Risk of spontaneous preterm birth elevated after first cesarean delivery at full dilatation: a retrospective cohort study of over 30,000 women.

BACKGROUND: Having a cesarean delivery at full dilatation has been associated with increased subsequent risk of spontaneous preterm birth. The Aberdeen Maternity and Neonatal Databank provides a rare opportunity to study subsequent pregnancy outcomes after a previous cesarean delivery at full dilatation over 40 years, with an ability to include a detailed evaluation of potential confounding factors. OBJECTIVE: This study aimed to investigate if having an initial cesarean delivery at full dilatation is associated with spontaneous preterm birth or other adverse pregnancy outcomes in the subsequent pregnancy. STUDY DESIGN: A retrospective cohort study was conducted including women with a first and second pregnancy recorded within the Aberdeen Maternity and Neonatal Databank between 1976 and 2017, where previous cesarean delivery at full dilatation at term in the first birth was the exposure. The primary outcome was spontaneous preterm birth (defined as spontaneous birth <37 weeks). Multivariate logistic regression was used to investigate any association between cesarean delivery at full dilatation and the odds of spontaneous preterm birth. Cesarean delivery at full dilatation in previous pregnancy was compared with: (1) any other mode of birth, and (2) individual modes of birth, including planned cesarean delivery, cesarean delivery in first stage of labor (<10-cm dilatation), and vaginal birth (including spontaneous vaginal birth, nonrotational forceps, Kielland forceps, vacuum-assisted birth, breech vaginal birth). Other outcomes such as antepartum hemorrhage and mode of second birth were also compared. RESULTS: Of the 30,253 women included, 900 had a previous cesarean delivery at full dilatation in the first pregnancy. Women with previous cesarean delivery at full dilatation had a 3-fold increased risk of spontaneous preterm birth in a second pregnancy (unadjusted odds ratio, 2.63; 95% confidence interval, 1.82-3.81; adjusted odds ratio, 3.31; 95% confidence interval, 2.17-5.05) compared with those with all other modes of first birth, adjusted for maternal age, diabetes mellitus, body mass index, smoking, preeclampsia, antepartum hemorrhage, socioeconomic deprivation (Scottish Index of Multiple Deprivation 2016), year of birth, and interpregnancy interval (in second pregnancy). When compared with women with vaginal births only, women with cesarean delivery at full dilatation had 5-fold increased odds of spontaneous preterm birth (adjusted odds ratio, 5.37; 95% confidence interval, 3.40-8.48). Compared with first spontaneous vaginal birth, first instrumental births (nonrotational forceps, Kielland forceps, and vacuum births) were not associated with increased risk of spontaneous preterm birth in the second birth. After an initial cesarean delivery at full dilatation, 3.7% of women had a repeated cesarean delivery at full dilatation and 48% had a planned cesarean delivery in the second birth. CONCLUSION: This study is a substantial addition to the body of evidence on the risk of subsequent spontaneous preterm birth after cesarean delivery at full dilatation, and demonstrates a strong association between cesarean delivery at full dilatation in the first birth and spontaneous preterm birth in subsequent pregnancy, although the absolute risk remains small. This is a large retrospective cohort and includes a comprehensive assessment of potential confounding factors, including preeclampsia, antepartum hemorrhage, and lengths of first and second stage of labor. Future research should focus on understanding possible causality and developing primary and secondary preventative measures.

Detection and evaluation of signals associated with exposure to individual and combination of medications in pregnancy: a signal detection study protocol.

INTRODUCTION: Considering the high prevalence of polypharmacy in pregnant women and the knowledge gap in the risk-benefit safety profile of their often-complex treatment plan, more research is needed to optimise prescribing. In this study, we aim to detect adverse and protective effect signals of exposure to individual and pairwise combinations of medications during pregnancy. METHODS AND ANALYSIS: Using a range of real-world data sources from the UK, we aim to conduct a pharmacovigilance study to assess the safety of medications prescribed during the preconception period (3 months prior to conception) and first trimester of pregnancy. Women aged between 15 and 49 years with a record of pregnancy within the Clinical Practice Research Datalink (CPRD) Pregnancy Register, the Welsh Secure Anonymised Information Linkage (SAIL), the Scottish Morbidity Record (SMR) data sets and the Northern Ireland Maternity System (NIMATS) will be included. A series of case control studies will be conducted to estimate measures of disproportionality, detecting signals of association between a range of pregnancy outcomes and exposure to individual and combinations of medications. A multidisciplinary expert team will be invited to a signal detection workshop. By employing a structured framework, signals will be transparently assessed by each member of the team using a questionnaire appraising the signals on aspects of temporality, selection, time and measurement-related biases and confounding by underlying disease or comedications. Through group discussion, the expert team will reach consensus on each of the medication exposure-outcome signal, thereby excluding spurious signals, leaving signals suggestive of causal associations for further evaluation. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Independent Scientific Advisory Committee, SAIL Information Governance Review Panel, University of St. Andrews Teaching and Research Ethics Committee and Office for Research Ethics Committees Northern Ireland (ORECNI) for access and use of CPRD, SAIL, SMR and NIMATS data, respectively.

