By Dr Sesh Kamal Sunkara
In vitro fertilization (IVF) involves the retrieval of an egg and fertilization with sperm in the laboratory (in vitro) as opposed to the process happening within the human body (in vivo), with a natural conception. IVF was first introduced to overcome tubal factor infertility but has since been used to alleviate all types of infertility and nearly four million babies have been born worldwide as a result of assisted reproductive technology.
The birth of Louise Brown in 1978, the world’s first IVF baby was from a natural menstrual cycle without the use of any stimulation drugs. As success rates were low with natural cycles in the early days of IVF, ovarian stimulation regimens were introduced into IVF to maximize success rates. The aim was to retrieve more eggs to overcome the attrition in numbers at fertilization, cleavage, and implantation. However, with the introduction of ovarian stimulation regimens the complication of ovarian hyperstimulation syndrome (OHSS) arose.
There have been several discussions among IVF clinicians on what the ideal number of eggs should be to optimize IVF outcome and minimize risk of OHSS. We analysed a large database of over 400, 000 cycles provided by the Human Fertilisation and Embryology Authority (HFEA) in order to establish the association between egg number and live birth rate in IVF.
We found that live birth rate increased with increasing number of eggs retrieved up to 15 eggs and plateaued from 15 to 20 eggs with a decline in live birth rate beyond 20. The analysis of the data suggested that around 15 eggs may be the optimal number to aim for in a fresh IVF cycle in order to maximize treatment success whilst minimizing the risk of OHSS. We also established a nomogram which is the first of its kind that allows prediction of live birth for a given egg number and female age group. This is potentially valuable for patients and clinicians in planning IVF treatment protocols and counselling regarding the prognosis for a live birth occurrence, especially in women with either predicted or a previous poor ovarian response.
The full paper and supplementary data has been made publicly available here, as published in Human Reproduction by Sesh Kamal Sunkara, Vivian Rittenberg, Nick Raine-Fenning, Siladitya Bhattacharya, Javier Zamora and Arri Coomarasamy. Above table appears with full permission from Human Reproduction and Oxford Journals.
By David A. Leon
Making a difference to the health of populations, however small, is what most people in public health hope they are doing. Epidemiologists are no exception. But often caught up in the minutiae of our day-to-day work, it is easy to lose sight of the bigger picture. Is health improving, mortality declining, are things moving in a positive direction? Getting out and taking in the view (metaphorically as well as literally) can have a salutary effect. It broadens our perspectives and challenges our assumptions. Looking at recent trends in European life expectancy is a case in point.
Since 1950 estimated life expectancy at birth of the world’s population has been increasing. Initially, this was accompanied by a convergence in mortality experience across the globe—with gains in all regions. However, in the final 15 years of the 20th century, convergence was replaced with divergence, in part due to declines in life expectancy in sub-Saharan Africa. However, this global divergence was also the result of declining life expectancy in Europe. Home to 1 in 10 of the world’s population, and mainly comprised of industrialized, high-income countries, Europe has over 50 states. These include Sweden and Iceland that have consistently been ranked among the countries with the highest life expectancies in the world. But while for the past 60 years all Western European countries have shown increases in life expectancy, the countries of Central and Eastern Europe (CEE), Russia and other parts of the former Soviet Union have had a very different, and altogether more negative experience.
Trends in life expectancy between 1970 and the latest year available are shown in the Figure 1 for an illustrative selection of countries. These data were taken from one of two open sources : (i) the WHO Health for All Database or (ii) the Human Mortality Database, depending on which one had the longest time series. Differences between the sources are minimal for the purposes of this editorial. It is important to emphasize at the outset, that with one exception (discussed below), the trends shown in the Figure 1 are overwhelmingly driven by changes in mortality in adult life, not in infancy or childhood and are not the result of artefact.
Former communist countries of Eastern Europe
Between 1970 and the end of the 1980s, life expectancy at birth in the former communist countries of CEE (Czech Republic, Hungary, Poland and Slovakia), Russia and the Baltic states (Estonia, Latvia and Lithuania) stagnated or declined (Figure 1). This led to an increasing gap between them and Western European countries as the latter steadily improved. However, within a few years of the collapse of the Berlin wall in 1989, life expectancy started to steadily increase in the countries of CEE. This vividly illustrates that mortality can decline rapidly in response to political, social and economic change. Interestingly, once underway, the post-1989 increase in life expectancy in these countries has continued at a steady rate that is very similar to Western Europe. These parallel trajectories mean that the East–West gap, measured in terms of absolute differences in years of life expectancy, is proving very difficult to eliminate, despite earnest hopes to the contrary.
The trajectories of Russia and other Soviet countries, including the three Baltic States in the Figure 1, were strikingly different to those of the CEE countries. The anti-alcohol
