Rethinking causal assumptions about maternal BMI, gestational weight gain, and adverse pregnancy outcomes.

BACKGROUND: The aim of this study was to evaluate commonly assumed causal relationships between body mass index (BMI), gestational weight gain (GWG), and adverse pregnancy outcomes, which have formed the basis of guidelines and interventions aimed at limiting GWG in women with overweight or obesity. We explored relationships between maternal BMI, total GWG (as a continuous variable and as 'excessive' GWG), and pregnancy outcomes (including infant birthweight measures and caesarean birth). METHODS: Analysis of individual participant data (IPD) from the i-WIP (International Weight Management in Pregnancy) Collaboration, from randomised trials of diet and/or physical activity interventions during pregnancy reporting GWG and maternal and neonatal outcomes. Women randomised to the control arm of 20 eligible randomised trials (4370 of 8908 participants) from the i-WIP dataset of 36 randomised trials (total 12,240 women). The main research questions were to characterise the relationship between maternal BMI and (a) total GWG, (b) the risk of 'excessive' GWG (using the Institute of Medicine's guidelines), and (c) adverse pregnancy outcomes as mediated via GWG versus other pathways to determine the extent to which the observed effect of maternal BMI on pregnancy outcomes is mediated via GWG. We utilised generalised linear models and regression-based mediation analyses within an IPD meta-analysis framework. RESULTS: Mean GWG decreased linearly as maternal BMI increased; however, the risk of 'excessive' GWG increased markedly at BMI category thresholds (i.e. between the normal and overweight BMI category threshold and between the overweight and obese BMI category threshold). Increasing maternal BMI was associated with increased risk of all pregnancy outcomes assessed; however, there was no evidence that this effect was mediated via effects on GWG. CONCLUSIONS: There is evidence of a meaningful relationship between maternal BMI and GWG and between maternal BMI and adverse pregnancy outcomes. There is no evidence that the effect of maternal BMI on outcomes is via an effect on GWG. Our analyses also cast doubt on the existence of a relationship between 'excessive' GWG and adverse pregnancy outcomes. Our findings challenge the practice of actively managing GWG throughout pregnancy.

Fetal Growth and Adiposity of Infants Born Large for Gestational Age in Three Harmonized Randomized Trials.

OBJECTIVE: Infants born large for gestational age (LGA) are at an increased risk of short- and longer-term adverse outcomes. Understanding fetal growth and adiposity and their trajectories may help inform interventions to prevent birth of LGA infants. We aimed to compare fetal growth and adiposity measures of infants born LGA with those born not LGA, to determine whether the discrepancy at birth was primarily due to larger size throughout gestation, or instead to different trajectories of fetal growth. STUDY DESIGN: This was a secondary analysis of secondary outcomes of fetal growth and adiposity from three harmonized randomized trials-the LIMIT, GRoW, and Optimise randomized trials. These trials recruited women in early pregnancy, and a singleton gestation, from three major public metropolitan Adelaide maternity hospitals. Maternal body mass index (BMI) ranged from 18.5 to ≥40.0 kg/m2. Data were obtained from enrolled women who underwent research ultrasounds at 28 and 36 weeks' gestation. Outcome measures were ultrasound measures of fetal biometry and adiposity. RESULTS: Infants born LGA had larger fetal biometry measures, and higher growth trajectories, from 20 weeks' gestation. Fetal adiposity measures were consistently larger among infants born LGA and these differences increased over time. We did not find evidence that the differences in biometry and adiposity measurements varied according to maternal BMI. CONCLUSION: Infants born LGA had larger fetal biometry measures at all time points from 20 weeks' gestation, compared with infants born not LGA suggesting any interventions to prevent LGA likely need to commence earlier in pregnancy or prior to conception. KEY POINTS: · Infants born LGA had larger fetal biometry measures from 20 weeks' gestation.. · Infants born LGA had larger fetal adiposity measures.. · Interventions to prevent LGA need to start earlier in pregnancy or prior to conception..

Understanding the pathways between prenatal and postnatal factors and overweight outcomes in early childhood: a pooled analysis of seven cohorts.

BACKGROUND/OBJECTIVES: Childhood overweight and obesity are influenced by a range of prenatal and postnatal factors. Few studies have explored the integrative pathways linking these factors and childhood overweight. This study aimed to elucidate the integrative pathways through which maternal pre-pregnancy body mass index (BMI), infant birth weight, breastfeeding duration, and rapid weight gain (RWG) during infancy are associated with overweight outcomes in early childhood from ages 3 to 5 years. SUBJECTS/METHODS: Pooled data from seven Australian and New Zealand cohorts were used (n = 3572). Generalized structural equation modelling was used to examine direct and indirect associations of maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration, and RWG during infancy with child overweight outcomes (BMI z-score and overweight status). RESULTS: Maternal pre-pregnancy BMI was directly associated with infant birth weight (ß 0.01, 95%CI 0.01, 0.02), breastfeeding duration ≥6 months (OR 0.92, 95%CI 0.90, 0.93), child BMI z-score (ß 0.03, 95%CI 0.03, 0.04) and overweight status (OR 1.07, 95%CI 1.06, 1.09) at ages 3-5 years. The association between maternal pre-pregnancy BMI and child overweight outcomes was partially mediated by infant birth weight, but not RWG. RWG in infancy exhibited the strongest direct association with child overweight outcomes (BMI z-score: ß 0.72, 95%CI 0.65, 0.79; overweight status: OR 4.49, 95%CI 3.61, 5.59). Infant birth weight was implicated in the indirect pathways of maternal pre-pregnancy BMI with RWG in infancy, breastfeeding duration, and child overweight outcomes. The associations between breastfeeding duration (≥6 months) and lower child overweight outcomes were fully mediated by RWG in infancy. CONCLUSIONS: Maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration and RWG in infancy act in concert to influence early childhood overweight. Future overweight prevention interventions should target RWG in infancy, which showed the strongest association with childhood overweight; and maternal pre-pregnancy BMI, which was implicated in several pathways leading to childhood overweight.

