This study proposes a measure of reproductive losses starting from conception to age 15 as an assessment of childbearing ‘efficiency’. It is suggested that losses are due to miscarriages, abortions, stillbirths and deaths to age 15. Data were drawn from various sources for seven regions embracing 129 developing countries. Mortality is an important loss in severely disadvantaged regions, especially in sub-Saharan Africa, but the abortion rates are lower there. This is reversed in the more advanced regions, where mortality is low but abortion rates are higher. Total losses numerically depend upon the rates in combination with the numbers of conceptions. The general ‘efficiency’ in moving from conception to a surviving child aged 15 was estimated. The abortion component of wastage has apparently not improved over time, but the mortality component has done so. Abortion rates are found to drive reproductive efficiency downwards; but efficiency is positively correlated with contraceptive use once abortion is controlled for. This implies that as efficiency is improved more couples gain confidence to turn to contraceptive use to avoid unplanned pregnancies and births.

A study was carried out, from 2012 to 2015, in 10 French départements to estimate the serological prevalence of Q fever and the frequency of abortive episodes potentially related to Coxiella burnetii in a large sample of cattle, sheep and goat herds. The serological survey covered 731 cattle, 522 sheep and 349 goat herds, randomly sampled. The frequency of abortive episodes potentially related to C. burnetii was estimated by investigating series of abortions in 2695 cattle, 658 sheep and 105 goat herds using quantitative polymerase chain reaction analyses and complementary serological results when needed. The average between-herd seroprevalence was significantly lower for cattle (36·0%) than for sheep (55·7%) and goats (61·0%) and significantly higher for dairy herds (64·9% for cattle and 75·6% for sheep) than for meat herds (18·9% for cattle and 39·8% for sheep). Within-herd seroprevalence was also significantly higher for goats (41·5%) than for cattle (22·2%) and sheep (25·7%). During the study period, we estimated that 2·7% (n = 90), 6·2% (n = 48) and 16·7% (n = 19) of the abortive episodes investigated could be ‘potentially related to C. burnetii’in cattle, sheep and goat herds, respectively. Overall, strong variability was observed between départements and species, suggesting that risk factors such as herd density and farming practices play a role in disease transmission and maintenance.

Risk factors for Brucella infection, the association and impact of Brucella seropositivity on abortions were investigated in cattle (n=1291) reared in smallholder household herds (n=203) from six geographical areas of Zimbabwe between September 2004 and 2005. Data on management, abortion and herd structure were collected. Sera were tested for Brucella antibodies using the Rose Bengal test and a competitive enzyme-linked immunosorbent assay. Data were analysed by generalized estimating equation and logistic regression models. Brucella antibodies were estimated at 5·5% and 22·9% for individual cattle and herds, respectively. Abortions were reported in 3·2% of cows and 22·0% herds. The age of cows and Brucella seropositivity predicted abortion. For herds, Brucella seropositivity, geographical area, purchase of cattle and large herd size were independently associated with increased odds of abortion. Exposure to Brucella had a significant impact on abortion. These results highlight the important risk factors for Brucella spp. infection in smallholder herds. Thus, brucellosis control programmes which take these factors into consideration will be beneficial.

Topical application of the juvenile hormone mimic 1™75 to pregnant Glossina morsitans 15 or 20 days after emergence resulted in a significant increase in abortions of eggs and larvae of all developmental stages. Small doses (0.25 ng per fly) were sufficient to elicit a response which was more pronounced if application occurred 20 days after emergence. Flies fed once on rabbit ears, which had been treated with 5 ng of the mimic per ear, resulted in abortions and the effect persisted for up to 40 days. The hormone mimic did not induce abortions in isolated pregnant uteri kept in organ cultures for up to 7 days.