Parents who talked about assisted conception showed greater warmth
Children conceived using donor sperm or eggs or through surrogacy do as well emotionally as those conceived naturally, research suggests.
The Cambridge University study which followed children up to the age of seven found little difference in family relationships between the two groups.
But teachers saw more emotional issues in the assisted conception group.
The study, of 198 families, is being detailed at a European reproductive health conference in Barcelona.
There has been concern that donor conception children may have more emotional problems than those conceived naturally, that parents may behave less positively towards them or that the child may not feel fully accepted as part of the family.
Polly Casey, from the Centre for Family Research at Cambridge University looked at the psychological well-being of the parents and children and the quality of their relationships.
Children were given a "map" with them at the centre, and asked to plot where family members and friends should be placed based on the emotional closeness of each relationship.
Parents were interviewed, and both mothers and teachers filled out questionnaires looking at the child's conduct and emotional wellbeing.
The team has followed 39 surrogacy families, 43 donor insemination families, 46 egg donation families, and 70 families where children had been conceived naturally.
But only 39% of egg donation parents, 29% of donor insemination parents, and 89% of surrogacy parents had told their children how they were conceived, far fewer than had said they would do so when their child was one.
Fears the child would not love their non-genetic parent, or that they would be upset by the news were major reasons for keeping the information from them.
The data presented to the conference is based on findings from around half the families studied.
There was no distinction between where children placed themselves on their maps in relation to their mothers and fathers, however they were conceived.
Miss Casey said: "We found that the family types did not differ in the overall quality of the relationship between mothers and their children and fathers and their children."
However mothers who had used egg donation or surrogacy to conceive were more sensitive to their child's anxieties than mothers of those conceived via donor insemination.
There was also slightly more chance of "emotional over-involvement" with their children from assisted reproduction mothers as opposed to natural conception mothers.
Mothers' questionnaire responses showed no difference between the groups.
But teachers - who did not know how children were conceived and who were told they were taking part in a child development study, reported a slightly higher level of emotional difficulties such as anxiety issues among the assisted reproduction group.
The researchers say this may have been because parents "played down" problems they had noticed, or that the children behaved differently at school than at home.
The study also found "significant disparities" between assisted conception families who were open with the children and those who were not.
Parents in the families who talked about the conception displayed greater sensitivity and warmth to the child.
Olivia Montuschi of the UK's Donor Conception Network, said: "What's important for children is a warm and secure family environment.
"If that's present, there are likely to be good quality relationships within the family."
She added: "There is a dearth of information on donor conception families, so this work is to be welcomed, but what I would like to see is longer term studies following both parents' and children's experiences."