What you should know about endometriosis during pregnancy

Endometriosis is a disorder in which tissue that normally lines the uterus, called the endometrium, grows outside the uterine cavity. It can adhere to the outside of the uterus, the ovaries, and the fallopian tubes. The ovaries are responsible for releasing an egg each month, and the fallopian tubes carry the egg from the ovaries to the uterus.
When any of these organs are damaged, blocked, or irritated by endometrium, it can become more difficult to get and stay pregnant. Your age, health, and the severity of your condition will also affect your chances of carrying a baby to term.
One study found that while 15–20 percent of fertile couples attempting to become pregnant will be successful each month, that number drops to 2–10 percent for couples affected by endometriosis.

Symptoms
Will symptoms get better or worse during pregnancy?
Pregnancy will temporarily halt the painful periods and heavy menstrual bleeding that are often characteristic of endometriosis. It might provide some other relief as well.
Some women benefit by the increased levels of progesterone during pregnancy. It’s thought that this hormone suppresses and perhaps even shrinks endometrial growths. In fact, progestin, a synthetic form of progesterone, is often used to treat women with endometriosis.
Other women, however, will find no improvement. You may even find that your symptoms worsen during pregnancy. That’s because as the uterus expands to accommodate the growing fetus, it can pull and stretch misplaced tissue. That can cause discomfort. An increase in estrogen can also feed endometrial growths.
Your experience during pregnancy may be very different from other pregnant women with endometriosis. The severity of your condition, your body’s hormone production, and the way your body responds to pregnancy will all affect how you feel.
Even if your symptoms do improve during pregnancy, they will resume after the birth of your baby. Breastfeeding may delay the return of symptoms, but once your period returns, your symptoms will likely return too.
Risks
Risks and complications
Endometriosis may increase your risk for pregnancy and delivery complications. This may be caused by the inflammation, structural damage to the uterus, and hormonal influences endometriosis causes.

Miscarriage
Several studies have documented that miscarriage rates are higher in women with endometriosis than in women without the condition. This holds true even for women with mild endometriosis. One retrospective analysis concluded that women with endometriosis had a 35.8 percent chance of miscarriage versus 22 percent in women without the disorder. There’s nothing you or your doctor can do to stop a miscarriage from happening, but it’s important to recognize the signs so you can seek the medical and emotional help you might need to properly recover.
If you’re fewer than 12 weeks pregnant, miscarriage symptoms resemble those of a menstrual period:
bleeding
cramping
low back pain
You might also notice the passage of some tissue.
Symptoms after 12 weeks are mostly the same, but bleeding, cramping, and tissue passage might be more severe.

Preterm birth
According to an analysis of several studies, pregnant women with endometriosis are 1.5 times more likely than other expectant moms to deliver before 37 weeks of gestation. A baby is considered preterm if he or she is born before 37 weeks of gestation.
Babies born prematurely tend to have a low birth weight and are more likely to experience health and developmental problems. Symptoms of preterm birth or early labor include:
Regular contractions. Contractions are a tightening around your midsection, which may or may not hurt.
Change in vaginal discharge. It may become bloody or the consistency of mucus.
Pressure in your pelvis.
If you’re experiencing any of these symptoms, see your doctor. They may be able to administer drugs to stop the labor or bolster your baby’s development should birth be imminent.
Placenta previa
During pregnancy, your uterus will develop a placenta. The placenta is the structure that supplies oxygen and nourishment to your growing fetus. It normally attaches to the top or side of the uterus. In some women, the placenta attaches to the bottom of the uterus at the opening of the cervix. This is known as placenta previa.
Placenta previa increases your risk for a ruptured placenta during labor. A ruptured placenta can cause severe bleeding, and put you and your baby in danger.
Women with endometriosis may be at increased risk for this life-threatening condition. The main symptom is bright red vaginal bleeding. If the bleeding is minimal, you may be advised to limit your activities, including sex and exercise. If bleeding is heavy, you may need a blood transfusion and an emergency C-section.