It is quite common among the people I know to believe that bringing up children was easier during our parents' time than now.  I think this belief is also reinforced by our parents telling us how they brought up so many kids single-handedly.  Very often, we do feel somewhat inadequate compared to our parents when it comes to taking care of babies.
 
However, I think it is not entirely true that our parents were really able to bring up all their children 'single-handedly', that they were more 'capable' than we are.  Of course, there were very capable women last time who really did take care of easily 7 or 8 or even 10 kids.  Nevertheless, there are also women our generation who are equally capable, just that these days, nobody has so many kids anymore.

1. Extended Family

It is common for couples to live with their parents, or an entire extended family last time.  Hence, they did have help, not just from their parents, but from other relatives staying with them as well.  Even if they stayed on their own, families then were more closely knitted and help was freely sought and rendered.  Things are certainly very much different now.

2. Kampong ('village')

Apart from the extended family, there was also the 'kampong'.  People stayed within a community and neighbours often provided society as well as help to each other.  Since the kids of the neighbourhood would be playing together, parents watching over their kids would also be watching over the other kids as well.  Nowadays, one can hardly find any 'kampong spirit' anymore.

3. Domestic Helpers

Contrary to popular belief, domestic helpers were not uncommon during our parents' generation.  In fact, due to lower educational level, especially among the women, a lot of women worked as domestic helpers, much like our foreign maids.  Their wages were certainly not as exorbitant as our foreign maid levy cum wages.  The richer families could even afford several 'ah mahs', each dedicated to taking care of one child in the family.

4. Older Children

Bringing up children actually has economies of scales if one has many children.  This was the case in the previous generation.  The older children would be taking care of the younger ones, sharing their mother's burden.