Nutritional advice for improving outcomes in multiple pregnancies

Perinatal and Neonatal Outcomes Following In Vitro Fertilisation in Poor Ovarian Responders: A Prospective Single-Centre Observational Study

OBJECTIVE

To compare the risk of adverse perinatal and neonatal outcomes between individuals with poor ovarian response (POR) and those with normal ovarian response (NOR) following in vitro fertilisation (IVF).

DESIGN

A prospective single-centre observational study.

SETTING

University hospital.

POPULATION

Overall, 1663 patients who underwent embryo transfer cycles between June 2017 and August 2019 were evaluated.

METHODS

The patients were divided into the POR and NOR groups based on the Bologna diagnostic criteria. The risk of perinatal and neonatal complications was then compared between groups with adjustment made for confounding factors.

MAIN OUTCOME MEASURES

The risk of perinatal and neonatal complications between the POR and NOR groups.

RESULTS

Compared with the NOR group, the POR group had poor pregnancy outcomes but comparable overall risks of poor perinatal and neonatal outcomes. The overall incidence rate of complications was 25.42% and 25.30% in the POR and NOR groups respectively [risk ratio (RR): 1.01; 95% confidence interval (CI): 0.63-1.59]. In subgroup analysis of singleton live births, the overall risk of total complications was higher in the POR group than in the NOR group (24.07% vs. 15.21%; RR: 1.77; 95% CI: 1.04-3.00); however, the risks became comparable between them after logistic regression adjustment.

CONCLUSIONS

The overall risk of perinatal and neonatal complications among singleton live births was higher in patients with POR than in those with NOR; however, the risks became similar after logistic regression adjustment. Our findings provide overall comforting evidence for POR patients with IVF treatment.

Exploring basal metabolic rate and dietary adequacy in twin pregnancies: the VENERE study

BACKGROUND

Twin pregnancies present unique challenges in maternal healthcare. However, current guidelines primarily address singleton pregnancies, resulting in a knowledge gap regarding their specific metabolic and dietary needs. This study aimed to follow women with twin pregnancies through all three trimesters, assessing basal metabolic rate (BMR), dietary intake, and diet quality.

METHODS

A two-year prospective observational study was conducted at AOU Careggi Hospital, Florence, Italy, involving 35 twin-pregnant women, with 32 completing the study. Participants underwent calorimetric, anthropometric, and dietary assessments during the first (8-13 weeks), second (14-27 weeks), and third trimesters (28-34 weeks). BMR was measured using indirect calorimetry and compared with predictive equations. Dietary intake was evaluated using 7-day food diaries and the Medi-Lite adherence score.

RESULTS

Indirect calorimetry revealed an increase in BMR by 16%, rising from 1479 ± 196 kcal in the first trimester to 1733 ± 224 kcal in the third trimester. Hronek's equation, previously validated for singleton pregnancies, was identified as the most accurate predictive tool for estimating BMR. Dietary analysis revealed that mean daily energy intake increased from 1660 ± 244 kcal in the first trimester to 1889 ± 262 kcal in the third trimester, consistently below recommendations, with insufficient macro- and micronutrient consumption. Poor diet quality was characterized by low intake of fruits, vegetables, legumes, and fresh fish, and high consumption of processed meats, cheese, and sugar-sweetened beverages. Adherence to the Mediterranean diet was moderate across all three trimesters.

CONCLUSIONS

This study highlights the increased energy demands and nutritional inadequacies in twin pregnancies, underscoring the need for tailored dietary guidelines and interventions.

Nutritional Intake in Dichorionic Twin Pregnancies: A Descriptive Analysis of a Multisite United States Cohort

INTRODUCTION

Twin gestations have greater nutritional demands than singleton gestations, yet dietary intakes of women with twin gestations have not been well described.

METHODS

In a prospective, multi-site US study of 148 women with dichorionic twin gestations (2012-2013), we examined longitudinal changes in diet across pregnancy. Women completed a food frequency questionnaire during each trimester of pregnancy. We examined changes in means of total energy and energy-adjusted dietary components using linear mixed effects models.

