Call the Midwife: Series 13

Season overview

Role: Meticulous television and film archivist.
Task: Produce a JSON object for "Call the Midwife" Season 13.
Keys: overview (160-220 word summary), primer (array of exactly 4 concise bullet points).
Constraints: Use ONLY provided synopsis and sources. No invented facts, names, dates, etc. No markdown, no asterisks, no headings, no bullet points (in the text, though the primer is an array). Output valid JSON only.
Input Material:
TMDB Synopsis: 1969 setting. More babies born in hospitals than ever. High pressure on maternity beds nationwide. Poplar is coping better due to Nonnatus House and the popularity of home births under the Sisters.
Source 1: 1950s London setting (general overview).
Source 3: British period drama about nurse midwives in East End of London in the late 1950s, 1960s, and 1970s.
Source 4: Premiered Jan 15, 2012. Based on book trilogy by Jennifer Worth.
Source 5: Set in poverty-stricken East End of London during the 1950s.
Overview:
Setting: 1969.
Context: Increasing number of babies being born in hospitals compared to previous years.
Conflict/Pressure: High pressure on maternity beds across the country.
Local Situation: Poplar is managing the situation better than most areas.
Reason for Poplar's success: The work of Nonnatus House and the popularity of home births conducted under the auspices of the Sisters.
Drafting (aiming for 160-220 words):
The thirteenth season of the British period drama Call the Midwife is set in 1969. During this period, the landscape of childbirth is shifting, as more babies are being born in hospitals than ever before. This trend has resulted in extremely high pressure on maternity beds throughout the country. However, the community of Poplar is coping better than most other areas. This relative stability is attributed to the ongoing work performed by Nonnatus House. Additionally, the popularity of home births, which are conducted under the auspices of the Sisters, helps to manage the local demand. The series continues its depiction of the lives of a group of nurse midwives working in the poverty-stricken East End of London, a setting that has spanned the late 1950s, 1960s, and 1970s.