Abstract
Objective
To perform analyses of maternal and fetal complications in overweight and obese women.
Methods
Eighty-seven women with singleton pregnancies with BMI > 25–29.9 kg/m2 and 83 women with singleton pregnancies with BMI > 30 kg/m2 were studied for maternal and fetal complications at Nehru Hospital, B.R.D. Medical College, Gorakhpur during June 2007–October 2008. Forty-five women with BMI 20–24.9 kg/m2 were selected to serve as control.
Results
Compared with women with normal BMI, the outcomes which were more common in overweight and obese women were gestation hypertension (p < 0.05); pre-eclampsia (p < 0.001); preterm delivery (p < 0.05); induction of labor (p < 0.05); instrumental vaginal delivery (p > 0.05); cesarean section (p < 0.01); increased operative time (p < 0.01); still births (p < 0.05); early neonatal deaths (p < 0.05); Apgar score < 7 at 5 min (p < 0.05); and admission to NICU (p < 0.001). No significant differences were noted among groups regarding hypoglycemia hyperbilirubinemia and respiratory distress.
Conclusion
Overweight and obesity are definite risk factors for adverse pregnancy outcomes. This may be due to altered metabolic state in obesity.
Keywords: Obesity, Pregnancy, Body mass index, Perinatal outcomes, Morbidity
Introduction
During the last decade, there has been a drastic change in socioeconomic conditions and food habits. Along with this the magnitude of obesity is increasing especially in the urban set ups and may stand out to be a major problem in future. While obesity is an established risk factor for diabetes mellitus, hypertension, coronary artery disease and stroke, much less is known about maternal obesity and pregnancy outcomes.
Materials and Methods
A prospective study was conducted at the maternity unit of Nehru hospital, B.R.D. Medical College, Gorakhpur. Women with singleton pregnancies, who delivered between June 2007 and October 2008, were included in the study. Women with multiple pregnancies, medical disorders, and body mass index (BMI) <19.8 kg/m2 were excluded. Detailed history and examination was collected on data collection sheets.
Maternal BMI was calculated at first antenatal visit and at the time of admission for delivery. Pre-pregnancy BMI could not be reliably obtained in our population because women do not commonly weigh themselves, or have recall. Maternal BMI at the time of labor rather than booking was used to determine the effect of the current BMI on pregnancy outcome. For the purpose of our study, the subjects were divided into groups using Garrow’s grading [1] of obesity based on the Quetlet`s index or BMI which is calculated as weight in kilogram/height in meter [2].
| Grade | Status | BMI (kg/m2) |
|---|---|---|
| 0 | Normal | 20.0–24.9 |
| 1 | Overweight | 25.0–29.9 |
| 2 | Obese | 30.0–40.0 |
| 3 | Morbidly obese | >40.0 |
The prepregnancy variables included age, parity, and socioeconomic status. The antepartum variables analyzed were gestational diabetes, gestational hypertension (GHTN), preeclampsia–eclampsia, anemia, preterm, prolonged pregnancy, intra-uterine growth retardation (IUGR), placental abruption, and miscarriages. Intrapartum variables studied were induction of labor, failed induction, mode of delivery (vaginal delivery/cesarean section), and operative time during cesarean section, instrumental vaginal delivery, vaginal birth after cesarean (VBAC), failed trial of labor in previous one cesarean section, and shoulder dystocia. The postpartum variables studied were postpartum hemorrhage, pyrexia, endometritis, urinary tract infection (UTI), chest infection, prolonged postnatal stay, and impaired wound healing.
The neonatal variables analyzed were low birth weight baby (<2,000 gm), macrosomia (>4,000 gm), prematurity, postmaturity syndrome, APGAR score, neonatal resuscitation, admission to neonatal intensive care unit (NICU), early neonatal death, intranatal death, still birth, neonatal hypoglycemia, neonatal hyperbilirubinemia, and respiratory distress syndrome.
The statistical analysis was performed using χ2 test, odd ratios, and 95 % confidence intervals. The statistical significance was defined as p < 0.05.
Results
Eighty-seven overweight women, 83 obese women, and 45 women with normal BMI were compared and statistically analyzed for obstetric behavior and pregnancy outcomes. The mean age, parity, and socioeconomic status were comparable in all the three groups.
A significantly higher rates of gestational hypertension (p < 0.05), pre-eclampsia (p < 0.001), prolonged pregnancy (p < 0.05), and placental abruption (p < 0.05) were noted in the overweight and obese women as compared to controls. No significant differences were noted among the groups as regards anemia, PROM, and IUGR. There was a higher rate of gestational diabetes and miscarriages among overweight and obese women as compared to controls, but did not attain statistical significance (Table 1).
