MANY women who become mothers, seem to forget the bit called pregnancy, that long run-up before there were toys everywhere, childcare to sort out, baby clothes to wash and an extra mouth to feed. Our memories of the nine months of growing that baby inside become foggy.

Not so for Guardian journalist and author Chitra Ramaswamy, who has written a book about the experience of pregnancy. She wrote it in fits and starts: in the local café, at Edinburgh’s Botanical Gardens, sitting on a park bench with her iPad in one hand and the other on a buggy as she pushed her son to sleep. She wrote during moments stolen, while her partner, the journalist Claire Black, looked after their son.

The result is Expecting, a memoir which begins with a test “whose result is revealed not by a mark on a page but by a stream of one’s own bog-standard urine” and ends with her leaving an operating theatre on a gurney, her freshly born baby on her chest.

Through nine chapters, quoting along the way Sylvia Plath, Nan Shepherd, Sharon Olds, James Joyce and others, she explores each month of pregnancy.

The book also touches on a backstory, the business of orchestrating the conception itself, which was not straightforward for Ramaswamy and her partner. “We were two women for a start,” she writes. “The story was the kind of romantic comedy that would never get made, with all the madcap races across cities and highly charged encounters in hotel rooms you might expect. Stories that were good for dinner parties but bad for life.”

There are, of course, a great many books written about pregnancy and birth. But Ramaswamy's is remarkable for its warm honesty and refusal to churn out the familiar tired metaphors, the usual stream of information about what to eat, how much sleep to get, and when to start taking folic acid supplements.

Her perspective is also refreshing. Ramaswamy is a second-generation immigrant of Indian heritage, raising a son within a same-sex relationship. She’s a Londoner who has settled in Edinburgh with a Scottish woman. Because of this she seems to have a kind of outsider’s-eye for the way pregnancy is circumscribed by rules and expectations. Ramaswamy is a questioner, and an observer who refuses to ignore some of the more difficult feelings pregnancy can provoke.

“There was a stage in my pregnancy where I was so fed up I ate loads of shell fish," she tells me, sitting at the kitchen table in her Leith home. "But I don’t regret it. It was delicious and I was going crazy that day on the Isle of Ulva.” She laughs. “I needed that langoustine. There’s a First World problem for you.”

More seriously, she adds: “You’re uniquely vulnerable when pregnant, because you so want to do everything right and you are aware of the responsibility of carrying this life. But at the same time you are a person in your own right, who has walked the planet on their own for some time, and it’s a very odd thing to suddenly be reduced to this vessel.”

The idea of Expecting came to her early on in pregnancy. “One of the first things I do when a new experience happens to me, is go and read about it,” she says. But in the pregnancy and birth sections of shops she found mainly “very prescriptive manuals” and “books that politicised pregnancy, the sort of feminist polemics written by the likes of Naomi Woolf”. What was missing, she felt, were books conveying “the actual experience of being pregnant”. “I wanted to write an honest book that was not going to make women feel bad about themselves. But actually tell them that it’s OK and that your experience is valid and interesting and it’s amazing.”

Hers was a painstakingly planned pregnancy. Before she and Black even began the search for a donor, bought the home insemination kits or purchased ovulation tests, there was the business of becoming civil partners, which was necessary “to ensure we would both be the parents of a baby that might never be” and “a leap of faith that no heterosexual couple is required to make”.

Because this aspect was so public, many people knew that the couple were trying for a baby, and they experienced “a lot of prurience around it”. Often they would come away from a round of questions by friends or acquaintances, feeling as if it were “an assault”.

“Which one of you is going to do it?" they'd be asked. "How did you make that decision? Was it really hard to make? And, if it doesn’t work, would you adopt?”

“I do understand where it comes from,” says Ramaswamy, “and I try to be sympathetic towards it, but sometimes you’re just like – enough of the questions.”

Rather than buy sperm through a company offering donor services, the couple found the man who would eventually be father of their child through “friends of friends”. “We made the decision to do it in quite an informal way,” she recalls. “I liked the idea of there being some connection with whoever we did it with, so that if the child ever wanted to meet that person or know more about them, Claire and I would be in a position to facilitate it and make that happen.”

