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Am J Perinatol 2015; 32(14): 1298-1304
DOI: 10.1055/s-0035-1563717
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Maternal Obesity Class as a Predictor of Induction Failure: A Practical Risk Assessment Tool

Authors

  • Stefania Ronzoni

    1   Division of Feto Maternal Medicine, Department of Obstetric and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada

  • Hadar Rosen

    1   Division of Feto Maternal Medicine, Department of Obstetric and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada

  • Nir Melamed

    2   Division of Feto Maternal Medicine, Department of Obstetric and Gynecology, Sunnybrook Health Science Center, University of Toronto, Toronto, Ontario, Canada

  • Shay Porat

    3   Department of Obstetrics and Gynecology, Hadassah-Hebrew, University Medical Center, Mt Scopus Campus, Jerusalem, Israel

  • Dan Farine

    1   Division of Feto Maternal Medicine, Department of Obstetric and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada

  • Cynthia Maxwell

    1   Division of Feto Maternal Medicine, Department of Obstetric and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
Further Information

Publication History

15 July 2015

21 July 2015

Publication Date:
09 September 2015 (online)

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Abstract

Objective To assess the impact of body mass index (BMI) on the rate of cesarean section (rCS) in induction of labor (IOL).

Study Design A total of 7,543 singleton term pregnancies undergoing IOL (cervical dilatation at admission, CDA ≤ 3 cm) were divided according to BMI: underweight (n = 325); normal weight (NW) (n = 4,633); overweight (OW) (n = 1,610); and obese (n = 975). Age, parity, macrosomia, gestational age (GA), gestational weight gain (GWG), CDA, and IOL indications were considered.

Results A higher rate of macrosomia (15.0 vs. 11.1%; p < 0.0001), earlier induction (GA 39.7 ± 1.3 vs. 40.1 ± 1.3 weeks; p < 0.0001) for maternal indications (39.1 vs. 21.1%; p < 0.001), and lower CDA (≤1cm; 66.4 vs. 61.4%; p < 0.005) were observed in obese versus NW. The rate of weight gain above the recommended range was higher in obese (obese 70.6% vs. NW 43.9%; p < 0.001), despite a significantly lower mean GWG compared with NW (14 ± 7.5 vs. 16.5 ± 5.6 kg; p < 0.001). Compared with NW, OW and obese demonstrated a significantly higher rCS (OW 31.1% and obese 36.9% vs. NW 24.7%; p < 0.001). BMI represented an independent factor affecting the rCS (vs. NW; OW odds ratio [OR] 1.4; confidence interval [CI] 1.2–1.7; p < 0.001; obese OR 2.3; CI 1.9–2.7 p < 0.001).

Conclusion In the case of IOL, obesity represents an independent factor associated with a significant increase of CS to be considered during induction counselling.

Keywords

body mass index - cesarean section - induction of labor - obesity

Note

Findings presented at SMFM 35th Annual Meeting—The Pregnancy Meeting, San Diego, CA, February 2–7, 2015, Abstract #229.