Maternal multimorbidity and preterm birth in Scotland: an observational record-linkage study.

BACKGROUND: Multimorbidity is common in women across the life course. Preterm birth is the single biggest cause of neonatal mortality and morbidity. We aim to estimate the prevalence of multimorbidity in pregnant women and to examine the association between maternal multimorbidity and PTB. METHODS: This is a retrospective cohort study using electronic health records from the Scottish Morbidity Records. All pregnancies among women aged 15 to 49 with a conception date between 1 January 2014 and 31 December 2018 were included. Multimorbidity was defined as the presence of two or more pre-existing long-term physical or mental health conditions, and complex multimorbidity as the presence of four or more. It was calculated at the time of conception using a predefined list of 79 conditions published by the MuM-PreDiCT consortium. PTB was defined as babies born alive between 24 and less than 37 completed weeks of gestation. We used Generalised Estimating Equations adjusted for maternal age, socioeconomic status, number of previous pregnancies, BMI, and smoking history to estimate the effect of maternal pre-existing multimorbidity. Absolut rates are reported in the results and tables, whilst Odds Ratios (ORs) are adjusted (aOR). RESULTS: Thirty thousand five hundred fifty-seven singleton births from 27,711 pregnant women were included in the analysis. The prevalence of pre-existing multimorbidity and complex multimorbidity was 16.8% (95% CI: 16.4-17.2) and 3.6% (95% CI: 3.3-3.8), respectively. The prevalence of multimorbidity in the youngest age group was 10.2%(95% CI: 8.8-11.6), while in those 40 to 44, it was 21.4% (95% CI: 18.4-24.4), and in the 45 to 49 age group, it was 20% (95% CI: 8.9-31.1). In women without multimorbidity, the prevalence of PTB was 6.7%; it was 11.6% in women with multimorbidity and 15.6% in women with complex multimorbidity. After adjusting for maternal age, socioeconomic status, number of previous pregnancies, Body Mass Index (BMI), and smoking, multimorbidity was associated with higher odds of PTB (aOR = 1.64, 95% CI: 1.48-1.82). CONCLUSIONS: Multimorbidity at the time of conception was present in one in six women and was associated with an increased risk of preterm birth. Multimorbidity presents a significant health burden to women and their offspring. Routine and comprehensive evaluation of women with multimorbidity before and during pregnancy is urgently needed.

Maternal and perinatal outcomes of prolonged second stage of labour: a historical cohort study of over 51,000 women.

BACKGROUND: Prolonged second stage of labour has been associated with adverse maternal and perinatal outcomes. The maximum length of the second stage from full dilatation to birth of the baby remains controversial. Our aim was to determine whether extending second stage of labour was associated with adverse maternal and perinatal outcomes. METHODS: A retrospective cohort study was conducted using routinely collected hospital data from 51592 births in Aberdeen Maternity Hospital between 2000 and 2016. The hospital followed the local guidance of allowing second stage of labour to extend by an hour compared to national guidelines since 2008 (nulliparous and parous). The increasing duration of second stage of labour was the exposure. Baseline characteristics, maternal and perinatal outcomes were compared between women who had a second stage labour of (a) ≤ 3 h and (b) > 3 h duration for nulliparous women; and (a) ≤ 2 h or (b) > 2 h for parous women. An additional model was run that treated the duration of second stage of labour as a continuous variable (measured in hours). All the adjusted models accounted for: age, BMI, smoking status, deprivation category, induced birth, epidural, oxytocin, gestational age, baby birthweight, mode of birth and parity (only for the final model). RESULTS: Each hourly increase in the second stage of labour was associated with an increased risk of obstetric anal sphincter injury (aOR 1.21 95% CI 1.16,1.25), having an episiotomy (aOR 1.48 95% CI 1.45, 1.52) and postpartum haemorrhage (aOR 1.27 95% CI 1.25, 1.30). The rates of caesarean and forceps delivery also increased when second stage duration increased (aOR 2.60 95% CI 2.50, 2.70, and aOR 2.44 95% CI 2.38, 2.51, respectively.) Overall adverse perinatal outcomes were not found to change significantly with duration of second stage on multivariate analysis. CONCLUSIONS: As the duration of second stage of labour increased each hour, the risk of obstetric anal sphincter injuries, episiotomies and PPH increases significantly. Women were over 2 times more likely to have a forceps or caesarean birth. The association between adverse perinatal outcomes and the duration of second stage of labour was less convincing in this study.

