Women with high BMI: Should they be managed differently due to antagonising action of leptin in labour?

Is Obesity a Risk Factor for Disorders of Amniotic Fluid?

OBJECTIVES

Prior studies show conflicting evidence as to whether obesity in the absence of other medical or pregnancy-related conditions contributes to amniotic fluid disorders. The purpose of this study is to determine the association between late-pregnancy obesity with oligohydramnios (amniotic fluid index [AFI] ≤5 cm or maximum vertical pocket [MVP] <2 cm) and/or polyhydramnios (AFI ≥24 cm or MVP ≥8 cm).

METHODS

This is a retrospective cohort study of 961 women with singleton gestations who had one or more obstetrical ultrasounds at a single institution at 36 0/7 weeks gestation or beyond between August 1, 2015, and May 1, 2020. Patients were included if they had valid pregnancy dating and a documented AFI and/or MVP. Patients were categorized based on body mass index or BMI (eg, normal, overweight, Class I Obesity, Class II Obesity, or Class III Obesity).

RESULTS

A total of 6.2% of patients met criteria for oligohydramnios based on AFI, MVP or both (n = 60). There was no significant association between oligohydramnios and increasing BMI, regardless of obesity class (P = .21). In terms of polyhydramnios, 5.6% of patients met criteria based on AFI, MVP, or both (n = 54). Similarly, there was also no significant association between polyhydramnios and increasing BMI, regardless of obesity class (P = .66).

CONCLUSIONS

Elevated maternal BMI was not significantly associated with disorders of amniotic fluid, regardless of the severity of obesity.

Cervical ripening balloon compared with vaginal dinoprostone for cervical ripening in obese women at term: A prospective cohort study

OBJECTIVE

To evaluate vaginal delivery in obese women who underwent cervical ripening at term using a dinoprostone vaginal insert or a cervical ripening balloon (CRB), and to assess maternal and neonatal morbidity according to the method.

METHODS

A prospective cohort study including obese women with a live singleton fetus in cephalic presentation who required cervical ripening at term (≥37 weeks) for maternal and/or fetal disease using a dinoprostone vaginal insert or a CRB. The primary outcome was vaginal delivery. Secondary outcomes were a favorable cervix (Bishop score >6) after 24 h, the time from device insertion to delivery, and composite maternal and neonatal morbidity.

RESULTS

In total, 135 consecutive women were analyzed (107 CRB, 79.3%; 28 dinoprostone vaginal insert, 20.7%). Vaginal delivery (86 [80.4%] after CRB vs 19 [67.9%] after dinoprostone vaginal insert; P = 0.248), favorable cervix within 24 h after device placement (52 [48.6%] vs 17 [60.7%]; P = 0.264), and maternal morbidity (12 [11.2%] vs 4 [14.3%]; P = 0.646) were similar between the groups. The time from device insertion to delivery also did not differ between the groups. Neonatal morbidity was significantly higher after the dinoprostone vaginal insert (11 [39.3%] vs 20 [18.7%]; P = 0.030). Cervical ripening using the dinoprostone vaginal insert, compared with the CRB, was significantly associated with neonatal morbidity (adjusted odds ratio 4.00, 95% confidence interval 1.34-12.5), but not with maternal morbidity (adjusted odds ratio 1.23, 95% confidence interval 0.30-4.38).

CONCLUSIONS

Vaginal delivery, a favorable cervix after 24 h, the time from device insertion to delivery, and maternal morbidity did not significantly differ between the CRB and the dinoprostone vaginal insert for cervical ripening in obese women at term. Nevertheless, neonatal morbidity was significantly associated with the dinoprostone vaginal insert, compared with the CRB, among obese women who required cervical ripening at term.

