The Effect of China’s Two-Child Policy on the Child Sex Ratio: Evidence From Shanghai, China

Objective: The bias towards males at birth has resulted in a major imbalance in the Chinese sex ratio that is often attributed to China’s one-child policy. Relaxation of the one-child policy has the potential to reduce the imbalance in the sex ratio away from males. In this study, we assessed whether the bias towards males in the child sex ratio was reduced as a result of the two-child policy in China. Medical records data from one large municipal-level obstetrics hospital in Shanghai, East China. Design: Matching and difference-in-differences (MDID) techniques were used to investigate the effect of the two-child policy on the imbalance in the sex ratio at birth after matching for pregnancy status and socioeconomic factors. Results: Analyzing 133,358 live births suggest that the relaxation of the one-child policy had a small, but statistically significant effect in reducing the imbalance in the male to female sex ratio at birth. Conclusion: The results demonstrate that relaxation of the one-child policy reduced the imbalance in the male to female sex ratio at birth from 1.10 to 1.05 over the study period at one of the major obstetrics and gynecology hospitals in China.

Observable variations in human sex ratio at birth

The human sex ratio at birth (SRB), defined as the ratio between the number of newborn boys to the total number of newborns, is typically slightly greater than 1/2 (more boys than girls) and tends to vary across different geographical regions and time periods. In this large-scale study, we sought to validate previously-reported associations and test new hypotheses using statistical analysis of two very large datasets incorporating electronic medical records (EMRs). One of the datasets represents over half (∼ 150 million) of the US population for over 8 years (IBM Watson Health MarketScan insurance claims) while another covers the entire Swedish population (∼ 9 million) for over 30 years (the Swedish National Patient Register). After testing more than 100 hypotheses, we showed that neither dataset supported models in which the SRB changed seasonally or in response to variations in ambient temperature. However, increased levels of a diverse array of air and water pollutants, were associated with lower SRBs, including increased levels of industrial and agricultural activity, which served as proxies for water pollution. Moreover, some exogenous factors generally considered to be environmental toxins turned out to induce higher SRBs. Finally, we identified new factors with signals for either higher or lower SRBs. In all cases, the effect sizes were modest but highly statistically significant owing to the large sizes of the two datasets. We suggest that while it was unlikely that the associations have arisen from sex-specific selection mechanisms, they are still useful for the purpose of public health surveillance if they can be corroborated by empirical evidences.

Levels and trends in sex ratio at birth in provinces of Pakistan from 1980 to 2020 with scenario-based missing female birth projections to 2050: a Bayesian modeling approach

BACKGROUND: Pakistan has a strong preference for boys over girls; previous evidence on sex preference is primarily reported at the postnatal stage in which the child mortality rate is higher for females than males. Prenatal sex discrimination in Pakistan, reflected in the inflated sex ratio at birth (SRB; ratio of male to female births) has been barely mentioned before this study.OBJECTIVE: We estimate the SRB and missing female births in Pakistan provinces from 1980 to 2020 and identify provinces with imbalanced SRB. We provide scenario-based projections of missing female births in provinces without the existing SRB inflation.METHODS: An extensive SRB database of 832,091 birth records was compiled from all available surveys and censuses. To synthesize different data sources and provide annual estimates and their associated uncertainties of SRBs across provinces, we adopted a Bayesian hierarchical time series model.RESULTS: As per our model, Balochistan has had SRB imbalance since 1980. The maximum SRB was estimated as 1.121 (95% credible interval [1.066; 1.142]) in 1997. Assuming different start year of SRB inflation process in provinces without existing imbalance, the largest female birth deficit is projected to be 76.2 thousand in Punjab in 2033 when the SRB inflation starts in 2021.CONTRIBUTION: This is the first study on estimating the SRB from 1980 to 2020 and providing scenario-based projections of missing female births up to 2050 by Pakistan province. We identified the Balochistan province with imbalanced SRB and demonstrated important disparities in the occurrence and quantity of female birth deficits before 2050.

Effect of Blastocyst Quality on Human Sex Ratio at Birth in Single Blastocyst Frozen Thawed Embryo Transfer Cycle

ObjectiveThis study aimed to determine whether blastocyst quality affect on sex ratio at birth through in single blastocyst frozen thawed embryo transfer cycle.Materials and MethodsWe ran this retrospective study on 4205 singleton infants born following single blastocyst frozen thawed embryo transfer from January 2016 to October 2020 at a single institution. We compared the sex ratios of these infants with respect to blastocyst quality, embryo growth rate and morphology.ResultsThe main outcomes of this study were that the sex ratio at birth of single blastocyst frozen thawed embryo transfer babies was 56.67% which was higher than the normal level (51.22%). The sex ratio of mothers older than 40 years was significantly lower than that of mothers younger than 40 years (0.39vs1.3, P<0.05). Transplanting good quality blastocysts significantly increased the proportion of boys (1.35vs0.94, P<0.05). Transplanting grade 5 and 6 blastocysts significantly increased the proportion of male babies born compared with grade 3 and 4 blastocysts (1.91vs1.28, P<0.05). There were no significant differences in the sex ratio with respect to the inner cell mass (ICM) score. In addition, the higher the trophectoderm (TE) score, the higher the sex ratio (2.79vs1.18vs0.91, P<0.05).ConclusionsOur study indicated that blastocyst quality, especially trophoblastic cell score, had a significant effect on sex ratio.

