Obstetrical Society Research Articles

Thrombosis-related characteristics of pregnant women with antithrombin deficiency, protein C deficiency and protein S deficiency in Japan

Background We previously conducted a primary survey of pregnant women with hereditary thrombophilia based on national surveillance in Japan, but did not examine their thrombosis-related characteristics. Antithrombin (AT) deficiency, protein C (PC) deficiency and protein S (PS) deficiency are the major types of hereditary thrombophilia in Japan.MethodsWe examined their detailed information related to thrombosis, and evaluated peripartum outcomes in comparison with control data obtained from the Japan Society of Obstetrics and Gynecology.ResultsDefinite or probable AT deficiency, PC deficiency and PS deficiency were observed in 80, 50, and 317 pregnancies, respectively, from 2014 to 2018 in Japan, with prevalence rates among total deliveries of 0.011%, 0.007%, 0.044%. The number of pregnancies with AT, PC and PS deficiency might have been as many as 27, 17 and 108 every year if complete answers had been provided. In the peripartum period of current pregnancies, 27.5% of women with AT deficiency, 28.0% with PC deficiency and 13.2% with PS deficiency developed thrombosis (p < 0.001 vs. control). Pregnant women with AT and PC deficiency were more susceptible to thrombosis than those with PS deficiency (P < 0.01). Of the thromboses, 92.3% occurred during pregnancy, 62.8% at less than 15 gestational weeks. The earliest onset of thrombosis was 5 gestational weeks. Prophylactic anticoagulation significantly prevented the onset of both antepartum and postpartum thrombosis (p < 0.0001). The rate of recurrent pregnancy loss in women with low PC or PS activities was significantly higher than in controls (p < 0.0001); however, it is unknown whether recurrent pregnancy loss is related to hereditary PS deficiency. There seem to have been few serious maternal or fetal/neonatal complications due to placental insufficiency related to a hypercoagulable state other than growth restriction.ConclusionsThis survey revealed the thrombosis-related characteristics of pregnant women with hereditary thrombophilia in Japan. We suggest prophylactic anticoagulation to prevent maternal or fetal/neonatal complications.

Intrauterine manipulator use during laparoscopic hysterectomy for endometrial cancer: association for pathological factors and oncologic outcomes

ObjectiveTo examine the association between intrauterine manipulator use and pathological factors and oncologic outcomes in patients with endometrial cancer who had laparoscopic hysterectomy in Japan.MethodsThis was a nationwide retrospective cohort...

Respectful Abortion Care initiative: How a large-scale virtual training for providers in India increased knowledge of the new 2021 Medical Termination of Pregnancy Act.

In a historic move to ensure comprehensive abortion care, India amended the 1971 Medical Termination of Pregnancy (MTP) Act in 2021, creating an unprecedented opportunity for accelerating safe, respectful, and rights-based abortion services. The Federation of Obstetric and Gynecological Societies of India (FOGSI), together with World Health Organization (WHO) India and the Ministry of Health and Family Welfare, set up a flagship initiative "Respectful Abortion Care" (RAC) to provide training to obstetricians and gynecologists on the new Act, and also address their values and biases. Virtual training sessions were organized during the COVID-19 pandemic to disseminate the amendments made under the MTP Act and address provider values and biases. The primary focus was on private providers as they account for more than half of all abortion services in India (52.9%). The RAC modules were systematically designed and delivered by 690 Master Trainers, trained by FOGSI and WHO. A total of 9051 FOGSI members (22%, with 50% from private clinics) completed the RAC trainings. Pretests and post-tests were conducted for impact assessment. Significant improvement was seen on knowledge of criteria for termination of pregnancy for significant birth defects (52%-83%). The post-training survey showed a high level of commitment to promote RAC: >95% were strongly motivated to perform or assist in abortion; 89% reported that the WHO value clarification exercises were helpful in facilitating open discussions on sensitive topics in a comfortable manner; 96% expressed a strong commitment to addressing the issue of respect and confidentiality in abortion care. RAC was a unique initiative around the MTP Act amendment 2021 in India, which demonstrated that collaboration and leadership by professional associations can help motivate providers and lead to improved knowledge and commitment from public and private sector providers.

Professional societies of obstetrics and gynecology as agents of change in sexual and reproductive health: FIGO's 10-country safe abortion advocacy project in Africa and Latin America.

