You can expect countless changes over the course of your pregnancy. Your body size will change, your mood will change, your attitude will change, even your shoe size might change. The body goes through a lot during pregnancy, and some of the changes you experience might be surprising to you. Most of these changes are brought on by elevated levels of hormones in your body. Your body regulates itself outside of pregnancy, but all bets are off once gestation starts. You own normalcy is put on the back burner as your body works to keep your baby healthy inside of you. As you sing to your baby from outside the womb, you might even notice a change in your voice.
It makes sense that the vocal cords would change during pregnancy. Elevated levels of progesterone and estrogen cause the muscles to loosen up more than usual. Specifically, relaxin is a major hormone that is present during your pregnancy, and its main job is to make your ligaments become looser than ever before. Since muscle control is a major part of vocalizing, many singers actually find that their range changes when they become pregnant. A recent study showed that pregnant singers often experience more difficulty hitting high notes, as they can’t constrict their vocal cords enough. Conversely, they noticed an increased ability to hit low notes, which involves relaxing the vocal muscles. If you’re a singer and are about to become pregnant, expect your range to temporarily shift from soprano to alto as hormones run rampant through your body.
For most women, this vocal change will not have any major effect. Other than being unable to hit those high notes to your favorite Katy Perry song in the car, your life will be largely unaffected by this change. It is too subtle to affect the speaking voice. However, for women who are professional singers, this change can be quite inconvenient. While you can’t prevent relaxin from forming during your pregnancy, you can keep your vocal chords in prime condition by warming them up every day. That way, when your pregnancy is over, you’ll be able to return to your normal range more quickly. If you’re worried about it, consider seeking out a vocal coach who specializes in pregnancy to learn ways to control your lax pipes. As with many changes, your body will go back to its normal state after delivery.
Source: Filipa Martins Baptista Lã et al: Pregnancy and the Singing Voice. Journal of Voice Volume 26 Issue 4 pp. 431-439 July 2012