Right at the start of your prenatal check-up, you will be screened for any conditions and infections that may be standing in the way of your baby's healthy development. Your doctor can start treatment in time to treat and prevent any complications, if necessary.
If anything seems unusual or different, you should see your doctor right away. Don't wait for your next scheduled prenatal visit. Recognized early, infections can effectively dealt with without causing harm.
A - often unnoticed - vaginal infection can be a serious threat. The vaginal environment usually has an acidic pH of 4.0 to 4.4. This level is maintained by lactic acid bacteria communities in the bay that act as a natural barrier to the spread of harmful bacteria. During pregnancy in particular, this environment can be more easily disrupted due to fluctuations in hormone levels. A pH above 4.5 is a sure sign that certain types of bacteria  can make you more prone to premature contractions. There are several ways today to monitor your vaginal acid level yourself, for example with a test strip or self-testing gloves. 

Other infections can put you and your baby at risk. These include gastrointestinal infections, urinary tract infections and sexually transmitted diseases. 

Infectious diseases
It's a good idea to learn about dangerous viral infections like cytomegalovirus, hepatitis, and HIV, even though these infections tend to be rare.
Cytomegalovirus (CMV) is a widespread herpes virus that is completely harmless  to most people. The virus is widespread throughout the world. In Europe, the rates of infected individuals range from 30% to 100%. If an expectant mother is primarily infected during pregnancy, the fetus's immune system cannot yet fight the virus. 
Consequences may include miscarriage, premature birth or damage to the baby's organs. There is no so far, some special precaution. Regular hand washing and careful hygiene is the best protection. A simple blood test can show if you have CMV.