In 2019, FIGO started implementing its abortion project focusing on advocacy. The Advocacy for Safe Abortion (ASA) Project was conducted in partnership with 10 national professional societies of obstetrics and gynecology in Latin America and Africa. The project aimed to strengthen national societies, support them to be leaders in sexual and reproductive health, and enable them to obtain context-specific advocacy goals that improve access to safe abortion. Innovative monitoring and evaluation methodology enabled tracking of outcomes, consideration of their contribution to success, and cross-country evaluation. The project saw success through some key strategies: institutional capacity strengthening; enhanced work through collaborations; training to increase knowledge and reduce abortion-related stigma with a broad array of stakeholders; and generation and use of evidence to influence decision-makers. This article describes the project and methodology used and provides tangible examples of how societies have been agents of change in their countries and of the need for such important work to continue.

Survey on the implementation status and reproductive outcomes of oocyte and ovarian tissue cryopreservation in Japan: Historical comparison with nationwide surveys.

To clarify the reproductive outcomes of fertility preservation (FP) treatment. We conducted a mailed-in questionnaire survey at institutions certified by the Japan Society of Obstetrics and Gynecology to investigate the number of oocyte cryopreservations (OC) and ovarian tissue cryopreservations (OTC) performed from December 2016 to the end of 2020. And, we conducted a detailed investigation of cases in which frozen specimens were used during the investigation period, and made historical comparisons with previous nationwide studies. Responses were received from 114 out of 150 facilities (response rate: 76.0%) for OC and 43 out of 51 for OTC (response rate: 84.3%). Breast cancer was the most common disease among patients whose FP specimens were used. During the study period, 1237 OCs and 198 OTCs were performed. In addition, 57 cycles of embryo transfer (ET) using cryopreserved oocytes and 12 cases of ovarian tissue transplantation (OTT) were performed. The mean age of patients who underwent ET using cryopreserved oocytes was 34.8 (±5.8) years, with a median age of 36 years. The pregnancy rate per ET using cryopreserved oocytes was 26.3% and the live birth rate (LBR) was 17.5%. Further, the LBR per patient was 43.3%, and the pregnancy rate following OTTs was 33.3%. Also, controlled ovarian stimulation using the random start method or the combination of aromatase inhibitors had no effect on pregnancy outcome. Implementation of both OCs and OTCs have markedly increased over time in Japan, with comparable reproductive outcomes as other reports.

The German guideline "Obesity in pregnancy": comparison with the international approach.

Obesity is an increasing problem, even in young women of reproductive age. Obesity has a negative impact on conception, the course of pregnancy, and neonatal outcomes. Caring for obese pregnant women has becoming an important aspect of standard prenatal care. The Guideline "Obesity and Pregnancy" of the German Society of Gynecology and Obstetrics aims to create evidence-based recommendations which can be used to improve the care of obese pregnant women. As obesity is a worldwide problem, many societies for obstetrics and gynecology have created national guidelines. We reviewed the following guidelines for obesity and pregnancy: American College of Obstetricians and Gynecologists (ACOG) 2021, Royal College of Obstetrics and Gynecology (RCOG) 2018; AND Society of Obstetricians and Gynecologists of Canada (SOGC) 2019. These guidelines were compared to the German guideline. There are some variations between the guidelines, though no major contradictions exist. Disparities were found regarding the recommendations for substitution of high folic acid and Vitamin D. Furthermore, the recommended time for screening for gestational diabetes and the methods to control fetal growth differ between the guidelines. Regarding place of birth, RCOG allows delivery in midwifery-led units in the absence of other high-risk circumstances, while others request facility of care by neonatologists and medical staff trained in care of obese women. Induction of labor at term due to increased risk of intrauterine demise is mostly limited to women with a body mass index of 40 kg/m2. Only one guideline considers induction of all obese women. For intrapartum management, the majority allows tolerating of longer labor times to delivery if fetal monitoring is sufficient and fetal stress is excluded. Special encouragement of breastfeeding and healthy lifestyle is commonly recommended; only in the Canadian guideline, postpartum depression evaluation is requested due to the overall high prevalence of depression and anxiety in obese women. All guidelines consider pregnancies in obese women as high-risk pregnancies and emphasize the need for preconception counseling. There are special needs in pregnancy care and in the intrapartum and postpartum management to be observed.

Retraction: Comparison between 200, 400 and 600 microgram rectal misoprostol before cesarian section: A randomized clinical trial.

