Smoking during pregnancy and children’s emotional and behavioural trajectories

Abstract Background The nature of the relationship between maternal tobacco smoking during pregnancy and the occurrence of children's behavioural problems is still a matter of controversy. We tested this association using data collected among a sample of children followed from pregnancy to early adolescence (age 11.5 years), accounting for multiple parents’, children's and family characteristics. Methods Data come from 1424 mother-child pairs participating in the EDEN mother-child cohort set up in France. Using repeated measures (3, 5.5, 8 and 11.5 years) of the mother-reported Strengths and Difficulties Questionnaire, we estimated trajectories of children's emotional and behavioural difficulties. Two aspects of maternal smoking were studied: the timing and the level of use (cigarettes/day) during the first trimester of pregnancy. Multinomial regression models controlled for confounding factors including maternal mental health and socioeconomic characteristics using propensity scores with the overlap weighting technique. Results Contrary to bivariate analyses, in propensity score-controlled regression models, maternal smoking throughout pregnancy was no longer significantly associated with offspring emotional or behavioural difficulties. Maternal heavy smoking (≥10cigarettes/day) remained significantly associated with intermediate levels of overall emotional and behavioural difficulties (OR 1.64, 95%CI 1.04-2.58) and conduct problems (OR 3.05 95%CI 1.22-7.61), as well as with high levels of conduct problems symptoms (OR 2.82 95%CI 0.88-9.06) - although the latter did not reach statistical significance. Conclusions The association between maternal smoking in pregnancy and offspring emotional and behavioural difficulties appears to be largely explained by women's other characteristics. However, maternal heavy smoking appears to be related to offspring behavioural difficulties beyond the role of confounding characteristics. Key messages • The association between maternal smoking in pregnancy and offspring emotional and behavioural difficulties seem largely explained by the family's socio-demographic and behavioural characteristics. • Maternal heavy smoking appears to be related to offspring behavioural difficulties beyond the role of confounding characteristics.


Background:
The nature of the relationship between maternal tobacco smoking during pregnancy and the occurrence of children's behavioural problems is still a matter of controversy. We tested this association using data collected among a sample of children followed from pregnancy to early adolescence (age 11.5 years), accounting for multiple parents', children's and family characteristics. Methods: Data come from 1424 mother-child pairs participating in the EDEN mother-child cohort set up in France. Using repeated measures (3, 5.5, 8 and 11.5 years) of the mother-reported Strengths and Difficulties Questionnaire, we estimated trajectories of children's emotional and behavioural difficulties. Two aspects of maternal smoking were studied: the timing and the level of use (cigarettes/day) during the first trimester of pregnancy. Multinomial regression models controlled for confounding factors including maternal mental health and socioeconomic characteristics using propensity scores with the overlap weighting technique.

Results:
Contrary to bivariate analyses, in propensity score-controlled regression models, maternal smoking throughout pregnancy was no longer significantly associated with offspring emotional or behavioural difficulties. Maternal heavy smoking (10cigarettes/day) remained significantly associated with intermediate levels of overall emotional and behavioural difficulties (OR 1.64, 95%CI 1.04-2.58) and conduct problems (OR 3.05 95%CI 1.22-7.61), as well as with high levels of conduct problems symptoms (OR 2.82 95%CI 0.88-9.06)although the latter did not reach statistical significance.

Conclusions:
The association between maternal smoking in pregnancy and offspring emotional and behavioural difficulties appears to be largely explained by women's other characteristics. However, maternal heavy smoking appears to be related to offspring behavioural difficulties beyond the role of confounding characteristics.

Key messages:
The association between maternal smoking in pregnancy and offspring emotional and behavioural difficulties seem largely explained by the family's socio-demographic and behavioural characteristics.
Maternal heavy smoking appears to be related to offspring behavioural difficulties beyond the role of confounding characteristics. Healthcare professionals can claim conscientious objection (CO), but regional governments must guarantee women's rights. In recent years, international human rights authorities argued that access to safe abortion was limited in Italy due to widespread CO.

Methods:
An ecological study was conducted using 1997-2019 ministerial data on the number of gynecologists registered as conscientious objectors, the proportion of abortions performed timely (within 14 days of the request), and within 8-10 weeks of pregnancy. The extra workload for non-objecting gynecologists was calculated as the ratio between the workload for non-objectors and the (theoretical) workload for each gynecologist on duty. The correlation between the extra workload for non-objectors and the proportion of abortions performed within 14 days of the request or beyond 21, as well as the correlation between waiting time and gestational age at the time of the procedure. Data were analyzed for Italy and stratified for its 21 Regions.

Results:
CO among gynecologists turned out to be stable around an average of 70% (median 69%, IQR 64-71%) in the last decades, with 62% of abortions performed within 14 days and 82% of procedures performed by the 10th week of pregnancy.
In 13 regions (statistically significant in 5) the increase in workload for non-objectors was inversely correlated with abortions performed within 14 days, and directly correlated with those performed later than 21 days. In all regions (statistically significant in 18) a direct correlation was found between procedures performed timely and those performed within 8 weeks of pregnancy.

Conclusions:
Data from the last 20 years confirm previous findings and CO still seems to have a strong impact on women's right to access safe and timely abortion in Italy. More efforts are needed to narrow the gap between the provisions of the law and its implementation.

Key messages:
A high proportion of objecting staff makes it difficult to guarantee women's rights to access timely and safe abortion. Effective organizational strategies and a proper legal framework are needed to cope with the high percentage of conscientious objectors among health professionals.