How can the so-high health costs be overcome as a F1 student and F2 dependants?

I am currently an international student in MS, USA with my F-1 visa. My spouse and 3-year old dependent also live here with F-2 visa. I have medical insurance covered by the school, but my family do not have. My spouse is also pregnant and will deliver the baby in April, 2017. Medical care is much much expensive in USA. To illustrate, we were charged with almost $1,000 for only one visit to the women clinic. We were only informed about the cost of one item (Ultrasound and it is ~$250) and the remaining part was a horrible surprise. We cannot accommodate it in anyway and we also seem ineligible for Medicaid etc. Thus, how can we overcome such exaggeratedly high health expenses with student conditions? Does any legal solution/support exist for such a case?