With a light snow falling outside, three health care workers from the Baltimore-based aid group Jhpiego were busy repacking their bags inside BWI Thurgood Marshall Airport to make sure the mosquito repellent, sunscreen and water purifiers could all fit.

The trio were headed to earthquake-ravaged Haiti on an 8 a.m. flight this morning, and they didn't want to leave anything behind. They knew their colleagues on the ground were counting on them to bring supplies to treat the needy and food and other basic necessities for them.

Jhpiego, an affiliate of Johns Hopkins University, has worked in Haiti for 15 years, but the devastating natural disaster a week ago ruined the infrastructure the group had built to ensure some of the most vulnerable populations — pregnant women and newborns — could get essential care.

"They're often neglected populations, and during a disaster they can be even more neglected," said Dr. Willibrord Shasha, an obstetrician-gynecologist who has worked for Jhpiego since 1981. "We want to make sure they are not forgotten."

Shasha was joined on the two-week trip by other veteran workers, Richard Lamporte, a member of Jhpiego's leadership team; and Anna Pfitzer, a senior program manager. All leave behind spouses and a couple of kids for the mission.

They expected to fly today from Baltimore to Puerto Rico and then to the Dominican Republic. From there, they hoped to hitch a ride with another aid group for the rest of their trip to Port-au-Prince in Haiti or catch a military helicopter.

Lamporte said planning is difficult because communications are still spotty and dangers, such as increasingly desperate people, aftershocks and unstable buildings, persist.

"We didn't even know until last Friday that our workers in Haiti were all safe, and we still don't know about all of their families," he said of the six Haitians who work for the group. "We do know we have to be self-sufficient; we brought tents, sleeping bags and all our food, in addition to all the supplies we could carry."

The group is not an emergency relief organization, though they expected to do some treatment because of the overwhelming needs. The workers will try and re-establish a system that connects pregnant women to clinics and medical professionals. With much of the infrastructure damaged or demolished, they expected the aid to come largely from field clinics in the short term.

"We'll do what we need to do to support the team there," said Lamporte, an experienced outdoorsman and emergency medical technician. "This about recovery and reconstruction."