Syphilis during pregnancy is medically serious, and especially poses a risk to the fetus. A fetus can get syphilis from the mother at any time during the pregnancy because it can cross the placenta. This can raise the risk of defects, congenital anomalies, pre-term birth and stillbirth. If a fetus does not contract the disease in utero, birth could cause exposure to syphilis sores or rash that can transfer the infection, and in infants an untreated case of syphilis poses severe risk for health problems and death. There is one treatment for syphilis during pregnancy: administration of penicillin.
Even though syphilis during pregnancy is rare, many governments legislate that women be tested after a first examination confirming a pregnancy. Retesting is sometimes mandated in the second or third trimester, or sometimes during the birth process, and additional testing could be recommended if a woman has engaged in any risky behaviors that might cause exposure to the disease or if a woman’s sexual partner has syphilis diagnosed. Similarly, if testing for syphilis is positive, testing for HIV tends to be recommended because syphilis creates greater risk for the disease. In other scenarios, a diagnosis of HIV could also lead to need to test for syphilis.
Early testing for syphilis can be of extraordinary benefit. Most women diagnosed in the first trimester can be easily cured with administration of a course of penicillin, which is typically given via shot. This tends to have little effect on the fetus and can help cure a fetus that is already infected with the disease. Diagnosis in the second half of pregnancy is not as worry-free. There is possibility that treatment may cause pre-term labor or stillbirth, but treatment is still pursued because risk to the fetus is much greater without it.
Only penicillin is thought effective in curing syphilis during pregnancy, but this poses a potential problem for anyone allergic to this medicine. This problem is handled in several ways. About 10% of people who have had an adverse reaction to penicillin in the past remain allergic to it for life. Many other people can tolerate it again, and the current state of allergy can be determined with skin scratch tests.
If it appears that allergic reaction is still strong, then doctors treat syphilis during pregnancy by first performing desensitization with diluted levels of penicillin V. This means virtually all people can receive penicillin shortly after desensitization treatment, which typically only takes a few hours. They may need more watchful administration of the drug in a hospital or emergency setting where it is easy to treat an adverse reaction, should it occur.