Obstetric outcomes during delivery hospitalizations among obese pregnant women in the United States

The rates of both maternal and fetal adverse outcomes increase significantly with higher body mass index. The aim of this study was to calculate national estimates of adverse maternal and fetal outcomes and associated hospitalization cost among obese pregnant women using a national database. This study was a retrospective analysis of data retrieved from Nationwide Inpatient Sample database, collected during 2010–2014. The primary outcomes of this study were adverse maternal and fetal outcomes, hospital length of stay, and hospitalization cost. There was a total of 18,687,217 delivery-related hospitalizations, of which 1,048,323 were among obese women. Obese women were more likely to have cesarean deliveries (aOR 1.70, 95% CI 1.62–1.79) and labor inductions (aOR 1.51, 95% CI 1.42–1.60), greater length of stay after cesarean deliveries (aOR 1.14, 95% CI 1.08–1.36) and vaginal deliveries (aOR 1.48, 95% CI 1.23–1.77). They were also more likely to have pregnancy-related hypertension, preeclampsia, gestational diabetes, premature rupture of membranes, chorioamnionitis, venous thromboembolism, excessive fetal growth, and fetal distress. Obese pregnant women had significantly greater risk for adverse obstetrical outcomes, which substantially increased the hospital and economic burden. Risk stratification of pregnant patients based on obesity could also help obstetricians to make better clinical decisions and improve patient outcomes.

Association between plasma leptin and cesarean section after induction of labor: a case control study

Background

Obesity in pregnancy is common, with more than 50% of pregnant women being overweight or obese. Obesity has been identified as an independent predictor of dysfunctional labor and is associated with increased risk of failed induction of labor resulting in cesarean section. Leptin, an adipokine, is secreted from adipose tissue under the control of the obesity gene. Concentrations of leptin increase with increasing percent body fat due to elevated leptin production from the adipose tissue of obese individuals. Interestingly, the placenta is also a major source of leptin production during pregnancy. Leptin has regulatory effects on neuronal tissue, vascular smooth muscle, and nonvascular smooth muscle systems. It has also been demonstrated that leptin has an inhibitory effect on myometrial contractility with both intensity and frequency of contractions decreased. These findings suggest that leptin may play an important role in dysfunctional labor and be associated with the outcome of induction of labor at term. Our aim is to determine whether maternal plasma leptin concentration is indicative of the outcome of induction of labor at term. We hypothesize that elevated maternal plasma leptin levels are associated with a failed term induction of labor resulting in a cesarean delivery.

Methods

In this case-control study, leptin was measured in 3rd trimester plasma samples. To analyze labor outcomes, 174 women were selected based on having undergone an induction of labor (IOL), (115 women with successful IOL and 59 women with a failed IOL). Plasma samples and clinical information were obtained from the UI Maternal Fetal Tissue Bank (IRB# 200910784). Maternal plasma leptin and total protein concentrations were measured using commercially available assays. Bivariate analyses and logistic regression models were constructed using regression identified clinically significant confounding variables. All variables were tested at significance level of 0.05.

Results

Women with failed IOL had higher maternal plasma leptin values (0.5 vs 0.3 pg, P = 0.01). These women were more likely to have obesity (mean BMI 32 vs 27 kg/m², P = 0.0002) as well as require multiple induction methods (93% vs 73%, p = 0.008). Logistic regression showed Bishop score (OR 1.5, p < 0.001), BMI (OR 0.92, P < 0.001), preeclampsia (OR 0.12, P = 0.010), use of multiple methods of induction (OR 0.22, P = 0.008) and leptin (OR 0.42, P = 0.017) were significantly associated with IOL outcome. Specifically, after controlling for BMI, Bishop Score, and preeclampsia, leptin was still predictive of a failed IOL with an odds ratio of 0.47 (P = 0.046). Finally, using leptin as a predictor for fetal outcomes, leptin was also associated with of fetal intolerance of labor, with an odds ratio of 2.3 (P = 0.027). This association remained but failed to meet statistical significance when controlling for successful (IOL) (OR 1.5, P = 0.50).