Table 1.
Antenatal variables
| Antenatal variables | BMI groups | p Value | ||
|---|---|---|---|---|
| Odd ratio (95 % CI) | 20–24.9 | 25–29.9 | 30–40.0 | |
| Prolonged pregnancy | 02 (04.44) | 15 (18.30) | 15 (18.75) | <0.05 |
| Odd ratio (95 % CI) | – | 0.15 (0.09–0.21) | 0.14 (0.08–0.20) | |
| GDM | – | 04 (04.60) | 07 (08.43) | >0.05 |
| GHTN | 01 (02.22) | 15 (18.30) | 12 (15.00) | <0.05 |
| Odd ratio (95 % CI) | – | 0.11 (0.05–0.17) | 0.13 (0.07–0.19) | |
| Pre eclampsia | 01 (02.22) | 15 (18.30) | 31 (38.75) | <0.001 |
| Odd ratio (95 % CI) | – | 0.11 (0.05–0.17 | 0.03 (0.03–0.09) | |
| Anemia | 15 (33.33) | 33 (37.93) | 22 (26.50) | >0.05 |
| Odd ratio (95 % CI) | – | 0.82 (0.76–0.88) | 1.39 (1.27–1.51) | |
| IUGR | 01 (02.22) | 11 (13.41) | 16 (20.00) | <0.05 |
| Odd ratio (95 % CI) | – | 0.15 (0.09–0.21) | 0.9 (0.03–0.15) | |
| Abruption | – | 03 (03.66) | 08 (10.00) | <0.05 |
| Missed abortion | – | 05 (05.75) | 03 (03.61) | <0.05 |
| PROM/PPROM | 04 (09.10) | 15 (21.13) | 10 (14.70) | >0.05 |
| Odd ratio (95 % CI) | – | 0.37 (0.27–0.47) | 0.58 (0.48–0.68) | |
Among intrapartum variables (Table 2), a significantly higher rate of induced labor (p < 0.05), instrumental vaginal delivery (p > 0.05), cesarean section (p < 0.01), failed VBAC (p < 0.01) and increased operative time in cesarean section (p < 0.01) were noted in obese and overweight subjects. However, significant differences in regard to emergency and elective cesareans were not present among the groups. Rate of shoulder dystocia was higher among obese women but did not reach statistical significance.
Table 2.
Intrapartum variables
| Intrapartum variables | BMI groups | p Value | ||
|---|---|---|---|---|
| Odd ratio (95 % CI) | 20–24.9 | 25–29.9 | 30–40.0 | |
| Spontaneous VD | 35 (94.29) | 36 (80.00) | 29 (76.31) | >0.05 |
| Odd ratio (95 % CI) | – | 4.12 (3.34–4.90) | 5.12 (408–516) | |
| Operative VD | 02 (05.71) | 09 (20.00) | 09 (23.68) | >0.05 |
| Odd ratio (95 % CI) | 0.24 (0.14–0.34) | 0.19 (0.09–0.29) | ||
| Shoulder dystocia | – | – | 03 (07.89) | |
| VBAC | 06 (85.70) | 01 (11.10) | 04 (33.30) | <0.01 |
| Odd ratio (95 % CI) | 48.0 (26.1–69.9) | 12.0 (07.3–16.7) | ||
| Induction of labor | 03 (06.80) | 21 (26.92) | 22 (30.90) | <0.05 |
| Odd ratio (95 % CI) | – | 0.21 (0.13–0.29) | 0.18 (0.12–0.24) | |
| Cesarean Section | 10 (22.22) | 37 (45.12) | 42 (52.50) | <0.01 |
| Odd ratio (95 % CI) | 0.21 (0.13–0.29) | 0.18 (0.12–0.24) | ||
| Failed VBAC | 01 (14.29) | 08 (88.80) | 08 (66.60) | <0.01 |
| Odd ratio (95 % CI) | 0.02 (0.04–0.08) | 0.08 (0.08–0.24) | ||
| Increased operative time | 2 (20.00) | 26 (70.27) | 30 (71.43) | <0.01 |
| Odd ratio (95 % CI) | – | 0.11 (0.4–1.01) | 0.10 (0.02–0.18) | |
Among postpartum variables (Table 3), significantly higher number of overweight and obese women (p < 0.01) had prolonged postnatal stay in comparison to women with normal weight. Significantly higher rates of pyrexia (p < 0.01) and impaired wound healing (p < 0.05) were seen in these groups in contrast to controls). No statistically significant difference was seen among the groups regarding postpartum hemorrhage, urinary tract infections and endometritis.
Table 3.