Combatting the imbalance of sex ratio at birth: medium-term impact of India’s National Programme of Beti Bachao Beti Padhao in the Haryana State of India

The Government of India initiated the Beti Bachao Beti Padhao (B3P) programme in 2015 as a flagship initiative to reduce gender imbalance in sex ratio at birth (SRB) and to ensure social protection of girls. The present study was conducted to evaluate the medium-term impact of B3P implementation in Haryana state, from 2015 to 2019, on SRB. Monthly data on SRB were collected for the entire state of Haryana through a civil registration system. Segmented time series regression analysis was used to estimate the variations in SRB after the B3P programme with the help of Winter’s additive interrupted time series model. The SRB in Haryana increased from 876 girls per 1000 boys in 2015 to 923 in 2019. The results of the model demonstrated that before the inception of intervention (pre-slope), there was a significant monthly change in SRB of 0.217 (95% confidence interval: 0.144–0.290). Following the B3P programme, SRB was found to increase by 0.835 per month, which implied that an increase of 0.618 (confidence interval: 0.338, 0.898) every month in SRB can be attributed to the B3P programme. This indicated that SRB for the state of Haryana increased at the rate of 7.42 units per year as a result of the B3P programme. B3P has led to a significant improvement in SRB in Haryana state. The continuity of efforts in the same direction with a sustained focus on behaviour change will further help achieve the goal of gender parity in births and child survival.

Comparison of the Pregnancy and Neonatal Outcomes of ICSI Performed With Frozen Versus Fresh TESA Sperm in Patients With Obstructive Azoospermia: a Retrospective Study

BackgroundIt is commonly believed that using frozen sperms after TESA was effective for OA patients. Nevertheless, scholars are worried about the prognosis of ICSI with frozen testicular sperm. In this study, we aim to compare the pregnancy and neonatal outcomes of ICSI using cryopreserved versus fresh spermatozoa collected by TESA.MethodsA total of 317 cases of OA patients treated with ICSI in a university affiliated hospital from January 2016 to December 2020 were included in this retrospective study, and they were divided into two groups according to the sperm used for ICSI: Frozen sperm group (N=154) and Fresh sperm group(N=163). The outcomes were measured by the following indicators: Two pronucleus (2PN) fertilization rate, 2PN cleavage rate, high-quality blastocyst rate, average number of embryos transferred, implantation rate, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, preterm birth rate, live birth rate (LBR) , sex ratio at birth (male) and average newborn birth weight.ResultsThe present data showed no statistically significant difference in 2PN fertilization rates, 2PN cleavage rates, high-quality blastocyst rates and the average number of embryos transferred in the two groups. Similarly, no difference was found in implantation rate, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, premature delivery rate, LBR and sex ratio at birth (P>0.05). The average newborn birth weight was similar in the two groups (2932.61±728.40 vs 3100.32±515.64) (P>0.05), but there was a higher incidence of Low-Birth-Weight newborn in the frozen group (20.91% vs 8.49%)(P<0.05). ConclusionsAs for men with obstructive azoospermia, the use of frozen testicular sperm by TESA was efficient. There was a similar pregnancy outcome of ICSI using frozen or fresh spermatozoa collected by TESA. However, it may lead to higher incidence of newborns of low birth weight, which needs further research based on larger samples.

Projecting sex imbalances at birth at global, regional and national levels from 2021 to 2100: scenario-based Bayesian probabilistic projections of the sex ratio at birth and missing female births based on 3.26 billion birth records

IntroductionSkewed levels of the sex ratio at birth (SRB) due to sex-selective abortions have been observed in several countries since the 1970s. They will lead to long-term sex imbalances in more than one-third of the world’s population with yet unknown social and economic impacts on affected countries. Understanding the potential evolution of sex imbalances at birth is therefore essential for anticipating and planning for changing sex structures across the world.MethodsWe produced probabilistic SRB projections from 2021 to 2100 based on different scenarios of sex ratio transition and assessed their implications in terms of missing female births at global, regional and national levels. Based on a comprehensive SRB database with 3.26 billion birth records, we project the skewed SRB and missing female births with a Bayesian hierarchical time series mixture model. The SRB projections under reference scenario S1 assumed SRB transitions only for countries with strong statistical evidence of SRB inflation, and the more extreme scenario S2 assumed a sex ratio transition for countries at risk of SRB inflation but with no or limited evidence of ongoing inflation.ResultsUnder scenario S1, we projected 5.7 (95% uncertainty interval (1.2; 15.3)) million additional missing female births to occur by 2100. Countries affected will be those already affected in the past by imbalanced SRB, such as China and India. If all countries at risk of SRB inflation experience a sex ratio transition as in scenario S2, the projected missing female births increase to 22.1 (12.2; 39.8) million with a sizeable contribution of sub-Saharan Africa.ConclusionThe scenario-based projections provide important illustrations of the potential burden of future prenatal sex discrimination and the need to monitor SRBs in countries with son preference. Policy planning will be needed in the years to come to minimise future prenatal sex discrimination and its impact on social structures.