Hilaria Baldwin "dreads" losing her hair after having a baby.

Alec and Hilaria Baldwin

Alec and Hilaria Baldwin

The 34-year-old fitness and wellness expert gave birth to her fourth child Romeo, whom she has with her husband Alec Baldwin, 10 weeks ago and has admitted she's expecting her long tresses to start falling out over the next few weeks as they did when she delivered Carmen, five, and sons Rafael, three, Leonardo, 22 months.

Taking to her Instagram account, the brunette beauty said: "It has been my greatest joy in life becoming a mother...we all know that it is hard, and comes with aches and pains, but one thing I wasn't prepared for the first time around was the postpartum hair loss. I would actually say that it is the thing I dread the most when having a baby.

"Mine always starts to shed around now, picks up (like horror film style) around 3 months, then reduces to normal shedding 6 weeks after that. Then, the regrowth awkward process begins...tiny, sticking up hairs, all over my head.

"I always have to reassure myself that it will grow back, but, nevertheless, I do find that it is upsetting each time around--even though I know what to expect now.

"I tried short haircuts, I tried bangs....this time around, my friend Dr. Arash Akhavan (@dermatologyandlasergroup ) suggested taking vitamins.

"He said it won't stop the hair loss, but may speed up the regrowth. (Side note: he is super cool and seems at first glance like he would be one of those unnatural docs...but is a wealth of information when it comes to more natural skin products).

"Postpartum hair loss has been a popular question here, and I would love to hear your experiences, remedies, and questions. (sic)"

However, despite the downsides of postpartum, Hilaria would love another baby.

She said recently: "I have a daughter and then I have three boys. And my daughter is very sure that she is going to have a sister."

Carmen already has a big sister in Ireland, Alec's 22-year-old daughter from his previous relationship with Kim Basinger, but is determined to have a younger one too.

Hilaria added: "She does have a sister - she has Ireland, and Ireland is so wonderful and they have a great relationship.

"But there's something about a little sister that she really wants."