The organic market has done a great job more recently at including pregnant and new mom's in they marketing. I do refer pregnant and new mom's to two different resources:
https://kimberlysnyder.com/ = Kimberly is all organic and recently had a baby herself so she markets her products and health recommendations toward that space.
https://www.floliving.com/ = Alisa Vitti has a great line of supplements specifically for women. Her focus is female 'issues', helping women prepare for pregnancy, and post-pregnancy assistance.
I feel there is still a lot of room in this space that has not been addressed.

According to Mintel 25% of British parents think ingredients in personal care products can be harmful to their babies and 18% buy natural/organic products.

Natural, organic trend is not new and even more pronounced in the mother & baby sector. A lot of parents believe it’s a better and safer choice for their babies. Natural, organic and food grade ingredients are extremely popular (what’s good to be eaten is safe for the skin too) with organic coconut oil being on the top of the list. A lot of mums use pure organic coconut oil to moisturise their and their babies’ skin.

Another important trend that has been embraced by that segment (apart from FREE FROM) is LESS IS MORE. The less ingredients product contains the better for me and my baby. A great example of that is a UK brand: Sister & Co. Skin Food and their product "Dream Cream for Mothers and Babies"  A few ingredients, water free balm consisting of cold pressed oils, waxes and butters.

There is already some market established for mother & baby. The white space exists for a product range that features both mum and dad. Skinfood company already have a product available which is dedicated for father and baby GOODFATHER Mild Emulsion: A mild emulsion with shea butter and three types of vegetable oil to moisturize and hydrate delicate infant skin.

Women beyond their first few months of pregnancy can experience pelvic girdle pain secondary to ligament laxity accompanying hormonal changes. Simple pelvic belts can be used to stabilize the pelvis and reduce pain. Not sure if this applies, but it is an alternative to pain medication.

It is very important for pregnant women to eat all natural foods. They have to stay away from all processed foods, sugar, sugar substitutes (except stevia), gluten and trans-fats. They must eat lots of healthy fats like avocado, olive oil, nuts seeds etc. They also need all natural healthy proteins like beef, pork chicken and cold water fish. Last they need many servings per day of all natural vegetables and dark fruits. They reason I say all natural is the additives, preservatives, dyes, hormones and antibiotics in processed foods and many others is not only bad for the mother and baby but causes inflammation like sugar, which is very bad for both. Lastly stay away from alcohol which is bad, acidic and causes inflammation besides other problems. Also she must drink lots of water, I recommend AQUA-OH which helps eliminate acids, which will help with inflammation. She should drink one half her body weight in ounces per day. I would also stay away from any foods that contain GMO.

In the contemporary world, women at both the stages are very careful in choosing food & beauty products for herself and the new comer. They always wants to stick with natural and Non-genetically modified (NGMO) products. Ingredients used in product is also very important. Therefore, opportunity exists for natural, NGMO based products.

Women generally shades hair more than normal in both the phases. Hair care products mainly designed for addressing hair and skin care need of Women in both the phase might be very big opportunity, keeping in mind the current awareness level of consumers regarding the products they use everyday life.

When I was pregnant my doc only suggested me to take multivitamin supplement (Materna), on top of following the food guide. After becoming a holistic nutritionist, I learnt that a healthy, balanced diet with organic and natural food is pretty much enough - esp some food can naturally beat depression or simply make one feel good e.g. dark leafy greens, salmon, walnut, tomatoes, fish (or take quality fish oil pill) and dark chocolate.