Conclusions

Maternal plasma leptin may be a useful tool for determining which women are likely to have a failed induction of labor and for counseling women about undertaking an induction of labor versus proceeding with cesarean delivery.

Induction of labour in pregnant individuals with obesity

People with obesity may require induction of labour (IoL) due to a higher incidence of pre-existing comorbidities and pregnancy complications, as well as to prevent post-term pregnancies and late-term stillbirths. IoL at 39-40 weeks is associated with fewer caesarean births and lower morbidity for the pregnant person and neonate when compared with expectant management. Ensuring the success and safety of IoL in people with obesity requires adherence to evidence-based protocols for the management of labour induction and augmentation. Cervical ripening as well as the latent and active phases of labour in people with obesity may be considerably prolonged, requiring higher cumulative doses of oxytocin. This should be guided by intrauterine pressure catheters and early provision of neuraxial analgesia, where possible. There is insufficient evidence to recommend one method of IoL over another. The need for higher doses of prostaglandins and concurrent agents for cervical ripening should be studied in prospective studies.

Risk Factors for Carbetocin Failure after a Cesarean Section: Is Obesity One of Them?

Obese pregnant women have increased rates of fetal macrosomia, long labor, and cesarean sections, which lead to an increased risk of postpartum hemorrhage (PPH). Carbetocin is useful for the prevention of PPH after a cesarean section. Our study aimed to investigate predictors of carbetocin failure after a cesarean section, and specifically whether obesity is associated with carbetocin failure. We retrospectively analyzed all women who received carbetocin after a cesarean section. Carbetocin failure was defined as changes in hematocrit and hemoglobin, blood loss ≥ 1000 mL, and the need for an additional uterotonic agent or second-line therapies for persistent PPH. Univariate and multivariate analyses were performed to investigate predictors of carbetocin failure. The study included 600 women, with 131 (21.8%) obese women. Overall, 44 (7.3%) carbetocin failures were reported, and rates of obese women were similar between groups (carbetocin failure, 11.4% vs. 22.9%; p = 0.08). Previous PPH (p < 0.001), a cesarean section during labor (p = 0.01), cervical ripening (p = 0.02), and birthweight (p = 0.01) were significantly different between groups. In the multivariable logistic regression analysis adjusted for potential confounders, cervical ripening (adjusted odds ratio (OR) 2.23, 95% confidence interval (CI) 1.01–4.80), compared with spontaneous labor, was significantly associated with carbetocin failure. Obesity was not associated with carbetocin failure after cesarean sections.

The Myometrium in Pregnant Women with Obesity

Obesity is a worldwide public health problem, affecting at least one-third of pregnant women. One of the main problems of obesity during pregnancy is the resulting high rate of cesarean section. The leading cause of this higher frequency of cesarean sections in obese women, compared with that in nonobese women, is an altered myometrial function that leads to lower frequency and potency of contractions. In this article, the disruptions of myometrial myocytes were reviewed in obese women during pregnancy that may explain the dysfunctional labor. The myometrium of obese women exhibited lower expression of connexin43, a lower function of the oxytocin receptor, and higher activity of the potassium channels. Adipokines, such as leptin, visfatin, and apelin, whose concentrations are higher in obese women, decreased myometrial contractility, perhaps by inhibiting the myometrial RhoA/ROCK pathway. The characteristically higher cholesterol levels of obese women alter myometrial myocyte cell membranes, especially the caveolae, inhibiting oxytocin receptor function, and increasing the K+ channel activity. All these changes in the myometrial cells or their environment decrease myometrial contractility, at least partially explaining the higher rate of cesarean of sections in obese women.

Use of the Robson classification to understand the increased risk of cesarean section in case of maternal obesity

Background

The aim of this study was to identify characteristics of pregnant women with obesity that contribute to increased cesarean rate.

