Postpartum contraception Improves health by lengthening birth internals. Women are more likely to report pregnancies as unintended if they occur in an interval of 24 months or less.
Preventing these unintended pregnancies helps avoid financial, psychological and health costs.

On a global scale: if children are spaced 3-5 years apart:
The mother is 2.5 x more likely to survive childbirth
The baby is 1.5 x more likely to survive the 1st week of life
and 2.5 x more likely to survive to age 5.

Maternal complications like: third trimester bleeding and anemia.