If you had a prior history of sexually transmitted disease, especially gonorrhea, chlamydia, or pelvic inflammatory disease you may be more at risk for an ectopic pregnancy, which can be life threatening if not diagnosed and treated promptly. Your doctor will want to know as soon as you suspect you are pregnant, to confirm the pregnancy is in the uterus and not ectopic (a pregnancy outside the uterus, usually in the fallopian tube, but less likely elsewhere in the abdomen, where it doesn't belong.)
There is also a higher chance of infertility with prior sexually transmitted disease. Patients with a history of endometriosis (tissue that normally lines the uterus being found in the abdomen where it shouldn't be, such as on the tubes, ovaries, bowel and lining of the abdominal cavity, causing cyclic pain) also have a higher chance of infertility and ectopic pregnancy.
Patients with fibroids (benign smooth muscle tumors of the uterus which are very common and can become quite large) can have infertility, preterm labor and delivery, and issues with miscarraige as well as placental implantation. Extensive preconceptual counseling and testing should be done to determine whether these fibroids should be left in or taken out before attempting to conceive - there are pros and cons to both, and each decision must be individualized to that patient's location and size of fibroid, as well as her prior obstetrical history.
Patients who have had surgical procedures on their cervix for dysplasia (precancerous cervical changes caused by the HPV virus) have a higher chance of cervical incompetence (the cervix opens prematurely and painlessly and the baby is lost) and the cervix will need to be followed more closely during the pregnancy. If the cervix starts to shorten or open prematurely, or other pregnancies were lost to documented cervical incompetence, a preventative cervical cerclage (stitch in the cervix) can be done at 12 to 14 weeks of pregnancy.