Gestational metformin administration in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized control studies

Position paper of the Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), and the Italian Study Group of Diabetes in pregnancy: Metformin use in pregnancy

OBJECTIVE

This document purpose is to create an evidence-based position statement on the role of metformin therapy in pregnancy complicated by obesity, gestational diabetes (GDM), type 2 diabetes mellitus (T2DM), polycystic ovary syndrome (PCOS) and in women undergoing assisted reproductive technology (ART).

METHODS

A comprehensive review of international diabetes guidelines and a search of medical literature was performed to identify studies presenting data on the use of metformin in pregnancy. The document was approved by the councils of the two scientific societies.

RESULTS

In condition affecting the fertility, as PCOS, metformin use in pre-conception or early in pregnancy may be beneficial for clinical pregnancy, even in ART treatment, and in obese-PCOS women may reduce preterm delivery. In obese women, even in the presence of GDM or T2DM, metformin use in pregnancy is associated with a lower gestational weight gain. In pregnancy complicated by diabetes (GDM or T2DM), metformin improves maternal glycemic control and may reduce insulin dose. Neonatal and infant outcomes related to metformin exposure in utero are lacking. Metformin use in women with GDM or T2DM is associated with lower birth weight. However, an increased tendency to overweight-obesity has been observed in children, later in life.

CONCLUSIONS

Metformin may represent a therapeutic option in selected women with obesity, PCOS, GDM, T2DM, and in women undergoing ART. However, more research is required specifically on the long-term effects of in utero exposition to metformin.

Effect of Metformin (MTF) Intervention During Pregnancy in Women With Polycystic Ovarian Syndrome (PCOS): A Systematic Review

Metformin (MTF) is a commonly prescribed medication for women with polycystic ovarian syndrome (PCOS), but its impact on pregnancy outcomes in women with PCOS remains controversial. This systematic review aims to evaluate the effects of MTF intervention on pregnancy outcomes in women with PCOS and the impact of MTF on offspring. A comprehensive search is conducted in PubMed, Google Scholar, and ScienceDirect databases from 2019 up to May 16, 2023. Only review articles and meta-analyses are included, focusing on women with PCOS who received MTF during pregnancy or as part of infertility treatment. The primary outcomes of interest are clinical pregnancy rate (CPR), miscarriage rate, preterm birth rate, and live birth rate. Secondary outcomes are the safety profile of MTF. Data extraction and quality assessment are performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the assessment using the multiple systematic reviews (AMSTAR) 2 tool, respectively. The initial search produced 1877 studies. Thirteen studies were included in the review. While the use of MTF during pregnancy in women with PCOS may have some benefits in reducing certain pregnancy complications such as pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), preeclampsia, preterm delivery, reducing the risk of ovarian hyperstimulation syndrome (OHSS) in women with PCOS undergoing in vitro fertilization (IVF); however, there is no significant difference in clinical pregnancy and live birth rates overall, but subgroup analysis suggests potential benefits for women with a higher body mass index (BMI). MTF is associated with a larger fetal head circumference and potential long-term effects on offspring's BMI and obesity. Further research is needed to better understand the optimal dosing of MTF, long-term effects, and effects in specific subgroups. The heterogeneity of the included studies limited the ability to analyze the data effectively, leading to challenges in drawing definitive conclusions.

Gestational diabetes and other adverse pregnancy outcomes in polycystic ovary syndrome

PURPOSE OF REVIEW

This review provides an update on gestational diabetes (GDM) and other adverse pregnancy outcomes in individuals with polycystic ovary syndrome (PCOS), one of the most common metabolic disorders and causes of infertility.

RECENT FINDINGS

Recent studies using Rotterdam diagnostic criteria for PCOS have supported prior literature suggesting that pregnant individuals with PCOS are at an increased risk of GDM. Risk factors for GDM in this population include overweight/obesity, insulin resistance, hyperandrogenism, amenorrhea, and history of miscarriage. It is possible that subtypes of PCOS (metabolic vs. lean/reproductive) pose differential risk. There are no current screening or treatment guidelines specifically for individuals with PCOS for GDM prevention. Although metformin has been studied for GDM prevention in PCOS, there has been no proven benefit. For infertility treatment, assisted reproductive technology and in-vitro fertilization do not appear to increase the risk of GDM in individuals with PCOS desiring pregnancy.

SUMMARY

Recent studies of pregnant individuals with PCOS suggest an increased risk of adverse pregnancy outcomes, including GDM. Larger, prospective studies using standardized diagnostic criteria are warranted to determine if the risk is from PCOS generally, or if there are subtypes of PCOS (metabolic vs. lean/reproductive) at a higher risk of GDM than others.

Metformin Treatment Modulates Long Non-Coding RNA Isoforms Expression in Human Cells

Long noncoding RNAs (lncRNAs) undergo splicing and have multiple transcribed isoforms. Nevertheless, for lncRNAs, as well as for mRNA, measurements of expression are routinely performed only at the gene level. Metformin is the first-line oral therapy for type 2 diabetes mellitus and other metabolic diseases. However, its mechanism of action remains not thoroughly explained. Transcriptomic analyses using metformin in different cell types reveal that only protein-coding genes are considered. We aimed to characterize lncRNA isoforms that were differentially affected by metformin treatment on multiple human cell types (three cancer, two non-cancer) and to provide insights into the lncRNA regulation by this drug. We selected six series to perform a differential expression (DE) isoform analysis. We also inferred the biological roles for lncRNA DE isoforms using in silico tools. We found the same isoform of an lncRNA (AC016831.6-205) highly expressed in all six metformin series, which has a second exon putatively coding for a peptide with relevance to the drug action. Moreover, the other two lncRNA isoforms (ZBED5-AS1-207 and AC125807.2-201) may also behave as cis-regulatory elements to the expression of transcripts in their vicinity. Our results strongly reinforce the importance of considering DE isoforms of lncRNA for understanding metformin mechanisms at the molecular level.

