Abstract

Background: Increasing incidence has been seen among women of reproductive age with every one out of five women being affected by obesity. Obesity poses unfavorable outcomes for both mother and child causing ten percent of gestational diabetes and pre-eclampsia, neonatal deaths.

Objective: To find the association of obesity in pregnancy with maternal and perinatal outcomes.The objective is to investigate the association between maternal obesity during pregnancy and various fetomaternal outcomes and outcome of occurrence of cesarean section deliveries, gestational diabetes, preeclampsia, macrosomia, low birth weight babies, and shoulder dystocia among pregnant women with obesity compared to non-obese pregnant women. The study will assess the relative risk and confidence intervals for all the described outcomes.

Subject and Methods: This cohort study was performed in the Department of Obstetrics and Gynaecology, Kulsoom Bai Valika Hospital, site area, Karachi from February to August 2021. A total of 220 patients were included, 110 patients with a BMI equal to or more than 30 kg/m2 were exposed group and 110 cases BMI less than 30 kg/m2 were in the non-exposed group. A detailed history and examination, baseline investigations were carried out. Performa was given to patients of each group, and outcomes were recorded.

Results: The average age of the patients was 28.73±6.52 years. The rate of cesarean section and PIH was 3 times more likely in obese groups than non-obese groups [RR=2.74 95%CI: 1.69-3.31] and [RR=3.08 95%CI: 2.11-4.49] respectively. The rate of GDM and preeclampsia was also 2 times more likely in the obese group than the non-obese group [RR=1.48 95%CI: 1.07-2.05] and [RR=2; 95%CI: 1.05-3.79] respectively. The rate of low birth weight was not statistically significant between obese and non-obese groups (p=0.053). While rate of macrosomia 7 times and Shoulder Dystocia time 5 more likely in obese groups than non- obese groups [RR=6.85; 95%CI: 3.24-14.48] and [RR=4.80; 95%CI: 2.56-8.99] respectively.

Conclusion: Obesity is a challenge of the present era for obstetricians, which is reaching the status of epidemic worldwide. This study shows that obesity in pregnant females is directly proportional to poor fetomaternal outcomes, therefore pregnant obese females should be managed as a high-risk case.

Keywords: Maternal obesity, GDM, preeclampsia, cesarean section, macrosomia, shoulder dystocia.

INTRODUCTION

Globally, Obesity was classified as a disease in 2013 by the American Medical Association and is a preventable cause of mortality [1-3]. Increasing incidence has been seen among women of reproductive age with every one out of five women being affected by obesity [2-4]. In Pakistan, studies have found obesity to contribute to 24.5%-63.39% [4-6]. According to estimates of a study in 2013. Obesity and overweight females were seen in 60% compared to 34% normal weight females [7].

Obesity during pregnancy contributes to 21.3% of antenatal women being affected which increases the chances of intrapartum, postpartum, and perinatal morbidities and mortalities [8]. Obesity poses unfavorable outcomes for both mother and child causing 10% chances of gestational diabetes and pre-eclampsia, 

11% neonatal deaths, and 3 times more chances of hypertension, and diabetes [9, 10]. The study compared obese (BMI 230 kg/m2) and normal-weight women BMI 20-24.9 kg/m) maternal and perinatal outcomes, found preeclampsia (1.58% vs. 0.54%), gestational diabetes

(5.02% vs. 5.35%), c-section (25.37% vs. 10.06%),

shoulder dystocia (0.27% vs. 0.11%), fetal macrosomia (12.68% vs. 5.22%), low birth weight infants (6.29% vs.

7.26%) [11].

There are several causes of maternal obesity. Not only does obesity itself increase the risk to maternal health but its associated co-morbidities like diabetes mellitus and hypertension are also the culprits behind poor fetomaternal outcomes. Additionally, obesity, metabolic disease, neuropsychiatric, and cognitive disorders are found prevalent in neonates born to obese mothers [12].

The rationale for the study is to determine the recent magnitude of problems caused by obesity in Pakistan and to encourage multidisciplinary involvement including Nutrition consultation to all overweight or 

obese women, so they can be encouraged to follow a proper lifestyle modification to have a safe pregnancy and better outcome [13]. Pregnant women who have gone through bariatric surgery are prone to nutritional deficiencies, so the need for vitamin supplementation must be evaluated when indicated. Obese patients who need cesarean delivery must be evaluated for need of thromboprophylaxis with heparin to prevent thromboembolism. Anesthetist consultation early in labor should be considered for obese women and weight- reduction specialists’ consultation before attempting another pregnancy should be advised.

