Causes for Concern during Your First Trimester - dummies

Causes for Concern during Your First Trimester

By Joanne Stone, Keith Eddleman, Mary Duenwald

In each trimester, a few things may, in some cases, go less than smoothly. The following paragraphs describe some of the things that can happen during the first trimester of your pregnancy and what they may mean to you.


Early in pregnancy, around the time of your missed period, experiencing a little bleeding from the vagina isn’t uncommon. The amount of bleeding is usually less than what you would expect with a period and lasts for only one or two days.

This is called implantation bleeding, and it happens when the fertilized egg attaches to the uterus’s lining. Bleeding due to implantation isn’t a cause for concern, but many women may be confused by it and mistake it for their period.

Bleeding also may occur later in the first trimester, but it doesn’t necessarily indicate a miscarriage. About one-third of women experience bleeding during the first trimester, and the majority of them go on to have perfectly healthy babies. Bleeding is especially common in women carrying more than one fetus — and again, most go on to have normal pregnancies.

Bright red bleeding usually indicates active bleeding, while dark staining usually indicates old blood that is making its way out from the cervix and vagina. Most of the time, an ultrasound exam doesn’t show any evidence of the source of the bleeding.

However, sometimes a collection of blood, known as a subchorionic or retroplacental hemorrhage or collection, is visible and indicates an area of bleeding from behind the placenta. It usually takes several weeks for this blood to be reabsorbed. During this time, some dark blood continues to pass out through the cervix and vagina.

In some cases, bleeding can be the first sign of an impending miscarriage. In this case, the bleeding often accompanies abdominal cramping. However, keep in mind that the vast majority of women who experience bleeding go on to have a completely normal pregnancy.

If you notice some bleeding, let your practitioner know. If the bleeding is a small amount and not associated with a lot of abdominal cramping, it isn’t an emergency. However, if you’re bleeding very heavily (much more than a period), call your practitioner as soon as you can.


The great majority of pregnancies proceed normally. But about one in five ends in early miscarriage, often before a woman even knows she’s pregnant. If a miscarriage occurs early in a pregnancy, you may mistake it for a regular menstrual period.

About half the time, chromosomal abnormalities in the embryo cause the miscarriage. In another 20 percent of cases, the embryo may have structural defects that are too small to be detectable by ultrasound or pathological examination.

Having one miscarriage doesn’t mean that you have an increased chance of it happening again. Also, no routine everyday activities can cause a miscarriage.

Miscarriage may lead to cramping and bleeding. You may feel abdominal pains that are stronger than menstrual cramps, and you may pass fetal and placental tissue. In cases where all the tissue is passed, your practitioner doesn’t need to do anything else.

Often, though, some tissue remains in your uterus, and you may need medication to encourage its passing or have a D&C (dilation and curettage) procedure, designed to empty the uterus. Your doctor dilates, or gently opens, the cervix with surgical instruments and then empties the remaining contents of the uterus with a suction device and/or a scraping of the uterus.

A D&C can be performed either in the doctor’s office or in an operating suite, depending on the doctor, the gestational age, and any other important medical problems.

Sometimes, you may have no overt signs of miscarriage. Your practitioner may discover during a routine prenatal visit that the fetus is no longer alive, which is known as a missed abortion. If you have a missed abortion very early in your pregnancy, a D&C may not be necessary.

But if it happens later in the first trimester, you may need to have a D&C to reduce the risk of heavy bleeding or incomplete passage of tissue. Depending on your obstetrical history and your desire to try to determine the cause of the miscarriage, you may decide to have the tissue sent for genetic analysis (to find out whether the chromosomes were normal or abnormal).

Because half of all miscarriages are due to chromosomal abnormalities, it may be useful to find out whether this was the cause.

Unfortunately, most miscarriages can’t be prevented. Many, if not most, of them may simply be nature’s way of handling an abnormal pregnancy. However, having a miscarriage doesn’t mean that you can’t have a perfectly normal pregnancy in the future. In fact, even in women who have had two consecutive miscarriages, the chances are very good (about 70 percent) that the next pregnancy will be successful without any special treatment.

Ectopic pregnancy

An ectopic pregnancy occurs when the fertilized egg implants outside the uterus — in one of the fallopian tubes, the ovary, the abdomen, or the cervix. An ectopic pregnancy is a serious threat to the mother’s health. Fortunately, ultrasound has advanced to the point that it can detect ectopic pregnancies very early.

Signs of an ectopic pregnancy that you may notice include vaginal bleeding, abdominal pain, pelvic pain, dizziness, and feeling faint. You may not have any symptoms, in which case your doctor identifies the condition during an ultrasound.

Your doctor can treat the problem in one of several ways, depending on the location of the embryo or fetus, how far along the pregnancy is, and the particular symptoms you are experiencing. Unfortunately, a doctor can’t move the embryo or fetus to the uterus so that the pregnancy can continue as normal.