The latter technique has proved to be less deleterious for the embryo, therefore it is advisable to perform the biopsy around day 5 or 6 of development. Sex selection is the attempt to control the sex of offspring to achieve a desired sex in case of X chromosome linked diseases. It can be accomplished in several ways, both pre- and post-implantation of an embryo, as well as at birth. Pre-implantation techniques include PGD, but also sperm sorting. Others
Other assisted reproduction techniques include:

Mitochondrial replacement therapy (MRT, sometimes called mitochondrial donation) is the replacement of mitochondria in one or more cells to prevent or ameliorate disease. MRT originated as a special form of IVF in which some or all of the future babys mitochondrial DNA comes from a third party. This technique is used in cases when mothers carry genes for mitochondrial diseases. The therapy is approved for use in the United Kingdom. In gamete intrafallopian transfer (GIFT) a mixture of sperm and eggs is placed directly into a womans fallopian tubes using laparoscopy following a transvaginal ovum retrieval. Reproductive surgery, treating e.g. fallopian tube obstruction and vas deferens obstruction, or reversing a vasectomy by a reverse vasectomy. In surgical sperm retrieval (SSR) the reproductive urologist obtains sperm from the vas deferens, epididymis or directly from the testis in a short outpatient procedure. By cryopreservation, eggs, sperm and reproductive tissue can be preserved for later IVF. Risks
The majority of IVF-conceived infants do not have birth defects.
Such subsidies are subject to conditions, however. In Belgium, a fixed payment of €1,073 is made for each full cycle of the IVF process. The woman must be aged under 43 and may not carry out more than six cycles of ART. There is also a limit on the number of transferable embryos, which varies according to age and the number of cycles completed. In France, ART is subsidized in full by national health insurance for women up to age 43, with limits of 4 attempts at IVF and 6 at artificial insemination. Germany tightened its conditions for public funding in 2004, which caused a sharp drop in the number of ART cycles carried out, from more than 102,000 in 2003 to fewer than 57,000 the following year. Since then the figure has remained stable. 17 countries limit access to ART according to the age of the woman. 10 countries have established an upper age limit, varying from 40 (Finland, Netherlands) to 50 (including Spain, Greece and Estonia). Since 1994, France is one of a number of countries (including Germany, Spain, and the UK) which use the somewhat vague notion of "natural age of procreation". In 2017, the steering council of Frances Agency of Biomedicine established an age limit of 43 for women using ART. 10 countries have no age limit for ART. These include Austria, Hungary, Italy and Poland. Most European countries allow donations of gametes by third parties. But the situations vary depending on whether sperm or eggs are concerned.