MATERIALS AND METHODS

This Cohort study with a non-probability consecutive sampling technique was conducted in the Department of Obstetrics and Gynecology, Hospital Karachi, Pakistan from February 2021 to August 2021. The study was approved by the institutional ethics committee approval from the Hospital ethics committee Kulsumbai Valika Social Security SITE Hospital. [Reference no: 0047

/ Dated: 10.02.2021]. All patients signed a written informed consent form.

Inclusion criteria were applied (1) age >16- 45 years,

All term delivered patients, of any parity, of any

mode of delivery, admitted in the inpatient department.

Exposed and Non-exposed groups: Patients with a BMI equal to or more than 30kg/m2 were the exposed group and the non-exposed group was patients with a BMI less than 30 kg/m2. Exclusion criteria were applied

(1) Patients with bleeding disorders. (2) Patients with end-stage renal disease, and liver diseases. (3) Chronic hypertension (4) Type 1 and 2 diabetes.

The sample size was 105 in each group calculated through the WHO sample size calculator by taking a confidence level of 95 % and power of test at 80%.

Operational Definition

Obese and Non-Obese: Obese patients were labelled as patients with a BMI equal to or more than 30kg/m2, and non-obese patients were labeled as those with a BMI less than 30kg/m2.

Maternal Outcomes:

Gestational Diabetes: was labeled by oral glucose tolerance test with fasting glucose more than 90 mg/dl, after 1 hour more than 186 mg/dl, after 2 hours more than 153 mg/dl, or single RBS more than 140mg/dl, a single reading of FBS more than 100mg/dl.

Pre-Eclampsia: it was labeled when a patient was presenting with high blood pressures>140/90mmhg two occasions 4 hours apart and proteinuria (1+ on dipstick).

C-Section: means delivery by cesarean section including both elective C-section and emergency C-section.

Perinatal Outcomes:

Low Birth Weight: Infants born with a birth weight of less than 2500gm.

Macrosomia: it was diagnosed if the delivered baby’s weight is more than 4000gms at the time of Shoulder Dystocia: it was defined as vaginal cephalic delivery that requires additional obstetric maneuvers to deliver the fetus after the head has been delivered and gentle traction has

Data Collection Procedure

After approval, the cases fulfilling the inclusion criteria i.e., all term delivered patients, of any party, of any mode of delivery, admitted in Gynae Obs department of KVSS social security SITE hospital, aged between 16 to 45 years, and excluding patients with bleeding disorders, renal or liver disease, chronic hypertension was included. Written patient informed consent was taken from the patient or next of kin by the Researcher’s Postgraduate Trainee. Data collection was conducted by investigators. A detailed history and examination, baseline investigations were carried out. BMI was based on height and weight recorded at the first prenatal visit. BMIs were divided into two categories obese (BMI 30.0 kg/m2 and above) and non-obese (BMI less than 30kg/m2). Patients were allocated into two groups Obese group will include patients after checking body mass index equal to or greater than 30kg/m2. While the Non-obese group will include patients with a BMI less than 30kg/m2. Performance was given to the patient of each group, and outcomes were assessed, gestational diabetes based on an oral glucose tolerance test with fasting glucose more than 90 mg/dl, after 1 hour more than 186 mg/dl, after 2 hours more than 153 mg/dl or single RBS more than 140mg/dl, a single reading of FBS more than 100mg/dl, preeclampsia on basis of high blood pressures>140/90on two occasions 4 hours apart, proteinuria (1+ on dipstick), mode of delivery either SVD, elective c section or emergency c section, Low birth weight infants born with a birth weight of less than 2500gm Macrosomia was diagnosed if fetal weight is more than 4000gms at the time of birth, shoulder dystocia was defined as vaginal cephalic delivery that requires additional obstetric maneuvers to deliver the fetus after the head has delivered and gentle traction has failed.

