Of the 722 women with PCOS included in the study, 83.5% were primiparas, and 16.5% were multiparas. The average maternal age (±SD) was 31.7 ± 6.1 years, gestational age was 38.7 ± 1.7 weeks, and the average pre-pregnancy BMI was 23.6 ± 1.7 kg/m2. Among the 722 subjects, 47(6.5%), 460 (63.7%), 152(21.1%), and 63(8.7 %)were underweight, normal weight, overweight, and obese, respectively, prior to pregnancy. Approximately 169(23%),323(45%), and 230(32%)women experienced inadequate, adequate, and excessive weight gain during pregnancy, respectively, according to the 2009 IOM guidelines. Analysis of the pregnancy outcomes revealed that 22.6%, 12.3%, 5.4%, and 10.9% of the study subjects developed GDM, GH, PE, and PPH, respectively. Regarding the mode of delivery, 56.8%, 8.3%, and 34.9% of the women required vaginal, assisted vaginal, and cesarean section delivery, respectively. Furthermore, 8.7%, 1.8%, and 18.8% of the newborns were macrosomia, SGA, and LGA, respectively.
Table 2 shows the relationship between pre-pregnancy BMI and the pregnancy outcomes. Compared with the women with normal weight before pregnancy, underweight women were positively correlated with the risk of SGA birth (OR 12.35, 95% CI 3.56-42.82) and vaginal delivery (OR 2.21, 95% CI 1.09-4.50), but were negatively correlated with the risk of LGA (OR 0.21, 95% CI 0.05-0.88). Overweight and obese women had increased risk of developing gestational hypertension (OR 4.86, 95% CI 2.82-8.39; and OR 6.05, 95% CI 2.97-12.33, respectively), undergoing cesarean section delivery (OR 1.71, 95% CI 1.15-2.55; and OR 2.10, 95% CI 1.18-3.74, respectively), and having an infant with LGA (OR 2.57, 95% CI 1.64-4.04; and OR 2.22, 95% CI 1.12-4.39, respectively) . Overweight women were more likely to develop PE (OR 4.08, 95% CI 1.95-8.51) and result in macrosomia at birth (OR 2.15, 95% CI 1.14-4.05) when compared with normal weight PCOS women.
As Table 3 shows, significantly lower (P<0.05) incidences of GH and PPH were observed in the inadequate GWG groups, whereas significantly higher (P<0.001) LGA and macrosomia incidences were reported in the excessive GWG group relative to the other 2 groups. The results from multivariate logistic regression demonstrated that compared with the women in the adequate GWG group, individuals in the inadequate GWG group had a lower risk of developing GH(OR 0.28, 95% CI 0.12-0.66)and PPH(OR 0.38, 95% CI 0.17-0.84), while those in the excessive GWG group were more likely to deliver macrosomia(OR 1.93, 95%CI 1.05-3.54)and give birth to LGA infants (OR 1.94, 95%CI 1.27-2.96). Further subgroup analyses based on stratification of body mass indices revealed that when compared with the adequate GWG group women with the same BMI, inadequate GWG decreased the risks of GH(OR 0.24, 95%CI 0.08-0.71) and PPH(OR 0.38, 95%CI 0.16-0.95)in women with BMI <25 kg/m2 before pregnancy (Table 4). Moreover, excessive GWG was related to the higher possibility of LGA birth(OR 2.41, 95%CI 1.40-4.18)in women with BMI <25kg/ m2, as well as the likelihood of undergoing a cesarean section(OR 2.06, 95%CI 1.01-4.20)in women with BMI ≥25kg/ m2 (Table 5).
Table 1. Recommendations for total weight gain during pregnancy, by pregnancy body mass index, according to the guidelines of the Institute of Medicine and National Research Council (2009).
