Change in smoking status during two consecutive pregnancies: a population-based cohort study

Unique influences of pregnancy and anticipated parenting on cigarette smoking: results and implications of a within-person, between-pregnancy study

Not all pregnant individuals want to become parents and "parenting intention" can also vary within individuals during different pregnancies. Nevertheless, the potential impact of parenting intention on health-related behavior during pregnancy has been heavily underexplored. In this study, we employed a within-person between pregnancy design to estimate the effect of parenting-specific influences on smoking, separate from pregnancy-specific and individual-level influences. We quantified within-mother differences in smoking during pregnancies of infants they reared (n = 84) versus pregnancies of infants they placed for adoption at birth (n = 65) using multivariate mixed-effects Poisson regression models. Mean cigarettes/day declined as the pregnancy progressed regardless of whether infants were reared or placed. However, participants smoked fewer cigarettes/day during reared pregnancies. Relative to "adopted" pregnancies, smoking during "reared" pregnancies was lower by 24%, 41%, and 54% in first (95% CI 0.64-0.90; p = 0.001), second (95% CI 0.48-0.72; p < 0.001), and third trimesters (95% CI 0.36-0.59; p < 0.001), respectively, independent of between-pregnancy differences in maternal age, fetal sex, parity, and pregnancy complications. Female sex and nulliparity were protective. Parenting intention was associated with a protective effect on pregnancy smoking independent of pregnancy-specific influences and individual characteristics. Failure to consider the impact of parenting intention on health-related behavior during pregnancy could perpetuate an unrealistic expectation to "do what's best for the baby" and stigmatize women with unintended or unwanted pregnancies.

Female dietary patterns and outcomes of in vitro fertilization (IVF): a systematic literature review

Background

Infertility affects up to 15% of couples. In vitro fertilization (IVF) treatment has modest success rates and some factors associated with infertility and poor treatment outcomes are not modifiable. Several studies have assessed the association between female dietary patterns, a modifiable factor, and IVF outcomes with conflicting results. We performed a systematic literature review to identify female dietary patterns associated with IVF outcomes, evaluate the body of evidence for potential sources of heterogeneity and methodological challenges, and offer suggestions to minimize heterogeneity and bias in future studies.

Methods

We performed systematic literature searches in EMBASE, PubMed, CINAHL, and Cochrane Central Register of Controlled Trials for studies with a publication date up to March 2020. We excluded studies limited to women who were overweight or diagnosed with PCOS. We included studies that evaluated the outcome of pregnancy or live birth. We conducted an initial bias assessment using the SIGN 50 Methodology Checklist 3.

Results

We reviewed 3280 titles and/or titles and abstracts. Seven prospective cohort studies investigating nine dietary patterns fit the inclusion criteria. Higher adherence to the Mediterranean diet, a ‘profertility’ diet, or a Dutch ‘preconception’ diet was associated with pregnancy or live birth after IVF treatment in at least one study. However, causation cannot be assumed. Studies were potentially hindered by methodological challenges (misclassification of the exposure, left truncation, and lack of comprehensive control for confounding) with an associated risk of bias. Studies of the Mediterranean diet were highly heterogenous in findings, study population, and methods. Remaining dietary patterns have only been examined in single and relatively small studies.

Conclusions

Future studies with rigorous and more uniform methodologies are needed to assess the association between female dietary patterns and IVF outcomes. At the clinical level, findings from this review do not support recommending any single dietary pattern for the purpose of improving pregnancy or live birth rates in women undergoing IVF treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00757-7.

Maternal smoking behaviour across the first two pregnancies and small for gestational age birth: Analysis of the SLOPE (Studying Lifecourse Obesity PrEdictors) population-based cohort in the South of England

