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04th Apr 2021

How much your breast grows when you are pregnant might reveal your baby’s sex

Trine Jensen-Burke

breast growth in pregnancy

Our bodies are amazing.

And never is this more evident than when we are pregnant and literally growing another human from conception to birth.

One of the first things to start changing when we become pregnant is our boobs. Possibly even before you even realise that you are expecting, you might notice your boobs feeling more tender, firmer and look bigger.

The minute we become pregnant, our hormones start changing, and our bodies start preparing for birth and breastfeeding. Fatty tissue grows and blood flow increases to help the milk ducts and mammary glands grow.

And did you know the size of them when you are pregnant may, in fact, be a clue as to whether or not you are having a boy or a girl…?

According to research, it is more common that your boobs are bigger if you are pregnant with a boy.

In a small study published in the American Journal of Biology, ninety-three women were recruited to participate in a three-stage longitudinal study. They received 3D breast scans to calculate their breast volume at the 12th, 22nd and 32nd week of their pregnancy.

Researchers then used these values to draw comparisons between women who were having a boy and those who carried a girl.

Interestingly, the results indicated that a greater increase in breast size—not just size alone—predicted that a mother was more likely to be having a boy.

This, scientists have speculated, could be down to the simple reason that on average, boys tend to be slightly bigger than girls at birth, meaning that they may simply have different nutritional needs and may require more breastmilk when fed.

According to a small study, where the breastmilk from 25 healthy, well‐nourished women with babies aged 2- to 5-months was analyzed, researchers found that mothers of boys produced milk that had 25% greater energy content than mamas of girls.

In another study, 500 samples of breast milk from 61 mothers over 12 months echoed these findings, as it was found that breast milk from mums who were nursing boys that a higher carbohydrate content than mums of baby girls.