Supplementary Online Material
Article: The Impact of Obstetric Mode of Delivery on Childhood Behavior
Journal: Social Psychiatry and Psychiatric Epidemiology
Authors: Sukainah Y Al Khalaf1, Sinéad M O’Neill2,3, Linda M O’Keeffe1,2, Tine B Henriksen4, Louise C
Kenny3, John F Cryan5, Ali S Khashan1,3
Affiliations: 1Department of Epidemiology and Public Health, University College Cork, Cork, Ireland
2
National Perinatal Epidemiology Centre (NPEC), Department of Obstetrics and Gynaecology, Wilton, Cork,
Ireland; 3The Irish Centre for Fetal and Neonatal Translational Research (INFANT), Department of Obstetrics
and Gynaecology, University College Cork, Cork, Ireland; 4Perinatal Epidemiology Research Unit, Department
of Pediatrics, Aarhus University Hospital, Skejby, Denmark; 5Alimentary Pharmabiotic Centre, Department of
Anatomy and Neuroscience, University College Cork, Cork, Ireland
Corresponding Author: Ali Khashan, Email: a.khashan@ucc.ie; OR Linda O’Keeffe, Email: l.okeeffe@ucc.ie
Table S1: Summary of the association between mode of delivery and abnormal SDQ scores at age three years
Variable (N)
n (%) abnormal
SDQ
Crude OR (95%CI)
aOR (95%CI)
Effect of mode of delivery by sex
OR (95% CI)
Male
Female
P-value
for interaction
females vs. males
Spontaneous vaginal
(37,711)
Instrumental vaginal
(9,524)
Elective CS
(8,456)
Emergency CS
(8,900)
Peer Problems (≥4)b
2,820 (7.5)
Ref.
Ref.
Ref.
Ref.
-
908 (9.5)
1.30 (1.01, 1.68)*
1.34 (1.02, 1.77)*
1.09 (0.77, 1.55)
1.92 (1.28, 2.87)*
0.034
564 (6.7)
0.88 (0.66, 1.18)
0.99 (0.73, 1.34)
1.00 (0.70, 1.45)
0.96 (0.57, 1.62)
0.895
910 (10.2)
1.41 (1.11, 1.80)*
1.38 (1.06, 1.80)*
1.32 (0.97, 1.82)*
1.47 (0.95, 2.28)
0.704
Spontaneous vaginal
(37,719)
Instrumental vaginal
(9,524)
Elective CS
(8,456)
Emergency CS
(8,900)
Conduct problems (≥4)a
2,647 (7.1)
Ref.
Ref.
Ref.
Ref.
-
760 (8)
1.14 (0.88, 1.50)
1.03 (0.78, 1.36)
0.97 (0.68, 1.39)
1.12 (0.74, 1.70)
0.584
580 (6.9)
0.98 (0.72, 1.32)
1.10 (0.81, 1.50)
0.93 (0.62, 1.41)
1.34 (0.85, 2.11)
0.244
894 (10)
1.48 (1.15, 1.90)*
1.29 (0.98, 1.69)
1.21 (0.86, 1.69)
1.42 (0.93, 2.17)
0.542
Spontaneous vaginal
(37,712)
Instrumental vaginal
(9,524)
Elective CS
(8,456)
Emergency CS
(8,900)
Emotional problems (≥5)c
8,727 (23.1)
Ref.
Ref.
Ref.
Ref.
-
1,921 (20.2)
0.84 (0.71, 0.99)*
0.96 (0.80, 1.15)
0.94 (0.74, 1.19)
0.99 (0.75, 1.30)
0.765
1,706 (20.2)
0.84 (0.70, 1.00)
0.90 (0.74, 1.08)
0.85 (0.66, 1.10)
0.94 (0.72, 1.22)
0.601
1,861 (20.9)
0.87 (0.74, 1.05)
0.91 (0.78, 1.12)
0.88 (0.69, 1.12)
1.00 (0.76, 1.31)
0.489
Spontaneous vaginal
(37,726)
Instrumental vaginal
(9,524)
Elective CS
(8,456)
Emergency CS
(8,900)
Pro-social behavior (≤4) d
1,193 (3.2)
Ref.
Ref.
Ref.
Ref.
-
273 (2.9)
0.91 (0.61, 1.35)
0.99 (0.69, 1.41)
0.71 (0.40, 1.25)
1.17 (0.65, 2.12)
0.220
313 (3.7)
1.18 (0.77, 1.81)
0.90 (0.60, 1.34)
1.26 (0.70, 2.29)
1.11 (0.55, 2.22)
0.776
363 (4.1)
1.30 (0.90, 1.89)
1.08 (0.76, 1.53)
1.10 (0.65, 1.86)
1.14 (0.64, 2.00)
0.929
Hyperactivity (≥7)a
Spontaneous vaginal
1,476 (3.9)
Ref.
Ref.
Ref.
Ref.
