Climbing the Ladder

How to Prepare for Maternity Leave
Being pregnant is chaotic enough with announcements, planning, preparations and doctor visits. And that's just your personal life! Your professional life is going to be significantly altered, too, and the earlier you prepare for it, the easier your transition into maternity leave will be for you and the co-workers who will be affected by your absence.
Even if you're not the only person in your office that performs your job function, there are probably small nuances and side projects you're working on that are specific to you. If these things can't wait until you return, you may have to prepare instructions for your temporary replacement. For some projects simple notes on what to do if specific things happen will be enough and for others step-by-step instructions are necessary. Keep in mind that you've been doing this job for a while, so when writing detailed instructions remember to put yourself in the shoes of someone who knows nothing about what you do.
News travels fast and you don't want your boss to hear the news through office gossip. Once you've decided to tell people at work that you're pregnant, it's a good idea that one of the first people you tell is your boss. Then throughout your pregnancy as you make important decisions, keep your boss up-to-date on decisions you've made that will affect your work. Your due date, how long you plan on taking maternity leave and if you plan on coming back to work are very important details for your boss to know.
Very soon after or even before you tell your boss, make an appointment with HR so you can discuss maternity leave. There will be some paperwork and questions they need to ask, so making an appointment is necessary to give HR enough time to give you all the information you need to get everything in order. Even if a co-worker recently discussed maternity leave with HR, it doesn't mean everything will be the same for you. Also, get everything in writing so you can refer back to it later if necessary.
With pregnancy there are a lot of unforeseen circumstances, but you should still have a "leave date" set. Obviously if your baby is premature you'll need to leave sooner, but the leave date will give your boss, HR and co-workers an idea of when to expect your absence. Some women want time before their due date to prepare; others will work right up to the due date or past it depending on when they go into labor. No matter what you decide, keep people informed so they're ready to transition into your role.
Maternity leave is different from company to company and state to state. Some businesses classify maternity leave as temporary disability and give you a portion of your wages while you're gone. Some businesses don’t allow maternity leave at all! In either case, it's a good idea to save up all your personal, vacation and sick time. These will either give you the time off you need to adjust and recover or maximize the amount of time off you get in addition to your temporary disability time.
Remember to relax. It will be difficult for the people around you to adjust especially if you don't have a direct replacement, but odds are the whole company won't collapse because you're on maternity leave. If you prepare everyone early for your absence they should be able to manage without you. Besides, this is a time in your life when you should be focusing on yourself and your baby—not worrying about your co-workers.