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 U.S.: timing, safety, and legal basics
A practical guide to home insemination, from ovulation timing and fresh sperm handling to safety and U.S. legal basics.
How long does 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 about 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 - the informal name for epididymal congestion or testicular congestion - refers to a dull ache or pressure in the testicles after sexual arousal without ejaculation.
Egg Donation in the United States: Process, Costs, Success Rates, Risks, and State Law
Egg donation can be the most realistic path to pregnancy for some people, but in the United States it is never just 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 in the US: Definition, Common Setups, Day-to-Day Life, Communication, and Planning
In the US, 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 standardized lab assessment of a semen sample and is often the first test when male fertility issues are suspected.
Preimplantation Genetic Testing 2025 - Process, Costs and Legal Landscape in the United States
Preimplantation genetic testing (PGT) lets embryos created through IVF or ICSI be tested for specific genetic conditions before transfer to 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 fertilization: IVF process, timeline, success rates, and costs explained clearly
In vitro fertilization, often called IVF, is a medically supervised fertility treatment with clear steps but many decisions: protocol choice, timing, transfer strategy, safety planning, 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 specialized form of in vitro fertilization developed primarily to overcome significant male factor infertility.
Intrauterine Insemination: IUI Steps, Success Rates, Timing, Risks, and Costs Explained Clearly
Intrauterine insemination, or IUI, is a well-established fertility treatment.Intracervical insemination: ICI process, timing, chances of success, safety, costs and differentiation 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 fertilization still takes place inside the body.
Assisted reproduction in the United States 2025: methods, success rates & costs
“Assisted reproduction” isn’t a single procedure but a toolkit.
Linea nigra in pregnancy – causes, care, facts
Linea nigra is a darker line down the middle of the belly that often shows up 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: spotting fertile days and reading warning signs
Cervical mucus changes across 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: identify fertile days reliably
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.