Methods

Retrospective cohort in a single academic institution between 2012 and 2019. Women who delivered during this period were classified according to the Robson classification. Women with normal body mass index (N = 11,797) and with obesity (N = 2991) were compared. The contribution of each Robson group to the overall caesarean rate were compared.

Results

The overall cesarean rate was higher for women with (28.1%) than without (14.2%, p < 0.001) obesity. This result came mainly from Robson group 5a (history of one cesarean). After adjustment for medical factors within this group, the association between maternal obesity and cesarean during labor was significant.

Conclusions

The higher cesarean rate in women with obesity is explained by Robson group 5a in which obesity is an independent risk factor of in labor cesarean delivery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03410-z.

Guideline No. 392-Pregnancy and Maternal Obesity Part 2: Team Planning for Delivery and Postpartum Care

OBJECTIVE

This guideline will review key aspects in the pregnancy care of women with obesity. Part I will focus on Preconception and Pregnancy Care. Part II will focus on Team Planning for Delivery and Postpartum Care.

INTENDED USERS

All health care providers (obstetricians, family doctors, midwives, nurses, anaesthesiologists) who provide pregnancy-related care to women with obesity.

TARGET POPULATION

Women with obesity who are pregnant or planning pregnancies.

EVIDENCE

Literature was retrieved through searches of Statistics Canada, Medline, and The Cochrane Library on the impact of obesity in pregnancy on antepartum and intrapartum care, maternal morbidity and mortality, obstetric anaesthesia, and perinatal morbidity and mortality. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to September 2018. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the authors. Then the Maternal-Fetal Medicine Committees peer reviewed the content and submitted comments for consideration, and the Board of the Society of Obstetricians and Gynaecologists of Canada (SOGC) approved the final draft for publication. Areas of disagreement were discussed during meetings at which time consensus was reached. The level of evidence and quality of the recommendation made were described using the Evaluation of Evidence criteria of the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in these guidelines may increase obstetrical provider recognition of the issues affecting pregnant individuals with obesity, including clinical prevention strategies, communication between the health care team, the patient and family as well as equipment and human resource planning. It is hoped that regional, provincial and federal agencies will assist in the education and support of coordinated care for pregnant individuals with obesity.

GUIDELINE UPDATE

SOGC guideline will be automatically reviewed 5 years after publication. However, authors can propose another review date if they feel that 5 years is too short/long based on their expert knowledge of the subject matter.

SPONSORS

This guideline was developed with resources funded by the SOGC.

SUMMARY STATEMENTS

RECOMMENDATIONS.

The Edmonton Obesity Staging System Predicts Mode of Delivery After Labour Induction

OBJECTIVE

This study sought to evaluate the use of the Edmonton Obesity Staging System (EOSS) in predicting cesarean delivery among term, nulliparous, singleton pregnancies in women with overweight or obesity who are undergoing an induction of labour.

METHODS

A prospective cohort study was performed in Edmonton, Alberta. Women undergoing an induction of labour at term were recruited to either a sample cohort, including women with a body mass index of ≥25 kg/m² at first antenatal visit, or a control cohort with a body mass index of 18.5 to 24.9 kg/m². Participating women provided a self-reported health history and consented to review of their medical records allowing allocation into EOSS categories. The primary outcome was the rate of cesarean delivery based on EOSS category. Secondary outcomes consisted of a summary score of adverse maternal, delivery, and neonatal events (Canadian Task Force Classification II-2).

RESULTS

Overall, 345 women were recruited, with a participation rate of 93.7%. The sample cohort consisted of 276 women with overweight or obesity, whereas the control cohort included 69 normal-weight women. The overall rate of cesarean delivery was 30.4% for the control cohort and 35.8%, 29.9%, 43.2%, and 90.5% for women assigned an EOSS category 0, 1, 2, and 3, respectively (P < 0.001). A summary score was not indicative of overall rate of adverse maternal, delivery, and neonatal events (P = 0.22).

