John B. Wyon

Applications of field studies to research on the physiology of human reproduction; lactation and its effects upon birth intervals in eleven Punjab villages, India.

A field study on lactation and its effects upon birth intervals was undertaken in 11 Punjab villages India. From a variety of sources genalogies parish records and special field studies it has been found that in societies practicing little or no birth control average birth intervals range from barely more than 2 years to nearly 3 years. Within populations older mothers tend to have longer birth intervals than younger mothers. The relevance of lactation to birth spacing has long been suspected. Several studies the first in 1942 have shown that when the infant survives the average birth interval is as much as a year longer than when the child is born dead or dies neonatally. This Khanna study provides a broad scope of prospective as well as retrospective data for approximately 1500 couples of childbearing potential over a 3-5 year period. It is evident that in the Punjab villages of the Khanna study lactation substantially prolonged postpartum amenorrhea. When an infant survived 1 month or more lactation usually lasted well over a year and the median length of postpartum amenorrhea was 11 months; whereas if the child was stillborn or died in the first month of life the mother did not lactate and the median length of postpartum amenorrhea was in the vicinity of 2 months.

A case study of birth interval dynamics

Abstract A birth interval free from pregnancy wastage may be viewed as the sum of three sub-intervals: (1) the period ofpost-partum amenorrhoea following a birth; (2) the menstruating interval extending from end of post-partum amenorrhoea to next conception; and (3) the months of pregnancy losses, then in addition to the above three components there is a fourth component, which may be termed ‘time added by pregnancy wastage’. A basic understanding of birth intervals requires the ability to relate the central tendencies and variability of birth intervals to the means and variances of these four components. The present analysis draws upon uniquely detailed materials from the India-HarvardLudhiana Population Study that took place in eleven villages of the Punjab, India, during the years 1953–59. Means and variances of post-partum amenorrhoea, menstruating intervals, and time added by pregnancy wastage are estimated for two broad age classes and the results related to corresponding statistics for total birth ...

Delayed marriage and prospects for fewer births in Punjab villages

ResumenAlgunas autoridades han calculado los efectos que sobre la fertilidad conlleva el matrimonio de mujeres de mayor edad. En la India ,ha menudo existe un intervalo entre el matrimonio y el momento en que las parejas comienzan a cohabitar. Sucesivos censos en la India, indican un marcado incremento en la edad de matrimonio durante las últimas seis décadas; el significado que ello pueda lener en el comienzo real del coito, es asunto de controversia. Datos sobre estudios de población de Khanna efectuados en once aldeas de Punjab permiten determinar las tendencias de edad en el momento del matrimonio y la cohabitación.Las evidencias de cambio en la edad de cohabitación se derivaron de la actual edad de las esposas y de acuerdo a la edad de cohabitación: La edad promedio de las esposas nacidas en las aldeas entre 1910 y 1939 se incrementó de 13.6 a 15.4 años, pero la edad media de cohabitación permaneció casi constantes alrededor de los 16 años. El intervalo entre matrimonio y cohabitación, es cerca de medio año. Puede inferirse que la edad media de cohabitación para las cohortes mas jóvenes, ha disminuído.Desde 1950 la edad media de matrimonio de cohortes de mujeres quienes comenzaron la cohabitación al mismo tiempo, se incrementó en un año en un período de 5 años, y la edad media de cohabitación pasó de 16.5 a 17.5 entre 1950–54 y 1955–59. Esta evidencia del reciente incremento en la edad mediade cohabitación es sustentada por un incremento en la edad media de las novias de acuerdo a un estudio hecho en las aldeas en 1956 y 1959, por la declinante proporción de mujeres ya cohabitando entre las edades de 15–19 y 20–24 entre 1956–1959 y por el incremento del solo promedio de edad de cohabitación entre 1956 y 1959.Un estimativo de los efectos del incremento en la edad de las mujeres al tiempo de cohabitación, es que el promedio de nacimientos vivos cuando las mujeres tengan 45 años habrá disminuído en casi un hijo, o 15%. Este modesto chequeo de las ratas de reproducción llevado a cabo por las gentes de estas aldeas, sugiere el valor de los estudios acerca de cómo ellos y otras gentes residiendo en áreas de presión demográfica, han retardado sus carreras reproductivas.

Childbirth in rural Punjab India.

The high infant mortality of 159/1000 live births in typical rural villages of the Punjab India was due more to environmental causes than to factors related to obstetrical care. Compared with industrialized countries of the West the neonatal death rate was 4 times the expected level whereas the postneonatal rate of the remaining 11 months of the 1st year was 18 times greater. Neonatal death rates averaged 76/1000 live births over a 2-year period and perinatal rates averaged 89/1000 deliveries. 3/4 births were attended by untrained midwives 6% by midwives with a brief elementary course of instruction and 15% by persons with midwifery and brief nursing training. The remaining 3% included delivereis by physicians by friends or relations or unattended. Practitioners of indigenous medicine did not practice obstetrics. The trained village midwife had the best record of accomplishment as judged by perinatal death rates 56/1000 deliveries. Neonatal death rates were almost twice as great for untrained as for trained attendants. Differences in professional qualifications had little influence on choice of attendant at childbirth. With rare exceptions demanded by complications all deliveries were in the home and the attendant in 97% was a midwife of the village where birth occurred. Risk of death for infants as judged by either perinatal or neonatal death rates was greatest among the 1st born and those of late pregnancies. Maternal death rate as estimated for a small sample was excessively high. Tetanus neonatorum was a common cause of death among infants delivered by both trained and untrained midwives. The greatest difference in deaths according to delivery by trained or untrained attendants was in postnatal asphyxia which was 3 times as frequent among infants delivered by untrained midwives. All deaths from cerebral birth injuries were among children delivered by untrained midwives.