The above article, published online on January 7th, 2019 in Wiley Online Library (wileyonlinelibrary.com) has been retracted by agreement between the journal's Editor-in-Chief, Hiroaki Kajiyama, Japan Society of Obstetrics and Gynecology, and John Wiley & Sons, Australia, Ltd. The retraction has been agreed on following concerns about the validity of the presented data raised by a third party. As part of the investigation, an independent statistical expert concluded that there are inconsistencies in the data that could only be verified by examining the underlying clinical trial data. The authors have not responded to repeated requests for the original data and have not provided any explanation into the overlap between this study and one published in 2018 in a different journal. Furthermore, while the institute where the research was conducted confirmed that this clinical study was approved by an institutional ethics committee, documentation of the approval is not available. The authors have not responded when asked to agree to this retraction.

Policy recommendations to reduce high cesarean section rate in Türkiye.

According to the latest data, the majority of babies are delivered via cesarean section (C-section) in Türkiye. This is a medically unacceptable situation and reflects the highest rate in the world. Despite Türkiye enacting a law prohibiting elective C-sections, the rate has not decreased; rather increased. Therefore, this article and accompanying annex have been prepared to propose policy recommendations aimed at reducing the C-section rate. This article summarizes what has been done so far and outlines areas for improvement to reduce the C-section rate, offering a different perspective on policy. The C-section rate has reached such a critical level in Türkiye that a concerted effort involving the Turkish Ministry of Health, healthcare and obstetrics societies, physicians, midwives, healthcare professionals, public and the media is necessary. Health authorities in Türkiye should consider all policy recommendations in addressing this issue.

Joint Statement on Comprehensive Education for Adolescents and Young People to Support Their Healthy Development and Wellbeing: Adolescent Health Academy, Indian Academy of Pediatrics, Federation of Obstetric and Gynecological Societies of India, Indian Association of Preventive and Social Medicine, and Indian Public Health Association

Joint Statement on Comprehensive Education for Adolescents and Young People to Support Their Healthy Development and Wellbeing: Adolescent Health Academy, Indian Academy of Pediatrics, Federation of Obstetric and Gynecological Societies of India, Indian Association of Preventive and Social Medicine, and Indian Public Health Association

Opportunity window: vascular risk prevention in women. Adverse pregnancy outcomes and risk of vascular disease. Consensus document of the Spanish Society of Obstetrics and Gynecology (SEGO) and the Spanish Interdiscuplinary Committee for Vascular Preventi

Opportunity window: vascular risk prevention in women. Adverse pregnancy outcomes and risk of vascular disease. Consensus document of the Spanish Society of Obstetrics and Gynecology (SEGO) and the Spanish Interdiscuplinary Committee for Vascular Preventi

Association between anti‐Müllerian hormone levels and polycystic ovary syndrome in a general cohort of young women in Japan

AbstractPurposePolycystic ovary syndrome (PCOS) significantly affects women. This study investigated the association between serum anti‐Müllerian hormone (AMH) levels and menstrual cycle disorders, and AMH for PCOS in a general cohort of young Japanese women.MethodsWe measured serum AMH levels in 528 healthy female students at two universities in Japan between 2014 and 2020. We investigated the association between serum AMH levels and hormone levels, menstrual cycle, and body mass index.ResultsThe mean (±standard deviation) AMH level was 4.78 ± 2.88 ng/mL. Correlations were observed between serum AMH and luteinizing hormone (LH) or LH/follicle‐stimulating hormone (FSH) levels in women with irregular menstruation (LH: r = 0.542, p &lt; 0.001; LH/FSH: r = 0.584, p &lt; 0.001). The optimal serum AMH cutoff value that predicted LH ≥7.1 IU/L and LH/FSH ≥1.21 (PCOS diagnostic criteria revised by Japan Society of Obstetrics and Gynecology) in women with menstrual irregularities was 5.30 ng/mL (area under the curve: 0.815, sensitivity: 84.2%, specificity: 70.3%).ConclusionsSerum AMH can be measured during annual health checkups and may be a useful biomarker for early and arcuate diagnosis and intervention in women with PCOS.

Detailed report on the clinicopathological factors of patients with endometrial cancer in Japan: a JSOG gynecologic tumor registry-based study.