Effects of an antenatal dietary intervention in women with obesity or overweight on child outcomes at 8-10 years of age: LIMIT randomised trial follow-up.

BACKGROUND: The LIMIT randomised controlled trial looked at the effect of a dietary and lifestyle intervention compared with routine antenatal care for pregnant women with overweight and obesity on pregnancy outcomes. While women in the intervention group improved diet and physical activity with a reduction of high birth weight, other outcomes were similar. We have followed the children born to women in this study at birth, 6 and 18 months and 3-5 years of age and now report follow-up of children at 8-10 years of age. METHODS: Children at 8-10 years of age who were born to women who participated in the LIMIT randomised trial, and whose mother provided consent to ongoing follow-up were eligible for inclusion. The primary study endpoint was the incidence of child BMI z-score > 85th centile for child sex and age. Secondary study outcomes included a range of anthropometric measures, neurodevelopment, child dietary intake, and physical activity. Analyses used intention to treat principles according to the treatment group allocated in pregnancy. Outcome assessors were blinded to the allocated treatment group. RESULTS: We assessed 1,015 (Lifestyle Advice n = 510; Standard Care n = 505) (48%) of the 2,121 eligible children. BMI z-score > 85th percentile was similar for children of women in the dietary Lifestyle Advice Group compared with children of women in the Standard Care Group (Lifestyle Advice 479 (45%) versus Standard Care 507 (48%); adjusted RR (aRR) 0.93; 95% CI 0.82 to 1.06; p = 0.302) as were secondary outcomes. We observed that more than 45% of all the children had a BMI z-score > 85th percentile, consistent with findings from follow-up at earlier time-points, indicating an ongoing risk of overweight and obesity. CONCLUSIONS: Dietary and lifestyle advice for women with overweight and obesity in pregnancy has not reduced the risk of childhood obesity, with children remaining at risk of adolescent and adult obesity. Other strategies are needed to address the risk of overweight and obesity in children including investigation of preconception interventions to assess whether this can modify the effects of maternal pre-pregnancy BMI. The LIMIT randomised controlled trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12607000161426).

Maternal and neonatal outcomes following the introduction of the Fetal Pillow at a tertiary maternity hospital: A retrospective cohort study.

BACKGROUND: Caesarean birth at full cervical dilatation can be technically challenging and may be associated with increased risks of maternal and neonatal morbidity, often secondary to difficulties in delivering a deeply impacted fetal head. The Fetal Pillow is a device designed to elevate an impacted fetal head out of the pelvis and reduce birth trauma. AIMS: To evaluate birth outcomes following the introduction of the Fetal Pillow at a tertiary maternity hospital. MATERIALS AND METHODS: This retrospective cohort study included all caesarean births at full cervical dilatation where the Fetal Pillow was utilised and compared with caesarean births where the Fetal Pillow was not used from October 2018 to December 2019. Maternal outcomes included uterine incision extension, blood loss, high dependency unit admission and postoperative length of stay. Neonatal outcomes included Apgar scores, resuscitation, cord arterial blood pH and lactate, nursery admission, birth trauma, jaundice and seizures. RESULTS: There were 53 caesarean births where the Fetal Pillow was utilised and 48 where it was not. Baseline characteristics were similar between groups with mean maternal age across both groups of 30.4 (±5.3) years, mean gestational age at birth of 39.5 (±1.2) weeks and mean infant birth weight of 3543 (±441) g. There were no statistically significant differences between the two study groups for the maternal and neonatal outcomes considered. CONCLUSIONS: There was no evidence that use of the Fetal Pillow to elevate an impacted fetal head during caesarean birth when cervical dilatation is >7 cm was associated with a reduced rate of adverse maternal and neonatal outcomes.

A Randomized Trial of Prenatal n-3 Fatty Acid Supplementation and Preterm Delivery.

BACKGROUND: Previous studies have suggested that maternal supplementation with n-3 long-chain polyunsaturated fatty acids may reduce the incidence of preterm delivery but may also prolong gestation beyond term; however, more data are needed regarding the role of n-3 long-chain polyunsaturated fatty acids in pregnancy. METHODS: We performed a multicenter, double-blind, randomized trial in which women who were pregnant with single or multiple fetuses were assigned to receive either fish-oil capsules that contained 900 mg of n-3 long-chain polyunsaturated fatty acids (n-3 group) or vegetable-oil capsules that contained trace n-3 long-chain polyunsaturated fatty acids (control group) daily, beginning before 20 weeks of gestation and continuing to 34 weeks of gestation or delivery, whichever occurred first. The primary outcome was early preterm delivery, defined as delivery before 34 completed weeks of gestation. Other pregnancy and neonatal outcomes were also assessed. RESULTS: A total of 5544 pregnancies in 5517 women were randomly assigned at six centers in Australia; 5486 pregnancies were included in the primary analysis. Early preterm delivery occurred in the case of 61 of 2734 pregnancies (2.2%) in the n-3 group and 55 of 2752 pregnancies (2.0%) in the control group; the between-group difference was not significant (adjusted relative risk, 1.13; 95% confidence interval [CI], 0.79 to 1.63; P = 0.50). There were no significant differences between the groups in the incidence of interventions in post-term (>41 weeks of gestation) deliveries, in adverse events, or in other pregnancy or neonatal outcomes, except that a higher percentage of infants born to women in the n-3 group than in the control group were very large for gestational age at birth (adjusted relative risk, 1.30; 95% CI, 1.02 to 1.65). Percentages of serious adverse events did not differ between the groups. Minor gastrointestinal disturbances were more commonly reported in the n-3 group than in the control group. CONCLUSIONS: Supplementation with n-3 long-chain polyunsaturated fatty acids from early pregnancy (<20 weeks of gestation) until 34 weeks of gestation did not result in a lower incidence of early preterm delivery or a higher incidence of interventions in post-term deliveries than control. (Funded by the Australian National Health and Medical Research Council and the Thyne Reid Foundation; ORIP Australian New Zealand Clinical Trials Registry number, ACTRN12613001142729.).

