| Subject | Contents |
| Definition | First trimester pregnancy is the early stage of pregnancy from conception to 12 weeks gestation, or about 14 weeks from the first day of the last normal menstrual period (LNMP).
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| Alternative Names | Early pregnancy; Pregnant - first trimester
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| Causes, incidence, and risk factors | Pregnancy is a normal condition and, in most situations, should not be approached as a problem or disease. A pregnancy begins with conception, when a sperm from a fertile male joins with an ovum (egg) of a fertile female. Any fertile female engaged in a sexual relationship with a fertile male is at risk of becoming pregnant. |
| Symptoms | Missed menstrual period(s)FatigueBreast enlargement or breast discomfort (tenderness) Abdominal distentionNausea/vomiting Light-headedness or actual fainting ( syncope ) Skin areas appearing abnormally dark or light |
| Signs and tests | A pelvic examination may reveal an enlarged uterus, a bluish or purple coloration of the vaginal walls and cervix , and softening of the cervix. Weight changes are also noted (usually increased; decreased if nausea and vomiting are significant). The abdominal girth increases, and the fundus (top of the enlarged uterus) may be felt by touch (palpated). Tests include: A positive urine and/or serum HCG ( pregnancy test ) A pregnancy ultrasound to confirm or check accurate dates for pregnancy Pregnancy may also alter the results of numerous laboratory tests. |
| Treatment | The majority of desired pregnancies in the United States are carried to term. Pregnancy is a naturally occurring function and, prior to modern medicine, was allowed to follow its own course. Also prior to modern medicine, infant and maternal mortality were high. It is now well understood that prenatal care results in significant improvement in the quality of the pregnancy and the outcome for the infant and mother. Modern prenatal care includes: Good nutrition and health habits before and during pregnancy Frequent prenatal examinations to detect early problems Routine ultrasounds to detect fetal abnormalities and problems Routine screening for:
Sexually transmitted diseases Rubellaimmunity Blood type problems (Rh and ABO) Diabetes Genetic disorders if there is a family history or age of the mother indicates the need Blood pressure abnormalities Urine protein Women who choose to have an abortion usually do so in the very early stages of the pregnancy (usually between 8 and 12 weeks gestation). However, abortion is legal through the 24th week of pregnancy. The abortion procedure, however, becomes more difficult with advancing gestational age, and many providers do not perform pregnancy terminations in the second trimester. Because abortion is a controversial issue in the United States, many women who make such a decision feel as if they cannot share that information with others. Therefore, it is important for women who are contemplating an abortion to examine their existing support system and identify those people who may be capable of helping them through what may be a difficult time. It is also important that they choose a reputable provider or clinic that advocates choice for women, and is a safe environment in which they can obtain adequate counseling regarding all options for pregnancy resolution, have the procedure performed, and obtain the support and follow-up care that may be necessary after the abortion. Women who plan to continue a pregnancy to term need to choose a health care provider who will provide prenatal care, delivery, and postpartum services. Provider choices in most communities include physicians specializing in obstetrics and gynecology (OB/GYN), certified nurse midwives (CNMs), some family practice physicians, and some family nurse practitioners (FNPs) or physician assistants (PAs) who work in conjunction with a physician. The family health care providers, or generalists, are proficient in managing women throughout normal pregnancies and deliveries. If an abnormal pregnancy is identified, a generalist will refer the patient to obstetric specialist. The principal goals of prenatal care are to monitor both the pregnant woman and the fetus throughout the pregnancy, and to identify any factors that could change the outlook for the pregnancy from normal to high-risk. Prenatal care also focuses on providing accurate information regarding nutritional requirements throughout the pregnancy and postpartum period; activity recommendations or restrictions; common complaints that may arise during pregnancy (for example, backache , joint pain , nausea , heartburn , headaches , urinary frequency , leg cramps , and constipation ) and how to manage them, preferably without medications. Pregnant women are advised to avoid all medications, unless specifically deemed necessary and recommended by a prenatal health care provider. Potential substances and/or exposures (for example, alcohol/drug use, smoking , some herbal preparations, and common over-the-counter medications) that may interfere with normal development of the fetus should also be avoided. The projected date for delivery is called the estimated date of confinement (EDC). The EDC may be calculated using Naegele's Rule. Subtract 3 from the month of the LNMP (last normal menstrual period) to determine month of EDC. Then, add 7 to the first day of the LNMP to determine the day of the month for the EDC. If the LNMP was 6/29, then the EDC is 4/6. If the LNMP was 2/2, then the EDC is 11/9. Note: Naegele's Rule is based on a 28-day menstrual cycle. Therefore, dates may need to be adjusted for women who normally have shorter or longer menstrual cycles. Prenatal visits are typically scheduled every 4 weeks during the first 32 weeks of gestation, every 2 weeks from 32 to 36 weeks gestation, and weekly from 36 weeks to delivery. Weight gain , blood pressure, fundal height, and fetal heart tones (as appropriate) are usually measured and recorded at each visit, and routine urine screening tests are performed. |
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| Expectations (prognosis) | Approximately 10% of known pregnancies terminate by spontaneous abortion ( miscarriage ) -- usually during the first trimester. Estimates suggest that as high as 50% to 70% of all conceptions terminate spontaneously before the woman is even aware of pregnancy. Nature is extremely conservative, and studies suggest that there is a much higher rate of spontaneous abortion in defective fetuses than in normal fetuses. |
| Complications | Abnormal processes, which may prove dangerous to the health of the mother and/or fetus, may occur in up to 20% of pregnancies. |
| Calling your health care provider | Call for an appointment if you suspect you are pregnant, are currently pregnant and are not receiving prenatal care, or if you are unable to manage common complaints without medication. Call your health care provider if you suspect you are pregnant and are on medications for diabetes, thyroid disease, seizures, or high blood pressure. Notify your health care provider if you are currently pregnant and have been exposed to a sexually transmitted disease, chemicals, radiation, or unusual pollutants. Call your health care provider if you are currently pregnant and you develop fever /chills or painful urination. It is urgent that you call your health care provider if you are currently pregnant and notice any amount of vaginal bleeding , the membranes rupture (water breaks), or you experience physical or severe emotional trauma. |
| Prevention | A wide variety of contraceptive methods, designed to prevent pregnancy, are currently available. The user effectiveness rates vary from less than 1 pregnancy per 100 women per year with Depo-Provera injections or progestin implants to 20 to 30 pregnancies per 100 women per year with the rhythm or calendar methods. The only 100% effective means of contraception is complete abstinence. |
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