CONCLUSION

The EOSS may help predict the chance of cesarean delivery in a high-risk group of nulliparous women with overweight or obesity who are undergoing an induction of labour at term.

Risk factors for failed induction of labor among pregnant women with Class III obesity

INTRODUCTION

Our aim was to identify risk factors for failed induction in morbidly obese patients undergoing the induction of labor at term.

MATERIAL AND METHODS

This was a retrospective multicenter study on a cohort of 235 patients with a body mass index greater than 40 kg/m² and giving birth to a singleton in cephalic presentation, who had an induction of labor from 38 weeks of amenorrhea. Scheduled cesareans and spontaneous vaginal deliveries were excluded. Maternal, peri-partum and neonatal characteristics were analyzed according to the delivery route.

RESULTS

In all, 235 patients were included. Of these, 62.5% patients delivered vaginally and 37.5% by cesarean section. The frequency of nulliparity was greater in patients who had a cesarean section (56 [interquartile range, IQR, 38.1] vs 56 [IQR 63.6], P < .001). In multivariate analysis, nulliparity (odds ratio [OR] 2.81, 95% confidence interval [CI] 1.58-4.97], P < .001), low Bishop's score (OR .794, 95% CI .70-.90, P < .001) and weight gain (OR 1.04, 95% CI 1.01-1.08, P = .033) were independent risk factors for failed induction. Umbilical cord pH at birth lower than 7 (0 vs 7 [IQR 8.0], P < .001) and lower than 7.20 (36 [IQR 24.5] vs 35 [IQR 39.8], P = .014) as well as the Apgar at 1 minute (14 [IQR 9.5] vs 17 [IQR 19.3], P = .032) was significantly higher in infants born by cesarean section.

CONCLUSIONS

In this cohort, 63% of women with Class III obesity had successful inductions of labor; risk factors for failed induction include nulliparity and unfavorable Bishop score.

Directive clinique No 392 - Grossesse et obésité maternelle Partie 2 : Planification en équipe de l'accouchement et soins post-partum

OBJECTIF

La présente directive clinique aborde les aspects essentiels des soins prénataux chez les femmes atteintes d'obésité. La partie 1 porte sur la préconception et les soins prénataux. La partie 2 porte sur la planification en équipe de l'accouchement et les soins post-partum. UTILISATEURS CONCERNéS: Tous les fournisseurs de soins de santé (obstétriciens, médecins de famille, sages-femmes, infirmières, anesthésiologistes) qui prodiguent des soins relatifs à la grossesse auprès de femmes atteintes d'obésité.

POPULATION CIBLE

Femmes atteintes d'obésité qui sont enceintes ou prévoient le devenir. DONNéES PROBANTES: Des recherches ont été menées en consultant les ressources de Statistique Canada, de Medline et de Cochrane Library en vue d'en tirer la littérature relativement aux effets de l'obésité durant la grossesse sur les soins prénataux et intrapartum, la morbidité et la mortalité maternelles, l'anesthésie obstétricale ainsi que sur la morbidité et la mortalité périnatales. Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. Aucune restriction de date ou de langue n'a été employée. Les recherches ont été mises à jour régulièrement, et les résultats ont été incorporés à la directive clinique jusqu'en septembre 2018. Nous avons également tenu compte de la littérature grise (non publiée) obtenue sur les sites Web d'organismes d'évaluation des technologies de la santé et d'autres organismes pertinents, dans des collections de directives cliniques et des registres d'essais cliniques, et auprès d'associations nationales et internationales de médecins spécialistes. MéTHODES DE VALIDATION: Le contenu et les recommandations ont été rédigés et acceptés par les auteurs. Les membres du comité de médecine fœto-maternelle ont ensuite passé en revue le contenu et formulé des commentaires aux fins d'examen. Enfin, le conseil d'administration de la Société des obstétriciens et gynécologues du Canada (SOGC) a approuvé la publication de la version définitive de la directive. Les points de désaccord ont été abordés lors de réunions pour enfin arriver à un consensus. La qualité des données et des recommandations a été déterminée à l'aide des critères d'évaluation décrits par le Groupe d'étude canadien sur les soins de santé préventifs. AVANTAGES, PRéJUDICE ET COûTS: La mise en place des recommandations des présentes directives peut améliorer la reconnaissance des fournisseurs de soins obstétricaux relativement aux problèmes qui touchent les personnes enceintes atteintes d'obésité, notamment au moyen de stratégies de prévention clinique; de la communication entre l'équipe de soins de santé, la patiente et la famille; et de la planification de l'équipement et des ressources humaines. Il est à espérer que les organismes régionaux, provinciaux et fédéraux participeront à la formation et au soutien en matière de soins coordonnés pour les personnes enceintes atteintes d'obésité. MISE à JOUR DE LA DIRECTIVE CLINIQUE: Les directives de la SOGC sont automatiquement passées en revue 5 ans après leur publication. Les auteurs peuvent toutefois proposer une autre date de réévaluation s'ils croient qu'une période de 5 ans est trop courte ou trop longue en fonction de leurs connaissances du sujet à titre d'experts en la matière.