DATA ANALYSIS

SPSS.20 is used to perform statistical analysis. Mean +/- SD was calculated from the age of the patient, and BMI, gestational age, and parity. Frequency percentage was calculated for the outcome of the study, and pregnancy-induced hypertension, gestational diabetes, birth through C-section, low birth weight, macrosomia, and shoulder dystocia. Maternal and perinatal outcomes were compared between obese and non-obese groups. The Chi-square test was applied, keeping the p-value ≤0.05. Relative risk was calculated, relative risk of more

Table 1: Baseline characteristics of women in exposed and non- obese groups.

Table 2: Comparison of the rates of Maternal Outcomes in both

obese and non-obese groups

*Relative Risk (RR)

than 1 was considered significant. Stratification was done regarding age and gestational age. Post-stratification Chi-square test was applied, keeping p value <0.05. Relative risk was calculated, relative risk of more than 1 was considered significant.

RESULTS

The study included a total of 220 patients with an average age of 28.73±6.52 years. Among them, 110 patients with a BMI equal to or more than 30kg/m2 were obese group, while 110 cases BMI less than 30 kg/m2 were in the non-obese group. Table 1 presents the Mean age, gestational age, BMI, and parity according to obese and in-obese groups.

Table 2 displays the rates of maternal outcomes in both obese and non-obese groups. Maternal outcomes such as cesarean section, GDM, PIH, preeclampsia, macrosomia, and shoulder dystocia were significantly associated with the obese group. The rate of cesarean section and PIH was 3 times more likely in obese groups than non-obese groups [RR=2.74 95%CI: 1.69- 3.31] and [RR=3.08 95%CI: 2.11-4.49] respectively. The rate of GDM and preeclampsia was also 2 times more likely in the obese group than the non-obese group [RR=1.48 95%CI: 1.07-2.05] and [RR=2; 95%CI: 1.05-

3.79] respectively. The rate of low birth weight was not statistically significant between obese and non-obese groups (p=0.053). While the rate of macrosomia 7 times and Shoulder Dystocia time 5 more likely in obese groups than non-obese groups [RR=6.8595%CI:3.24-14.48] and [RR=4.80;95%CI:2.56-8.99] respectively.

Table 3 presents the rate of poor perinatal outcomes for both groups respectively. Stratification analysis according to age and gestational age was performed. It shows that above 30 years’ cesarean section, GDM, pre-eclampsia, and shoulder dystocia rates were higher in the obese group while PIH and low birth weight

Table 3: Comparison the rate of poor Perinatal Outcomes for both

obese and non-obese groups

*Relative Risk (RR);

*Not applicable due to zero cell (NA).

were higher in the non-obese group. In the below 30 years group, all the poor outcomes were prevalent in the obese group. The stratification analysis according to gestational age shows that all poor outcomes were more common in the obese group at all gestational ages. Analysis suggests that maternal BMI greater than or equal to 30 kg/m² may be a risk factor for adverse maternal and perinatal outcomes.

DISCUSSION

Obesity is globally recognized as a key public health issue, [14, 15] which leads to so many diseases like hypertension, coronary heart disease, type 2 diabetes mellitus, and renal disease which has led to a sharp rise in mortality and morbidity [16, 17].

During pregnancy, obesity increases the risk of fetomaternal complications. Obese women are known to be at risk of antenatal, intrapartum, postpartum, and neonatal complications such as hypertensive disorders of pregnancy, gestational diabetes mellitus, venous thromboembolism, cesarean section, preterm delivery, fetal macrosomia, and unexplained stillbirths [18-25]. Additionally, metabolic disease [26], neuropsychiatric, and cognitive disorders are increasingly found in children of obese women [27].

In the present study, the average age of the patients was 28.73±6.52 years. In Melchor et al. study maternal age of normal weight was 33.82 ± 4.86, and in obesity patients age was 34.05 ± 4.94.

In developed countries, obesity has sharply increased in the past 2 decades. WHO has labeled obesity as a major health threat, specifically due to its association with cardiovascular complications [27]. In the latest European Perinatal Health Report, it was found that the prevalence of obesity (BMI ≥ 30 kg/m²) in pregnant women was least in Poland (7.1%), Slovenia (9.0%), and France (9.9%), while most of the European countries had rates of 12- 14%, and in Scotland, the rate of obesity in pregnancy was 20.7% [28].

