Maternal pregravid systolic blood pressure is a previously unrecognized factor associated with the likelihood of having a boy or girl in a subsequent pregnancy. Higher systolic blood pressure before pregnancy is a robust independent predictor of delivering a male baby (P < 0.0001).

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Maternal pregravid systolic blood pressure is a previously unrecognized factor associated with the likelihood of having a boy or girl in a subsequent pregnancy. Higher systolic blood pressure before pregnancy is a robust independent predictor of delivering a male baby (P < 0.0001).