The effects of dietary and lifestyle interventions among pregnant women with overweight or obesity on early childhood outcomes: an individual participant data meta-analysis from randomised trials.

BACKGROUND: The impact of maternal obesity extends beyond birth, being independently associated with an increased risk of child obesity. Current evidence demonstrates that women provided with a dietary intervention during pregnancy improve their dietary quality and have a modest reduction in gestational weight gain. However, the effect of this on longer-term childhood obesity-related outcomes is unknown. METHODS: We conducted an individual participant data meta-analysis from RCTs in which women with a singleton, live gestation between 10+0 and 20+0 weeks and body mass index (BMI) ≥ 25 kg/m2 in early pregnancy were randomised to a diet and/or lifestyle intervention or continued standard antenatal care and in which longer-term maternal and child follow-up at 3-5 years of age had been undertaken. The primary childhood outcome was BMI z-score above the 90th percentile. Secondary childhood outcomes included skinfold thickness measurements and body circumferences, fat-free mass, dietary and physical activity patterns, blood pressure, and neurodevelopment. RESULTS: Seven primary trials where follow-up of participants occurred were identified by a systematic literature search within the International Weight Management in Pregnancy (i-WIP) Collaborative Group collaboration, with six providing individual participant data. No additional studies were identified after a systematic literature search. A total of 2529 children and 2383 women contributed data. Approximately 30% of all child participants had a BMI z-score above the 90th percentile, with no significant difference between the intervention and control groups (aRR 0.97; 95% CI 0.87, 1.08; p=0.610). There were no statistically significant differences identified for any of the secondary outcome measures. CONCLUSIONS: In overweight and obese pregnant women, we found no evidence that maternal dietary and/or lifestyle intervention during pregnancy modifies the risk of early childhood obesity. Future research may need to target the pre-conception period in women and early childhood interventions. TRIAL REGISTRATION: PROSPERO, CRD42016047165.

A multi-centre, open label, randomised, parallel-group, superiority Trial to compare the efficacy of URsodeoxycholic acid with RIFampicin in the management of women with severe early onset Intrahepatic Cholestasis of pregnancy: the TURRIFIC randomised trial.

BACKGROUND: Severe early onset (less than 34 weeks gestation) intrahepatic cholestasis of pregnancy (ICP) affects 0.1% of pregnant women in Australia and is associated with a 3-fold increased risk of stillbirth, fetal hypoxia and compromise, spontaneous preterm birth, as well as increased frequencies of pre-eclampsia and gestational diabetes. ICP is often familial and overlaps with other cholestatic disorders. Treatment options for ICP are not well established, although there are limited data to support the use of ursodeoxycholic acid (UDCA) to relieve pruritus, the main symptom. Rifampicin, a widely used antibiotic including in pregnant women, is effective in reducing pruritus in non-pregnancy cholestasis and has been used as a supplement to UDCA in severe ICP. Many women with ICP are electively delivered preterm, although there are no randomised data to support this approach. METHODS: We have initiated an international multicentre randomised clinical trial to compare the clinical efficacy of rifampicin tablets (300 mg bd) with that of UDCA tablets (up to 2000 mg daily) in reducing pruritus in women with ICP, using visual pruritus scores as a measuring tool. DISCUSSION: Our study will be the first to examine the outcomes of treatment specifically in the severe early onset form of ICP, comparing "standard" UDCA therapy with rifampicin, and so be able to provide for the first-time high-quality evidence for use of rifampicin in severe ICP. It will also allow an assessment of feasibility of a future trial to test whether elective early delivery in severe ICP is beneficial. TRIAL IDENTIFIERS: Australian New Zealand Clinical Trials Registration Number (ANZCTR): 12618000332224p (29/08/2018). HREC No: HREC/18/WCHN/36. EudraCT number: 2018-004011-44. IRAS: 272398. NHMRC registration: APP1152418 and APP117853.

Effects of an antenatal dietary intervention in women with obesity or overweight on child outcomes at 3-5 years of age: LIMIT randomised trial follow-up.

While the effects of an antenatal dietary intervention for women with obesity or overweight on pregnancy and newborn health have been extensively studied, the longer-term effects into childhood are unknown. We followed children born to women who participated in the LIMIT randomised trial, where pregnant women were randomised to an antenatal dietary and lifestyle intervention or standard antenatal care. Our aim was to assess the effect of the intervention, on child outcomes at 3-5 years of age on children whose mothers provided consent. We assessed 1418 (Lifestyle Advice n = 727; Standard Care n = 691) (66.9%) of the 2121 eligible children. There were no statistically significant differences in the incidence of child BMI z-score >85th centile for children born to women in the Lifestyle Advice Group, compared with the Standard Care group (Lifestyle Advice 444 (41.73%) versus Standard Care 417 (39.51%); adjusted relative risk (aRR) 1.05; 95% confidence intervals 0.93-1.19; p = 0.42). There were no significant effects on measures of child growth, adiposity, neurodevelopment, or dietary intake. There is no evidence that an antenatal dietary intervention altered child growth and adiposity at age 3-5 years. This cohort of children remains at high risk of obesity, and warrants ongoing follow-up.

