Generally, the best chance of pregnancy is when sex happens 1-2 days before ovulation. If you have a regular 28-day cycle, count back 14 days from when you expect your next period to start. Plan on having sex every other day around that time -- say, days 12 and 14.  Keep in mind that having sex every day may lower a man's sperm count. Your cycle may be longer or shorter, so an online ovulation calculator may help you figure out the likely day.
Secondary infertility is the inability to become pregnant or carry a pregnancy to term after you’ve already had a baby, and it's more common than you might think, accounting for about 50 percent of infertility cases. In fact, more couples experience secondary infertility than primary infertility (infertility the first time around). It’s especially common in women who wait until their late 30s or even 40s, when fertility takes a nosedive, to have their second babies.
That’s about the time frame women between the ages of 35 and 40 should give themselves, before discussing fertility concerns with their doctor. For women under 35, experts recommend trying for about a year—really trying, as in unprotected, well-timed intercourse—before having any testing or treatment; women over 40 may want to consult an obstetrician/gynecologist right away. See your doctor sooner than later if you’ve suffered multiple miscarriages, have a history of pelvic inflammatory disease (a serious complication of some STDs), or experience any other symptoms of infertility. Meanwhile, learn these infertility myths you don’t have to worry about.
While PGD was originally designed to screen for embryos carrying hereditary genetic diseases, the method has been applied to select features that are unrelated to diseases, thus raising ethical questions. Examples of such cases include the selection of embryos based on histocompatibility (HLA) for the donation of tissues to a sick family member, the diagnosis of genetic susceptibility to disease, and sex selection.[97]
Sunni Muslim nations generally allow IVF between married couples when conducted with their own respective sperm and eggs, but not with donor eggs from other couples. But Iran, which is Shi'a Muslim, has a more complex scheme. Iran bans sperm donation but allows donation of both fertilised and unfertilised eggs. Fertilised eggs are donated from married couples to other married couples, while unfertilised eggs are donated in the context of mut'ah or temporary marriage to the father.[176]
IVF increasingly appears on NHS treatments blacklists.[160] In August 2017 five of the 208 CCGs had stopped funding IVF completely and others were considering doing so.[161] By October 2017 only 25 CCGs were delivering the three recommended NHS IVF cycles to eligible women under 40.[162] Policies could fall foul of discrimination laws if they treat same sex couples differently from heterosexual ones.[163] In July 2019 Jackie Doyle-Price said that women were registering with surgeries further away from their own home in order to get around CCG rationing policies.[164]
In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm outside the body, in vitro ("in glass"). The process involves monitoring and stimulating a woman's ovulatory process, removing an ovum or ova (egg or eggs) from the woman's ovaries and letting sperm fertilise them in a liquid in a laboratory. After the fertilised egg (zygote) undergoes embryo culture for 2–6 days, it is implanted in the same or another woman's uterus, with the intention of establishing a successful pregnancy.
In 2008, a California physician transferred 12 embryos to a woman who gave birth to octuplets (Suleman octuplets). This led to accusations that a doctor is willing to endanger the health and even life of women in order to gain money. Robert Winston, professor of fertility studies at Imperial College London, had called the industry "corrupt" and "greedy" stating that "one of the major problems facing us in healthcare is that IVF has become a massive commercial industry," and that "what has happened, of course, is that money is corrupting this whole technology", and accused authorities of failing to protect couples from exploitation: "The regulatory authority has done a consistently bad job. It's not prevented the exploitation of women, it's not put out very good information to couples, it's not limited the number of unscientific treatments people have access to".[101] The IVF industry has been described as a market-driven construction of health, medicine and the human body.[102]

Repeated failed rounds of IVF can help identify causes of infertility. For example, if sperm and egg quality are normal, then the conception issue may be rooted at the embryonic or implantation level. In other words, if IVF fails to result in pregnancy despite successful fertilization, embryonic development or implantation may be to blame. Still this is a very expensive way to start getting answers.