In this study, maternal and perinatal outcomes like cesarean section, GDM, PIH, preeclampsia, macrosomia, and shoulder dystocia were significantly associated with obese groups as compared to non-obese groups. The 

results of a study conducted on singleton pregnancies compared obese (BMI ≥30 kg/m2) and normal-weight women (BMI 20-24.9 kg/m2) for maternal and perinatal outcomes, found preeclampsia (1.58% vs. 0.54%),

gestational diabetes (5.03 vs. 5.35%), c section (25.37%

10.06%), shoulder dystocia (0.27% vs. 0.11%), fetal macrosomia (12.68% vs. 5.22%), low birth weight infants (6.29% vs. 7.26%) 11.

It is calculated through a systemic review of articles that a rise of 1 kg/m2 in BMI increases the risk of gestational diabetes mellitus by 0.92%. It was found in another review that the risk of preeclampsia increases to double with each 5-7 kg/m2 rise in pre-pregnancy BMI [29]. In the Melchor et al. study, it was found that maternal obesity increases the rates of hypertensive disorders of pregnancy but not diabetes both pre-gestational and gestational. The specific association of obesity vs. gestational diabetes is not clear. Obesity is considered a high risk factor for gestational diabetes whereas the majority of obese women do not develop such disorder [30]. In this study rate of cesarean section and PIH was 3 times more likely in obese groups than in non-obese groups. The rate of GDM and preeclampsia was also 2 times more likely in the obese group than non-obese group respectively. It is calculated through a systemic review of articles that a rise of 1 kg/m2 in BMI increases the risk of gestational diabetes mellitus by 0.92% [31]. It was found in another review that the risk of preeclampsia increases to double with each 5-7 kg/m2 rise in pre- pregnancy BMI [31].

In our study, the prevalence of gestational diabetes is much lower in obese women than that found in other studies conducted in North America and Western Europe [29-32], and this could be the rationale behind the absence of differences in the rate of gestational diabetes between obese and normal- weight population. While macrosomia was found 7 times more likely and Shoulder Dystocia 5 times more likely in obese women.

Meta-analysis of data found that a high pre-pregnancy body mass index is linked with infant macrosomia [33]. There is a direct proportionality between maternal obesity and higher birth weight. This study is found to be consistent with the wider literature on obesity in pregnancy and maternal BMI <50 [34]. Similarly, the association between maternal obesity with poor infant condition immediately after birth has been supported by both a wider maternal obesity review [35] and studies of pregnant women with BMI>50 [36].

CONCLUSION

In conclusion, Obesity in pregnancy is increasing worldwide, reaching epidemic proportions in many countries and frequently creating challenges for obstetricians. In this study, our results indicate that maternal obesity is associated with an increased risk of adverse maternal and fetal/neonatal complications.

Pregnancy in this population of women should, therefore,

be considered and managed as high-risk.

The strength of the study utilizes a robust retrospective case-control design, providing a valuable association between maternal obesity and fetomaternal outcomes. The comprehensive examination of various outcomes including cesarean section rates, gestational diabetes, and preeclampsia, contributes to a holistic understanding of the impact of maternal obesity. The limitation of this study is retrospective nature may be prone to recall bias and limited access to certain data points. External factors such as socioeconomic status and lifestyle choices. Which could influence outcomes, were not extensively explored. Prospective, multicenter studies could validate and expand upon these findings, enhancing their generalizability. Long-term follow-up studies assessing the impact of maternal obesity on the health of offspring could provide valuable insights into intergenerational effects.

A prospective study could involve enrolling pregnant women early in their gestation and regularly monitoring their outcomes, allowing for real-timing data collection and minimizing recall bias. Implementing a multidisciplinary approach involving obstetricians, nutritionists, and mental health professionals can offer comprehensive pre-pregnancy counseling. Addressing lifestyle modifications, nutritional guidance, and mental health support during preconception can potentially reduce the risks associated with maternal obesity, enhancing both maternal and fetal well-being.

ETHICAL APPROVAL

Ethical approval was obtained from the Institutional Ethics Committee of Kulsumbai Valika Social Security (KVSS), SITE Hospital, Karachi (REF letter No. 0047/ Dated: 10-02-2023). All procedures performed in studies involving human participants were following the ethical standards of the institutional and/ or national research committee and the Helsinki Declaration.

CONSENT FOR PUBLICATION

Written informed consent was taken from the participants.

AVAILABILITY OF DATA

The data set may be acquired from the corresponding

author upon a reasonable request.

