Does irregular periods contribute to weight gain?

See beloow: It's actually the other way around. Weight gain is a risk factor for irregular periods.

Wt Gain => Irregular: Irregular periods are caused when your body's signals for ovulation and menstruation get confused by hormonal imbalances that can be related to your thyroid (TSH), pituitary (LH/FSH/prolactin), ovaries (estrogen/progesterone). Many external factors can affect the hormones: malnutrition, stress, obesity, for example. Hormonal contraception can help to regulate your periods, which is healthier.