Effect of metformin in addition to an antenatal diet and lifestyle intervention on fetal growth and adiposity: the GRoW randomised trial.

BACKGROUND: The infants born to women who are overweight or obese in pregnancy are at an increased risk of being born macrosomic or large for gestational age. Antenatal dietary and lifestyle interventions have been shown to be ineffective at reducing this risk. Our aim was to examine the effects of metformin in addition to a diet and lifestyle intervention on fetal growth and adiposity among women with a BMI above the healthy range. METHODS: Women who had a body mass index ≥25 kg/m2 in early pregnancy, and a singleton gestation, were enrolled in the GRoW trial from three public maternity hospitals in metropolitan Adelaide. Women were invited to have a research ultrasounds at 28 and 36 weeks' gestation at which ultrasound measures of fetal biometry and adiposity were obtained. Fetal biometry z-scores and trajectories were calculated. Measurements and calculations were compared between treatment groups. This secondary analysis was pre-specified. RESULTS: Ultrasound data from 511 women were included in this analysis. The difference in femur length at 36 weeks' gestation was (0.07 cm, 95% CI 0.01-0.14 cm, p = 0.019) and this was was statistically significant, however the magnitude of effect was small. Differences between treatment groups for all other fetal biometry measures, z-scores, estimated fetal weight, and adiposity measures at 28 and 36 weeks' gestation were similar. CONCLUSIONS: The addition of metformin to dietary and lifestyle advice in pregnancy for overweight and obese women has no clinically relevant effect on ultrasound measures of fetal biometry or adiposity. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ( ACTRN12612001277831 ).

Skin and subcutaneous fascia closure at caesarean section to reduce wound complications: the closure randomised trial.

BACKGROUND: Wound infection is a common complication following caesarean section. Factors influencing the risk of infection may include the suture material for skin closure, and closure of the subcutaneous fascia. We assessed the effect of skin closure with absorbable versus non-absorbable suture, and closure versus non-closure of the subcutaneous fascia on risk of wound infection following Caesarean section. METHODS: Women undergoing caesarean birth at an Adelaide maternity hospital were eligible for recruitment to a randomised trial using a 2 × 2 factorial design. Women were randomised to either closure or non-closure of the subcutaneous fascia and to subcuticular skin closure with an absorbable or non-absorbable suture. Participants were randomised to each of the two interventions into one of 4 possible groups: Group 1 - non-absorbable skin suture and non-closure of the subcutaneous fascia; Group 2 - absorbable skin suture and non-closure of the subcutaneous fascia; Group 3 - non-absorbable skin suture and closure of the subcutaneous fascia; and Group 4 - absorbable skin suture and closure of the subcutaneous fascia. The primary outcomes were reported wound infection and wound haematoma or seroma within the first 30 days after birth. RESULTS: A total of 851 women were recruited and randomised, with 849 women included in the analyses (Group 1: 216 women; Group 2: 212 women; Group 3: 212 women; Group 4: 211 women). In women who underwent fascia closure, there was a statistically significant increase in risk of wound infection within 30 days post-operatively for those who had skin closure with an absorbable suture (Group 4), compared with women who had skin closure with a non-absorbable suture (Group 3) (adjusted RR 2.17; 95% CI 1.05, 4.45; p = 0.035). There was no significant difference in risk of wound infection for absorbable vs non-absorbable sutures in women who did not undergo fascia closure. CONCLUSION: The combination of subcutaneous fascia closure and skin closure with an absorbable suture may be associated with an increased risk of reported wound infection after caesarean section. TRIAL REGISTRATION: Prospectively registered with the Australian and New Zealand Clinical Trials Registry, number ACTRN12608000143325 , on the 20th March, 2008.

In overweight and obese women, fetal ultrasound biometry accurately predicts newborn measures.

INTRODUCTION: The aim of this study was to evaluate the association between fetal ultrasound and newborn biometry and adiposity measures in the setting of maternal obesity. MATERIAL AND METHODS: The study population involved 845 overweight or obese pregnant women, who participated in the Standard Care Group of the LIMIT randomised trial (ACTRN12607000161426, 9/03/2007). At 36 weeks gestation, fetal biometry, estimated fetal weight (EFW) and adiposity measures including mid-thigh fat mass (MTFM), subscapular fat mass (SSFM), and abdominal fat mass (AFM) were undertaken using ultrasound. Neonatal anthropometric measurements obtained after birth included birthweight, head circumference (HC), abdominal circumference (AC) and skinfold thickness measurements (SFTM) of the subscapular region and abdomen. RESULTS: At 36 weeks gestation, every 1 g increase in EFW was associated with a 0.94 g increase in birthweight (95% CI 0.88-0.99; P < 0.001). For every 1 mm increase in the fetal ultrasound measure, there was a 0.69 mm increase in birth HC (95% CI 0.63-0.75, P < 0.001) and 0.69 mm increase in birth AC (95% CI 0.60-0.79, P < 0.001). Subscapular fat mass in the fetus and the newborn (0.29 mm, 95% CI 0.20-0.39, P < 0.001) were moderately associated, but AFM measurements were not (0.06 mm, -0.03 to 0.15, P = 0.203). There is no evidence that these relationships differed by maternal body mass index. CONCLUSION: In women who are overweight or obese, fetal ultrasound accurately predicts neonatal HC and AC along with birthweight.