In this study, we collected data over 8 years (2012-2019) from the Japan Society of Obstetrics and Gynecology (JSOG) tumor registry to determine the status of endometrial cancer in Japan, and analyzed detailed clinicopathological factors. The JSOG maintains a tumor registry that gathers information on endometrial cancer treated at the JSOG-registered institutions. Data from the patients whose endometrial cancer treatment was initiated from 2012 to 2019 were analyzed retrospectively. A total of 82,969 patients with endometrial cancer underwent treatment from 2012 to 2019. Chemotherapy alone or in combination with hormonal therapy is more common among endometrial cancer patients under 40 years compared with those over 40 years. The number of patients with endometrial cancer, treated with laparoscopic or robot-assisted surgery was observed to have increased yearly. Small cell carcinomas and undifferentiated carcinomas were more likely to be diagnosed at an advanced stage. Lymphadenectomy was most commonly performed for stage IIIC2 disease, whereas positive peritoneal washing cytology was most common for stage IVB and serous carcinoma. Multi-year summary reports provided detailed clinicopathological information regarding endometrial cancer that could not be obtained in a single year. These reports were useful in understanding treatment strategies and trends over time based on age, histology, and stage.

Investigation of optimal weight gain during pregnancy: A retrospective analysis of the Japanese perinatal registry database.

This study aimed to determine the weight gain during pregnancy that minimizes the predicted probability of various perinatal adverse events according to the pre-pregnancy body mass index (BMI) and make recommendations for optimal weight gain in Japan. The Japan Society of Obstetrics and Gynecology perinatal database for 2015-2017 was used. From the 719 723 deliveries included in this database, parturients with underlying diseases or missing data were excluded, and 419 114 deliveries were analyzed. A questionnaire survey was also conducted to weigh each perinatal adverse event. For each of the nine outcomes, a restricted cubic spline model was made to estimate the association between the "expected gestational weight gain at 40 weeks" and the outcome risk. Since the classes of medical facilities were generally the same, weights were assigned according to the mean of the questionnaires rather than by the class of the facility. For each pre-pregnancy BMI, the weight gains during pregnancy that minimized the predicted probability of various adverse perinatal events were 12-15, 10-13, 7-10, and upper limit of 5 kg for the underweight, normal-weight, obese 1, and obese ≥2 groups, respectively. The weight gain during pregnancy that minimizes the predicted probability of various perinatal adverse events according to the pre-pregnancy BMI was established.

Assisted reproductive technology in Japan: A summary report for 2021 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

The Japan Society of Obstetrics and Gynecology (JSOG) registry gathers comprehensive data from registered assisted reproductive technology (ART) facilities in Japan. Herein, we report 2021 ART cycle characteristics and outcomes. Descriptive statistics were used to summarize and analyze 2021 data. In 2021, 625 ART facilities participated in the registry; 27 facilities did not conduct ART cycles and 598 registered treatment cycles. In total, 498 140 cycles were registered, and there were 69 797 neonates (increases of 10.7% and 15.5%, respectively, from the previous year). The number of freeze-all invitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles decreased in 2021; the number of neonates born was 2268 for IVF-embryo transfer (ET) cycles and 2850 for ICSI cycles. Frozen-thawed ET (FET) cycles increased markedly from 2020 (11.2% increase). In 2021, 239 428 FET cycles were conducted, resulting in 87 174 pregnancies and 64 679 neonates. For fresh transfers, the total single ET, singleton pregnancy rate, and singleton live birth rates were 82.7%, 97.0%, and 97.3%; for FET, these rates were 84.9%, 96.9%, and 97.1%. The 2021 Japanese ART registry analysis showed marked increases in both total treatment cycles and live births from the previous year.

Uterine Leiomyomas and Infertility: A Comparison of National and International Guidelines.

