The association between dietary patterns and risk of miscarriage: a systematic review and meta-analysis.

IMPORTANCE: The evidence on the association between diet and miscarriage risk is scant and conflicting. OBJECTIVE: To summarize the evidence on the association between periconceptual diet and miscarriage risk in healthy women of reproductive age. DATA SOURCES: Electronic databases were searched from inception to August 2022 without restriction of regions, publication types, or languages. STUDY SELECTION AND SYNTHESIS: Experimental or observational studies were considered for inclusion. The population was healthy women of reproductive age. Exposure was periconception diet. Study quality was assessed using the modified Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for each food category. MAIN OUTCOMES: Miscarriage rate (as defined by primary studies). RESULTS: We included 20 studies (11 cohort and 9 case-control), of which 6 presented data suitable for meta-analysis (2 cohort and 4 case-control, n = 13,183 women). Our primary analyses suggest a reduction in miscarriage odds with high intake of the following food groups: fruit (OR, 0.39; 95% CI, 0.33-0.46), vegetables (OR, 0.59; 95% CI, 0.46-0.76), fruit and vegetables (OR, 0.63; 95% CI, 0.50-0.81), seafood (OR, 0.81; 95% CI, 0.71-0.92), dairy products (OR, 0.63; 95% CI, 0.54-0.73), eggs (OR, 0.81; 95% CI, 0.72-0.90), and cereal (grains) (OR, 0.67; 95% CI, 0.52-0.87). The evidence was uncertain for meat, red meat, white meat, fat and oil, and sugar substitutes. We did not find evidence of an association between adherence to predefined dietary patterns and miscarriage risk. However, a whole diet containing healthy foods as perceived by the trialists, or with a high Dietary Antioxidant Index score (OR, 0.43; 95% CI, 0.20-0.91) may be associated with a reduction in miscarriage risk. In contrast, a diet rich in processed food was demonstrated to be associated with increased miscarriage risk (OR, 1.97; 95% CI, 1.36-3.34). CONCLUSION AND RELEVANCE: A diet abundant in fruit, vegetables, seafood, dairy, eggs, and grain may be associated with lower miscarriage odds. Further interventional studies are required to accurately assess the effectiveness of periconception dietary modifications on miscarriage risk. PROSPERO REGISTRATION: CRD42020218133.

The effect of frozen embryo transfer regimen on the association between serum progesterone and live birth: a multicentre prospective cohort study (ProFET).

