6 Pregnancy Hormones You'd Better Get Used To

1. Human Chorionic Gonadotropin (hCG): The big kahuna of pregnancy hormones, hCG is produced by the placenta, and tells your body that there's a life form growing inside! Rising hCG levels may also cause morning sickness. And higher levels can=more barfiness.

2. Progesterone: Progesterone keeps the uterine muscle relaxed and helps your body tolerate foreign DNA (i.e., your fetus!). But it can also prompt lower-than-normal blood pressure occasionally dizziness, and GI symptoms like heartburn, reflux, gas, and constipation.

3. Estrogen: Estrogen plays a key role in fetal development and helps your uterus respond to oxytocin. Elevated estrogen levels may also prompt spider veins, your out-of-control appetite, and skin changes. (That pregnancy glow? Thank estrogen!)

4. Oxytocin: Oxytocin is the hormone that's responsible for contractions in labor. It signals the uterus to contract; as more is released, contractions get longer and closer. It's also released when the nipples are stimulated to help produce breast milk.

5. Prolactin: This milk-producing hormone-which increases 10 to 20 times during pregnancy—has a tranquilizing effect and helps with the release of breast milk.

6. Relaxin: Relaxin helps loosen the ligaments holding your pelvic bones together, and relaxed the uterine muscle—which helps baby move through the birth canal easier.

Fun fact: Preggos have 10 times the normal amount of this hormone in their bodies!