Clinical management of pregnancy in women with polycystic ovary syndrome: An expert opinion

Polycystic ovary syndrome (PCOS) is associated with a higher risk for pregnancy and birth complications according to the specific features associated with PCOS. The features include obesity before and during pregnancy, hyperandrogenism, insulin resistance, infertility, cardiometabolic risk factors, and poor mental health. PCOS is not often recognized as a risk factor for poor pregnancy and birth outcomes in pregnancy care guidelines, while its associated features are. Pregnancy-related risk profile should ideally be assessed for modifiable risk factors (e.g., lifestyle and weight management) at preconception in women with PCOS. Hyperglycaemia should be screened using a 75-g oral glucose tolerance test at preconception or within the first 20 weeks of pregnancy if it has not been performed at preconception and should be repeated at 24-28 weeks of pregnancy. In the absence of evidence of benefit for strategies specific to women with PCOS, the international evidence-based guidelines for the assessment and management of PCOS recommend screening, optimizing, and monitoring risk profile in women with PCOS (at preconception, during and postpregnancy) consistent with the recommendations for the general population. Recommended factors include blood glucose, weight, blood pressure, smoking, alcohol, diet, exercise, sleep and mental health, emotional, and sexual health among women with PCOS. The guidelines recommend Metformin in addition to lifestyle for assisting with weight management and improving cardiometabolic risk factors, particularly in those with overweight or obesity. Letrozole is considered the first-line pharmacological treatment for anovulatory infertility in PCOS. Individualized approach should be considered in the management of pregnancy in PCOS.

Application of Gestational Blood Glucose Control During Perinatal Period in Parturients with Diabetes Mellitus: Meta-Analysis of Controlled Clinical Studies

Background

Gestational diabetes mellitus (GDM) is a common metabolic disorder. Hyperglycemia may cause gestational hypertension, increase the probability of infection, abnormal embryonic development, and increase the abortion rate. Oral hypoglycemic drugs may be another effective means of blood glucose control in addition to insulin injection. We included controlled clinical studies for meta-analysis to understand the effect of oral hypoglycemic drugs in gestational diabetes.

Methods

The databases were searched with the keywords “Glycemic control” & “gestational diabetes”: Embase (January, 2000–August, 2021), Pubmed (January, 2000–August, 2021), Web of Science (January, 2000–August, 2021), Ovid (January, 2000–August, 2021), and ClinicalTrials.org to obtain the randomized controlled trial (RCT) literatures related to the treatment of gestational diabetes with oral hypoglycemic drugs, after screening, the R language toolkit was used for the analysis.

Results

A total of 10 articles with a total of 1,938 patients were included, 7 studies used metformin as an hypoglycemic agent. Meta-analysis showed that oral metformin had no significant difference in fasting blood glucose levels after the intervention compared with insulin injection [MD = −0.35, 95%CI(−0.70,1.40), Z = 0.66, P = 0.51], with no significant difference in postprandial blood glucose levels after intervention [MD = −2.20, 95%CI(−5.94,1.55), Z = −1.15, P = 0.25], and no statistical difference in glycosylated hemoglobin [MD = 0.10, 95%CI(−0.17,−0.04), Z = −0.94, P = 0.31]. Metformin was more conducive to reducing maternal weight during pregnancy than insulin [MD = −1.55, 95%CI(−2.77,−0.34), Z = −2.5, P = 0.0123], metformin reduced the abortion rate compared with insulin [RR = 0.81, 95%CI(0.63,1.05), Z = −2.61, P = 0.015], and reduced cesarean section rate [RR = 0.66, 95%CI(0.49,0.90), Z = −3.95, P = 0.0001].

Discussion

The application of oral hypoglycemic drug metformin in blood glucose control of gestational diabetes can play a hypoglycemic effect equivalent to insulin and can control the weight of pregnant women, reduce the rate of abortion and cesarean section, and improve pregnancy outcomes.

Metformin: Sex/Gender Differences in Its Uses and Effects—Narrative Review

Metformin (MTF) occupies a major and fundamental position in the therapeutic management of type 2 diabetes mellitus (T2DM). Gender differences in some effects and actions of MTF have been reported. Women are usually prescribed lower MTF doses compared to men and report more gastrointestinal side effects. The incidence of cardiovascular events in women on MTF has been found to be lower to that of men on MTF. Despite some promising results with MTF regarding pregnancy rates in women with PCOS, the management of gestational diabetes, cancer prevention or adjunctive cancer treatment and COVID-19, most robust meta-analyses have yet to confirm such beneficial effects.

Current Resources for Evidence-Based Practice, March 2022

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of systemic racism and its effect on maternal health in the United States and commentaries on reviews focused on barriers and facilitators to HPV vaccination and delayed cord clamping in preterm infants.