Polypharmacy during pregnancy and associated risk factors: a retrospective analysis of 577 medication exposures among 1.5 million pregnancies in the UK, 2000-2019.

BACKGROUND: The number of medications prescribed during pregnancy has increased over the past few decades. Few studies have described the prevalence of multiple medication use among pregnant women. This study aims to describe the overall prevalence over the last two decades among all pregnant women and those with multimorbidity and to identify risk factors for polypharmacy in pregnancy. METHODS: A retrospective cohort study was conducted between 2000 and 2019 using the Clinical Practice Research Datalink (CPRD) pregnancy register. Prescription records for 577 medication categories were obtained. Prevalence estimates for polypharmacy (ranging from 2+ to 11+ medications) were presented along with the medications commonly prescribed individually and in pairs during the first trimester and the entire pregnancy period. Logistic regression models were performed to identify risk factors for polypharmacy. RESULTS: During the first trimester (812,354 pregnancies), the prevalence of polypharmacy ranged from 24.6% (2+ medications) to 0.1% (11+ medications). During the entire pregnancy period (774,247 pregnancies), the prevalence ranged from 58.7 to 1.4%. Broad-spectrum penicillin (6.6%), compound analgesics (4.5%) and treatment of candidiasis (4.3%) were commonly prescribed. Pairs of medication prescribed to manage different long-term conditions commonly included selective beta 2 agonists or selective serotonin re-uptake inhibitors (SSRIs). Risk factors for being prescribed 2+ medications during the first trimester of pregnancy include being overweight or obese [aOR: 1.16 (1.14-1.18) and 1.55 (1.53-1.57)], belonging to an ethnic minority group [aOR: 2.40 (2.33-2.47), 1.71 (1.65-1.76), 1.41 (1.35-1.47) and 1.39 (1.30-1.49) among women from South Asian, Black, other and mixed ethnicities compared to white women] and smoking or previously smoking [aOR: 1.19 (1.18-1.20) and 1.05 (1.03-1.06)]. Higher and lower age, higher gravidity, increasing number of comorbidities and increasing level of deprivation were also associated with increased odds of polypharmacy. CONCLUSIONS: The prevalence of polypharmacy during pregnancy has increased over the past two decades and is particularly high in younger and older women; women with high BMI, smokers and ex-smokers; and women with multimorbidity, higher gravidity and higher levels of deprivation. Well-conducted pharmaco-epidemiological research is needed to understand the effects of multiple medication use on the developing foetus.

The optimal route of progesterone administration for luteal phase support in a frozen embryo transfer: a systematic review.

OBJECTIVE: To investigate the optimal route of progesterone administration for luteal phase support in a frozen embryo transfer. DESIGN: Systematic review. PATIENTS: Women undergoing frozen embryo transfer (FET). INTERVENTIONS: We conducted an extensive database search of Medline (PubMed), Embase, Web of Science, and Cochrane Trials Register using relevant keywords and their combinations to find randomized controlled trials (RCTs) comparing the routes (i.e., oral, vaginal, intramuscular) of progesterone administration for luteal phase support (LPS) in artificial FET. MAIN OUTCOME MEASURES: Clinical pregnancy, live birth, miscarriage. RESULTS: Four RCTs with 3245 participants undergoing artificial endometrial preparation (EP) cycles during FET were found to be eligible. Four trials compared vaginal progesterone with intramuscular progesterone and two trials compared vaginal progesterone with oral progesterone. One study favored of vaginal versus oral progesterone for clinical pregnancy rates (RR 0.45, 95% CI 0.22-0.92) and other study favored intramuscular versus vaginal progesterone for clinical pregnancy rates (RR 1.46, 95% CI 1.21-1.76) and live birth rates (RR 1.62, 95% CI 1.28-2.05). Tabulation of overall evidence strength assessment showed low-quality evidence on the basis that for each outcome-comparison pair, there were deficiencies in either directness of outcome measurement or study quality. CONCLUSION: There was little consensus and evidence was heterogeneous on the optimal route of administration of progesterone for LPS during FET in artificial EP cycles. This warrants more trials, indirect comparisons, and network meta-analyses. PROPERO NO: CRD42021251017.