Maternal cardiometabolic markers are associated with fetal growth: a secondary exploratory analysis of the LIMIT randomised trial.

BACKGROUND: To determine the association between maternal cardiometabolic and inflammatory markers with measures of fetal biometry and adiposity. METHODS: Women included in this exploratory analysis were randomised to the 'Standard Care' group (N = 911) from the LIMIT randomised trial involving a total of 2212 pregnant women who were overweight or obese (ACTRN12607000161426, Date of registration 9/03/2007, prospectively registered). Fetal biometry including abdominal circumference (AC), estimated fetal weight (EFW), and adiposity measurements (mid-thigh fat mass, subscapular fat mass, abdominal fat mass) were obtained from ultrasound assessments at 28 and 36 weeks' gestation. Maternal markers included C reactive protein (CRP), leptin and adiponectin concentrations, measured at 28 and 36 weeks' gestation and fasting triglycerides and glucose concentrations measured at 28 weeks' gestation. RESULTS: There were negative associations identified between maternal serum adiponectin and fetal ultrasound markers of biometry and adiposity. After adjusting for confounders, a 1-unit increase in log Adiponectin was associated with a reduction in the mean AC z score [- 0.21 (- 0.35, - 0.07), P = 0.004] and EFW [- 0.23 (- 0.37, - 0.10), P < 0.001] at 28 weeks gestation. Similarly, a 1-unit increase in log Adiponectin was association with a reduction in the mean AC z score [- 0.30 (- 0.46, - 0.13), P < 0.001] and EFW [- 0.24 (- 0.38, - 0.10), P < 0.001] at 36 weeks gestation. There were no consistent associations between maternal cardiometabolic and inflammatory markers with measurements of fetal adiposity. CONCLUSION: Adiponectin concentrations are associated with measures of fetal growth. Our findings contribute to further understanding of fetal growth in the setting of women who are overweight or obesity.

Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy.

BACKGROUND: Multiple pregnancy is a strong risk factor for preterm birth, and more than 50% of women with a twin pregnancy will give birth prior to 37 weeks' gestation. Infants born preterm are recognised to be at increased risk of many adverse health outcomes, contributing to more than half of overall perinatal mortality. Progesterone is produced naturally in the body and has a role in maintaining pregnancy, although it is not clear whether administering progestogens to women with multiple pregnancy at high risk of early birth is effective and safe. Since publication of this new review in Issue 10, 2017, we have now moved one study (El-Refaie 2016) from included to studies awaiting classification, pending clarification about the study data. OBJECTIVES: To assess the benefits and harms of progesterone administration for the prevention of preterm birth in women with a multiple pregnancy. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 November 2016) and reference lists of retrieved studies. SELECTION CRITERIA: We included randomised controlled trials examining the administration of a progestogen by any route for the prevention of preterm birth in women with multiple pregnancy. We did not include quasi-randomised or cross-over studies. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed reports identified by the search for eligibility, extracted data, assessed risk of bias and graded the quality of the evidence. MAIN RESULTS: We included 16 trials, which all compared either vaginal or intramuscular (IM) progesterone with a placebo or no treatment, and involved a total of 4548 women. The risk of bias for the majority of included studies was low, with the exception of three studies that had inadequate blinding, or significant loss to follow-up or both, or were not reported well enough for us to make a judgement. We graded the evidence low to high quality, with downgrading for statistical heterogeneity, design limitations in some of the studies contributing data, and imprecision of the effect estimate. 1 IM progesterone versus no treatment or placebo More women delivered at less than 34 weeks' gestation in the IM progesterone group compared with placebo (risk ratio (RR) 1.54, 95% confidence interval (CI) 1.06 to 2.26; women = 399; studies = 2; low-quality evidence). Although the incidence of perinatal death in the progesterone group was higher, there was considerable uncertainty around the effect estimate and high heterogeneity between studies (average RR 1.45, 95% CI 0.60 to 3.51; infants = 3089; studies = 6; I2 = 71%; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (RR 1.05, 95% CI 0.98 to 1.13; women = 2010; studies = 5; high-quality evidence); preterm birth less than 28 weeks (RR 1.08, 95% CI 0.75 to 1.55; women = 1920; studies = 5; moderate-quality evidence); infant birthweight less than 2500 g (RR 0.99, 95% CI 0.90 to 1.08; infants = 4071; studies = 5; I2 = 76%, moderate-quality evidence)). No childhood outcomes were reported in the trials. 2 Vaginal progesterone versus no treatment or placebo by dose There were no clear group differences in incidence of preterm birth before 34 weeks (average RR 0.90, 95% CI 0.66 to 1.23; women = 1503; studies = 5; I2 = 36%; low-quality evidence). Although fewer births before 34 weeks appeared to occur in the progesterone group, the CIs crossed the line of no effect. Incidence of perinatal death was higher in the progesterone group, although there was considerable uncertainty in the effect estimate and the quality of the evidence was low for this outcome (RR 1.23, 95% CI 0.74 to 2.06; infants = 2287; studies = 3; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (average RR 0.97, 95% CI 0.89 to 1.06; women = 1597; studies = 6; moderate-quality evidence); preterm birth less than 28 weeks (RR 1.53, 95% CI 0.79 to 2.97; women = 1345; studies = 3; low-quality evidence); infant birthweight less than 2500 g (average RR 0.95, 95% CI 0.84 to 1.07; infants = 2640; studies = 3; I2 = 66%, moderate-quality evidence)). No childhood outcomes were reported in the trials. For secondary outcomes, there were no clear group differences found in any of the other maternal outcomes except for caesarean section, where women who received vaginal progesterone did not have as many caesarean sections as those in the placebo group, although the difference between groups was not large (8%) (RR 0.92, 95% CI 0.86 to 0.98; women = 1919; studies = 5; I2 = 0%). There were no clear group differences found in any of the infant outcomes except for mechanical ventilation, which was required by fewer infants whose mothers had received the vaginal progesterone (RR 0.70, 95% CI 0.52 to 0.94; infants = 2695; studies = 4). AUTHORS' CONCLUSIONS: Overall, for women with a multiple pregnancy, the administration of progesterone (either IM or vaginal) does not appear to be associated with a reduction in risk of preterm birth or improved neonatal outcomes. Future research could focus on a comprehensive individual participant data meta-analysis including all of the available data relating to both IM and vaginal progesterone administration in women with a multiple pregnancy, before considering the need to conduct trials in subgroups of high-risk women (for example, women with a multiple pregnancy and a short cervical length identified on ultrasound).

