Facts & Insights

Lutealfasen är tiden mellan ägglossning och nästa mens. Här går vi igenom progesteronets roll, vad en kort lutealfas kan betyda, hur progesteron mäts och vad forskningen faktiskt säger om behandling.

Most people get pregnant within a year, and it is common for it to take a few months. Here's what research says about time to pregnancy – and when it's...

Moderate exercise does not seem to impair fertility, while the evidence regarding very strenuous exercise is limited and contradictory. Here, we review what the research actually shows – for both...

A sperm test measures volume, concentration, motility, morphology, and vitality. Here, we review WHO's reference values from 2021 and why a single test rarely provides the complete picture.

The fertile window is about six days, ending on the day of ovulation. Here we review how to calculate it, what signs and tests are available, and what research says...

Sleep and circadian rhythm are connected to hormone balance and the menstrual cycle. Here, we review what research actually shows about sleep duration, shift work, and fertility – and what...

Vitamin B12 plays a role in cell formation and nerve function, and research suggests a connection with fertility in both women and men. Here we review what the evidence shows—and...

Melatonin is the body's sleep hormone and an antioxidant that has been studied as a supplement in IVF. We review what the limited research data says about eggs, embryos, and...

Research suggests that smoking negatively affects fertility in both women and men. Here's the evidence – and why it's never too late to quit.

An objective review of what research says about alcohol and fertility – and why the recommendation is to abstain when trying to conceive.

What research and authorities say about caffeine when trying to conceive and during pregnancy – with cautious conclusions and real sources.

An objective review of how thyroid function – particularly hypothyroidism and thyroid antibodies – may be related to fertility and pregnancy, and what research and clinical guidelines say.

What choline is, why the need for it increases during pregnancy, and which foods are good sources – based on EFSA's reference values and current research.

Iron is needed for oxygen transport and women lose iron during menstruation. This is the limited state of research on iron, iron deficiency, and fertility.

Iodine is needed for thyroid hormones, which control metabolism and fetal brain development. Here, we review what research and authorities say about iodine before and during pregnancy.

Intrauterine insemination (IUI) is a simpler fertility treatment where washed sperm are inserted directly into the uterus around ovulation. It is often used as a first step before IVF, or...

Both overweight and underweight can affect fertility, primarily by disrupting ovulation. The good news: even a small change in weight (2–5%) can improve ovulation and the chance of becoming pregnant.

Stress appears to indirectly affect fertility – high stress has been linked to a lower chance of conception and to hormonal imbalances via cortisol. However, many people become pregnant in...

According to EU-approved health claims, zinc contributes to normal fertility and reproduction, and selenium to normal spermatogenesis. Both are included in a good prenatal – but most people get the...

Myo-inositol is one of the most studied supplements for PCOS and can improve insulin sensitivity, testosterone, and the menstrual cycle. However, the 2023 guidelines emphasize that evidence for pregnancy outcomes...

What you eat affects sperm quality. A Mediterranean-inspired diet is associated with better sperm concentration and motility, likely due to antioxidants combating oxidative stress. Processed foods and trans fats have...

The vaginal flora is normally dominated by lactic acid bacteria, which protect the environment. Research suggests that a lactobacilli-dominated flora is associated with better IVF outcomes, while imbalance has been...

Vitamin D appears to play a role in fertility. Women with a deficiency are more likely to have a lower chance of success with IVF, and deficiency is common in...

Fertility declines gradually with age, mainly because egg quality deteriorates. The decline starts slowly around 32 years and accelerates after about 37. This concerns group statistics – not a prognosis...