Maternal smoking is established to cause adverse birth outcomes, but evidence considering maternal smoking change across successive pregnancies is sparse. We examined the association between self-reported maternal smoking during and between the first two pregnancies with the odds of small for gestational age (SGA) birth (<10th percentile) in the second infant. Records for the first two pregnancies for 16791 women within the SLOPE (Studying Lifecourse Obesity PrEdictors) study were analysed. This is a population-based cohort of prospectively collected anonymised antenatal and birth healthcare data (2003-2018) in Hampshire, UK. Logistic regression was used to relate maternal smoking change to the odds of SGA birth in the second infant. In the full sample, compared to never smokers, mothers smoking at the start of the first pregnancy had higher odds of SGA birth in the second pregnancy even where they stopped smoking before the first antenatal appointment for the second pregnancy (adjusted odds ratio (aOR) 1.50 [95% confidence interval 1.10, 2.03]). If a mother was not a smoker at the first antenatal appointment for either her first or her second pregnancy, but smoked later in her first pregnancy or between pregnancies, there was no evidence of increased risk of SGA birth in the second pregnancy compared to never smokers. A mother who smoked ten or more cigarettes a day at the start of both of her first two pregnancies had the highest odds of SGA birth (3.54 [2.55, 4.92]). Women who were not smoking at the start of the first pregnancy but who subsequently resumed/began smoking and smoked at the start of their second pregnancy, also had higher odds (2.11 [1.51, 2.95]) than never smokers. Smoking in the first pregnancy was associated with SGA birth in the second pregnancy, even if the mother quit by the confirmation of her second pregnancy.

Smoking Cessation and Preterm Birth in Second Pregnancy Among Women who Smoked in Their First

INTRODUCTION

The benefit of smoking cessation in reducing the risk of preterm birth is well established. Relatively less well understood is the prevalence of smoking cessation maintenance at the next pregnancy and the associated preterm risk reduction. The aim of this study was to estimate the prevalence of maintenance of smoking cessation at second pregnancy and the associated relative risk of preterm birth.

METHODS

This was a longitudinal study with retrospectively obtained records of births to multiparous women who smoked in the pregnancy of their first birth in New South Wales, 1994-2016 (N = 63 195 mothers). Relative risks (RR) of preterm birth of the second child were estimated for smoking cessation with adjustment for final gestational age of the first birth, maternal age at the first birth, change in socioeconomic disadvantage between the first and second pregnancy, interpregnancy interval, and calendar time.

RESULTS

Approximately 34% (N = 21 540) of women who smoked during their first pregnancy did not smoke in the second pregnancy. Smoking cessation among women who smoked at first pregnancy was associated with a 26% (95% CI: 21%, 31%) decrease in risk of preterm birth at a second pregnancy.

CONCLUSION

Despite smoking during the first pregnancy, smoking cessation was achieved and maintained by more than one-third of women in their second pregnancy with encouraging levels of preterm risk reduction. It is well-established that the period after birth provides an opportunity to reduce smoking-related morbidity for both the mother and neonate. Our results indicate that this period also offers an opportunity to prevent morbidity of future pregnancy.

IMPLICATIONS

A considerable amount of research has been undertaken on the effects of smoking during pregnancy on birth outcomes, the influence of postpartum smoking on the health of the mother and newborn child, and postpartum smoking cessation. However, follow-up of women after giving birth does not tend to be long enough to observe smoking and outcomes of subsequent pregnancies. We show that smoking cessation in the subsequent pregnancy is achievable by a large proportion of women despite smoking in their first pregnancy, which translates to clear reductions in risk of preterm birth in the subsequent pregnancy.

Maternal smoking during pregnancy: Trends and determinants in the conception to community study

BACKGROUND

Despite earlier declines, maternal smoking during pregnancy continues to be a public health problem. We examined trends and factors associated with maternal smoking during and between pregnancy over six years.

METHODS

Participants were 27 532 pregnant women in Tasmanian public hospitals whose smoking status was gathered by midwives during perinatal care between July 2008 and June 2014. Generalized linear modeling was used to examine the trends in prevalence of maternal smoking over time and factors associated with change in smoking status both within and between pregnancies.

RESULTS

Smoking during pregnancy decreased from 25.9% in 2008 to 16.4% in 2014 (57.9% decline). Multivariable regression analysis suggested that maternal alcohol consumption during pregnancy, living in a highly socioeconomically disadvantaged area, and being an Aboriginal or Torres Strait Islander significantly increased the risk of maternal smoking during pregnancy. Being older, married, or in a de facto relationship, and intending to breastfeed were associated with reduced risk of smoking during pregnancy. Between index (first birth recorded in data set) and last pregnancy, 35.1% of smokers quit, but 5.1% of nonsmokers started smoking. Only 8.1% of mothers who smoked during the first half of pregnancy quit by the second half.

