Let share my experience of using both Medela mini-electric and Avent manual pump.
The feeling of using Avent manual pump is much better than Medela mini-electiric. The nipple is not too much painful as I can adjust the pressure and the frequency of each press. In addition, the volume of milk being pump out is more for Avent manual pump than Medela mini-electric. The maximum milk being pumped out are 4oz using Medela mini-electric and 8oz using Avent manual pump. Both cases are performed on the first meal in the morning.
In addition, my daughter dislike the noise being produced by the Medela mini-electric as I pump out the milk during her sucking.
I strongly recommend you to buy the Avent manual pump for using in the office.
beautyshirley,
I've been pumping milk since going back work after the maternity leave. For my experience, you need to use hands for pumping even after using pumps. This can maximize the amount obtained and tell the body to generate more milk. Of course, letting bb suck more is most important. It takes time for both of you to adjust to 埋身餵.
Drink more water/milk/juice and soup before and after each pumping and feeding. This will greatly increase your milk production.