FUNDING

Declared none.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

ACKNOWLEDGEMENTS

In compliance with the ICMJE uniform disclosure form the authors acknowledge all investigators, staff at the participating centers, and all patients for their commitment to the study.

AUTHORS’ CONTRIBUTION

SS, and SR, participated in the study design, data collection, drafting, and critical review. AM, TRA performed data collection, and analysis and wrote the description of the results. KA and MB participated in data collection and wrote the Discussion. SS, SR, AM, TRA, KA, and MB participated in the finalization of the article. All authors read and approved the final manuscript. All authors read and approved the final manuscript.

REFERENCES

1. Afshin A, Forouzanfar MH, Reitsma MB, Sur P, Estep K, Lee A et Health effects of overweight and obesity in 195 countries over 25 years. N Engl J Med 2017; 377(1): 13-27.

2. Simko M, Totka A, Vondrova D, Samohyl M, Jurkovicova J, Trnka M, et al. Maternal body mass index and gestational weight gain and their association with pregnancy complications and perinatal Int J Environ Res Public Health 2019; 16(10): 1751.

3. Hilder L, Zhichao Z, Parker M, Jahan S, Chambers G. Australia’s mothers and babies AIHW, editor. Perinatal statistics series no 30. Canberra: AIHW; 2014. https://www.aihw.gov.au/ getmedia/674fe3d3-4432-4675-8a96-cab97e3c277f/18530.pdf. aspx?inline=true

4. Yasir I, Ahmed F, Khan M. Assessment of body mass index and association of obesity with lifestyle among MBBS students of ANMC, Islamabad: A descriptive cross sectional study. Isra Med J 2017; 9(3): 126-60.

5. Ghafoor MU, Mahmood-ur Rahman, Irshad Screening tools for obesity; evaluation of waist hip ratio, waist circumference and BMI among hypertensive patients in a tertiary care hospital. Professional Med 2016; 23(07): 844-57.

6. Adil M, Maula F, Nadeem M, Zaman S, Bilal M, Nawaz R, et al. Prevalence of overweight and obesity in health Gomal J Med Sci 2013; 11(1): 59-62.

7. Papachatzi E, Papadopoulos V, Dimitriou G, Paparrodopoulos S, Olivgeris PM, Vantarakis A. Prepregnancy maternal obesity and fetal-perinatal death in a Mediterranean country. J Perinat Med 2015; 43(3): 291-8.

8. Uebel K, Pusch K, Gedrich K, Schneider KM, Hauner H, Bader Effect of maternal obesity with and without gestational diabetes on offspring subcutaneous and preperitoneal adipose tissue development from birth up to year-1. BMC Pregnancy Childbirth 2014; 14: 138.

9. Korejo R, Naseeb S, Yasmin H, Ahmed Audit of perinatal mortality at Jinnah Postgraduate Medical Centre Karachi. J BahriaUni Med Dental Coll 2014; 4(1): 20-4.

10. Nazli R, Akhtar T, Lutfullah G, Khan MA, Haider J, Aslam H. Prevalence of obesity and associated risk factors in a female population of rural Peshawar - Pakistan. Khyber Med Uni Med J 2015; 7(1): 19-24.

11. Melchor I, Burgos J, Del Campo A, Aiartzaguena A, Gutiérrez J, Melchor Effect of maternal obesity on pregnancy outcomes in women delivering singleton babies: a historical cohort study. J Perinat Med 2019; 47(6): 625-30.

12. HowellKR,PowellTL.Effectsofmaternalobesityonplacentalfunction and fetal development. Reproduction 2017; 153(3): R97-R108.

13. American College of Obstetricians and ACOG Committee opinion no. 549: obesity in pregnancy. Obstet Gynecol 2013; 121(1): 213-7

14. Summary Chart of S. Medical Eligibility Criteria for Contraceptive Use. (Accessed on August 14, 2016). Available from: https://www. cdc.gov/reproductivehealth/contraception/pdf/summary-chart-us- medical-eligibility-criteria_508tagged.pdf

15. Cappuccio FP, Micah FB, Emmett L, Kerry SM, Antwi S, Martin- Peprah R, et al. Prevalence, detection, management, and control of hypertension in Ashanti, West Africa. Hypertension 2004; 43(5): 1017-22.

16. 1999 World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension. Guidelines J Hypertens 1999; 17(2): 151-83.

