Philipp Marx
Founder of RattleStork
Philipp Marx is a founder of RattleStork and a former international sperm donor. He writes from first-hand experience about sperm donation, co-parenting, and alternative paths to parenthood.
Before founding RattleStork, Philipp donated sperm in several countries. That experience showed him how differently people approach donor conception, trust, personal boundaries, and co-parenting.
At RattleStork, he combines that perspective with publicly available sources and practical guidance for donors, recipients, and prospective co-parents. His personal experience is not a substitute for medical or legal advice.
Articles by this author
Total published articles:220
Home insemination in the UK: timing, safety, and legal basics
A practical guide to home insemination, from ovulation timing and fresh sperm handling to safety and UK legal basics.
How long do sperm live? Real timelines in the mouth and saliva, in air, on skin, in water, and in a condom
Most people are not asking a biology question, they are trying to judge a specific situation: sperm in the mouth, semen drying on skin, a condom, water, or a cup.
Pregnant from pre-ejaculate? Risk without ejaculation, facts on fertile days and protection
Starting question: can you get pregnant from pre-ejaculatory fluid alone, without ejaculation inside the vagina.
Blue Balls (Epididymal Congestion): Causes, Symptoms & Relief
Blue balls - medically known as epididymal congestion or testicular congestion - describe a dull ache or sense of heaviness in the testicles after sexual arousal without ejaculation.
Egg Donation in the UK: Process, Costs, Success Rates, Risks, and the Legal Framework
Egg donation can be the most realistic route to pregnancy for some people, but in the UK it is never only a medical decision.
Sperm cramps - an internet myth with no medical basis
The phrase “sperm cramps” sounds technical, but it is not a medical term.
Co-Parenting: Definition, Common Setups, Day-to-Day Life, Communication and Planning
Co-parenting means sharing parenthood intentionally, without a romantic relationship being required.
Semen analysis: process, preparation, understanding results, and next steps
A semen analysis is the standardised lab assessment of a semen sample and is often the first test when male fertility issues are suspected.
Pre-implantation Genetic Testing 2025 - Pathway, Costs and Law in the United Kingdom
Pre-implantation genetic testing (PGT) allows embryos created in an IVF or ICSI cycle to be analysed for genetic conditions before being transferred into the uterus.
COVID‑19 vaccination and male fertility: Can it make you infertile?
What research and semen analyses tell us about COVID‑19 vaccination, male fertility, and unvaccinated donor sperm.
In vitro fertilisation: IVF steps, timeline, success rates and costs explained
In vitro fertilisation, usually called IVF, is a medically guided fertility treatment with clear steps but many decisions: protocol choice, timing, transfer strategy, safety management and budget.
Intracytoplasmic Sperm Injection: ICSI Steps, Who It Helps, Success Factors, Risks and Costs Explained Clearly
Intracytoplasmic sperm injection, often called ICSI, is a specialised form of in vitro fertilisation developed primarily to overcome significant male factor infertility.
Intrauterine Insemination: IUI Steps, Success Chances, Timing, Risks and Costs Explained Clearly
Intrauterine insemination, or IUI, is an established fertility treatment.Intracervical insemination: ICI process, timing, success rates, safety, costs and differences from IUI, IVF and ICSI
Intracervical insemination, or ICI, is a form of artificial insemination in which a semen sample is placed close to the cervix and fertilisation still takes place inside the body.
Assisted reproduction in the United Kingdom 2025: methods, success rates & costs
“Assisted reproduction” isn’t a single procedure but a toolkit.
Linea nigra in pregnancy – why it happens and what helps
Linea nigra is a darker line down the middle of the tummy that can appear during pregnancy.
Implantation: When it happens, how long it takes, and what symptoms are realistic
Implantation is one of the most searched topics during the wait after ovulation.
Luteal phase deficiency: causes, symptoms and evidence-based treatment
Luteal phase deficiency means progesterone is too low or too short-acting in the second half of the menstrual cycle; it is often discussed as “luteal insufficiency”.
Understanding cervical mucus: recognising fertile days and warning signs
Cervical mucus changes throughout the menstrual cycle.
Ovulation explained: finding your fertile days, signs and tests
Your chance of pregnancy clusters into just a few days per cycle.
LH surge and ovulation tests: find fertile days with confidence
The LH surge is an important timing signal around ovulation and helps you plan fertile days more realistically.
Breast growth and breast pain in pregnancy: causes, tips and FAQs
If your breasts feel tight, tingly or tender to the touch during pregnancy, that is often part of normal changes.