Normal baby growth ?

Hi,

I am 31 weeks pregnant, carrying twins, following is the detail of doppler conducted today:
1. Twin, live fetuses, both cephalic
2. Fetal maturity – 31 weeks, AC 245 and 220, est. fetal weights 1.5 kg and 1.1 kg
3. Umbilical artery of 1st fetus shows good forward diastolic flows with normal resistive indices for gestational age while that of 2nd fetus shows significantly high resistive indices with head sparing effect.

Middle cerebral arteries show normal flows.
PI RI S/D
Umb. Artery 0.83 and 2.2 0.57 and 0.88 2.33 and 8.3
Midd. Cerebral A. 2.0 and 1.0 0.82 and 0.6 5.5 and 2.5

Cerebroplacental ratio is normal for the 1st fetus and is reversed for the 2nd.

4. Both uterine arteries show color flows with normal resistive indices.
5. Umbilical veins show normal non pulsatile flow.
6. Liquor is borderline, AFI 10.8 cm

Following are my concers:
1. Are both babies growing normaly ?
2. Does this report indicates sign of pre term delivery?
3. Are there any suggestion on how to increase blood flow and liquor?

Many Thanks in Advance
Gunjan