Gestational weight gain outside the Institute of Medicine recommendations and adverse pregnancy outcomes: analysis using individual participant data from randomised trials.

BACKGROUND: High Body Mass Index (BMI) and gestational weight gain (GWG) affect an increasing number of pregnancies. The Institute of Medicine (IOM) has issued recommendations on the optimal GWG for women according to their pre-pregnancy BMI (healthy, overweight or obese). It has been shown that pregnant women rarely met the recommendations; however, it is unclear by how much. Previous studies also adjusted the analyses for various women's characteristics making their comparison challenging. METHODS: We analysed individual participant data (IPD) of healthy women with a singleton pregnancy and a BMI of 18.5 kg/m2 or more from the control arms of 36 randomised trials (16 countries). Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were used to describe the association between GWG outside (above or below) the IOM recommendations (2009) and risks of caesarean section, preterm birth, and large or small for gestational age (LGA or SGA) infants. The association was examined overall, within the BMI categories and by quartile of GWG departure from the IOM recommendations. We obtained aOR using mixed-effects logistic regression, accounting for the within-study clustering and a priori identified characteristics. RESULTS: Out of 4429 women (from 33 trials) meeting the inclusion criteria, two thirds gained weight outside the IOM recommendations (1646 above; 1291 below). The median GWG outside the IOM recommendations was 3.1 kg above and 2.7 kg below. In comparison to GWG within the IOM recommendations, GWG above was associated with increased odds of caesarean section (aOR 1.50; 95%CI 1.25, 1.80), LGA (2.00; 1.58, 2.54), and reduced odds of SGA (0.66; 0.50, 0.87); no significant effect on preterm birth was detected. The relationship between GWG below the IOM recommendation and caesarean section or LGA was inconclusive; however, the odds of preterm birth (1.94; 1.31, 2.28) and SGA (1.52; 1.18, 1.96) were increased. CONCLUSIONS: Consistently with previous findings, adherence to the IOM recommendations seem to help achieve better pregnancy outcomes. Nevertheless, even in the context of clinical trials, women find it difficult to adhere to them. Further research should focus on identifying ways of achieving a healthier GWG as defined by the IOM recommendations.

Nutrition During Pregnancy, Lactation and Early Childhood and its Implications for Maternal and Long-Term Child Health: The Early Nutrition Project Recommendations.

BACKGROUND: A considerable body of evidence accumulated especially during the last decade, demonstrating that early nutrition and lifestyle have long-term effects on later health and disease ("developmental or metabolic programming"). METHODS: Researchers involved in the European Union funded international EarlyNutrition research project consolidated the scientific evidence base and existing recommendations to formulate consensus recommendations on nutrition and lifestyle before and during pregnancy, during infancy and early childhood that take long-term health impact into account. Systematic reviews were performed on published dietary guidelines, standards and recommendations, with special attention to long-term health consequences. In addition, systematic reviews of published systematic reviews on nutritional interventions or exposures in pregnancy and in infants and young children aged up to 3 years that describe effects on subsequent overweight, obesity and body composition were performed. Experts developed consensus recommendations incorporating the wide-ranging expertise from additional 33 stakeholders. FINDINGS: Most current recommendations for pregnant women, particularly obese women, and for young children do not take long-term health consequences of early nutrition into account, although the available evidence for relevant consequences of lifestyle, diet and growth patterns in early life on later health and disease risk is strong. INTERPRETATION: We present updated recommendations for optimized nutrition before and during pregnancy, during lactation, infancy and toddlerhood, with special reference to later health outcomes. These recommendations are developed for affluent populations, such as women and children in Europe, and should contribute to the primary prevention of obesity and associated non-communicable diseases.

Effects of an antenatal dietary intervention in overweight and obese women on 6 month infant outcomes: follow-up from the LIMIT randomised trial.

BACKGROUND: The immediate impact of providing an antenatal dietary intervention during pregnancy has been extensively studied, but little is known of the effects beyond the neonatal period. Our objective was to evaluate the effect of an antenatal dietary intervention in overweight or obese women on infant outcomes 6 months after birth. METHODS: We conducted a follow up study of infants born to women who participated in the LIMIT trial during pregnancy. Live-born infants at 6-months of age, and whose mother provided consent to ongoing follow-up were eligible. The primary follow-up study endpoint was the incidence of infant BMI z-score ≥90th centile for infant sex and age. Secondary study outcomes included a range of infant anthropometric measures, neurodevelopment, general health, and infant feeding. Analyses used intention to treat principles according to the treatment group allocated in pregnancy. Missing data were imputed and analyses adjusted for maternal early pregnancy BMI, parity, study centre, socioeconomic status, age, and smoking status. Outcome assessors were blinded to the allocated treatment group. RESULTS: A total of 1754 infants were assessed at age 6 months (Lifestyle Advice n = 869; Standard Care n = 885), representing 82.1% of the eligible sample (n = 2136). There were no statistically significant differences in the incidence of infant BMI z-score ≥90th centile for infants born to women in the Lifestyle Advice group, compared with the Standard Care group (Lifestyle Advice 233 (21.71%) vs. Standard Care 233 (21.90%); adjusted relative risk (aRR) 0.99; 95% confidence interval 0.82 to 1.18; p = 0.88). There were no other effects on infant growth, adiposity, or neurodevelopment. CONCLUSION: Providing pregnant women who were overweight or obese with an antenatal dietary and lifestyle intervention did not alter 6-month infant growth and adiposity. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12607000161426).