PROMOTEURS

La présente directive a été élaborée à l'aide de ressources financées par la SOGC. DéCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Indications of caesarean section in overweight and obese versus normal-weight pregnant women: a retrospective cohort study

PURPOSE

The aim of this study was to test the hypothesis that indications of c-section in overweight or obese pregnant women are different from those with normal-weight.

METHODS

Retrospective cohort study at University Hospital of Puerto Real (Cádiz-Spain). We compared frequency distribution of c-section indications in overweight and obese versus normal-weight. The risk of c-section by different indications was calculated as relative risk.

RESULTS

A total of 4685 births were included in the study. There are significant differences in the frequency distribution of caesarean indications among normal weight and overweight or obese women. In overweight, we found an increased risk of c-section due to previous c-section (RR: 1.73; confidence interval [CI] 95% 1.24-2.42), obstructed/non-progressive labour (RR: 1.34; CI 95% 1.03-1.75), failed induction of labour (RR: 2.38; CI 95% 1.30-4.34) and foetal distress (RR: 1.73; CI 95% 1.21-2.49). This risk was even higher in obese women: previous c-section (RR: 3.25; CI 95% 2.24-4.71), obstructed/non-progressive labour (RR: 2; CI 95% 1.45-2.77), failed induction (RR: 2.52; CI 95% 1.15-5.51) and foetal distress (RR: 2.35; CI 95% 1.51-3.65).

CONCLUSIONS

The risk of caesarean section due to previous caesarean section, obstructed/non-progressive labour, failed induction of labour or foetal distress is greater in overweight and obese than in normal-weight. This increase in risk also increases progressively as maternal BMI increases.

Induction of labor in the obese patient

Obese women are at an increased risk of antepartum pregnancy complications and are therefore more likely to require an induction of labor than normal weight women. They also have an increased rate of failing an induction of labor, a rate that rises significantly with increasing body mass index, and subsequent surgical and neonatal complications of an intrapartum cesarean delivery. This increase in induction failure may be due to differences in the myometrium of obese women resulting in decreased contraction strength. There have been only a few studies comparing the efficacy of the various cervical ripening agents in obese women and at this point no recommendation can be made as to what method may result in the greatest chance of a successful induction.

Cumulative oxytocin dose during induction of labor according to maternal body mass index

OBJECTIVE

To determine the cumulative oxytocin dose needed to achieve vaginal delivery among obese and non-obese women.

METHODS

A retrospective study was undertaken of women with singleton, term (≥37 weeks) pregnancies who delivered at an institution in California, USA, between May 1 and July 31, 2012. Women were deemed to be obese when their body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) was 30 or above. Cumulative oxytocin doses were calculated for women who achieved vaginal delivery.