RESULTS

Mean energy intake (95% CI) across the three trimesters was 2010 kcal/day (1846, 2175), 2177 kcal/day (2005, 2349), 2253 kcal/day (2056, 2450), respectively (P = 0.01), whereas the Healthy Eating Index-2010 was 63.9 (62.1, 65.6), 64.5 (62.6, 66.3), 63.2 (61.1, 65.3), respectively (P = 0.53).

DISCUSSION

Women with twin gestations moderately increased total energy as pregnancy progressed, though dietary composition and quality remained unchanged. These findings highlight aspects of nutritional intake that may need to be improved among women carrying twins.

Review of Dietary Recommendations for Twin Pregnancy: Does Nutrition Science Keep Up with the Growing Incidence of Multiple Gestations?

Recommendations for nutrition and the use of dietary supplements for pregnant women are updated on regular basis but it remains to be seen to what extent they may be applicable in twin pregnancies. The aim of this narrative review is to present the current state of knowledge about the energy and nutrient demand in twin pregnancy. There is general consensus in literature that the energy demand is higher than in a singleton pregnancy, but there is a lack of position statements from scientific societies on specific energy intake that is required. In turn, recommended maternal weight gain, which favors the normal weight of the neonate, has been determined. There is even a larger knowledge gap when it comes to vitamins and minerals, the body stores of which are theoretically used up faster. The greatest number of studies so far focused on vitamin D, and most of them concluded that its concentration in maternal blood is lower in twin as compared to singleton pregnancy. Few randomized studies focus on iron supplementation and there are no other studies that would assess dietary interventions. In light of a growing incidence of multiple pregnancies, more studies are necessary to establish the nutritional demands of the mother and the course of action for adequate supplementation.

Micronutrients in Multiple Pregnancies-The Knowns and Unknowns: A Systematic Review

Maternal diet and nutritional status are of key importance with regard to the short- and long-term health outcomes of both the mother and the fetus. Multiple pregnancies are a special phenomenon in the context of nutrition. The presence of more than one fetus may lead to increased metabolic requirements and a faster depletion of maternal macro- and micro- nutrient reserves than in a singleton pregnancy. The aim of this systematic review was to gather available knowledge on the supply and needs of mothers with multiple pregnancies in terms of micronutrients and the epidemiology of deficiencies in that population. It was constructed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). The authors conducted a systematic literature search with the use of three databases: PubMed/MEDLINE, Scopus and Embase. The last search was run on the 18 October 2020 and identified 1379 articles. Finally, 12 articles and 1 series of publications met the inclusion criteria. Based on the retrieved studies, it may be concluded that women with multiple pregnancies might be at risk of vitamin D and iron deficiencies. With regard to other microelements, the evidence is either inconsistent, scarce or absent. Further in-depth prospective and population studies are necessary to determine if nutritional recommendations addressed to pregnant women require adjustments in cases of multiple gestations.

Interventions during pregnancy to prevent preterm birth: an overview of Cochrane systematic reviews

BACKGROUND

Preterm birth (PTB) is a major factor contributing to global rates of neonatal death and to longer-term health problems for surviving infants. Both the World Health Organization and the United Nations consider prevention of PTB as central to improving health care for pregnant women and newborn babies. Current preventative clinical strategies show varied efficacy in different populations of pregnant women, frustrating women and health providers alike, while researchers call for better understanding of the underlying mechanisms that lead to PTB.

OBJECTIVES

We aimed to summarise all evidence for interventions relevant to the prevention of PTB as reported in Cochrane systematic reviews (SRs). We intended to highlight promising interventions and to identify SRs in need of an update.

METHODS

We searched the Cochrane Database of Systematic Reviews (2 November 2017) with key words to capture any Cochrane SR that prespecified or reported a PTB outcome. Inclusion criteria focused on pregnant women without signs of preterm labour or ruptured amniotic membranes. We included reviews of interventions for pregnant women irrespective of their risk status. We followed standard Cochrane methods.We applied GRADE criteria to evaluate the quality of SR evidence. We assigned graphic icons to classify the effectiveness of interventions as: clear evidence of benefit; clear evidence of harm; clear evidence of no effect or equivalence; possible benefit; possible harm; or unknown benefit or harm. We defined clear evidence of benefit and clear evidence of harm to be GRADE moderate- or high-quality evidence with a confidence interval (CI) that does not cross the line of no effect. Clear evidence of no effect or equivalence is GRADE moderate- or high-quality evidence with a narrow CI crossing the line of no effect. Possible benefit and possible harm refer to GRADE low-quality evidence with a clear effect (CI does not cross the line of no effect) or GRADE moderate- or high-quality evidence with a wide CI. Unknown harm or benefit refers to GRADE low- or very low-quality evidence with a wide CI.

