There are many affects teenage pregnacy can have on the teens life. Here are some I can immediately think of, not listed in any pacific order of importance:

1. Education.

Being a parent limits the ability to continue studying cutting the chance of getting a well paid job to support your family and improving finances.

2. Freedom

Loss of freedom to socialise and go out with your friends partying. Can no longer just consider yourself and need to adjust lifestyle.

3. Health

The teen may not seek medical assistance or have regular check-ups so any problems could go unchecked.

4. Loss of friends, or respect from family

Friends drifting away as their lifestyle and responsibilities are different. Losing family support or respect is another possibility causing isolation.

I'm sure there are many more, not all of them detrimental. Some positives are possibly lifestyle changes (less drinking, partying, drugs) of benefit. With good support behind them, continuing their education and developing new friends and interests they wouldn't normally have made.

Personality, choices, opportunity all have an affect on how a teenager handles pregnancy, and how the pregnancy will affect their lives. Having loving support also making a big difference, without it, I imagine life would be a lot lonelier and scarier making a teen more vulnerable.