Welcome to our message boards and thanks for your post.
The incubation period with HPV can vary greatly, from weeks to months or even years, making it impossible in most cases to sort out the "when" and "from whom" questions. Either/both of you could have had HPV from a prior relationship. HPV testing is limited in it's application to specific cervical cancer screening situations, and is neither designed nor approved as a general means of checking infection status, determining how long one may have been infected, or whether or not HPV infection can currently be transmitted.
There is no way to know for certain if you have contracted HPV from your partner, although couples are generally presumed to share HPV infection (some experts might take issue with such a general statement, although I suspect not too strongly). What follows in this specific section is what I posted to someone else who had a question similar to yours re: HPV in a relationship: Transmission studies among couples are lacking, but it doesn't appear likely that couples sharing an HPV infection will "ping pong" the virus back and forth. Some research suggests that couples who use condoms might be able to clear both HPV and associated lesions (like cervical cell abnormalities) a bit more quickly, but more studies are needed to fully understand this. Suffice to say reinfection with your current partner probably isn't an issue, but some couples choose to use condoms regardless. Condom use has also been associated with lower rates of HPV-related diseases, like cervical cancer.
In terms of how "dangerous" HPV is, I think the best answer anyone can offer is that cancer is an uncommon outcome of HPV infection and the malignancy most often associated with "high risk" HPV, cancer of the cervix, is essentially preventable through regular screening and, if needed, treatment and follow up exams. Because cervical cancer usually takes years to develop, the disease is most often observed in women who have either never had a Pap test, or have gone many years without one.
As for treatment of cervical cell changes, review the pertinent section of our Web site at http://www.ashastd.org/hpv/hpv_learn_dysplasia.cfm#6
. Treatment options vary based on factors such as size, location, and distribution of lesions. Hysterectomy is not commonly indicated to treat cervical precancers, and even many cancers do not require this approach.
Re: pregnancy, go to http://www.ashastd.org/hpv/hpv_learn_dysplasia.cfm#7
. C-section is not generally recommended solely due to the presence of HPV, as the risks of neonatal transmission are slight. The issue with cervical HPV during pregnancy is the health of the cervix, not the baby.
For all points we've discussed, your partner should ask her health care provider to address them given her specific case and medical history.
Hopefully this has offered some insight. Your questions are very specific and very excellent; I hope you'll continue to participate in this forum.
All the best,