Hello, I really appreciate your concern. The use of speed can cause the baby to get less oxygen, which can lead to intra uterine growth retardation and low birth weight. Methamphetamine can also increase the likelihood of high blood pressure, premature labor, miscarriage, and placental abruption which increase risk to baby s life. Babies can be born addicted to methamphetamine and suffer withdrawal symptoms that include tremors, sleeplessness, muscle spasms, and feeding difficulties. Now stop worrying about what has already happened. I advise you to go for ultra sound and check for growth of your baby. Stop smoking meth strictly. Have healthy diet including fresh fruits and vegetables. Have relaxation exercise like yoga and meditation. Change in life style is certainly needed in your case. Hope my answer has solved your query. Take Care. Thank you.