Metformin for women who are overweight or obese during pregnancy for improving maternal and infant outcomes.

BACKGROUND: There has been considerable interest in providing antenatal dietary and lifestyle advice for women with obesity or who are overweight during pregnancy, as a strategy to limit gestational weight gain and improve maternal and infant health. However, such antenatal interventions appear to have a modest effect on gestational weight gain and other clinical pregnancy and birth outcomes and additional strategies are required.Metformin is an oral insulin-sensitising medication that acts to decrease blood glucose concentrations. Metformin is commonly used in the treatment of type 2 diabetes mellitus and polycystic ovarian syndrome, and is being used increasingly in the treatment of gestational diabetes, having been shown to result in decreased rates of caesarean birth and neonatal hypoglycaemia. Metformin may be an adjuvant therapy to current antenatal strategies in pregnant women with obesity or who are overweight, acting to reduce glucose production in the liver and improve glucose uptake in smooth muscle cells, and therefore improve the overall metabolic health of women in pregnancy and reduce the risk of known adverse pregnancy outcomes. OBJECTIVES: To evaluate the role of metformin in pregnant women with obesity or who are overweight, on maternal and infant outcomes, including adverse effects of treatment and costs. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (11 October 2017), and reference lists of retrieved studies. SELECTION CRITERIA: All published and unpublished randomised controlled trials evaluating metformin use (compared with placebo or no metformin) in women with obesity or who are overweight in pregnancy for improving outcomes, alone or in combination with other interventions were eligible for inclusion. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We used the GRADE approach to assess the quality of the evidence. MAIN RESULTS: We included three studies which randomised women (1099) with a body mass index (BMI) of 30 kg/m2 (1 study) and 35 kg/m2 (2 studies), with outcomes available for 1034 participants. None of the studies assessed women with a BMI between 25 kg/m2and 29.9 kg/m2, therefore we could not assess the use of metformin in women considered overweight. We did not identify studies of metformin in combination with another treatment. Two other studies are ongoing.All three included studies were randomised controlled trials and compared metformin with placebo, commencing early in the second trimester. Doses ranged from 500 mg twice daily to 3.0 g per day. All three studies (two in the UK, one in Egypt) included women attending hospitals for antenatal care.Two studies were generally at a low risk of bias across the majority of domains. We assessed the third study as being at an unclear risk of selection bias, performance and detection bias due to insufficient information in the report. We assessed the trial as being at a low risk of attrition bias and other bias; we felt it was at a high risk of reporting bias.The primary outcome for this review was infant birthweight large-for-gestational-age (> 90th centile for gestational age and infant sex). Women who received metformin or placebo had a similar risk of their baby being born large for his or her gestational age (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.70 to 1.30; 2 studies, 831 infants; high-quality evidence).Women who received metformin may have a slightly lower gestational weight gain (mean difference (MD) -2.60 kg, 95% CI -5.29 to 0.10; 3 studies, 899 women; low-quality evidence).Metformin may make little or no difference in the risk of women developing gestational hypertension (average RR 1.02, 95% CI 0.54 to 1.94; 3 studies, 1040 women; low-quality evidence) or pre-eclampsia (RR 0.74, 95% CI 0.09 to 6.28; 2 studies, 840 women; low-quality evidence). Metformin probably makes little or no difference in the risk of women developing gestational diabetes (RR 0.85, 95% CI 0.61 to 1.19; 3 studies, 892 women; moderate-quality evidence).One study of 400 women reported women receiving metformin were more likely to experience any adverse effect compared with women receiving placebo (RR 1.63, 95% CI 1.27 to 2.08; 1 study, 400 women). Adverse effects included abdominal pain, diarrhoea, or headache. When considering individual side effects, women receiving metformin were more likely to experience diarrhoea than women receiving placebo (RR 2.34, 95% CI 1.74 to 3.14; 797 women; 2 studies, 797 women; high-quality evidence). No other important differences were identified between Metformin and placebo for other maternal secondary outcomes, including: caesarean birth, birth before 37 weeks of pregnancy, shoulder dystocia, perineal tear, or postpartum haemorrhage.In terms of other infant outcomes, there was little or no difference in the infant birthweight (MD 6.39 g, 95% CI -81.15 to 93.92; 2 studies, 834 infants; high-quality evidence). There were no other important differences identified for other infant secondary outcomes in this review: hypoglycaemia (low blood sugar); hyperbilirubinaemia (jaundice); Apgar score less than 7 at five minutes; or stillbirth and neonatal death. Only one study reported admission to the neonatal intensive care unit (NICU), indicating similar rates of admission between women receiving metformin or placebo; no other admission data were reported to assess differences in costs. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the use of metformin for women with obesity in pregnancy for improving maternal and infant outcomes. Metformin was, however, associated with increased risk of adverse effects, particularly diarrhoea. The quality of the evidence in this review varied from high to low, with downgrading decisions based on study limitations and inconsistency.There were only a small number of studies included in this review. Furthermore, none of the included studies included women categorised as 'overweight' and no trials looked at metformin in combination with another treatment.Future research is required in order to further evaluate the role of metformin therapy in pregnant women with obesity or who are overweight, as a strategy to improve maternal and infant health, alone or as an adjuvant to dietary and lifestyle advice.