Uterine leiomyomas are the most common benign tumors of the female genital track, causing various symptoms and problems, including a possible impact on fertility.The relationship between fibroids and infertility has long been a debate among gynecologists. Management of fibroids in women with otherwise unexplained infertility worldwide lacks standardized, evidence-based guidelines. Therefore, a review of guidelines from the Royal Australian and New Zealand College of Obstetricians and Gynecologists, the American College of Obstetricians and Gynecologists, the Society of Obstetricians and Gynecologists of Canada, the Collège National des Gynécologues et Obstétriciens Français, and the American Society of Reproductive Medicine was conducted. There is agreement among all guidelines that the effect of fibroids on fertility is related to their position in the uterus and the alteration of the endometrial cavity. However, whether surgical intervention (laparotomy, laparoscopy, or hysteroscopy) is required varies among committees. More specifically, for submucous myomas, all guidelines agree that surgical intervention is needed. On the other hand, regarding intramural myomas, there is no consensus on what the approach may be. Novel treatments such as uterine artery embolization (UAE) and magnetic resonance-guided focused ultrasound surgery (MRgFUS) should only be used in clinical trial settings. Nevertheless, all guidelines agree that medical management of fibroids further delays efforts to conceive and has no role as a stand-alone treatment of fibroids; though, the use of GnRH analogues preoperatively can be useful to improve anemia and/or reduce fibroid volume. There is a need for updated international protocols to be introduced, in order to help clinicians dealing with fibroids and infertility to better suggest the optimal treatment.

The COVID-19 pandemic affects pregnancy complications and delivery outcomes in Japan: a large-scale nationwide population-based longitudinal study

The impact of the coronavirus disease 2019 (COVID-19) pandemic on pregnancy outcomes in Japan at the national level is unclear. This study aimed to assess the impact of the pandemic on pregnancy complications and delivery outcomes in Japan using nationwide population-based longitudinal data. Secondary data from the Japan Society of Obstetrics and Gynecology from 2016 to 2020 were analyzed. Obstetric information, pregnancy complications, and delivery information of pregnant women over 22 weeks of gestation were compared before and during the pandemic. The trends of hypertensive disorder of pregnancy, fetal growth restriction, and APGAR < 7 increased, whereas those of preterm birth and low birth weight decreased during the COVID-19 pandemic. Pregnancy complications and delivery outcomes have worsened during the COVID-19 pandemic in Japan. Social changes caused by unprecedented situations may have massively influenced pregnancy in several ways. Our findings suggest that even in mild lockdowns like those in Japan, the introduction of social fear during the pandemic might negatively impact pregnancy outcomes.

Effective gestational weight gain advice to optimize infant birth weight in Japan based on quantile regression analysis

The optimal range of gestational weight gain (GWG) was recently raised in Japan. This may help reduce small-for-gestational-age (SGA) infants, but may also increase large-for-gestational-age (LGA) infants. This study performed hypothetical experiments to determine effective GWG advice based on quantile regression analysis. In a total of 354,401 singleton pregnancies registered in the perinatal database of the Japan Society of Obstetrics and Gynecology (2013–2017), the proportions of SGA and LGA were 9.33% and 11.13%, respectively. Using regression coefficients of GWG across the birth weight-for-gestational-age quantile distribution, we analyzed changes in their proportions by simulating a uniform 3-kg extra increase in GWG or an increase or decrease based on GWG adequacy. A hypothetical experiment of a uniform increase in GWG resulted in SGA and LGA proportions of 7.26% (95% confidence interval 7.15–7.36) and 14.51% (14.37–14.66), respectively. By contrast, assuming a 3-kg increase in women with inadequate GWG and a 3-kg decrease in women with excessive GWG resulted in SGA and LGA proportions of 8.42% (8.31–8.54) and 11.50% (11.37–11.62), respectively. Our real-world data analysis suggests that careful adjustment of GWG based on GWG adequacy will be effective in optimizing infant birth weight in Japan

Uterine cervical conisation and chorioamnionitis: A nationwide observational study.

To investigate whether conisation increases chorioamnionitis (CAM) and assess whether this risk differs between preterm and term periods. Furthermore, we estimated mediation effects of CAM between conisation and preterm birth (PTB). A nationwide observational study. Japan. Singleton pregnant women derived from the perinatal registry database of the Japan Society of Obstetrics and Gynaecology between 2013 and 2019. The association between a history of conisation and clinical CAM was examined using a multivariable logistic regression model with multiple imputation. We conducted mediation analysis to estimate effects of CAM on PTB following conisation. Clinical CAM. Of 1 500 206 singleton pregnant women, 6961 (0.46%) underwent conisation and 1 493 245 (99.5%) did not. Clinical CAM occurred in 150 (2.2%) and 11 484 (0.8%) women with and without conisation, respectively. Conisation was associated with clinical CAM (odds ratio [OR] 3.09; 95% confidence interval (CI) 2.63-3.64; p < 0.001) (risk difference 1.57%; 95% CI 1.20-1.94). The association was detected among 171 440 women with PTB (OR 3.09; 95% CI 2.57-3.71), whereas it was not significant among 1 328 284 with term birth (OR 0.88; 95% CI 0.58-1.34). OR of total effect of conisation on PTB was 2.71, OR of natural indirect effect (effect explained by clinical CAM) was 1.04, and OR of natural direct effect (effect unexplained by clinical CAM) was 2.61. The proportion mediated was 5.9%. Conisation increased CAM occurrence. Obstetricians should be careful regarding CAM in women with conisation, especially in preterm period. Bacterial infections may be an important cause of PTB after conisation.

