Association of China’s universal two child policy with changes in births and birth related health factors: national, descriptive comparative study HT Li, M Xue, S Hellerstein, Y Cai, Y Gao, Y Zhang, J Qiao, J Blustein, JM Liu BMJ, BMJ [British Medical Journal]. doi: 10.1136/bmj.l4680 August 21, 2019 Wagner Faculty Jan Blustein