Effect of maternal obesity on labor induction in postdate pregnancy
To test the hypothesis that there is a higher rate of unsuccessful induction of labor (IOL) in post-term obese pregnant women compared to non-obese ones.
In this prospective cohort study, 144 obese (BMI > 30) and 144 non-obese (BMI < 29.9) post-term (> 41 weeks) pregnant women were recruited. IOL was done by misoprostol or amniotomy and oxytocin infusion according to the Bishop score. Comparison of percentage of failed IOL in both groups (primary outcome) was performed by the Chi-test. Logistic regression and multivariable regression were performed to assess the odds ratio (OR) of cesarean section (CS) and coefficient of delay in labor till vaginal delivery (VD) in obese versus (vs) non-obese groups. Adjustment for gestational age, parity, Bishop Score, membrane rupture and amniotic fluid index was done in both regression analyses.
CS rate was significantly higher in obese group [26.4 vs 15.9%; difference in proportion (95% CI) 0.1 (0.01, 0.19); P value 0.02]. 106 (73.6%) obese women and 121 (84.1%) non-obese women delivered vaginally. In addition, the duration till VD was significantly higher in obese group (22 vs 19 h, P value 0.01). After adjustment for possible confounding factors, the CS was still higher in the obese group in comparison to non-obese group (OR 2.02; 95% CI 1.1, 3.7; P value 0.02). This finding suggested that obesity was an independent factor for failure of IOL. In addition, after adjustment for these confounders, obesity had the risk of increasing labor duration by 2.3 h (95% CI 0.1, 4.5) in cases that ended in VD.
Based on our results, we conclude that there is a higher risk of CS in obese postdate pregnant women undergoing IOL in comparison to non-obese counterparts. Therefore, obstetricians should pay more attention to advising pregnant women about optimal weight gain during pregnancy and counseling about the chances of VD in cases of IOL.
KeywordsBishop score Induction of labor Obesity Failure of induction
AM: project development. AE-S: project development and revision of data. HM: project development, data collection and revision of the manuscript. DB: review of literature, data collection and manuscript writing. AA: data collection. EO: review of literature, data analysis and manuscript writing. MT: data collection. SE: manuscript revision. MK: data collection.
Compliance with ethical statements
Conflict of interest
The author reports no conflicts of interest in this work.
The study was performed in accordance with the Declaration of Helsinki ethical standards.
Informed consents were taken from study participants.
- 1.Ng M, Fleming T, Robinson M et al (2014) Global, regional, and national prevalence of overweight and obesity in children and adults during 1980–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet (London, England) 384(9945):766–781. https://doi.org/10.1016/s0140-6736(14)60460-8 (PubMed PMID: 24880830; PubMed Central PMCID: PMCPmc4624264. eng) CrossRefGoogle Scholar
- 3.Heslehurst N, Simpson H, Ells LJ et al (2008) The impact of maternal BMI status on pregnancy outcomes with immediate short-term obstetric resource implications: a meta-analysis. Obes Rev Off J Int Assoc Study Obes 9(6):635–683. https://doi.org/10.1111/j.1467-789X.2008.00511.x (PubMed PMID: 18673307; eng) CrossRefGoogle Scholar
- 5.Rahman MM, Abe SK, Kanda M et al (2015) Maternal body mass index and risk of birth and maternal health outcomes in low- and middle-income countries: a systematic review and meta-analysis. Obes Rev Off J Int Assoc Study Obes 16(9):758–770. https://doi.org/10.1111/obr.12293 (PubMed PMID: 26094567; eng) CrossRefGoogle Scholar
- 7.Arrowsmith S, Wray S, Quenby S (2011) Maternal obesity and labour complications following induction of labour in prolonged pregnancy. BJOG Int J Obstet Gynaecol 118(5):578–588. https://doi.org/10.1111/j.1471-0528.2010.02889.x (PubMed PMID: 21265999; PubMed Central PMCID: PMCPmc3085126. eng) CrossRefGoogle Scholar
- 9.Caughey AB, Stotland NE, Washington AE et al (2007) Maternal and obstetric complications of pregnancy are associated with increasing gestational age at term. Am J Obstet Gynecol. 196(2):155(e1–6). https://doi.org/10.1016/j.ajog.2006.08.040 (PubMed PMID: 17306661; PubMed Central PMCID: PMCPmc1941614. eng) CrossRefGoogle Scholar
- 14.Lassiter JR, Holliday N, Lewis DF et al (2016) Induction of labor with an unfavorable cervix: how does BMI affect success? (double dagger). J Matern Fetal Neonatal Med Off J Eur Assoc Perinat Med Fed Asia Ocean Perinat Soc Int Soc Perinat Obstet 29(18):3000–3002. https://doi.org/10.3109/14767058.2015.1112371 (PubMed PMID: 26513375; eng) CrossRefGoogle Scholar
- 17.Nuthalapaty FS, Rouse DJ, Owen J (2004) The association of maternal weight with cesarean risk, labor duration, and cervical dilation rate during labor induction. Obstet Gynecol 103(3):452–456. https://doi.org/10.1097/01.aog.0000102706.84063.c7 (PubMed PMID: 14990405; eng) PubMedCrossRefGoogle Scholar