Despite regulations, there'd been romantic relationships between members of the crew, and several pregnancies.

It also gives the cow a larger postpartum interval between pregnancies.

But the researchers who did the new study said they had found no link between fish consumption and longer pregnancies.

Weight gain between pregnancies can also be a problem.

But weight loss between pregnancies has its dangers, too.

Mothers who gain or lose lots of weight between pregnancies could be putting their baby at risk, say experts.

"Protecting the health of children by allowing sufficient time between pregnancies"

Rowan did not wait long enough between pregnancies to get her metabolism back to normal.

By lengthening the time between pregnancies, birth control can also improve adult women's delivery outcomes and the survival of their children.

Birth rates are among the highest in the world, with short intervals between pregnancies.