First trimester bleeding may be common, but that does not mean it is not concerning. According to the American Pregnancy Association, between 20 percent and 30 percent of women will bleed at some point in early pregnancy. Bleeding can indicate a miscarriage, but it may also be from other causes. While 15 percent to 20 percent of all pregnancies result in a miscarriage, not all miscarriages include bleeding as a warning sign.
Though not all of those losses are preventable, some may be, especially if they link back to an insufficient amount of progesterone in the first trimester. This hormone is thought to play an important role in a healthy pregnancy by priming the endometrial lining for implantation and providing sufficient nourishment to the developing fetus. But what happens if a pregnant person doesn't produce enough progesterone early on?
These patients may be more at risk for first trimester bleeding — and, ultimately, recurrent pregnancy loss. Luckily, practitioners today are armed with multiple tools to help them approach such cases with swift and effective interventions. Progesterone testing and therapy coupled with transvaginal ultrasound are among the top treatment choices.
Progestogen Therapy for a Healthy Pregnancy
Performing a serum progesterone test can help determine if a pregnant patient's hormone levels are increasing at a healthy rate. Research published in Annals of Epidemiology notes that some bleeding may be normal — especially around the seven-week mark when the luteal-placental shift occurs and a temporary progesterone drop can lead to spotting. But when progesterone levels are abnormally low, progestogen therapy may be a good option.
As a synthetic version of the natural hormone progesterone, progestogen works by triggering progesterone receptors. The American College of Obstetricians and Gynecologists (ACOG) indicates that patients who have experienced three or more miscarriages may benefit from the therapy when it is administered in the first trimester.
These recommendations align with October 2018 research published in the Cochrane Database of Systematic Reviews. In that paper, authors analyzed 13 moderate-quality trials among 2,556 patients with recurrent pregnancy loss. Among study participants who took some form of progestogen, overall loss rates dropped from 27.5 to 20.1 percent. Live birth rates jumped slightly, but the impact on certain measures such as low birth weight or birth defects remains unknown.
Progestogen can be taken orally, vaginally or by injection; researchers have not yet established whether one method is more successful than another.
The Role of Imaging in Monitoring for Miscarriage
When a patient presents with first trimester bleeding, clinicians may want to perform a transvaginal ultrasound in addition to blood testing for a few reasons. First, an ultrasound can help diagnose ectopic pregnancy, ovarian cysts or subchorionic hemorrhage, all of which have the potential to cause bleeding.
Additionally, research published in American Family Physician reports that imaging can help visually confirm a miscarriage, as evidenced by a gestational sac measurement of 25 mm or greater without an embryo, as well as an absence of heart activity once the crown-rump length reaches 7 mm or greater.
Measuring endometrial thickness, along with blood testing, can also help clinicians identify pregnancy viability and the potential need for progestogen therapy.
Rapid Response for Better Pregnancy Outcomes
With the Cochrane study citing a seven-percentage-point drop in miscarriage rates when progestogen therapy is used, it is clear that the deployment of effective, timely intervention may make all the difference. When a woman bleeds in her first trimester, it can be both clinically concerning and emotionally devastating. This is especially true if a patient has a history of recurrent miscarriage.
Clinicians should ensure that they have the tools to assess first-trimester bleeding and intervene when necessary so that patients can have the best chance of success — as well as peace of mind.