Engaging National Professional Society to Combat Postpartum Hemorrhage Using Bundle Approach - A FIGO-SAFOG-OGSB-MGH Project: Experience of Implementation in Bangladesh

Objective: To reduce the incidence and death due to post-partum Hemorrhage (PPH) and capacity building of health service providers by using PPH Emergency response using Bundle Approach. Method: Planning and implementation of WHO formulated PPH Bundles [Active Management of Third Stage of Labour (AMTSL), First response Bundle and Refractory PPH Bundle] by Obstetrical and Gynaecological Society of Bangladesh (OGSB) in 14 different levels of public and private hospitals in Bangladesh. After discussion with International Federation of Gynaecology and Obstetrics (FIGO) and South Asian Federation of Obstetrics and Gynaecology (SAFOG) team, a Memorandum of understanding (MOU) was signed; permission from Ministry of Health and Family welfare (MOHFW) was obtained through Directorate General of Health Services (DGHS) and also from all the institutions. The project period was from November 2019 to September 2022 in a spoke-and-hub fashion. A group of master trainers and a technical advisory group were developed comprising of senior obstetricians and gynecologist of Bangladesh. Data were obtained through record keeping of the respective hospitals and Management Information System (MIS) of DGHS, monitoring was done by OGSB and Massachusetts General Hospital (MGH)-FIGO team. Results: Consultative and planning meetings were organized among OGSB, FIGO, SAFOG and MGH: 16 master trainers, 74 trainers were produced and 740 health service providers (Doctor, Nurses, midwives) and 450 non clinical staffs were trained. All clinical and nonclinical bundles were implemented in 14 facilities in spoke-and-hub fashion. Occurrence of PPH, detection rate of PPH, filling up PPH checklist and debrief forms were improved. Data collection system, understanding about data improved a lot. Facility readiness, team work, data monitoring &amp; supervision, network integration and leadership skills were instituted and shown excellent positive changes. Regular simulations were continued which helped old &amp; new service providers to learn and continue proper use of the clinical and non-clinical interventions. Scale up was planned and continued. Conclusion: PPH emergency response using bundle approach was found to be an important practical way to reduce occurrence, death and disability related to PPH. Needs for surgery has reduced also. Quality of services improved in terms of providing standard care, record keeping and reporting. Regular supervision and monitoring; data management and personal motivation are the challenges. Bangladesh J Obstet Gynaecol, 2022; Vol. 37(2): 98-108

Maternal folic acid supplementation does not impact skeletal muscle function and metabolism in male and female CD-1 mouse offspring.

Folic acid fortification of all white flour, enriched pasta, and cornmeal products became mandatory in Canada to reduce risk of neural tube defects at birth. Furthermore, Health Canada and the Society of Obstetricians and Gynaecologists of Canada recommend women take daily prenatal folic acid supplements in addition to folic acid fortified foods during pregnancy. However, the influence of maternal folic acid supplementation on offspring development, specifically the highly abundant and metabolically active skeletal muscle, is currently unknown. Thus, the purpose of this study was to determine the effect of supplemental folic acid (four times higher than normal dietary consumption), in utero and throughout suckling on muscle size, function, and metabolism in male and female CD-1 mouse offspring. The major findings were that maternal exposure to supplemental folic acid (i) had no impact on postpartum growth rates or muscle mass in female and male offspring, (ii) had no impact on skeletal muscle contractile kinetics in females and male offspring, and (iii) increased maximal phosphofructokinase activity in extensor digitorum longus of female and male offspring. These findings suggest that exposure to folic acid supplementation in utero and throughout suckling at levels four times higher than recommended had minimal effect on skeletal muscle size, function, and metabolism regardless of sex. Future research is needed explore the underlying biological pathways and mechanisms affected by folic acid supplementation during pregnancy and lactation on offspring skeletal muscle tissue, specifically in humans.