This interesting study on medical students at the University of South Carolina posits gender-related values associated with interpretation of how work and life are related.
As far as OB/GYN (or Pediatric practice) counting as primary care -- this study was done in the US where the majority of prenatal care is delivered by OB/GYNs and children attend a pediatrician as opposed to GP, as opposed to the UK, where it's midwife care and GP care afterwards.
It is interesting to note that the men and women were statistically similar in terms of marital status or parental status, yet women tended to want to work shorter hours after qualifying than the men, and prioritised spending what leisure time they had with family and friends, whereas men tended to heavily prioritise sport, whether married or not, and whether parents or not. [from the study -- 'The value the female students place on time with family and friends is consistent with statements female physicians usually make, indicating they make significant career decisions, including specialty choice, based on family considerations ']
Men also tended to opt for the more interventionist areas of medicine, i.e. surgical specialties, where high adrenaline environments prevail, where relationship with a patient is more likely to consist of a review of data, x-rays, previous history, and perhaps where you get the chance to play superhero every day, saving a life by removing a tumour or appendix or whatever, whereas women were opting for medical roles that where more likely to feature one on one nurturing/teaching/encouragement/coaching through a process. It is interesting that more men than women are attracted to the more problem solving OB/GYN profession in the UK, where the OB is the 7th Cavalry of the profession.
As far as deeper values go I'm not sure -- men maybe like to have the prototypical male role of instant problem solving, with a scalpel? Whereas maybe women prefer to get immersed in process and communication? (Anecdotal perhaps, but a lot of women complain that when they complain about something going on in their lives their H's put on their Mr Fixit hat and annoy the women solving their ishoos instead of just listening and tut tutting and making a cuppa for them, which is what the women really want.)