Doctor, What’s Wrong? – First Trimester Bleeding

Posted by on Oct 22, 2019 in Pregnancy
Doctor, What’s Wrong? – First Trimester Bleeding

Bleeding early in a pregnancy is scary and sometimes can be concerning. It can be the first sign that there is something wrong with the pregnancy and the will end as a first trimester loss. Other times the bleeding has no significant correlation to the outcome of the pregnancy. 

So how to tell the difference and what can be done?

If any consolation, first trimester bleeding is common. Over 25% of pregnant patients experience vaginal bleeding sometime before week twelve of a pregnancy. For women who bleed in the first trimester, a little over half will miscarry. However, not all bleeding is the same. Some women will have a small amount of bleeding with no cramping while other women will experience heavy bleeding and cramping. 

Women who have heavy bleeding are three times more likely to miscarry.  Those women with light bleeding, no cramping, and lasting less than two days have no increased chance of miscarriage when compared to women who don’t bleed at all!

What causes first trimester bleeding? 

There are a number of reasons why a woman experiences first trimester bleeding. For women who have a miscarriage, the most common reason is that the pregnancy has the wrong number of chromosomes. As women age, the chance for a miscarriage increases and the primary reason is that the older eggs produce embryos with the wrong number of chromosomes. 

Some may have bleeding because the pregnancy implanted outside of the cavity of the uterus. These are ectopic pregnancies and they can be very dangerous, even resulting in the death of the patient. Some bleeding will be due to a poorly implanted pregnancy. Women who have undergone IVF and are using progesterone vaginal suppositories may have bleeding from inserting the progesterone. There are also rare causes such as molar pregnancies and gestational trophoblastic disease.

How do you diagnose the problem? 

YOU don’t. But, your doctor can. The mainstay of evaluating first trimester bleeding is the ultrasound and secondarily the pregnancy hormone level (beta human chorionic gonadotropin: hCG). Vaginal US can identify three types of first trimester pregnancies: intrauterine (intrauterine pregnancy: IUP), ectopic, and unknown location. Normal pregnancies will follow a known pattern of development so that the levels of the pregnancy hormone, their rate of rise, the appearance of a gestational sac in the uterus, and the presence of fetal heart motion can be used to categorize which type of pregnancy is present.

HCG: the pregnancy hormone: HCG is used to diagnose the presence of pregnancy. HCG is produced by the placenta after the pregnancy implants. Human embryos implant around 10 days after ovulation. HCG appears in the blood in a measurable quantity at three to four weeks from the first day of the last menstrual period. Initially, the level of hCG raises 60% or more every 48 hours. A slow rise may indicate an abnormal pregnancy or an ectopic pregnancy.

Ultrasound (US): Vaginal US has become the diagnostic test of preference for evaluating early pregnancies. The gestational sac can be seen as early as five weeks from LMP. By six weeks the IUP should be clearly visible on US. Ectopic pregnancies are more difficult to visualize on US. Some pregnancies are very abnormal and do not form a gestational sac which can be seen on US. That means that a woman could have a positive pregnancy test but the US may not show a gestational sac which is called a pregnancy of unknown location. Frequently, these will be treated as an ectopic pregnancy since failing to treat an ectopic may put the woman at risk for ruptured ectopic and serious risks.

Progesterone: Progesterone levels are frequently measured because a normal pregnancy should produce a normal amount of progesterone. A low level of progesterone may be an early sign of an abnormal pregnancy. It is important to realize that an abnormal pregnancy can cause the low progesterone and not the other way around. The presence of the low progesterone suggests that treating a patient with a low progesterone might save the pregnancy but reflecting upon the cause of first trimester losses demonstrates that adding progesterone will not save the pregnancy. For example, a pregnancy with the wrong number of chromosomes will not be fixed by adding progesterone. An ectopic pregnancy will not be saved by adding progesterone. Recently, it has been suggested that a very small group of patients with a history of unexplained recurrent pregnancy loss may actually benefit from first trimester progesterone therapy.

What can be done? Many times the bleeding will stop and no intervention is needed. Sometimes, it will become apparent that the pregnancy is not viable and a miscarriage will inevitably occur. These can be managed conservatively by simply waiting to let the body pass the pregnancy. Risks from this are minimal and include excessive bleeding or infection. Infection means a temperature greater that 100 F measured twice a few hours apart. Pregnant women will have slight temperature elevations due to the progesterone. 

A second way to manage an inevitable pregnancy loss medically is to use prostaglandins which cause the uterus to contract. Sometimes a progesterone blocking drug is added. 

Finally, a surgical procedure called a D&C (dilatation and curettage) can be performed. The D&C is used when there is excessive bleeding. A D&C can also be done if it is necessary to know the chromosome number of the pregnancy. For example, if the pregnancy loss is the second, then knowing the chromosome number (karyotype) can help to determine if further testing to evaluate recurrent pregnancy loss.

Bedrest-taking it easy: There is absolutely no credible evidence that either bedrest or taking it easy will prevent a pregnancy loss no matter how logical it seems.

How long to wait to try to conceive? If you do miscarry, physicians vary on how long to wait but a common rule of thumb is to wait two periods before trying again.