1.Early pregnancy ultrasound, measurement of fetal NT at 11-14 weeks of gestation. 2, Fasting blood for Down’s syndrome screening at 15-20 weeks of gestation. 3.Fetal system ultrasound examination is performed at 22-26 weeks of gestation. 4.Fetal system ultrasound is performed at 22-26 weeks of gestation. 75g OGTT test is performed at 24-28 weeks of gestation. 5.Fetal heart monitoring will be performed at 34 weeks of gestation. 6.Fetal heart monitoring and obstetric ultrasound once a week after 37 weeks of gestation.