Pre-pregnancy Weight category
|
Body Mass Index (kg/m2)
|
Recommended Range of Total Weight (kg)
|
Underweight
|
<18.5
|
12.5-18.0
|
Normal Weight
|
18.5-24.9
|
11.5-16.0
|
Overweight
|
25.0-29.9
|
7.0-11.5
|
Obese
|
≥30
|
5.0-9.0
|
Table 2. The relationship between BMI categories and maternal/fetal outcomes
|
Underweight
|
Overweight
|
Obesity
|
Outcome
|
Adjusted OR 95%CI
|
Adjusted OR 95%CI
|
Adjusted OR 95%CI
|
GH
|
0.24[0.03-1.80]
|
4.86[2.82-8.39]**
|
6.05[2.97-12.33]**
|
PE
|
0.55[0.07-4.29]
|
4.08[1.95-8.51]**
|
1.46[0.40-5.37]
|
GDM
|
0.56[0.21-1.51]
|
1.33[0.85-2.09]
|
1.23[0.65-2.32]
|
PPH
|
0.18[0.02-1.35]
|
1.60[0.91-2.81]
|
1.88[0.83-4.24]
|
Cesarean section
|
0.55[0.25-1.20]
|
1.71[1.15-2.55]*
|
2.10[1.18-3.74]*
|
Assisted vaginal delivery
|
0.36[0.08-1.56]
|
0.50[0.23-1.12]
|
0.41[0.12-1.42]
|
Vaginal delivery
|
2.21[1.09-4.50]*
|
0.75[0.51-1.09]
|
0.65[0.37-1.14]
|
Macrosomia
|
0.46[0.10-2.07]
|
2.15[1.14-4.05]*
|
1.54[0.52-4.55]
|
SGA
|
12.35[3.56-42.82]**
|
0.41[0.05-3.62]
|
NS
|
LGA
|
0.21[0.05-0.88]*
|
2.57[1.64-4.04]**
|
2.22[1.12-4.39]*
|
OR=odds ratio; CI=confidence interval; GH= gestational hypertension; PE=preeclampsia; GDM=gestational diabetes mellitus; PPH=postpartum hemorrhage; SGA= small for gestational age; LGA=large for gestational age; NS=the number in this category was too small to analyze;
Data was analyzed using multivariable logistic regression analysis. Models were adjusted for maternal age, height, gravidity, parity, gestational age at delivery, weight gain during pregnancy, cigarette smoke pre-pregnancy, and alcohol consumption pre-pregnancy.
Reference group: normal weight for pre-pregnancy
* p < 0.05; ** p < 0.001
Table3. The relationship between GWG categories and maternal/fetal outcomes
|
Pregnancy Outcomes by Gestational Weight Gain Category
|
Multivariable Logistic Regression Analyses
|
Outcome
|
Inadequate
(N=169)
|
Adequate
(N=323)
|
Excessive
(N=230)
|
p-Value
|
Inadequate Weight gain
|
Excessive Weight gain
|
GH(N)
|
7(4.1%)
|
42(13%)
|
40(17.4%)
|
<0.001
|
0.28[0.12-0.66]
|
1.15[0.69-1.91]
|
PE (N)
|
5(3%)
|
17(5.3%)
|
17(7.4%)
|
0.15
|
0.56[0.20-1.56]
|
1.36[0.66-2.78]
|
GDM(N)
|
64(37.9%)
|
69(21.4%)
|
30(13%)
|
<0.001
|
2.30[1.49-3.54]
|
0.49[0.30-0.80]
|
PPH (N)
|
8(4.7%)
|
38(11.8%)
|
33(14.3%)
|
0.008
|
0.38[0.17-0.84]
|
1.21[0.73-2.04]
|
Cesarean section (N)
|
56(33.1%)
|
108(33.4%)
|
88(38.3%)
|
0.43
|
0.88[0.58-1.34]
|
1.28[0.88-1.87]
|
Assisted vaginal delivery (N)
|
14(8.3%)
|
30(9.3%)
|
16(7.0%)
|
0.62
|
0.97[0.49-1.92]
|
0.64[0.34-1.24]
|
Vaginal delivery (N)
|
99(58.6%)
|
185(57.3%)
|
126(54.8%)
|
0.73
|
1.13[0.76-1.67]
|
0.91[0.64-1.29]
|
Macrosomia (N)
|
7(4.1%)
|
22(6.8%)
|
34(14.8%)
|
<0.001
|
0.67[0.27-1.66]
|
1.93[1.05-3.54]
|
SGA (N)
|
4(2.4%)
|
5(1.5%)
|
4(1.7%)
|
0.72
|
1.23[0.31-4.87]
|
1.25[0.32-4.95]
|
LGA (N)
|
18(10.7%)
|
53(16.4%)
|
72(31.3%)
|
<0.001
|
0.65[0.36-1.17]
|
1.94[1.27-2.96]
|
N = number of cases; GH= gestational hypertension; PE=preeclampsia; GDM=gestational diabetes mellitus; PPH=postpartum hemorrhage; SGA= small for gestational age; LGA=large for gestational age;
multivariable logistic regression analysis was adjusted for maternal age, height, gravidity, parity, gestational age at delivery, pre-pregnancy BMI, cigarette smoke pre-pregnancy, and alcohol consumption pre-pregnancy.