Evaluation of a smartphone nutrition and physical activity application to provide lifestyle advice to pregnant women: The SNAPP randomised trial.

Our objective was to evaluate the impact of a smartphone application as an adjunct to face-to-face consultations in facilitating dietary and physical activity change among pregnant women. This multicentre, nested randomised trial involved pregnant women with a body mass index ≥18.5 kg/m2 , with a singleton pregnancy between 10 and 20 weeks' gestation, and participating in 2 pregnancy nutrition-based randomised trials across metropolitan Adelaide, South Australia. All women participating in the SNAPP trial received a comprehensive dietary, physical activity, and behavioural intervention, as part of the GRoW or OPTIMISE randomised trials. Women were subsequently randomised to either the "Lifestyle Advice Only Group," where women received the above intervention, or the "Lifestyle Advice plus Smartphone Application Group," where women were additionally provided access to the smartphone application. The primary outcome was healthy eating index (HEI) assessed by maternal food frequency questionnaire completed at trial entry, and 28 and 36 weeks' gestation. Analyses were performed using intention-to-treat principles, with statistical significance at p = .05. One hundred sixty-two women participated: 77 allocated to the Lifestyle Advice plus Smartphone Application Group and 85 to the Lifestyle Advice Only Group. Mean difference in HEI score at 28 weeks of pregnancy was 0.01 (CI [-2.29, 2.62]) and at 36 weeks of pregnancy -1.16 (CI [-4.60, 2.28]). There was no significant additional benefit from the provision of the smartphone application in improving HEI score (p = .452). Although all women improved dietary quality across pregnancy, use of the smartphone application was poor. Our findings do not support addition of the smartphone application.

Vaginal progesterone pessaries for pregnant women with a previous preterm birth to prevent neonatal respiratory distress syndrome (the PROGRESS Study): A multicentre, randomised, placebo-controlled trial.

BACKGROUND: Neonatal respiratory distress syndrome, as a consequence of preterm birth, is a major cause of early mortality and morbidity. The withdrawal of progesterone, either actual or functional, is thought to be an antecedent to the onset of labour. There remains limited information on clinically relevant health outcomes as to whether vaginal progesterone may be of benefit for pregnant women with a history of a previous preterm birth, who are at high risk of a recurrence. Our primary aim was to assess whether the use of vaginal progesterone pessaries in women with a history of previous spontaneous preterm birth reduced the risk and severity of respiratory distress syndrome in their infants, with secondary aims of examining the effects on other neonatal morbidities and maternal health and assessing the adverse effects of treatment. METHODS: Women with a live singleton or twin pregnancy between 18 to <24 weeks' gestation and a history of prior preterm birth at less than 37 weeks' gestation in the preceding pregnancy, where labour occurred spontaneously or in association with cervical incompetence or following preterm prelabour rupture of the membranes, were eligible. Women were recruited from 39 Australian, New Zealand, and Canadian maternity hospitals and assigned by randomisation to vaginal progesterone pessaries (equivalent to 100 mg vaginal progesterone) (n = 398) or placebo (n = 389). Participants and investigators were masked to the treatment allocation. The primary outcome was respiratory distress syndrome and severity. Secondary outcomes were other respiratory morbidities; other adverse neonatal outcomes; adverse outcomes for the woman, especially related to preterm birth; and side effects of progesterone treatment. Data were analysed for all the 787 women (100%) randomised and their 799 infants. FINDINGS: Most women used their allocated study treatment (740 women, 94.0%), with median use similar for both study groups (51.0 days, interquartile range [IQR] 28.0-69.0, in the progesterone group versus 52.0 days, IQR 27.0-76.0, in the placebo group). The incidence of respiratory distress syndrome was similar in both study groups-10.5% (42/402) in the progesterone group and 10.6% (41/388) in the placebo group (adjusted relative risk [RR] 0.98, 95% confidence interval [CI] 0.64-1.49, p = 0.912)-as was the severity of any neonatal respiratory disease (adjusted treatment effect 1.02, 95% CI 0.69-1.53, p = 0.905). No differences were seen between study groups for other respiratory morbidities and adverse infant outcomes, including serious infant composite outcome (155/406 [38.2%] in the progesterone group and 152/393 [38.7%] in the placebo group, adjusted RR 0.98, 95% CI 0.82-1.17, p = 0.798). The proportion of infants born before 37 weeks' gestation was similar in both study groups (148/406 [36.5%] in the progesterone group and 146/393 [37.2%] in the placebo group, adjusted RR 0.97, 95% CI 0.81-1.17, p = 0.765). A similar proportion of women in both study groups had maternal morbidities, especially those related to preterm birth, or experienced side effects of treatment. In 9.9% (39/394) of the women in the progesterone group and 7.3% (28/382) of the women in the placebo group, treatment was stopped because of side effects (adjusted RR 1.35, 95% CI 0.85-2.15, p = 0.204). The main limitation of the study was that almost 9% of the women did not start the medication or forgot to use it 3 or more times a week. CONCLUSIONS: Our results do not support the use of vaginal progesterone pessaries in women with a history of a previous spontaneous preterm birth to reduce the risk of neonatal respiratory distress syndrome or other neonatal and maternal morbidities related to preterm birth. Individual participant data meta-analysis of the relevant trials may identify specific women for whom vaginal progesterone might be of benefit. TRIAL REGISTRATION: Current Clinical Trials ISRCTN20269066.