17. Gupta R. Trends in hypertension epidemiology in India. J Hum 2004; 18(2): 73-8.

18. Marchi J, Berg M, Dencker A, Olander EK, Begley Risks associated with obesity in pregnancy, for the mother and baby: a systematic review of reviews. Obes Rev 2015; 16(8): 621-38

19. Torloni MR, Betrán AP, Horta BL, Nakamura MU, Atallah AN, Moron AF, et Prepregnancy BMI and the risk of gestational diabetes: a systematic review of the literature with meta-analysis. Obes Rev 2009; 10(2): 194-203.

20. Wang Z, Wang P, Liu H, He X, Zhang J, Yan H, et Maternal adiposity as an independent risk factor for pre-eclampsia: a meta-analysis of prospective cohort studies. Obes Rev 2013; 14(6): 508-21.

21. Heslehurst N, Vieira R, Hayes L, Crowe L, Jones D, Robalino S, et al. Maternal body mass index and post-term birth: a systematic review and meta-analysis. Obes Rev 2017; 18(3): 293-308.

22. Chu SY, Kim SY, Schmid CH, Dietz PM, Callaghan WM, Lau J, et Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes Rev 2007; 8(5): 385-94.

23. Manzanares GS, Santalla HA, Vico ZI, Criado MSL, Pineda LA, Gallo VJL. Abnormal maternal body mass index and obstetric and neonatal J Matern Fetal Neonatal Med 2012; 25(3): 308-12.

24. Aune D, Saugstad OD, Henriksen T, Tonstad Maternal body mass index and the risk of fetal death, stillbirth, and infant mortality: a systematic review and meta-analysis. JAMA2014; 311(15): 1536-46.

25. Gaudet L, Ferraro ZM, Wen SW, Walker Maternal obesity and occurrence of fetal macrosomia: a systematic review and metaanalysis. Biomed Res Int 2014: 2014; 640291.

26. Liat S, Cabero L, Hod M, Yogev Obesity in obstetrics. Best Pract Res Clin Obstet Gynaecol 2015; 29(1): 79-90.

27. Azaïs H, Leroy A, Ghesquiere L, Deruelle P, Hanssens S. Effects of adipokines and obesity on uterine Cytokine Growth Factor Rev 2017; 34: 59-66.

28. EURO-PERISTAT European perinatal health report. Health and care of pregnant women and babies in Europe in 2010. Available from: http://www.europeristat.com/reports/european- perinatal-health-report-2010.html Accessed February 28, 2019

29. Kim SS, Zhu Y, Grantz KL, Hinkle SN, Chen Z, Wallace ME, et al. Obstetric and neonatal risks among obese women without chronic Obstet Gynecol 2016; 128(1): 104-12.

30. O’Brien TE, Ray Chan WS. Maternal body mass index and the risk of preeclampsia: A systematic overview. Epidemiology 2003; 14(3): 368-74.

31. White SL, Lawlor DA, Briley AL, Godfrey KM, Nelson SM, Oteng- Ntim E, et Early antenatal prediction of gestational diabetes in obese women: development of prediction tools for targeted intervention. PLoS One 2016: 11(12): e0167846.

32. Ovesen P, Rasmussen S, Kesmodel U. Effect of prepregnancy maternal overweight and obesity on pregnancy outcome. Obstet Gynecol 2011; 118 (2 Pt 1): 305-12.

33. Yu Z, Han S, Zhu J, Sun X, Ji C, Guo Pre-pregnancy body mass index in relation to infant birth weight and offspring overweight/ obesity: a systematic review and meta-analysis. PLoS ONE 2013; 8(4): e61627.

34. Marshall NE, Guild C, Cheng YW, Caughey AB, Halloran The effect of maternal body mass index on perinatal outcomes in women with diabetes. Am J Perinatol 2014; 31(3): 249-56.

35. Zhu T, Tang J, Zhao F, Qu Y, Mu Association between maternal obesity and offspring Apgar score or cord pH: a systematic review and meta-analysis. Sci Rep 2015; 5: 18386.

36. Alanis MC, Goodnight WH, Hill EG, Robinson CJ, Villers MS, Johnson Maternal super-obesity (body mass index > or = 50) and adverse pregnancy outcomes. Acta Obstetricia et Gynecologica Scandinavica 2010; 89(7): 924.