(37,712)
Instrumental vaginal
270 (2.8)
0.72 (0.49, 1.04)
0.75 (0.49, 1.13)
0.80 (0.49, 1.28)
0.62 (0.28, 1.36)
0.585
(9,524)
Elective CS
376 (4.4)
1.14 (0.80, 1.63)
1.16 (0.80, 1.70)
1.22 (0.77, 1.93)
1.07 (0.57, 2.01)
0.738
(8,456)
Emergency CS
347 (3.9)
1.00 (0.70, 1.41)
0.91 (0.61, 1.34)
0.84 (0.53, 1.34)
1.08 (0.56, 2.08)
0.532
(8,899)
Data refer to crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) in a weighted sample. P-value for interaction: 0.05 significance level.
All models were a priori adjusted for maternal age, educational level, preeclampsia, gestational age, birth weight and gender.
*Statistically significant P<0.05.
a
A priori adjusted + parity.
b
A priori adjusted + parity and ethnicity.
c A priori adjusted + BMI and parity.
d A priori adjusted + parity, BMI and ethnicity.
Summary of Table S1: In exploratory analyses, the association between mode of delivery and hyperactivity
sub-scale in the crude and adjusted analyses showed that children born by emergency CS (aOR=1.38, 95% CI
1.06, 1.80), and IVD (aOR=1.34, 95% CI 1.02, 1.77) had an increased odds compared with the reference group.
There was also evidence of an interaction between gender and mode of delivery, where IVD affected females
more than males (aOR=1.92, 95% CI 1.28, 2.87) than male children (aOR=1.09, 95% CI 0.77, 1.55, P-value for
interaction=0.03). Peer-problem scores were higher among children who delivered by emergency CS than those
who delivered by SVD in the unadjusted analyses. After adjustment for maternal and neonatal factors however,
the association disappeared. There was no association between mode of delivery and abnormal conduct
problems, emotional problems and pro-social behavior scores.
Table S2: Summary of the results from sensitivity analyses
Variable
aOR (95%CI)a
Term babies (≥39)
aOR (95%CI)b
Excluding
preeclampsia
aOR (95%CI)c
First pregnancies
aOR (95%CI)d
Parental stress
aOR (95%CI)e
Attachment quality
Personal social domain
Spontaneous vaginal
Ref.
Ref.
Ref.
Ref.
Ref.
Instrumental vaginal
0.83 (0.66, 1.04)
0.90 (0.73, 1.11)
0.96 (0.72 1.26)
0.91 (0.74, 1.11)
0.91 (0.75 1.11)
Elective CS
1.33 (1.07, 1.65)*
1.22 (1.02, 1.47)*
1.32 (0.87, 1.99)
1.22 (1.02, 1.45)*
1.23 (1.03, 2.46)*
Emergency CS
0.96 (0.76, 1.22)
1.06 (0.87, 1.28)
1.04 (0.78, 1.39)
1.01 (0.84, 1.22)
1.03 (0.85, 1.24)
Gross motor domain
Spontaneous vaginal
Ref.
Ref.
Ref.
Ref.
Instrumental vaginal
1.14 (0.98, 1.46)
1.20 (0.96, 1.50)
1.04 (0.78, 1.39)
1.14 (0.92, 1.42)
1.15 (0.92, 1.43)
Ref.
Elective CS
1.67 (1.33, 2.11)*
1.61 (1.33, 1.96)*
2.04 (1.38, 3.01)*
1.55 (1.29, 1.87)*
1.56 (1.29, 1.88)*
Emergency CS
1.17 (0.90, 1.55)
1.34 (1.09, 1.66)*
1.06 (0.77, 1.46)
1.28 (1.04, 1.57)*
1.28 (1.05, 1.57)*
Hyperactivity (≥7)b
Spontaneous vaginal
Ref.
Ref.
Ref.
Ref.
Ref.
Instrumental vaginal
1.36 (0.99, 1.86)
1.36 (1.02, 1.79)*
1.31 (0.94, 1.83)
1.36 (1.04, 1.79)*
1.35 (1.03, 1.77)*
Elective CS
0.95 (0.62, 1.46)
1.01 (0.73, 1.38)
0.70 (0.40, 1.24)
1.02 (0.75, 1.38)
1.00 (0.73, 1.36)
Emergency CS
1.50 (1.08, 2.08)*
1.42 (1.07, 1.86)*
1.21 (0.84, 1.74)
1.39 (1.06, 1.81)*
1.36 (1.04, 1.77)*
Data refer to adjusted odds ratios (OR) with 95% confidence intervals (CI) in a weighted sample. *Statistically significant P<0.05.
a Preterm babies were excluded from this model and only term babies with gestational age of ≥39wks were included
b
Preeclampsia cases were excluded from this model
c Multigravida women were excluded and only first pregnancies were included in this model
d Parental
e Quality
stress level included in the models.
of mother-child attachment was included in the models.
*Statistically significant P<0.05
Summary of Table S2: Overall, restricting the analysis to babies born at 39+ weeks gestation did not change
the conclusions although the estimates were slightly higher in this group compared to the analysis of all the
children. Excluding offspring of women with pre-eclampsia had very little effect on the associations. When we
included first pregnancies only, the OR of the association between elective CS and cognitive problems (personal
social domain) was slightly higher but no longer statistically significant. Delay in gross motor function however,
was higher among children born by elective CS compared with those born by SVD. The association between
emergency CS and hyperactivity was smaller in first time babies compared to the association in all babies and
was no longer statistically significant. To assess whether any of the observed associations may be mediated by
parental stress or mother-child attachment variables in the logistic models did not change the results materially.