Why does Jesus say woe to pregnant and nursing women during the tribulation escape?
Jesus says woe to pregnant and nursing women because they will be part of the fleeing remnant and must walk long distances to escape. Pregnancy makes them heavy and slow, while nursing mothers must carry and care for infants, so the hardship of the flight is especially severe for them.
Les explains that Jesus is speaking to the remnant of Jews who will flee Jerusalem when the Antichrist defiles the temple and turns on the Jewish people. In verse 19, the woe is directed to young mothers, probably in their 20s and early 30s, who are pregnant or nursing children. They are included in the escaping remnant, but it will be tough for them because they are heavy with child and have to walk long ways. This fits the whole cross section of society Jesus addresses: older, well-to-do people; working-class people; and young marrieds with their kids. The flight will be difficult, especially if it is winter or the Sabbath, because they will be walking and carrying goods.