purpose of the Study:
- To investigate risk factors and birth timing for iatrogenic, spontaneous, and preterm prelabor rupture of membranes.
- To analyze variations in preterm birth management across health services in New South Wales.
- To identify associations between maternal characteristics and different types of preterm birth.
Main Methods:
- Historical cohort study (2018-2023) using electronic health records.
- Inclusion of 113,244 singleton pregnancies.
- Multivariate logistic and Cox regression models to analyze incidence and time-to-event for preterm birth types.
Main Results:
- 7.0% of pregnancies resulted in preterm birth (7940 cases).
- Iatrogenic preterm births were most common (49.2%), followed by spontaneous (36.9%) and preterm prelabor rupture of membranes (13.9%).
- Previous preterm birth and antenatal care model were associated with all preterm birth types; hospital capacity influenced birth timing for specific types.
Conclusions:
- High incidence of iatrogenic preterm birth, especially in the late preterm period (32-36 weeks).
- Significant variation in birth timing for preterm prelabor rupture of membranes and iatrogenic preterm birth exists across higher-capacity maternity hospitals.
- Discrepancies suggest potential differences in clinical management or unmeasured confounding factors.
Introduction:
The aim of this study was to investigate the risk factors and timing of birth for different types of preterm birth, including iatrogenic preterm birth, spontaneous preterm birth, and preterm prelabor rupture of membranes across health services in New South Wales, Australia.
Material And Methods:
We conducted a historical cohort study between 2018 and 2023 using routinely collected electronic data across four local health districts in New South Wales. Maternal characteristics and outcomes were compared using summary statistics. Differences in the incidence of each preterm birth type were compared using multivariate logistic regression models. Cox regression was performed to assess the time-to-event for each preterm birth type and account for confounders.
Results:
A total of 113 244 singleton pregnancies were included, of which 7940 (7.0%) were born preterm. Of these, 3909 (49.2%) were iatrogenic preterm births, 2931 (36.9%) were spontaneous preterm births, and 1100 (13.9%) had preterm prelabor rupture of membranes. Iatrogenic late preterm (32-36 weeks' gestation) births accounted for 38.8% of all preterm births. All three categories of preterm birth were strongly associated with a history of previous preterm birth and model of antenatal care. Among higher capacity (level 4-6) maternity hospitals, there was significant variation in the gestational age of birth for those with preterm prelabor rupture of membranes and iatrogenic preterm birth affected by hypertensive disorders of pregnancy or pre-eclampsia.
Conclusions:
There was a high rate of iatrogenic preterm birth, especially in the late preterm period. There is variation in the timing of birth in higher capacity maternity hospitals, suggesting different management approaches and/or unmeasured confounding factors.
Related Concept Videos
01:52Regression Toward the Mean
01:12Relative Risk
01:29Bias in Epidemiological Studies
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
01:26Factors Affecting the Risk of Infection
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...
02:20Longitudinal Research