STUDY QUESTION: What is the association between serum progesterone levels on the day of frozen embryo transfer (FET) and the probability of live birth in women undergoing different FET regimens? SUMMARY ANSWER: Overall, serum progesterone levels <7.8 ng/ml were associated with reduced odds of live birth, although the association between serum progesterone levels and the probability of live birth appeared to vary according to the route of progesterone administration. WHAT IS KNOWN ALREADY: Progesterone is essential for pregnancy success. A recent systematic review showed that in FET cycles using vaginal progesterone for endometrial preparation, lower serum progesterone levels (<10 ng/ml) were associated with a reduction in live birth rates and higher chance of miscarriage. However, there was uncertainty about the association between serum progesterone levels and treatment outcomes in natural cycle FET (NC-FET) and HRT-FET using non-vaginal routes of progesterone administration. STUDY DESIGN SIZE DURATION: This was a multicentre (n = 8) prospective cohort study conducted in the UK between January 2020 and February 2021. PARTICIPANTS/MATERIALS SETTING METHODS: We included women having NC-FET or HRT-FET treatment with progesterone administration by any available route. Women underwent venepuncture on the day of embryo transfer. Participants and clinical personnel were blinded to the serum progesterone levels. We conducted unadjusted and multivariable logistic regression analyses to investigate the association between serum progesterone levels on the day of FET and treatment outcomes according to the type of cycle and route of exogenous progesterone administration. Our primary outcome was the live birth rate per participant. MAIN RESULTS AND THE ROLE OF CHANCE: We studied a total of 402 women. The mean (SD) serum progesterone level was 14.9 (7.5) ng/ml. Overall, the mean adjusted probability of live birth increased non-linearly from 37.6% (95% CI 26.3-48.9%) to 45.5% (95% CI 32.1-58.9%) as serum progesterone rose between the 10th (7.8 ng/ml) and 90th (24.0 ng/ml) centiles. In comparison to participants whose serum progesterone level was ≥7.8 ng/ml, those with lower progesterone (<7.8 ng/ml, 10th centile) experienced fewer live births (28.2% versus 40.0%, adjusted odds ratio [aOR] 0.41, 95% CI 0.18-0.91, P = 0.028), lower odds of clinical pregnancy (30.8% versus 45.1%, aOR 0.36, 95% CI 0.16-0.79, P = 0.011) and a trend towards increased odds of miscarriage (42.1% versus 28.7%, aOR 2.58, 95% CI 0.88-7.62, P = 0.086). In women receiving vaginal progesterone, the mean adjusted probability of live birth increased as serum progesterone levels rose, whereas women having exclusively subcutaneous progesterone experienced a reduction in the mean probability of live birth as progesterone levels rose beyond 16.3 ng/ml. The combination of vaginal and subcutaneous routes appeared to exert little impact upon the mean probability of live birth in relation to serum progesterone levels. LIMITATIONS REASONS FOR CAUTION: The final sample size was smaller than originally planned, although our study was adequately powered to confidently identify a difference in live birth between optimal and inadequate progesterone levels. Furthermore, our cohort did not include women receiving oral or rectal progestogens. WIDER IMPLICATIONS OF THE FINDINGS: Our results corroborate existing evidence suggesting that lower serum progesterone levels hinder FET success. However, the relationship between serum progesterone and the probability of live birth appears to be non-linear in women receiving exclusively subcutaneous progesterone, suggesting that in this subgroup of women, high serum progesterone may also be detrimental to treatment success. STUDY FUNDING/COMPETING INTERESTS: This work was supported by CARE Fertility and a doctoral research fellowship (awarded to P.M.) by the Tommy's Charity and the University of Birmingham. M.J.P. is supported by the NIHR Birmingham Biomedical Research Centre. S.F. is a minor shareholder of CARE Fertility but has no financial or other interest with progesterone testing or manufacturing companies. P.L. reports personal fees from Pharmasure, outside the submitted work. G.P. reports personal fees from Besins Healthcare, outside the submitted work. M.W. reports personal fees from Ferring Pharmaceuticals, outside the submitted work. The remaining authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT04170517.

Serum luteal phase progesterone in women undergoing frozen embryo transfer in assisted conception: a systematic review and meta-analysis.

OBJECTIVE: To investigate the association between luteal serum progesterone levels and frozen embryo transfer (FET) outcomes. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Women undergoing FET. INTERVENTION(S): We conducted electronic searches of MEDLINE, PubMed, CINAHL, EMBASE, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and grey literature (not widely available) from inception to March 2021 to identify cohort studies in which the serum luteal progesterone level was measured around the time of FET. MAIN OUTCOME MEASURE(S): Ongoing pregnancy or live birth rate, clinical pregnancy rate, and miscarriage rate. RESULT(S): Among the studies analyzing serum progesterone level thresholds <10 ng/mL, a higher serum progesterone level was associated with increased rates of ongoing pregnancy or live birth (relative risk [RR] 1.47, 95% confidence interval [CI] 1.28 to 1.70), higher chance of clinical pregnancy (RR 1.31, 95% CI 1.16 to 1.49), and lower risk of miscarriage (RR 0.62, 95% CI 0.50 to 0.77) in cycles using exclusively vaginal progesterone and blastocyst embryos. There was uncertainty about whether progesterone thresholds ≥10 ng/mL were associated with FET outcomes in sensitivity analyses including all studies, owing to high interstudy heterogeneity and wide CIs. CONCLUSION(S): Our findings indicate that there may be a minimum clinically important luteal serum concentration of progesterone required to ensure an optimal endocrine milieu during embryo implantation and early pregnancy after FET treatment. Future clinical trials are required to assess whether administering higher-dose luteal phase support improves outcomes in women with a low serum progesterone level at the time of FET. PROSPERO NUMBER: CRD42019157071.