A chapter of the book features a meeting between Ramaswamy, Black and the donor, at a pub in Leith, where they have lunch and take a photograph, for posterity, of mother and father together. “I thought that at some point,” she says, “these photos are going to be really interesting to my son. My big tummy, him inside, our donor standing beside me, and Claire behind the camera taking the photo: this is his beginning.”

In the book, she describes how the three of them wondered about the baby's potential skin colour “as all those with mixed-race children surely do at some point”. “Our donor, who is white, lifted his trouser leg to show us the colour of his skin," she writes. "It was pale and softly freckled, the lightest eggshell in the box. I was shocked by the simple fact that this baby in me … was made of a man whose legs I had never seen.”

During pregnancy, Ramaswamy – who'd never felt much desire to “fit in” – suddenly wanted to be more conventional. At the same time, she became aware that her pregnancy prompted strangers to make assumptions. Women in her yoga class would ask about her husband. “People would say, ‘What does your husband do?’ I think they thought I must be married to some Indian doctor. I always find that fascinating. In the 21st century, not even ‘your partner’. Your husband?”

When the couple walked their dog, people would put questions about their pet to just one of them, as if assuming that the animal must belong to one or other, but not both. “To them,” she recalls, “we were always just two friends. And I thought that if it was like that with a dog, what would it be like with a baby?”

Now, she is used to the fact that, since their son is mixed race, when they are out together people assume she is the mother and “Claire’s just my pal”. “But it can be hard to be always received in a way that you are not really in society. You can feel quite invisible”.

When she began talking about her real feelings about pregnancy, people often seemed to want to “shut her down”, she says: “I was shocked that whenever I would say to somebody what was really going on, I would have that feeling they did not want to hear it.”

She also began to notice how apologetic pregnant women were when talking about their experiences. That need to apologise even seemed to dog Ramaswamy when she was writing. People would ask what her book was about and she'd say: “Oh … pregnancy and birth”, as if the subject were shameful. At the heart of this reaction, she believes, is misogyny. “The African-American writer James Baldwin,” she says, “wrote that there is ‘a little white man inside all of us’. I’ve always had that voice there whispering. You just can’t get rid of it. There’s quite a lot of fighting you have to do within yourself to get through it, and writing this book has required that.”

Because talk about birth is so repressed, she says, most of us know little about our own arrival into the world. Ramaswamy herself only learned them when she interviewed her parents for the book. Her mother “told this sad story of how, at the end of my birth, they had had to use forceps and it had all got quite scary. She was so freaked out and weak when I was born that when they offered me to her, she refused to hold me because she was afraid she would drop me”. Her mother was particularly upset to overhear two Indian staff members in that London hospital, people from her own country of origin, saying she wasn't holding her daughter “because she’s not a boy”.

Ramaswamy’s own story of the birth of her son is both thrilling and petrifying: a rapid journey from home birth to transfer to hospital to epidural to caesarean. Yet despite its terrors, she remains positive about the experience. “I was amazed at how I rose to the challenge and took it all on. I felt like a warrior – and I’ve never felt like that before or since. I did think, 'I’ll never be afraid of things any more'. But of course, I went back to normal.”

She sometimes wonders if the reason the full story of birth never gets told is “partly because women don’t want to frighten other pregnant women. It’s too messy, too difficult. It’s exactly the same thing as our inability to talk about death”.

Death features heavily in Expecting. It’s there in Ramaswamy's portrayal of her mother’s treatment for breast cancer, which was taking place when she first became pregnant, and the shock she felt at seeing “the big space” underneath her mother's hospital gown after the mastectomy; her sudden recognition that this breast, now gone, “was how I stayed alive”. It’s there in her anxieties around whether her baby was moving or not. It’s there in her quoting of Leo Tolstoy, who wrote of how both birth and death were “like holes in this ordinary life, through which something higher showed”.

“Those holes close up again,” she says now, “They are not open all the time. We couldn’t live with them open all the time because it’s too exposing and too difficult and too crazy.”

Ramaswamy has been pregnant once only. Would she take that journey again? “Writing about it has put me off a bit," she says. "I feel bored of it. So sick of it. I wonder if I ever did do it again what it would be like. But I think second pregnancies are completely different anyway. A first pregnancy is something you only do once.”

Expecting: The Inner Life Of Pregnancy by Chitra Ramawamy is published by Saraband, £12.99