Reference group: adequate GWG group
Table 4. Pregnancy outcomes among women whose weight gain was below recommended levels by guidelines of the Institute of Medicine
|
BMI<25 kg/ m2
|
BMI≥25 kg/ m2
|
Outcome
|
Adjusted OR 95%CI
|
p-Value
|
Adjusted OR 95%CI
|
p-Value
|
GH
|
0.24 [0.08-0.71]
|
0.01
|
0.27[0.05-1.33]
|
0.11
|
PE
|
0.62 [0.19-2.01]
|
0.42
|
NS
|
|
GDM
|
2.55 [1.54-4.23]
|
<0.001
|
2.16[0.87-5.38]
|
0.10
|
PPH
|
0.38 [0.16-0.95]
|
0.04
|
0.22[0.02-1.95]
|
0.17
|
Cesarean section
|
0.83[0.52-1.33]
|
0.43
|
0.94[0.38-2.34]
|
0.89
|
Assisted vaginal delivery
|
0.88[0.42-1.84]
|
0.73
|
1.18[0.14-10.02]
|
0.88
|
Vaginal delivery
|
1.23[0.79-1.92]
|
0.35
|
1.06[0.43-2.63]
|
0.90
|
Macrosomia
|
0.78[0.28-2.14]
|
0.63
|
0.26[0.02-3.37]
|
0.30
|
SGA
|
1.43[0.36-5.67]
|
0.61
|
NS
|
|
LGA
|
0.54[0.25-1.16]
|
0.11
|
1.05[0.34-3.23]
|
0.93
|
OR=odds ratio; CI=confidence interval; GH= gestational hypertension; PE=preeclampsia; GDM=gestational diabetes mellitus; PPH=postpartum hemorrhage; SGA= small for gestational age; LGA=large for gestational age; NS=the number in this category was too small to analyze;
Data was analyzed using multivariable logistic regression analysis. Models were adjusted for maternal age, height, gravidity, parity, gestational age at delivery, cigarette smoke pre-pregnancy, and alcohol consumption pre-pregnancy.
Reference group: adequate GWG in the same BMI category
Table 5. Pregnancy outcomes among women whose weight gain was above recommended levels by guidelines of the Institute of Medicine
|
BMI<25 kg/m2
|
BMI≥25 kg/m2
|
Outcome
|
Adjusted OR 95%CI
|
p-Value
|
Adjusted OR 95%CI
|
p-Value
|
GH
|
0.43[0.17-1.11]
|
0.08
|
1.85[0.86-4.00]
|
0.12
|
PE
|
0.48[0.13-1.79]
|
0.27
|
2.08[0.69-6.32]
|
0.20
|
GDM
|
0.31[0.14-0.72]
|
0.006
|
0.56[0.27-1.17]
|
0.12
|
PPH
|
1.15[0.57-2.30]
|
0.70
|
1.50[0.70-3.21]
|
0.29
|
Cesarean section
|
0.94[0.57-1.54]
|
0.80
|
2.06[1.01-4.20]
|
0.048
|
Assisted vaginal delivery
|
0.88[0.42-1.83]
|
0.72
|
0.43[0.07-2.74]
|
0.37
|
Vaginal delivery
|
1.10[0.70-1.73]
|
0.69
|
0.56[0.28-1.12]
|
0.10
|
Macrosomia
|
1.90[0.87-4.17]
|
0.11
|
2.17[0.69-6.79]
|
0.19
|
SGA
|
1.29[0.28-5.82]
|
0.74
|
NS
|
|
LGA
|
2.41[1.40-4.18]
|
0.002
|
1.53[0.73-3.23]
|
0.26
|
OR=odds ratio; CI=confidence interval; GH= gestational hypertension; PE=preeclampsia; GDM=gestational diabetes mellitus; PPH=postpartum hemorrhage; SGA= small for gestational age; LGA=large for gestational age; NS=the number in this category was too small to analyze;
Data was analyzed using multivariable logistic regression analysis. Models were adjusted for maternal age, height, gravidity, parity, gestational age at delivery, cigarette smoke pre-pregnancy and alcohol consumption pre-pregnancy.
Reference group: adequate GWG in the same BMI category