Hi Crystal, Welcome to HealthcareMagic Forum.
The Fetal heart in the initial months of Second trimester should be around 140 beats per minute. The partial Pressure of Oxygen
tested in the Umbilical Vein
sample should be approximately 30mm Hg, but it varies. Your treating Doctor would know better.
Hope I have answered your Query, I will be available to answer your follow up Queries.
Wish you Good Health, Take Care.