RESULTS

Overall, 413 women were included. Among 357 women for whom BMI data were available, 204 (57.1%) were obese. Vaginal delivery was achieved in 379 women. Among women who received augmentation after spontaneous labor onset, obese women trended towards more cumulative oxytocin (minimum: 24.7 ± 100.5 mU among women with a BMI of 18.50-24.99; maximum: 1580.5 ± 2530.5 mU among women with a BMI of 35.00-39.99; P=0.086). Women who underwent induction of labor required significantly more oxytocin with increasing BMI class (P<0.001), despite no difference in length of labor.

CONCLUSION

Obese women required a larger cumulative oxytocin dose to achieve vaginal birth during labor induction, but not during augmentation of labor. The physiology of spontaneous labor could supersede or influence the metabolic derangement facing obese patients undergoing induction of labor.

A short review of adipokines, smooth muscle and uterine contractility

Obesity is a major health problem worldwide. The prevalence of obesity is increasing in both developed and developing countries. In the UK, for example, 60% of adults are overweight and 25% are obese. Obesity is associated with many pathological complications including respiratory, cardiovascular and endocrine, but it also affects fertility and is associated with many reproductive complications. This has led us and others to investigate links between women with high BMI, pregnancy outcome and uterine function. These studies in turn have led investigators to ask how obesity can have such an impact on reproduction and, as part of this, to consider the role of the adipokines released from adipose tissues. Our focus in this short review is on adipokines and myometrial activity, and for completeness we overview their effects on other smooth muscles. To date four adipokines (leptin, visfatin, apelin and ghrelin) have been investigated and all affect myometrial contractility, but some more potently than others. We consider the possible mechanisms involved in how adipokines may modify uterine contractility, and discuss the potential impact on labor and delivery.

The risk of prelabor and intrapartum cesarean delivery among overweight and obese women: possible preventive actions

OBJECTIVE

The purpose of this study was to investigate prelabor and intrapartum cesarean delivery in overweight and obese women by parity, previous cesarean delivery, and labor induction to assess what preventive actions might be possible.

STUDY DESIGN

We modeled relative risks (RRs) and risk differences of prelabor and intrapartum cesarean delivery by prepregnancy body mass index (obese, ≥30 kg/m(2); overweight, 25-29.9 kg/m(2); normal weight, 18.5-24.9 kg/m(2)) in a nationally representative sample of 12,297 French women. Models were stratified by parity and previous cesarean status. Covariates included maternal sociodemographic characteristics, medical conditions, pregnancy complications, and induction of labor.

RESULTS

Risks of prelabor cesarean delivery were elevated only for obese multiparous women. This reflected not only a higher prevalence of previous cesarean delivery (26.4% vs 17.9% for normal-weight women) but also higher risks of prelabor cesarean delivery for multiparous women with no previous cesarean delivery after adjustment for medico-obstetric factors (RR, 1.82; 95% confidence interval [CI], 1.25-2.64). Obese primiparous women and multiparous women with no previous cesarean delivery had similarly increased adjusted RRs for intrapartum cesarean delivery (RR, 1.64; 95% CI, 1.36-1.98; and RR, 1.66; 95% CI, 1.15-2.39, respectively), but the risk difference was higher for primiparous women, with an absolute increase of 0.10 (95% CI, 0.05-0.14) compared with 0.02 (95% CI, 0.00-0.04) for multiparous women. Increased intrapartum cesarean delivery risks for primiparous women were related to more frequent labor induction (42.6% vs 23.8% for normal-weight women).

CONCLUSION

It may be possible to reduce primary and thus repeat cesarean delivery rates among obese women by preventive actions targeting labor induction in primiparous women and prelabor cesarean deliveries in multiparous women. Further research is needed on the impact of limiting inductions on cesarean delivery risks for obese primiparous women.