Association of pregnancy complications/risk factors with the development of future long-term health conditions in women: overarching protocol for umbrella reviews.

INTRODUCTION: With good medical care, most pregnancy complications like pre-eclampsia, gestational diabetes, etc resolve after childbirth. However, pregnancy complications are known to be associated with an increased risk of new long-term health conditions for women later in life, such as cardiovascular disease. These umbrella reviews aim to summarise systematic reviews evaluating the association between pregnancy complications and five groups of long-term health conditions: autoimmune conditions, cancers, functional disorders, mental health conditions and metabolic health conditions (diabetes and hypertension). METHODS AND ANALYSIS: We will conduct searches in Medline, Embase and the Cochrane database of systematic reviews without any language restrictions. We will include systematic reviews with or without meta-analyses that studied the association between pregnancy complications and the future risk of the five groups of long-term health conditions in women. Pregnancy complications were identified from existing core outcome sets for pregnancy and after consultation with experts. Two reviewers will independently screen the articles. Data will be synthesised with both narrative and quantitative methods. Where a meta-analysis has been carried out, we will report the combined effect size from individual studies. For binary data, pooled ORs with 95% CIs will be presented. For continuous data, we will use the mean difference with 95% CIs. The findings will be presented in forest plots to assess heterogeneity. The methodological quality of the studies will be evaluated with the AMSTAR 2 tool or the Cochrane risk of bias tool. The corrected covered area method will be used to assess the impact of overlap in reviews. The findings will be used to inform the design of prediction models, which will predict the risk of women developing these five group of health conditions following a pregnancy complication. ETHICS AND DISSEMINATION: No ethical approvals required. Findings will be disseminated through publications in peer-reviewed journals and conference presentations.

Epidemiology of pre-existing multimorbidity in pregnant women in the UK in 2018: a population-based cross-sectional study.

BACKGROUND: Although maternal death is rare in the United Kingdom, 90% of these women had multiple health/social problems. This study aims to estimate the prevalence of pre-existing multimorbidity (two or more long-term physical or mental health conditions) in pregnant women in the United Kingdom (England, Northern Ireland, Wales and Scotland). STUDY DESIGN: Pregnant women aged 15-49 years with a conception date 1/1/2018 to 31/12/2018 were included in this population-based cross-sectional study, using routine healthcare datasets from primary care: Clinical Practice Research Datalink (CPRD, United Kingdom, n = 37,641) and Secure Anonymized Information Linkage databank (SAIL, Wales, n = 27,782), and secondary care: Scottish Morbidity Records with linked community prescribing data (SMR, Tayside and Fife, n = 6099). Pre-existing multimorbidity preconception was defined from 79 long-term health conditions prioritised through a workshop with patient representatives and clinicians. RESULTS: The prevalence of multimorbidity was 44.2% (95% CI 43.7-44.7%), 46.2% (45.6-46.8%) and 19.8% (18.8-20.8%) in CPRD, SAIL and SMR respectively. When limited to health conditions that were active in the year before pregnancy, the prevalence of multimorbidity was still high (24.2% [23.8-24.6%], 23.5% [23.0-24.0%] and 17.0% [16.0 to 17.9%] in the respective datasets). Mental health conditions were highly prevalent and involved 70% of multimorbidity CPRD: multimorbidity with ≥one mental health condition/s 31.3% [30.8-31.8%]). After adjusting for age, ethnicity, gravidity, index of multiple deprivation, body mass index and smoking, logistic regression showed that pregnant women with multimorbidity were more likely to be older (CPRD England, adjusted OR 1.81 [95% CI 1.04-3.17] 45-49 years vs 15-19 years), multigravid (1.68 [1.50-1.89] gravidity ≥ five vs one), have raised body mass index (1.59 [1.44-1.76], body mass index 30+ vs body mass index 18.5-24.9) and smoked preconception (1.61 [1.46-1.77) vs non-smoker). CONCLUSION: Multimorbidity is prevalent in pregnant women in the United Kingdom, they are more likely to be older, multigravid, have raised body mass index and smoked preconception. Secondary care and community prescribing dataset may only capture the severe spectrum of health conditions. Research is needed urgently to quantify the consequences of maternal multimorbidity for both mothers and children.

Predictive models of individual risk of elective caesarean section complications: a systematic review.