Postpartum variables
| Postpartum variables | BMI group | p Value | ||
|---|---|---|---|---|
| Odd ratio (95 % CI) | 20–24.9 | 25–29.9 | 30–40.0 | |
| Post partum hemorrhage | 00 | 02 (02.44) | 03 (03.75) | >0.05 |
| Pyrexia | 02 (04.44) | 04 (04.88) | 15 (18.75) | <0.01 |
| Odd ratio (95 % CI) | – | 0.91(0.85–0.97) | 0.20 (0.12–0.28) | |
| Endometritis | 02 (04.44) | 03 (03.66) | 07 (08.75) | >0.05 |
| Odd ratio (95 % CI) | – | 1.22 (1.22–1.32) | 0.49 (0.41–0.57) | |
| Post natal stay prolonged | 04 (08.88) | 19 (23.17) | 27 (33.75) | <0.01 |
| Odd ratio (95 % CI) | – | 0.32 (0.24–0.40) | 0.19 (0.11–0.27) | |
| Impaired wound healing | – | 09 (24.32) | 16 (38.10) | <0.05 |
| Urinary tract infection | – | 08 (09.19) | 10 (12.50) | >0.05 |
Macrosomic babies (>4 kg), low birth weight babies (<2 kg), preterm delivery, and postmaturity syndrome were significantly (<0.05) more in overweight and obese women in contrast to controls (Table 4).
Table 4.
Neonatal outcomes (gestational age and birth weight)
| Neonatal outcomes | BMI group | p Value | ||
|---|---|---|---|---|
| Odd ratio (95 % CI) | 20–24.9 | 25–29.9 | 30–40.0 | |
| Preterm (<37 weeks) | 05 (11–11) | 23 (28.05) | 23 (28.75) | <0.05 |
| Odd ratio (95 % CI) | – | 0.25 (0.17–0.33) | 0.24 (0.16–0.37) | |
| Post maturity (>40 weeks) | 02 (04.55) | 04 (05.63) | 06 (08.81) | <0.05 |
| Odd ratio (95 % CI) | – | 0.72 (0.64–0.80) | 0.44 (0.36–0.52) | |
| Low birth wt (<2 kg) | 03 (06.82) | 10 (14.10) | 13 (19.11) | <0.05 |
| Odd ratio (95 % CI) | – | 0.41 (0.31–0.51) | 0.26 (0.18–0.34) | |
| Macrosomia (>4 kg) | – | 05 (07.04) | 06 (08.82) | <0.05 |
A significantly higher rate of stillbirths (p < 0.05) and early neonatal death (p < 0.05) were noted in overweight and obese women as compared to controls (11, 12 vs. 1 % still birth rates and 3, 7, vs. 1 % early neonatal death rates). Neonates born to overweight and obese women exhibited a higher rate (p < 0.001) of admission to NICU > 24 h (35, 36 vs. 5 %). Significantly higher percentage of overweight and obese women (p < 0.05) had neonates with Apgar score <7 at 5 min (32, 36 vs. 14 %). No significant differences were noted among both the groups regarding hypoglycemia, hyperbilirubinemia, and respiratory distress syndrome (Table 5).
Table 5.
Neonatal Complications
| Neonatal complications | BMI group | p Value | ||
|---|---|---|---|---|
| Odd ratio (95 % CI) | 20–24.9 | 25–29.9 | 30–40.0 | |
| APGAR score (<7) | 14 (31.81) | 32 (45.07) | 36 (52.94) | <0.05 |
| Odd ratio (95 % CI) | – | 0.85 (0.79–0.91) | 0.41 (0.31–0.51) | |
| Intubation | 02 (04.55) | 05 (07.04) | 09 (13.24) | >0.05 |
| Odd ratio (95 % CI) | – | 0.63 (0.53–0.73) | 0.31 (0.23–0.39) | |
| Stay in NICU (>24 h) | 05 (11.36) | 35 (49.30) | 36 (52.94) | <0.01 |
| Odd ratio (95 % CI) | – | 0.13 (0.07–0.019) | 0.11 (0.05–0.17) | |
| Still birth | 01 (02.22) | 11 (13.41) | 12 (15.00) | <0.05 |
| Odd ratio (95 % CI) | – | 0.11 (0.05–0.17) | 0.13 (0.07–0.19) | |
| Early NN death | 01 (02.27) | 03 (04.23) | 07 (10.30) | <0.05 |
| Odd ratio (95 % CI) | – | 0.53 (0.45–0.61) | 0.20 (0.12–0.28) | |
| RDS | – | 04 (05.63) | 04 (05.88) | >0.05 |
| Photo therapy | 08 (18.18) | 12 (16.90) | 12 (16.18) | >0.05 |
| Odd ratio (95 % CI) | – | 1.09 (1.03–1.15) | 1.15 (1.07–1.23) | |
| Hypoglycemia | 04 (09.09) | 06 (08.45) | 06 (08.82) | >0.05 |
| Odd ratio (95 % CI) | – | 1.08 (1.02–1.14) | 1.03 (0.99–1.07) | |
Discussion
Concordant to the literature [2, 3], in our study, there was a significantly higher occurrence of gestational hypertension (15 and 18.3 % vs. 2.2 %) and pre-eclampsia (38.7 and 18.3 % vs. 2.2 %) in obese and overweight women. There was significantly higher rate of induction of labor (30.9 and 26.9 % vs. 6.8 %) and instrumental vaginal delivery (23.7 and 20 % vs. 5.7 %) as noted in other studies [2, 3]. The cesarean section rate was also higher in obese (52.5 %) and overweight (45.1 %) women as compared to controls (22.2 %). These results are consistent with many previous reports [2, 3].
