More bodily fluid tests will be taken throughout pregnancy, particularly at the initial prenatal workup.

Pap Smear

Unless you've had one in the twelve months leading up to conception, your provider will give you a pap smear at your initial prenatal visit. During your pelvic exam, she will scrape a small sample of cells from your cervix using a spatula-like instrument. The cells are collected and sent to a lab for microscopic analysis.

An abnormal pap smear result tells your doctor that something is going on with your cervix that requires further examination. Most abnormal pap smears are caused by infection with a common, sexually transmitted virus known as the human papilloma virus (HPV). HPV may remain silent in women infected with the virus, causing no apparent symptoms. However, the virus can cause cellular changes on your cervix. While most of these changes will resolve on their own, some strains of HPV can cause cervical cancer if left untreated. Because of this, most women are regularly screened with pap smears to detect any early changes that can be treated.

If your pap smear is abnormal, you may be offered a colposcopy, which is a way of looking at your cervix with a microscope. Pregnancy should not prevent your colposcopy. However, an endocervical curettage (ECC), a scraping of the cervical canal routinely done as part of the colposcopy, should not be performed while pregnant.

Group B Strep

Group B streptococcus (GBS) is a bacterium that can cause serious infections in a newborn, including pneumonia and meningitis. If a pregnant woman tests positive for it, she is usually prescribed intravenous antibiotics during labor and delivery to prevent transmission to her baby.

Swabs of both the rectum and vagina are taken and cultured (put in a medium that will allow the bacteria to grow, if it is present). The CDC advises that all pregnant women be screened for GBS at weeks 35 to 37 of gestation.

According to the CDC, nearly 2.6 million ultrasounds were performed in the United States in 2003. American women also had 66,901 amniocentesis procedures in 2003.

Sexually Transmitted Infections (STIs)

The CDC also recommends that all pregnant women be screened for several sexually transmitted diseases — chlamydia, gonorrhea, hepatitis B, hepatitis C, HIV, and syphilis — because of their potentially devastating effects on a fetus. HIV, hepatitis B and C, and syphilis testing require a blood draw, while chlamydia and gonorrhea are tested by means of a vaginal swab sample followed by laboratory analysis. If you have a history of preterm delivery, your provider may also take a swab sample for bacterial vaginosis. You may only be offered some of these tests by your provider based on your medical history and perceived risk factors. If you'd like to be tested for all of them, ask your doctor.

Chlamydia, gonorrhea, and syphilis are caused by bacteria and can be treated with antibiotics. Viral infections like hepatitis B and HIV cannot be cured, but treatment and precautionary measures can greatly decrease the risk to your baby. HIV medications taken during pregnancy can lower viral loads and dramatically diminish the risk of transmission to the fetus, as can appropriate treatment for syphilis. If you test positive for hepatitis B, your baby will be vaccinated shortly after birth to protect him from the effects of hepatitis.