Table 2. Prevalence of adverse pregnancy outcomes in Pingding County from 2017–2019 (1/1,000 pregnancies).

Year	Pregnancies		Low birth weight			Preterm births			Spontaneous abortion			Birth defects			Stillbirths
	n		n	Prevalence		n	Prevalence		n	Prevalence		n	Prevalence		n	Prevalence
Note: The data came from the National Free Pre-Pregnancy Checkups Project and was a cluster sampling of Pingding County.
2017	849		42	49.5		27	31.8		12	14.1		6	7.1		4	4.7
2018	788		37	47		29	36.8		29	36.8		7	8.9		1	1.3
2019	795		33	41.5		32	40.3		29	36.5		3	3.8		1	1.3
Total	2,432		112	46.1		88	36.2		70	28.8		16	6.6		6	2.7