Treating the placenta to prevent adverse effects of gestational hypoxia on fetal brain development.

Some neuropsychiatric disease, including schizophrenia, may originate during prenatal development, following periods of gestational hypoxia and placental oxidative stress. Here we investigated if gestational hypoxia promotes damaging secretions from the placenta that affect fetal development and whether a mitochondria-targeted antioxidant MitoQ might prevent this. Gestational hypoxia caused low birth-weight and changes in young adult offspring brain, mimicking those in human neuropsychiatric disease. Exposure of cultured neurons to fetal plasma or to secretions from the placenta or from model trophoblast barriers that had been exposed to altered oxygenation caused similar morphological changes. The secretions and plasma contained altered microRNAs whose targets were linked with changes in gene expression in the fetal brain and with human schizophrenia loci. Molecular and morphological changes in vivo and in vitro were prevented by a single dose of MitoQ bound to nanoparticles, which were shown to localise and prevent oxidative stress in the placenta but not in the fetus. We suggest the possibility of developing preventative treatments that target the placenta and not the fetus to reduce risk of psychiatric disease in later life.

Current pregnancy outcomes in women with cystic fibrosis.

OBJECTIVES: Women with cystic fibrosis (CF) now achieve a greater life expectancy and therefore have greater expectations from life. Literature reporting pregnancy outcomes in CF is still sparse. There remains a legacy of advising women with significant disease to avoid pregnancy. We aimed to assess current maternal and fetal outcomes in women with CF with varied pre-pregnancy lung function. STUDY DESIGN: Retrospective case note review of data from 15 pregnancies in 12 women with CF receiving care at a specialist centre between 2003 and 2011. Descriptive statistics were used for the quantitative data. The forced expiratory volume (FEV1) and forced vital capacity (FVC) were calculated and shown as the percentage of their predicted values for BMI, height and age. Changes in lung function pre, 6, and 24 months post delivery were calculated with the paired t-test. RESULTS: Mean maternal age was 28.9 (range 21-36, CI 26.8-31). Maternal FEV1 at booking ranged from 27 to 80% predicted (mean=63.6%, CI 54.62-71.38%). Cystic fibrosis-related diabetes (CFRD) was present in 8 of 14 (live birth) pregnancies. Average gestation at delivery was 38 weeks. There was a 100% vaginal delivery rate (11 spontaneous vertex, 2 ventouse, 1 forceps). Average fetal birth weight was 2.97 kg (range 2.2-3.83 kg, CI 2.72-3.23). The differences between the maternal pre- and 6 months post-pregnancy mean FEV1 (p=0.136) and FVC (p=0.225) were not statistically significant. CONCLUSION: With careful multidisciplinary antenatal and intrapartum management, successful outcomes have been obtained in this group of women with CF.

Validation and compliance of a home monitoring device in pregnancy: microlife WatchBP home.

OBJECTIVE: To assess the accuracy and patient compliance in using a novel home blood pressure monitoring device in high-risk pregnancy. METHODS: Device accuracy was assessed according to the British Hypertension Society protocol in 45 pregnant women, including 15 with preeclampsia. Twenty-one high-risk pregnant women used the device in addition to their antenatal care. RESULTS: The device achieved a mean difference +/- SD of 0.4 +/- 7.3/-0.4 +/- 5.5 mmHg (pregnancy) and -2.6 +/- 7.0/0.8 +/- 4.4 mmHg (preeclampsia) for systolic/diastolic pressure. Eighty-one percent of women did at least 6 measurements/day and all women did at least 2 measurements/week. CONCLUSION: The Microlife WatchBP Home is accurate for use in pregnancy and increases surveillance in compliant patients.