MAIN RESULTS

We included 83 SRs; 70 had outcome data. Below we highlight key results from a subset of 36 SRs of interventions intended to prevent PTB.

OUTCOME

preterm birthClear evidence of benefitFour SRs reported clear evidence of benefit to prevent specific populations of pregnant women from giving birth early, including midwife-led continuity models of care versus other models of care for all women; screening for lower genital tract infections for pregnant women less than 37 weeks' gestation and without signs of labour, bleeding or infection; and zinc supplementation for pregnant women without systemic illness. Cervical cerclage showed clear benefit for women with singleton pregnancy and high risk of PTB only.Clear evidence of harmNo included SR reported clear evidence of harm.No effect or equivalenceFor pregnant women at high risk of PTB, bedrest for women with singleton pregnancy and antibiotic prophylaxis during the second and third trimester were of no effect or equivalent to a comparator.Possible benefitFour SRs found possible benefit in: group antenatal care for all pregnant women; antibiotics for pregnant women with asymptomatic bacteriuria; pharmacological interventions for smoking cessation for pregnant women who smoke; and vitamin D supplements alone for women without pre-existing conditions such as diabetes.Possible harmOne SR reported possible harm (increased risk of PTB) with intramuscular progesterone, but this finding is only relevant to women with multiple pregnancy and high risk of PTB. Another review found possible harm with vitamin D, calcium and other minerals for pregnant women without pre-existing conditions.

OUTCOME

perinatal deathClear evidence of benefitTwo SRs reported clear evidence of benefit to reduce pregnant women's risk of perinatal death: midwife-led continuity models of care for all pregnant women; and fetal and umbilical Doppler for high-risk pregnant women.Clear evidence of harmNo included SR reported clear evidence of harm.No effect or equivalenceFor pregnant women at high risk of PTB, antibiotic prophylaxis during the second and third trimester was of no effect or equivalent to a comparator.Possible benefitOne SR reported possible benefit with cervical cerclage for women with singleton pregnancy and high risk of PTB.Possible harmOne SR reported possible harm associated with a reduced schedule of antenatal visits for pregnant women at low risk of pregnancy complications; importantly, these women already received antenatal care in settings with limited resources.

OUTCOMES

preterm birth and perinatal deathUnknown benefit or harmFor pregnant women at high risk of PTB for any reason including multiple pregnancy, home uterine monitoring was of unknown benefit or harm. For pregnant women at high risk due to multiple pregnancy: bedrest, prophylactic oral betamimetics, vaginal progesterone and cervical cerclage were all of unknown benefit or harm.

AUTHORS' CONCLUSIONS

Implications for practiceThe overview serves as a map and guide to all current evidence relevant to PTB prevention published in the Cochrane Library. Of 70 SRs with outcome data, we identified 36 reviews of interventions with the aim of preventing PTB. Just four of these SRs had evidence of clear benefit to women, with an additional four SRs reporting possible benefit. No SR reported clear harm, which is an important finding for women and health providers alike.The overview summarises no evidence for the clinically important interventions of cervical pessary, cervical length assessment and vaginal progesterone because these Cochrane Reviews were not current. These are active areas for PTB research.The graphic icons we assigned to SR effect estimates do not constitute clinical guidance or an endorsement of specific interventions for pregnant women. It remains critical for pregnant women and their healthcare providers to carefully consider whether specific strategies to prevent PTB will be of benefit for individual women, or for specific populations of women.Implications for researchFormal consensus work is needed to establish standard language for overviews of reviews and to define the limits of their interpretation.Clinicians, researchers and funders must address the lack of evidence for interventions relevant to women at high risk of PTB due to multiple pregnancy.