INTRODUCTION: With increasing caesarean section (c-section) rates, personalized communication of risk has become paramount. A reliable tool to predict complications would support evidence-based discussions around planned mode of birth. This systematic review aimed to identify, synthesize and quality appraise prognostic models of maternal complications of elective c-section. METHODS: MEDLINE, Embase, Web of Science, CINAHL and the Cochrane Library were searched on 27 January using terms relating to 'c-section', 'prognostic models' and complications such as 'infection'. Any study developing and/or validating a prognostic model for a maternal complication of elective c-section in the English language after January 1995 was selected for analysis. Data were extracted using a predetermined checklist: source of data; participants; outcome to be predicted; candidate predictors; sample size; missing data; model development; model performance; model evaluation; results; and interpretation. Quality was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST) tool. RESULTS: In total, 7752 studies were identified; of these, 16 full papers were reviewed and three eligible studies were identified, containing three prognostic models derived from hospitals in Japan, South Africa and the UK. The models predicted risk of blood transfusion, spinal hypotension and postpartum haemorrhage. The study authors deemed their studies to be exploratory, exploratory and confirmatory, respectively. From the three studies, a total of 29 unique candidate predictors were identified, with 15 predictors in the final models. Maternal age (n = 3), previous c-section (n = 2), placenta praevia (n = 2) and pre-operative haemoglobin (n = 2) were found to be common predictors amongst the included studies. None of the studies were externally validated and all had a high risk of bias due to the analysis technique used. CONCLUSION: Few models have been developed to predict complications of elective c-section. Existing models predicting blood transfusion, spinal hypotension and postpartum haemorrhage cannot be recommended for clinical practice. Future research should focus on identifying predictors known before surgery and validating the resulting models.

The impact of third- or fourth-degree perineal tears on the second pregnancy: A cohort study of 182,445 Scottish women.

This study aimed to investigate the reproductive impact of a third- or fourth-degree tear in primigravid women. A retrospective population-based cohort study was conducted using data from Scottish Morbidity Records (SMR02). Primigravid women with a vaginal birth in Scotland from 1997 until 2010 were included. Exposure was third- or fourth-degree tear in the first pregnancy. The second pregnancy rate, interpregnancy interval and third- or fourth-degree tear in a second pregnancy were the primary outcomes. A nested case-control study was used to determine factors associated with repeat third- or fourth-degree tears in a second vaginal birth. Cox regression analysis and logistic regression were used to look for associations. Initial third- or fourth-degree tear occurred in 2.8% women (5174/182445). The percentage of third- or fourth-degree tears in first vaginal births increased from 1% in 1997 to 4.9% in 2010. There was no difference in having a second pregnancy (adjusted Odds Ratio (aOR) 0.98 (99%CI 0.89-1.09)) or the median interpregnancy interval to second pregnancy (adjusted Hazard Ratio (aHR) 1.01 (99%CI 0.95-1.08)) after an initial third- or fourth-degree tear. Women were over four times more likely to have a repeat injury in a subsequent vaginal birth (n = 149/333, aOR 4.68 (99% 3.52-6.23)) and were significantly more likely to have an elective caesarean section in their second pregnancy (n = 887/3333, 26.6%; 12.75 (11.29-14.40)). Increased maternal age and birthweight ≥4500g were risk factors for repeat injury. Third- and fourth-degree tears are increasing in Scotland. Women do not delay or avoid childbirth after initial third- or fourth-degree tear. However, women are more likely to have a repeat third- or fourth-degree tear or an elective caesarean section in the second pregnancy. Strategies to prevent third- or fourth-degree tears are needed.

Forceps delivery for non-rotational and rotational operative vaginal delivery.

Forceps are a commonly used instrument for assisting vaginal birth. Accepted indications include prolonged labour, suspected foetal distress and maternal medical conditions that benefit from a shortened second stage of labour. Maternal and offspring outcomes of forceps-assisted birth have been extensively reported in observational studies, but randomised trial evidence is limited. Forceps-assisted delivery has a lower failure rate than vacuum-assisted delivery but is associated with a higher incidence of maternal pelvic floor trauma. Second-stage caesarean section is associated with less foetal-neonatal trauma than forceps-assisted delivery but markedly reduces the chance of a subsequent vaginal birth. This review outlines the existing evidence on prevention, indications and contraindications for forceps-assisted birth (non-rotational and rotational), short- and long-term complications for mother and baby, alternatives to use of forceps and how to manage an abandoned forceps-assisted birth. The essential components of informed consent are also discussed.

