When moms give birth to a big baby, there’s often a degree of awe and admiration to she who endured such a weighty pregnancy and delivery. But new research suggests such a big bundle of joy could carry some health concerns down the road. October is Breast Cancer Awareness Month, and with that, here’s one finding moms ought to be aware of: Women who deliver babies that weigh eight and a quarter pounds or heavier are two-and-a-half times more likely to develop breast cancer later on, compared with ladies who birthed lighter babies.

Data from two studies, published in the journal PLoS One (Ploss One), took into account other breast cancer risks like family history and use of hormones. One study saw that women who had breast cancer were more likely to have delivered large babies. The other study found that large infants heralded a hormonal mix of high levels of estrogen and growth factors that have been linked to breast cancer. Coupled with low levels of breast cancer-protective hormones, it’s a recipe for breast cancer risk.

Some risk factors for having sizable sons and daughters include gestational diabetes, gaining too much weight during pregnancy, and obesity. Moms-to-be can’t entirely control how large their little one will be, but slimming down prior to getting pregnant can help. It’s not healthy for mom or baby to be big, because larger babies could be more at risk for diabetes and obesity later in life.

Getting regular exercise and breastfeeding can lower breast cancer risk, too. In the spirit of Breast Cancer Awareness Month, be sure to look out for these symptoms: unexplained sudden weight loss, a painless lump in the breast, changes in breast size or shape, swelling in the armpit and nipple changes and discharge.

And of course, schedule regular breast cancer screenings with your doctor — especially if you’ve had a big baby.