Table 1. Characteristics of study populations
Maternal age(years)
≤24
25-34
≥35
Gravidity
Parity
Obesity
Primiparous
Male infants
(n=60028)
n (%)
28.18±4.74
14053 (23.4%)
39870(66.4%)
6105(10.2%)
1.87±1.14
1.22±0.47
8361(13.9%)
48176(80.3%)
Female infants
(n=49694)
n (%)
28.14±4.64
11486(23.1%)
33472 (67.4%)
4736(9.5%)
1.82±1.11
1.19±0.43
7109(14.3%)
41130(82.8%)
Ratio
P
1.22
1.19
1.29
1.18
1.17
0.14
0.25
<0.01
<0.001
<0.001
<0.001
0.07
<0.001
Ratio
P
1.23
1.03
1.17
1.15
1.21
1.27
1.18
1.21
0.81
0.99
1.19
0.47
0.36
0.25
0.13
0.85
0.39
0.76
0.98
<0.001
<0.001
0.58
Table 2. Comparison of pregnancy-related risk factors
GDM
DM
HDCP
Preeclampsia, eclampsia
PROM
Placenta previa
Placenta abrupture
oligohydramnios
FGR
malpresentation
Fetal distress
Male infants
(n=60028)
n (%)
2778(4.6%)
67(1.1‰)
2593(4.3%)
1777(3.0%)
9096(15.2%)
742(1.2%)
311(0.5%)
2286 (3.8%)
3190(5.3%)
2134(3.6%)
4944(8.2%)
Female infants
(n=49694)
n (%)
2254(4.5%)
65(1.3‰)
2217 (4.5%)
1549(3.1%)
7509(15.1%)
586(1.2%)
264 (0.5%)
1891(3.8%)
3918(7.9%)
2145(4.3%)
4139(8.3%)
GDM, gestational diabetes mellitus; HDCP, Hypertension Disorder Complicating Pregnancy
DM, preexisting diabetes mellitus; PROM, malpresentation, including breech presentation and shoulder
presentation; Preterm Rupture Of Membranes; FGR, Fetal Growth Restriction.
Table 3. Comparison of delivery mode and indication for cesarean delivery
Males
Spontaneous delivery
Operative vaginal deliverya
Cesarean delivery
Maternal request
Cephalopelvic disproportion/ Failure to progress
Fetal distress
(n=60028)
n (%)
26239(43.7%)
760(1.3%)
33029(55.0%)
10381(17.6%)
6032(10.0%)
4130(6.9%)
Females
(n=49694)
n (%)
Ratio
P
1.15
1.42
1.26
1.26
1.31
1.21
<0.001
<0.01
<0.001
<0.001
<0.001
0.80
22878(46.0%)
537 (1.1%)
26282 (52.9%)
8263(16.6%)
4591(9.2%)
3400(6.8%)
a
Operative vaginal delivery includes forceps delivery, vacuum extraction delivery, breech delivery and breech
extraction.
Table 4. Comparison of neonatal outcomes
Male infants
(n=60028)
n (%)
Gestational age (GA)
Mean GA(weeks)
Preterm
Term
Postterm
Neonatal outcome
Birth weight (BW)
Mean BW(g)
<2500g
2500-4000
>4000g
Severe asphyxia
NICU
Neonatal death
NICU, neonatal intensive care unit
Female infants
(n=49694)
n (%)
Ratio
P
39.01±2.15
4381(7.3%)
55647(92.7%)
0
39.16±2.09
3233(6.5%)
44373(89.3%)
2088(4.2%)
1.36
1.25
-
<0.001
<0.001
<0.001
<0.001
3318.08±527.26
3548(5.9%)
51628(86.0%)
4852(8.1%)
684(1.1%)
624(1.0%)
276(0.5%)
3224.15±567.70
3333(6.7%)
43852(88.2%)
2509(5.0%)
494(1.0%)
455(0.9%)
162(0.3%)
1.06
1.18
1.93
1.38
1.37
1.70
<0.001
<0.001
<0.001
<0.001
<0.05
<0.05
<0.01
Table 5 . The relationship between fetal gender and neonatal outcomes
Deliveries
Severe asphyxia（Apgar≤4）a
female
male
Admission to neonatal ICU b
female
male
Neonatal death c
female
male
a
No of individual
Modes / total No
Crude
OR(95%CI)
Adjusted
OR(95%CI)
494/49694
684/60028
1
1.2 (1.0-1.3)
1
1.1(1.0-1.3)
455/49694
624/60028
1
1.1 (1.0-1.3)
1
1.2(1.1-1.4)
162/49594
276/60028
1
1.4 (1.2-1.7)
1
1.2(0.9-1.5)
Adjusted for fetal distress, oligohydramnios, delivery mode, HDCP, placenta abruption,
malpresentation, birth weight.
b
Adjusted for fetal distress, delivery mode, maternal age, HDCP, placenta abruption, birth
weight.
c
Adjusted for fetal distress, oligohydramnios, delivery mode, HDCP, Breech, shoulder
presentation, placenta abruption, birth weight.