Teen girls who get along with their mothers may be less likely to have sex earlier in adolescence, a Dutch study suggests.

Researchers examined survey data for 2,931 boys and girls who were asked about their sex lives as well as their relationships with both parents when they were 12 years old, and again at age 16.

Girls who reported higher-quality relationships with their mothers were 44 percent less likely to start having sex during the study period.

"We found that a higher-quality relationship with mothers is a protective factor against early sexual initiation for girls, but not for boys," said lead study author Dr. Raquel Nogueira Avelar e Silva, a public health researcher at Erasmus Medical Center, in Rotterdam, The Netherlands.

"In addition, no protective effect was found for fathers, neither for girls, nor for boys," Nogueira Avelar e Silva added by email.

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While plenty of previous research has linked earlier sexual intercourse and riskier sexual behavior with poor parental relationships, much of this work has focused on the influence of mothers rather than father, researchers note in Pediatrics.

To assess how relationships with both parents influence teen behavior, researchers examined data from questionnaires asking teens how close they feel to each parent, and how much they enjoy spending time with each parent.

The questionnaires also inquired about sex, which was defined as heterosexual vaginal intercourse in the study, asking how often teens had sex, if at all.

Overall, 233 teens, or 8 percent of the survey participants, started having sex at some point between ages 12 and 15, the study found.

This included 77 girls and 156 boys.

Compared to girls who didn't start having sex during the study period, those who did reported less parental monitoring and lower relationship quality with their mothers and fathers.

Boys who had sex during the study period also reported less parental monitoring, and they had lower quality relationships with their fathers.

After researchers accounted for other factors that can influence how soon teens have sex, however, only the girls' relationships with mothers remained statistically meaningful.

It's possible that this is because mothers are the primary providers of sexual education in many families, or because mothers speak more openly about sexuality with their daughters than their sons, the authors write.

Because the study is observational, it doesn't prove that solid relationships with parents can prevent teens from having sex or that poor relationships encourage earlier intercourse, the authors note.

Another limitation of the study is that researchers relied on teens to accurately recall and report on their relationship quality with both parents as well as their sexual history, the authors point out. Teens who opted not to participate in the surveys were also less likely to be living with both parents, potentially having worse relationships than the youth who did participate.

"Having a warm relationship and talking openly, being less punitive with your children doesn't necessarily make your children less likely to start sexual intercourse," said Lucia O'Sullivan, a researcher at the University of New Brunswick in Canada who wasn't involved in the study.

It's more likely that children who have more positive relationships with their parents delay sexual intercourse for other reasons such as being more closely supervised, or having less stress at home or living in a higher functioning family that encourages kids to invest in educational and occupational goals that take precedence over early sexual relationships, O'Sullivan added by email.

Even so, the findings offer more evidence that parents can help teens develop communication skills that are essential for a healthy sex life, said Devon Hensel, an adolescent medicine researcher at Indiana University School of Medicine in Indianapolis who wasn't involved in the study.

"At any age, sex can be associated with negative outcomes such as unintended pregnancy or sexually transmitted infections, including HIV," Hensel said by email. "Such outcomes are an especially important reminder as to why adolescents need open, frequent and honest communication from multiple sources - but especially from their parents - as to how they can protect themselves."