Planned Cesarean Delivery at Term and Adverse Outcomes in Childhood Health.

IMPORTANCE: Planned cesarean delivery comprises a significant proportion of births globally, with combined rates of planned and unscheduled cesarean delivery in a number of regions approaching 50%. Observational studies have shown that offspring born by cesarean delivery are at increased risk of ill health in childhood, but these studies have been unable to adjust for some key confounding variables. Additionally, risk of death beyond the neonatal period has not yet been reported for offspring born by planned cesarean delivery. OBJECTIVE: To investigate the relationship between planned cesarean delivery and offspring health problems or death in childhood. DESIGN, SETTING, AND PARTICIPANTS: Population-based data-linkage study of 321,287 term singleton first-born offspring born in Scotland, United Kingdom, between 1993 and 2007, with follow-up until February 2015. EXPOSURES: Offspring born by planned cesarean delivery in a first pregnancy were compared with offspring born by unscheduled cesarean delivery and with offspring delivered vaginally. MAIN OUTCOMES AND MEASURES: The primary outcome was asthma requiring hospital admission; secondary outcomes were salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, cancer, and death. RESULTS: Compared with offspring born by unscheduled cesarean delivery (n = 56,015 [17.4%]), those born by planned cesarean delivery (12,355 [3.8%]) were at no significantly different risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, cancer, or death but were at increased risk of type 1 diabetes (0.66% vs 0.44%; difference, 0.22% [95% CI, 0.13%-0.31%]; adjusted hazard ratio [HR], 1.35 [95% CI, 1.05-1.75]). In comparison with children born vaginally (n = 252,917 [78.7%]), offspring born by planned cesarean delivery were at increased risk of asthma requiring hospital admission (3.73% vs 3.41%; difference, 0.32% [95% CI, 0.21%-0.42%]; adjusted HR, 1.22 [95% CI, 1.11-1.34]), salbutamol inhaler prescription at age 5 years (10.34% vs 9.62%; difference, 0.72% [95% CI, 0.36%-1.07%]; adjusted HR, 1.13 [95% CI, 1.01-1.26]), and death (0.40% vs 0.32%; difference, 0.08% [95% CI, 0.02%-1.00%]; adjusted HR, 1.41 [95% CI, 1.05-1.90]), whereas there were no significant differences in risk of obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, or cancer. CONCLUSIONS AND RELEVANCE: Among offspring of women with first births in Scotland between 1993 and 2007, planned cesarean delivery compared with vaginal delivery (but not compared with unscheduled cesarean delivery) was associated with a small absolute increased risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, and all-cause death by age 21 years. Further investigation is needed to understand whether the observed associations are causal.

Outcomes of pregnancy in women using illegal drugs and in women who smoke cigarettes.

OBJECTIVE: To compare obstetric outcomes in women using illegal drugs with women who smoke cigarettes. DESIGN: Retrospective cohort study. SETTING: Aberdeen, UK. POPULATION: All deliveries in Aberdeen in women using illegal drugs and women who smoked cigarettes during 1997-2007. MATERIAL AND METHODS: The women who used illegal drugs were identified from a database of affected pregnant women in Aberdeen. The Aberdeen Maternity and Neonatal Databank was used to identify women who smoke cigarettes and to obtain pregnancy outcome information. Sociodemographic characteristics, maternal and perinatal outcomes were compared using chi-squared test, independent sample t-test and logistic regression analysis. MAIN OUTCOME MEASURES: Preterm delivery, low birthweight (standardized birthweight score <-2) and admission to the neonatal unit. RESULTS: Of the 561 illegal drug users, 96% were also cigarette smokers. Compared with women who smoke cigarettes with no reported illegal drug use, they were significantly more likely to have a preterm delivery [adjusted odds ratio (aOR) 1.6 (95% confidence interval (CI) 1.3-2.1)], low birthweight baby [aOR 1.9 (95%CI 1.4-2.6)], baby admitted to the neonatal unit [aOR 13.3 (95%CI 10.9-16.3)], deep vein thrombosis [aOR (95%CI 8.8-50.8)] and antepartum hemorrhage [aOR (95%CI 1.2-2.1)]. They were less likely to be at the extremes of age, or to develop pregnancy-induced hypertension [aOR 0.3 (95%CI 0.2-0.4)]. CONCLUSION: Illegal drug use in pregnancy appears to increase the risk of adverse outcomes, over and above that related to cigarette smoking, but appears to be associated with lower prevalence of gestational hypertension.