Bleeding in the first trimester

Bleeding in the first trimester is a common reason women in early pregnancy seek medical attention.

The main differential diagnosis is as follows:

• miscarriage
• ectopic pregnancy
  • the most 'important' cause as missed ectopics can be potentially life-threatening
• implantation bleeding
  • a diagnosis of exclusion
• miscellaneous conditions
  • cervical ectropion
  • vaginitis
  • trauma
  • polyps

NICE released guidelines on the management of ectopic pregnancy and miscarriage in 2019. In these guidelines they discussed how to manage early bleeding:

Worrying symptoms suggestive of an ectopic

If a woman has a positive pregnancy test and any of the following she should be referred immediately to an early pregnancy assessment service:

• pain and abdominal tenderness
• pelvic tenderness
• cervical motion tenderness

>= 6 weeks gestation

If the pregnancy is > 6 weeks gestation (or of uncertain gestation) and the woman has bleeding she should be referred to an early pregnancy assessment service.

A transvaginal ultrasound scan is the most important investigation to identify the location of the pregnancy and whether there is a fetal pole and heartbeat.

< 6 weeks gestation

If the pregnancy is < 6 weeks gestation and women have bleeding, but NO pain or risk factors for ectopic pregnancy, then they can be managed expectantly. These women should be advised:

• to return if bleeding continues or pain develops
• to repeat a urine pregnancy test after 7-10 days and to return if it is positive