Effects of in Vitro Fertilization (IVF) Therapies on Metabolic, Endocrine and Inflammatory Status in IVF-Conceived Pregnancy

Ayla Coussa; Hayder A. Hasan; Thomas M. Barber

Disclosures

Clin Endocrinol. 2020;93(6):705-712. 

In This Article

Methods

Subjects

Women from multicultural population were recruited from three IVF clinic branches in the United Arab Emirates (Dubai, Abu Dhabi and Al Ain). Convenient sampling method was used to recruit participants who were to start IVF therapy and meeting the inclusion criteria. A list of women who were to commence IVF treatment was reviewed daily. Following exclusion of diabetes mellitus and thyroid dysfunction, those subjects who consented for recruitment into the study were invited to attend for a baseline fasting blood test (for 10 hours) on their screening visit (first day of their IVF treatment program). Anthropometric data were also obtained (weight, height, BMI), and medical history questionnaires completed by the principle investigator. Ethical approvals were obtained from local health authorities for each of the study centres, and the study complied with the code of ethics of the Declaration of Helsinki.

Inclusion and Exclusion Criteria

Women aged 18–39 years of age, presenting with any infertility concern and BMI 18.5–38 kg/m2, were eligible for inclusion in the study. In addition, women were eligible to participate if it was their first ever IVF cycle. Exclusion criteria included current or past history of diabetes mellitus, thyroid dysfunction and any other chronic medical condition such as hepatic, respiratory, haematological and cardiovascular disease. Other exclusion criteria included use of any therapy that may affect glucose homeostasis, thyroid and/or lipid profile, such as growth hormones, oral steroids, anti-inflammatory and bronchodilator drugs.

IVF Intervention

In this prospective cohort (observational), participants were followed for 12 weeks of their first IVF cycle. Each subject underwent IVF therapy as per clinical need, using the 'antagonist protocol', which relies on administration of agents to prevent premature ovulation (ie, gonadotropin-releasing hormone antagonist) and to ensure adequate oocyte growth.[18] The study consisted of four stages (shown in Figure 1):

Figure 1.

Study stages and IVF hormonal intervention. IVF, in vitro fertilization

Stage 1: Ovarian Stimulation and Follicle Growth (1-12 Days). Depending on baseline levels, follicle-stimulating hormone (FSH) was administered alone or combined with luteinizing (LH) (300 IU/day). While FSH is needed for ovarian follicular growth and endometrial development, LH ensures proper oocyte maturation. Follicle growth (size and numbers) was monitored with frequent ultrasound and blood tests for assessment of serum levels of reproductive hormones, and appropriate adjustment of IVF therapies. On day 6 of stimulation, gonadotropin-releasing hormone antagonist injection was administered (0.25 mg/day) for a better control of endogenous FSH and LH concentrations. One dose of human chorionic gonadotropin hormone 'trigger' (0.5 mg) was given 36 to 40 hours before schedule of egg retrieval to induce final egg maturation. All other medications were discontinued at that point.

Stage 2: Egg Retrieval to Embryo Transfer (Week 2). This includes the period from egg retrieval ('oocyte pick-up', OPU) to embryo transfer (ET) five days post-OPU. Egg retrieval is done by transvaginal ultrasound aspiration. During this stage, each retrieved egg undergoes fertilization with collected semen, under a microscope and using intracytoplasmic sperm injection technique (sperm is directly injected into cytoplasm of mature egg). Transvaginal ultrasound guidance is used during ET, which is associated with a higher percentage of pregnancy per transfer compared with transabdominal ultrasound guidance transfers.[19] Post-OPU, progesterone (tablet: 10 mg three times/day and injection: 50 mg/day) and oestrogen therapies (tablet: 2 mg three times/day) were initiated.

Stage 3: First Pregnancy Test (Week 4). This includes measurement of serum beta-human chorionic gonadotropin (β-HCG). Successful IVF therapy is defined as a clinically confirmed pregnancy with a positive serum β-HCG test and a gestational sac is observed on ultrasound, while unsuccessful refers to a negative β-HCG test at 4 weeks. Biochemical pregnancy represents a pregnancy confirmed by a positive β-HCG but no sac is visible on ultrasound, and ectopic pregnancy is the case where the embryo abnormally implants outside the uterus.[20] With all cases of negative β-HCG, ectopic or biochemical pregnancies, all reproductive therapies were discontinued at this stage. Biochemical and ectopic pregnancies were not included in the unsuccessful group data. For all successful pregnancies, subjects were required to continue taking their reproductive therapies (oestrogen and progesterone) for the first trimester (until around week 12 of pregnancy).

Stage 4: Final Blood Tests (Week 12). This included assessment of the two groups: women with successful IVF-conceived pregnancy and women with failed IVF.

Sample Size

The primary outcome of the study was to assess changes in glucose homeostasis in response to IVF therapy and during IVF-conceived pregnancy. Significant changes in glucose and insulin levels are expected to occur earlier in IVF-conceived pregnancy as an effect of IVF hormones. In order to detect a moderate difference (standardised difference = 0.5), with 80% power, at significance level of 0.05 and a ratio of 2:1 for pregnant to nonpregnant women, the sample size consisted of 96 pregnant and 48 nonpregnant women. According to the latest statistics, pregnancy success rate post–egg retrieval is about 30% and this declines with age.[21] Therefore, 275 participants were recruited initially to end up with 96 clinically confirmed pregnant.

Outcome Measures

Blood tests were conducted at baseline and 12-weeks and included the following: female reproductive hormones (FSH, LH, oestrogen (oestradiol E2 form) and progesterone), fasting plasma glucose, serum insulin, glycated haemoglobin A1c (HbA1c), lipid profile, thyroid-stimulating hormone (TSH), adiponectin and LBP. At 4-weeks of IVF hormonal therapy, fasting glucose and insulin levels were also measured, as well as oestrogen, progesterone and β-HCG pregnancy test.

Female reproductive hormones, insulin and TSH were measured with the electrochemiluminescence immunoassay ECLIA, using Cobas E immunoassay analyzers from Roche Diagnostics. Fasting plasma glucose was measured by enzymatic reference method with hexokinase-glucose-6-phosphate dehydrogenase. Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated as follows: (fasting plasma insulin x fasting plasma glucose)/405.[22,23] Total cholesterol (T-Chol), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured by homogenous enzymatic colorimetric method, with Roche/Hitachi Cobas C systems (Cobas C 311/501; Roche Diagnostics). Enzyme-linked immunosorbent assay was used to determine plasma LBP concentration with human LBP ELISA kit. Adiponectin was measured using human ADP/Acrp 30 ELISA kits, from Elabscience.

Statistical Analysis

Data analysis was performed with Statistical Package for the Social Sciences (SPSS) software version 21.0 for Windows (SPSS). Non-normal distribution of parameters was identified using Shapiro-Wilk test, and results are hence presented as median and interquartile range (IQR). Nonparametric Mann-Whitney U test for two independent samples was used to compare the two groups (pregnant vs nonpregnant), at baseline and at 12 weeks. Nonparametric Wilcoxon's test for two related samples was used to assess changes at baseline vs at 12 weeks within each group (pregnant or nonpregnant). A P value of ≤0.05 was used for significance level, with 95% confidence interval (CI).

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....