CONCLUSIONS

Maternal smoking during pregnancy is decreasing. To sustain the decline, preventive efforts must address the role of social determinants of health (eg, mothers who drink alcohol, live in highly disadvantaged areas, are younger and single) among women who smoke during pregnancy.

Use of smoking cessation pharmacotherapies during pregnancy is not associated with increased risk of adverse pregnancy outcomes: a population-based cohort study

BACKGROUND

Varenicline, bupropion and nicotine replacement therapy (NRT) are three effective pharmacotherapies for smoking cessation, but data about their safety in pregnancy are limited. We assessed the risk of adverse perinatal outcomes and major congenital anomalies associated with the use of these therapies in pregnancy in Australia.

METHODS

Perinatal data for 1,017,731 deliveries (2004 to 2012) in New South Wales and Western Australia were linked to pharmaceutical dispensing, hospital admission and death records. We identified 97,875 women who smoked during pregnancy; of those, 233, 330 and 1057 were exposed to bupropion, NRT and varenicline in pregnancy, respectively. Propensity scores were used to match exposed women to those who were unexposed to any smoking therapy (1:10 ratio). Propensity scores and gestational age at exposure were used to match varenicline-exposed to NRT-exposed women (1:1 ratio). Time-dependent Cox proportional hazards models estimated hazard ratios (HR) with 95% confidence intervals (95% CI) for any adverse perinatal event (a composite of 10 unfavourable maternal and neonatal outcomes) and any major congenital anomaly.

RESULTS

The risk of any adverse perinatal event was not significantly different between bupropion-exposed and unexposed women (39.2% versus 39.3%, HR 0.93, 95% CI 0.73-1.19) and between NRT-exposed and unexposed women (44.8% vs 46.3%, HR 1.02, 95% CI 0.84-1.23), but it was significantly lower in women exposed to varenicline (36.9% vs 40.1%, HR 0.86, 95% CI 0.77-0.97). Varenicline-exposed infants were less likely than unexposed infants to be born premature (6.5% vs 8.9%, HR 0.72, 95% CI 0.56-0.92), be small for gestational age (11.4% vs 15.4%, HR 0.68, 95% CI 0.56-0.83) and have severe neonatal complications (6.6% vs 8.2%, HR 0.74, 95% CI 0.57-0.96). Among infants exposed to varenicline in the first trimester, 2.9% had a major congenital anomaly (3.5% in unexposed infants, HR 0.91, 95% CI 0.72-1.15). Varenicline-exposed women were less likely than NRT-exposed women to have an adverse perinatal event (38.7% vs 51.4%, HR 0.58, 95% CI 0.33-1.05).

CONCLUSIONS

Pregnancy exposure to smoking cessation pharmacotherapies does not appear to be associated with an increased risk of adverse birth outcomes. Lower risk of adverse birth outcomes in varenicline-exposed pregnancies is inconsistent with recommendations that NRT be used in preference to varenicline.

FIGO's ethical recommendations on female sterilisation will do more harm than good: a commentary

The International Federation of Gynecology and Obstetrics (FIGO) Committee for the Ethical Aspects of Human Reproduction and Women's Health advises against tubal occlusion (TO) performed at the time of caesarean section (CS/TO) or following a vaginal delivery (VD/TO) if this sterilisation has not been discussed with the woman in an earlier phase of her pregnancy. This advice is neither in accordance with existing medical custom nor evidence based. Particularly in less-resourced locations, adherence to it would deny much wanted one-off sterilisation opportunities to hundreds of thousands of women, many of whom have no reliable contraceptive alternative. To be sure, a well-timed discussion in pregnancy about a potential peripartum TO is preferable and, if conducted as a matter of course (as the Committee appears to promote), would represent an enormous improvement on current practice. Earlier counselling has the advantage that it results in fewer women who regret having rejected the CS/TO or VD/TO option. However, there is no evidence that earlier counselling leads to a smaller proportion of regretted sterilisations. Consequently, where early TO counselling has been impossible, forgotten or deliberately omitted on pronatalist, traditional, financial, cultural or religious grounds, offering a perinatal sterilisation belatedly and in an unbiased, culturally sensitive manner is often verifiably better than not presenting that option at all, notably where high parity and uterine scars are particularly dangerous. Belated counselling, as will be demonstrated in this paper, saves many lives. The Committee's blanket rejection of belated counselling on perinatal sterilisation is therefore unjustified.