Neither it is advisable nor it should be taken for granted to travel in the 9th month of pregnancy. Whatever may be the situation, this is totally irresponsible on the part of husband to make wife travel in such adverse conditions.
God forbid, anything could have happened to mother and the new born. Thank god they both are safe and sound. But nevertheless harrowing time for co-passengers due to the travelling family. Totally Avoidable.
I'm myself a dad, so can actually relate to the incident.