Infections in pregnancy 


While pregnancy is not a time of frank immunocompromise, it is a time of more vulnerability to all sorts of infections. Pregnant women get the same  common colds and stomach flus that others get. However we watch them more carefully and support them more proactively. Click HERE to learn more about these common illnesses. 

A big batch of prenatal labs is done at the beginning of the pregnancy at the start of prenatal care. They include general things like blood type, but for the most part, they are tests for infectious diseases which could have an effect on both mom and baby. 


On this long page, the first section deals with infections tested in prenatal labs. The second section is equally important, and deals with other  common infections that are of special concern to pregnant women. 

Content in these pages is excerpted and remixed from the


Infections tested in the Prenatal Labs : 

Most of these are discussed on our pages Sexually transmitted Infections. For general information about these infections, check those pages. 


Chlamydia (CT)

CT is a very common sexually transmitted infection.

Women under 25 and others at higher risk should be screened for it annually.

Most CT infections are silent, meaning they are without signs or symptoms.

CT causes serious disease in the uterus or tubes, such as PID (Pelvic inflammatory disease ) and increase risk for tubal pregnancy. 

IN PREGNANCY Chlamydia can cause preterm labor, as wells disease in the newborn's eyes and lungs.  


Gonorrhea (GC) 

 GC is a very common infection especially among 15-24 year olds.

GC infections are asymptomatic or with subtle symptoms

GC can cause pain, scar tissue, infertility , risk of ectopic. and disseminated gonococcal infection (DGI). DGI in the bloodstream  characterized by arthritis, tenosynovitis, and/or dermatitis. 

GC increases risk of catching other infections like HIV 

A full course of two drugs is always required to treat GC due to growing resistance. 

IN PREGNANCY GC can cause blindness, joint infection, or a life-threatening blood infection in the baby


Hepatitis B (HB)

Disease ranges from mild to severe and life threatening. 

Many HB infections are asymptomatic.

HB is passed by body fluids from having sex with an infected person, sharing contaminated needles to inject drugs, or from an infected mother to her newborn. 

An effective HB vaccine is available, and should be given at birth. I can also be given later. 

IN PREGNANCY HB can pass to the newborn. But  this can be prevented by giving the infant HBIG (Hepatitis B immune globulin )and the first Hepatitis B vaccine at birth, and then completing the series. Almost all cases of Hepatitis B can be prevented if a baby born to an infected woman receives the necessary shots at the recommended times.


Hepatitis C (HC)

Disease from Hepatitis C ranges from  mild illness lasting a few weeks to a serious, lifelong illness that attacks the liver.

It  is spread primarily through contact with the blood of an infected person, through needles or at birth from mother to baby,  less frequently from sex, or personal care items like razors 

An estimated 3.2 million persons in the United States have chronic Hepatitis C virus infection. Most are asymptomatic. 

Approximately 75%–85% of people who become infected with Hepatitis C virus develop chronic infection.

IN PREGNANCY Hepatitis C is rarely passed from a pregnant woman to her baby. About 6 of every 100 infants born to mothers with Hepatitis C become infected with the virus.

There is no vaccine for HC. 


HIV, aka Aids Virus 

HIV and other STIs tend to run together. Having one increases the likelihood of having another. This is due to the high risk behaviors that lead to these infections, and the breaks in tissue integrity that come with certain STIs. 

IN PREGNANCY, HIV is spread by body fluids, birth, and breastfeeding. You can greatly lower your risk of transmitting HIV to your baby by taking antiretroviral therapy (ART) during pregnancy, labor, and delivery; having a C-section; and avoiding breastfeeding.

When HIV is diagnosed before or during pregnancy, perinatal transmission can be reduced to less than 1% if appropriate medical treatment is given, the virus becomes undetectable, and breastfeeding is avoided.



Syphilis is an STD that can cause long-term complications if not treated correctly. It is simple to cure with the right treatment.

Symptoms in adults are divided into stages. These stages are primary, secondary, latent, and late syphilis. These are a painless sore, a non itchy rash, then major organ disease. 

You can get syphilis by direct contact with a syphilis sore during sex. Syphilis can also be spread from an infected mother to her unborn baby.

IN PREGNANCY, Syphilis can pass to the baby. This can result in low birth weight, preterm labor or stillbirth. 

Treatment for syphilis is effective, but does not undo any damage already done. 

After treatment, syphilis can be acquired again. 

HPV (Human Papilloma Virus)

HPV is the most common sexually transmitted infection in the United States.

HPV can be passed even when an infected person has no signs or symptoms. 

In most cases, HPV goes away on its own and causes no problems. However, it can cause genital warts and cancer. 

IN PREGNANCY, HPV disease can progress. Screening may continue during pregnancy.  No link has been found between HPV and miscarriage, premature delivery, or other pregnancy complications. Also, the risk of transmitting the virus to the baby is considered very low. However, in very rare cases, a baby born to a woman who has genital warts will develop warts in the throat which will require treatment.

The best approach to HPV is prevention. All children ages 11 or 12 years should get vaccinated. Catch-up vaccines are recommended for males through age 21 and for females through age 26, if they were not vaccinated previously. 


Rubella, sometimes called German measles or three-day measles, is a contagious disease caused by a virus. The infection is usually mild with fever and rash.

IN PREGNANCY Birth defects occur if rubella is acquired by a pregnant woman: deafness, cataracts, heart defects, mental retardation, and liver and spleen damage (at least a 20% chance of damage to the fetus if a woman is infected early in pregnancy). 

Rubella vaccine (contained in MMR vaccine) can prevent this disease.It is normally given routinely to children, but can also be given to adult as needed.


Group B Strep (GBS) 

GBS is a common bacteria that colonized the genital area of 35 % of all women. It is not a sexually transmitted infection. It is most commonly asymptomatic. 

GBS can cause serious disease ( meningitis, pneumonia, and sepsis) in a newborn baby if it is not treated. That is why it is important that we screen IN PREGNANCY  for GBS. We do screening at 35-37 weeks. It is a painless vaginal and rectal swab with a Q tip. You may test positive this way, or if you have any GBS identified in your urine .If you had a baby with GBS disease in the past, you are also considered positive for life. 

We use antibiotics like penicillin to treat GBS. There are effective alternatives for those with penicillin allergy. Antibiotics must be given in labor and not before, since GBS grow back quickly. With antibiotic treatment,  the odds of delivering a baby with GBS disease drop from 1 in 4000 to 1 in 200,  a 20 fold decrease. Since active prevention began in the mid 1990s, the rate of group B strep disease among newborns in the first week of life has declined by 80%. 


Click HERE for a Patient pamphlet on GBS from the CDC ( Center for Disease Control). 



To learn more about other infections of perinatal significance, like

 Toxoplasmosis (Toxo) 

Varicella, aka chicken Pox Virus

Influenza, aka flu 

Pertussis, aka Whooping Cough 

Fifth disease, aka, Parvovirus B19

Herpes simplex 1 and 2 

Bacterial Vaginosis (BV) 


Click the Petri Dish Below.