Table 3 Factors associated with developmental delay according to multivariable logistic regression analysis

Variables in terms of children

 Child—Sex

  Female

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Male

1.15(1.1–1.21)

< 0.001*

1.01(0.97–1.05)

0.651

1.15(1.1–1.2)

< 0.001*

1.29(1.24–1.35)

< 0.001*

 Parity of more than three children

  No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Yes

1.56(1.12–2.16)

0.008*

1.48(1.07–2.04)

0.018*

1.47(1.07–2.02)

0.017*

1.03(0..74–1.45)

0.848

 Multiple birth

  Singleton

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Twins/multiple birth

1.17(0.94–1.46)

0.161

1.3(1.06–1.59)

0.013*

1.08(0.87–1.35)

0.477

1.12(0.91–1.37)

0.277

 Neonatal injury

  No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Yes

1.49(1.07–2.06)

0.018*

1.69(1.24–2.29)

0.001*

1.21(0.87–1.68)

0.260

0.83(0.58–1.2)

0.322

 Head circumference

  Normal

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Macrocephaly

0.94(0.84–1.06)

0.334

1.01(0.91–1.13)

0.793

1.07(0.96–1.19)

0.247

0.96(0.87–1.06)

0.414

  Microcephaly

1.21(1.02–1.43)

0.026*

1.18(1.01–1.39)

0.040*

1.12(0.95–1.33)

0.175

1.1(0.94–1.28)

0.217

 BMI at birth

  Normal

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Malnutrition

1.47(1.34–1.62)

< 0.001*

1.35(1.23–1.48)

< 0.001*

1.36(1.24–1.49)

< 0.001*

1.23(1.12–1.34)

< 0.001*

  Obesity

1.13(0.99–1.29)

0.075

1(0.88–1.15)

0.971

1.12(0.99–1.28)

0.079

1.11(0.98–1.25)

0.095

 BMI at physical examination

  Normal

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Malnutrition

1.36(1.13–1.64)

0.001*

1.83(1.56–2.15)

 < 0.001*

1.23(1.02–1.48)

0.027*

0.98(0.81–1.18)

0.804

  Obesity

1.16(1.06–1.26)

0.001*

1.1(1.01–1.19)

0.029*

1.28(1.18–1.39)

< 0.001*

1.09(1.01–1.18)

0.033*

Variables in terms of parents

 Advanced maternal age

  No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Yes

1.29(1.14–1.45)

< 0.001*

1.1(0.97–1.25)

0.132

1.14(1.01–1.28)

0.040*

1.11(0.99–1.24)

0.067

 Cesarean section

  No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Yes

1.03(0.98–1.08)

0.250

1.06(1.01–1.11)

0.026*

1.02(0.98–1.07)

0.399

1.03(0.99–1.07)

0.214

 Variables in terms of the environment and inheritance

  Per capita GDP

0.79(0.77–0.81)

< 0.001*

0.88(0.86–0.9)

 < 0.001*

0.69(0.68–0.71)

< 0.001*

0.78(0.76–0.79)

< 0.001*

 Family heredity history

  No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

  Yes

1.47(1.04–2.06)

0.027*

1.58(1.16–2.15)

0.004*

2.05(1.53–2.74)

< 0.001*

1.44(1.06–1.95)

0.019*