Columbia subject headings:
Human reproduction.
Infertility--Epidemiology.
Pregnancy--Complications--Epidemiology.
Reproductive health.
Harvard subject headings:
Human reproduction.
Infertility--Epidemiology.
Pregnancy--Complications--Epidemiology.
Reproductive health.
Princeton subject headings:
Human reproduction.
Infertility--Epidemiology.
Pregnancy--Complications--Epidemiology.
Reproductive health.