The dilemma Some years ago my husband and I made the hard decision not to have children. He wanted them but he accepted that I didn’t and was sad for a bit. I was conflicted and guilty but eventually we came to terms with our decision.

Then I found out I was pregnant. It was a huge shock but I couldn’t bring myself to have an abortion. I had an awful pregnancy and was very depressed but fortune delivered us a calm, happy baby and motherhood came quite easily, much to my surprise. My depression lifted, I was back to myself and could get back on with life. My husband was thrilled and we’ve both enjoyed being parents. We agreed not to have another as all my reasons in the first place still stand.

My child is now at the age when he is surrounded by the rest of the world who have siblings and he’s starting to ask why. I feel terribly guilty for denying him the sibling that (almost) everyone else gets and I know he’s always going to feel like he’s missed out. But I really don’t want another baby, I feel physically sick at the thought of it and want to just appreciate what we have and enjoy it.

I can’t shake the feeling that I am being terribly selfish and I should come to terms with the fact that I should be trying to give him a sibling. I would consider adoption but my husband wouldn’t.

Mariella replies Excuse me? I was totally catching your drift until that last sentence. Is an adopted baby not a baby? You don’t enlighten me on your reasons against parenthood but I can’t imagine it’s only about the dread of pregnancy, so why would an adopted baby be OK? You say you don’t want another because “all my reasons in the first place still stand” but I haven’t a clue what they were so I find myself with far more questions than I have answers to.

Perhaps you’re concerned about global population growth, which would be a noble reason for keeping to a single child. Or struggling with the responsibility or loss of control. You may well be really committed to your career and not want that to be knocked off track. Or so preoccupied with wrestling your original plan back from the quirks of fate that you’re not thinking straight.

Your child should not have a hand in the decision. It’s way too much responsibility

Choosing whether or not to have a family is a basic human right although not one available to all women. Whether it’s because contraception is unaffordable or unavailable, or, conversely, children are needed to sustain their parents’ meagre living in old age, many women have children out of necessity. Deciding when and if to give birth is an unimagined gift for millions in the developed world where any number of entirely justifiable considerations can enter the equation whether philosophical, medical or downright self-indulgent.

Predicting how we’ll feel at different stages in our lives is just one of the complications, particularly when it’s a choice that has an end date. I have friends who have chosen not to start a family and the majority are perfectly happy with the life they’ve opted for, so please don’t think I’m a proselytiser for procreation. You and your husband made a perfectly reasonable decision that the fates had a chuckle at.

Your child shouldn’t have a hand in the decision. It’s way too much responsibility and he will just as likely grow up celebrating his unique status as mourning the absence of bloodline playmates. There are plenty of only children in this world basking in the sole spotlight of their parents’ attention. You can easily mitigate for lack of siblings with sleepovers and, later, by making your home a welcoming place for their friends to congregate. Your child will have chances that might otherwise not have been possible were he to grow up in an environment where budgets must be stretched and time allocated among siblings.

Sound of Music style mythology aside, there are plenty of families out there with siblings whose needs go unnoticed thanks to their lack of pole position, or who fail to keep a connection with one another in adulthood. All that is really just a way of saying that there is no right choice when it comes to numbers. If your husband is desperate for another child and your kid eager for a companion you must have fairly strong convictions as to why your needs should take precedence.

Offering advice when I’m being asked whether you’re right without being privy to your reasoning makes it a guessing game. As I’m sure you’ve been told, every pregnancy is different and your next could be effortless or worse than the last so on that front it’s more about risk assessment. The future for all of us, no matter what contingency we put in place, is entirely unknown. If, as I suspect, your choices are partly informed by fear, the worst has already happened and it’s turned out fine. Why not think further on your choices with the whole family’s needs in mind, and in the liberating knowledge that controlling the future is as redundant an effort as stopping the tides?

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. Follow her on Twitter @mariellaf1