Get access

Trending Elective Preterm Deliveries Using Administrative Data

Authors

  • Lisa M. Korst,

    Corresponding author
    1. Childbirth Research Associates, North Hollywood, CA
    • Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA
    Search for more papers by this author
  • Moshe Fridman,

    1. AMF Consulting, Los Angeles, CA
    Search for more papers by this author
  • Michael C. Lu,

    1. Department of Obstetrics and Gynecology, David Geffen School of Medicine, UCLA, Los Angeles, CA
    2. Department of Community Health Sciences, School of Public Health, UCLA, Los Angeles, CA
    Search for more papers by this author
  • Laura Fleege,

    1. Department of Obstetrics and Gynecology, Burns Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
    Search for more papers by this author
  • Connie Mitchell,

    1. Maternal, Child and Adolescent Health Division, California Department of Public Health, Sacramento, CA
    Search for more papers by this author
  • Kimberly D. Gregory

    1. Department of Obstetrics and Gynecology, David Geffen School of Medicine, UCLA, Los Angeles, CA
    2. Department of Community Health Sciences, School of Public Health, UCLA, Los Angeles, CA
    3. Department of Obstetrics and Gynecology, Burns Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
    Search for more papers by this author

Correspondence:

Lisa M. Korst, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, 2020 Zonal Ave., #201, Los Angeles, CA 90033, USA.

E-mail: korst@usc.edu

Abstract

Background

We propose a methodology for identifying and analysing ‘elective’ preterm births (PTBs) using administrative data, and apply this methodology to California data with the objective of providing a framework to further explore the potential rationales for early delivery.

Methods

Using the California linked birth cohorts for 1999, 2002 and 2005, singleton PTBs were identified using birth certificate gestational age ≥ 24 and <37 weeks. Through a hierarchical scheme that first removed cases with standard or ‘hard’ indications for early delivery (e.g. severe preeclampsia, placenta previa), cases of ‘elective’ PTB were identified with coding for medical intervention, that is, elective caesarean or labour induction. We calculated rates of elective PTB, with subanalyses of early (<34 weeks of gestational age) and late PTB (34 to <37 weeks of gestational age) using hierarchical logistic regression models.

Results

Of 1 387 565 singleton deliveries, 99 614 (7.2%) were preterm. Elective PTBs increased 27.7% over the 6-year study period, with nearly all cases confined to the late PTB stratum; elective late PTB rates rose from 10.5% to 13.5% of all late PTBs (P < 0.0001). Indications for delivery in this Elective Group (‘soft indications’) included prior pelvic floor repair, mental health conditions, fetal anomalies, malpresentation and oligohydramnios. Six per cent of patients with a late PTB had a medical intervention with no hard or soft indication for delivery.

Conclusions

Using administrative data, we developed a method for identifying and trending the proportion of PTBs that is ‘elective’. This method can be used to explore and monitor potential strategies for the prevention of elective PTB.

Ancillary