Early Pregnancy Ultrasound: Ovarian cysts in early pregnancy

OMNI will also evaluate the ovaries during early pregnancy. Women almost always have normal ovaries on scan during the 1st trimester. If however an ovarian cyst is present, it is usually a normal finding of early pregnancy.

An ovarian cyst is an enlargement of the ovary that appears to be filled with fluid. The vast majority of ovarian cysts diagnosed in early pregnancy represent a physiological cyst known as the corpus luteum (cystic or haemorrhagic). This is a normal finding in early pregnancy. The corpus luteum supports the lining of the womb and in turn the pregnancy itself. The corpus luteum does this by producing the pregnancy hormone progesterone which helps nurture the pregnancy. Once the pregnancy gets beyond the 1st trimester, the corpus luteum is no longer needed and therefore this resolves spontaneously, not causing any harm whatsoever to the mother or baby.

Most ovarian cysts diagnosed in early pregnancy do not cause any symptoms. They tend to be an incidental finding and women are unaware of their presence. However, if an ovarian cyst ruptures, twists or if there is bleeding into the middle of the cyst, then lower abdominal pain on the side of the ovarian cyst occurs. Most ovarian cysts diagnosed in early pregnancy do not represent ovarian cancer; in fact the risk of ovarian cancer in pregnancy is extremely rare indeed (1 in 15,000 to 1 in 32,000 pregnancies).

If an ovarian cyst is found in the first trimester, and we are not concerned about the nature of the ovarian cyst, an interval scan will be arranged 6 weeks after the baby is delivered.

If we are concerned about the nature of the ovarian cyst diagnosed in early pregnancy, we will consult with our Gynaecological Oncology colleagues. This is a very rare event indeed.