The success rate of vaginal delivery in obese and overweight women with prior cesarean delivery is 22 % and is consistent with study by Chauhan et al. [4] and Bujold et al. [5]. In concordance with literature, there is increased operative blood loss (>1,000 ml) and increased perioperative total operative time (100 min) [2].
Similar to the findings in Baeten et al. [6], there was higher rate of preterm deliveries in obese and overweight women (28.8 and 28.1 % vs. 11.1 %) which is contrary to observations made by Sebire et al. [2].
Obesity in pregnancy is associated with postpartum complications [2]. In the present study, pyrexia (18.8 vs. 4.4 %), endometritis (8.8 % vs. 4.4 %), prolonged postnatal stay (33.8 % vs. 8.9 %), impaired wound healing (38.1 % vs. nil), and urinary tract infections (12.5 % vs. nil) all had a higher incidence in the study group.
Lu et al. [7] have demonstrated that obese women are more likely to deliver large for gestational age babies. Similar to results in the literature [3, 6], in our study, the rate of macrosomia among obese women was higher (8.8 % vs. nil). The rate of small for gestational age neonates (SGA) was also higher in obese and overweight women (19.1 and 14.1 % vs. 6.8 %). The higher incidence of SGA noted could be related to severe hypertension and preeclampsia.
An increased incidence of still births (15 and 13.4 % vs. 2.2 %), early neonatal death, and admission to NICU (52.9 and 49.3 % vs. 11.4 %) among obese and overweight women were noted in our study.
Conclusion
Based on the above study, we conclude that obesity is an independent risk factor for adverse pregnancy outcomes and hence it is a preventable risk factor for reducing maternal morbidity, perinatal morbidity, and mortality. A prepregnancy counseling and general awareness regarding weight control and food habits is really required, especially on seeing the increasing trend of overweight and obesity among women in the present day scenario.
References
- 1.Garrow JS. Indices of adiposity. Nutr Abstr Rev Ser. 1983;A53:697–708. [Google Scholar]
- 2.Sebire NJ, Jolly M, Harris JP, et al. Maternal obesity and pregnancy outcome: a study of 287 213 pregnancies in London. Int J Obes Relat Metab Discord. 2001;25:1175–1182. doi: 10.1038/sj.ijo.0801670. [DOI] [PubMed] [Google Scholar]
- 3.Weiss JL, Malone FD, Emig D, et al. FASTER research consortium. Obesity, obstetric complications and cesarean delivery rate—a population-based screening study. Am J Obstet Gynecol. 2004;190:1091–1097. doi: 10.1016/j.ajog.2003.09.058. [DOI] [PubMed] [Google Scholar]
- 4.Chauhan SP, Magann EF, Carroll CS, et al. Mode of delivery for the morbidly obese with prior cesarean delivery: vaginal versus repeat cesarean section. Am J Obstet Gynecol. 2001;185:349–354. doi: 10.1067/mob.2001.116729. [DOI] [PubMed] [Google Scholar]
- 5.Bujold E, Hammoud A, Schild C, et al. The role of maternal body mass index in outcomes of vaginal births after cesarean. Am J Obstet Gynecol. 2005;193:1517–1521. doi: 10.1016/j.ajog.2005.03.041. [DOI] [PubMed] [Google Scholar]
- 6.Baeten JM, Bukusi EA, Lambe M. Pregnancy complications and outcomes among overweight and obsess nulliparous women. Am J Public Health. 2001;91:436–440. doi: 10.2105/AJPH.91.3.436. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Lu GC, Rouse DJ, DuBard M, et al. The effect of the increasing prevalence of maternal obesity on perinatal morbidity. Am J Obstet Gynecol. 2001;185:845–849. doi: 10.1067/mob.2001.117351. [DOI] [PubMed] [Google Scholar]