[Incidence of singleton macrosomia in Beijing and its risk factors]

To evaluate the prevalence of macrosomia in Beijing in 2013 and identify its risk factors.

Retrospective six months analysis of 14 188 full-term singleton pregnant women from 15 hospitals with different levels in Beijing in 2013. Each participant's demographic data and medical information were collected individually by questionnaires. Multiple logistic regression analysis was used to examine the associations between variables and the risk of macrosomia.

(1)The total prevalence of macrosomia was 7.069% (1 003/14 188) in Beijing in 2013. (2)The prevalence varied between the 15 hospitals, the lowest was 5.36% (89/1 659), while the highest reached 8.80%(46/523). Furthermore, the incidence of macrosomia was 1.284 times (95% CI: 1.114- 1.480, P=0.001) higher in the second graded hospitals than that in the tertiary hospitals. (3) Multiple logistic regression analyses showed that risk factors for macrosomia were maternal height≥160 cm (adjusted OR=1.875, 95% CI: 1.559- 2.256), pre-pregnant body mass index (p-BMI) ≥24.0 kg/m(2) (24.0- 27.9 kg/m(2): adjusted OR=1.696, 95% CI: 1.426- 2.018; p-BMI≥28.0 kg/m(2): adjusted OR=2.393, 95% CI: 1.831- 3.127), gestational weight gain (GWG) ≥15.9 kg (adjusted OR=2.462, 95% CI: 2.125- 2.853), gravidity>1 (adjusted OR=1.408, 95% CI: 1.224- 1.620), gestational weeks≥40 (adjusted OR=2.007, 95%CI: 1.745-2.308) and gestational diabetes mellitus (adjusted OR=1.522, 95%CI: 1.298-1.784). GWG≥15.9 kg, p-BMI≥28.0 kg/m(2) and gestational weeks≥40 were three risk factors that had the strongest associations with macrosomia (all P<0.01).

The prevalence of macrosomia in hospitals with different levels is obvious different. Gestational weeks, p-BMI and GWG are three main controllable risk factors for macrosomia, thus should receive more attentions.