If you don’t get along well with your mother-in-law, you may wish she lived on the other side of the planet — but if you want a big family, be grateful she’s nearby.

A new study finds that married couples with a mother-in-law in close proximity have more babies.

Sheffield University’s Dr. Virpi Lummaa, who analyzed 300 years of church records to track births, marriages and deaths in farming communities in Finland, also found that a nearby mother-in-law resulted in less time between kids and a lower likelihood that those children would die in infancy.

Dr. Lummaa believes those families benefited from the extra pair of hands, as well as the additional love and attention the kids received from their grandma. The impact of having a grandfather around wasn’t as great, but Dr. Lummaa said, “That doesn’t mean they don’t do anything — it just doesn’t translate into better survival of their grandchildren.”

[The Daily Mail]